“essence of stealth is that the Blue Offensive circles [ for detection and weapon range] impact Red Defensive before Red Defensive can detect” - Michael Garcia. To surprise the enemy, following (signal-to-noise ratio) characteristics are required:
1. visual invisibility: visible engine smoke, physical size, camouflage (reduce the signal)
2. electronic invisibility: stifling increased noise due to usage of active sensors (radar, laser), radio communications & uplinks
3. infrared invisibility (reduce the heat signal imprint)
4. and maybe also cruise speed advantage (advance engines) while muffling the sound
Air has a very low emissivity, carbon particles have a high broadband emissivity, and water vapor emits in very specific bands. Carbon buildup on hot engine parts is a cumulative situation, and there are very few bright, shiny parts inside exhaust nozzles after a number of hours of operation. For this reason alone, it is likely that emissivity control will predominantly be employed on surfaces other than those exposed to engine exhaust gases, i.e., inlets and aircraft external parts.
Low observable (LO) aircrafts have leading and trailing edges of the wing and tail have identical sweep angles (a design technique called "planform alignment"). The fuselage and canopy have sloping sides. The canopy seam, bay doors, and other surface interfaces are sawtoothed. The engine is hidden deep.
“Right now, something is wrong with a light panel on that jet. Since maintenance needs to get into that panel, we have to pick the radar absorbent material off and clean all the fasteners out so they can fix the light,” Air Force low observables (LO) aircraft structures technician said. “Once the light is fixed we will re-bind the coating and material again to make it 100% ready.”
Planform return lobe structure is defined by the radiation pattern lobes resulting from surface wave reflections which occur at the leading and trailing edges of the airframe's major surfaces. The objective of lobing is to concentrate this unavoidable radar return into specific directions so as to minimise frontal/aft/beam aspect return and maximise scintillation in the direction of the lobe. Scintillation is a measure of how rapidly the size of the return varies with angle, the greater this variation, the more difficult a target is to track.
Basically the Luneberg lens is a passive radar augmentation device used to increase the radar reflectivit. Its made of concentric dielectric shell, made of polystyrene.
Electronic Warfare: Radar technology sends an electromagnetic ping forward, bouncing it off objects before analyzing the return signal to determine a target's location, size, shape and speed etc. However, if "jammers" tech are able to interfered with the electromagnetic signal, in order to block, jam, thwart or “blind” in some way, the enemy radar systems is then unable to detect or target.
A low observable (LO) fighter can escape detection only if it keeps its radar switched off, or under emission control (EMCON). To penetrate contested airspace and attack targets, the LO fighter relies on an AWACS positioned in the rear, which streams the air and ground situation over a directional and encrypted data link. The LO fighter uses its sensor fusion capability to fuse the information obtained from the AWACS sensors with the information obtained through its own passive (ESM, EO) sensors to track and engage adversary targets. Even if the target is detected on enemy surveillance radars, the “kill chain” of the weapon system can still be incomplete for it to work properly. (Hence, new systems are designed from the outset for sensor fusion — when different sensors detect and track the same target, the track and identification data are merged automatically.)
Lower-frequency radars do not provide what Pentagon officials call a “weapons quality” track needed to guide a missile onto a target. “Even if you can see an LO [low observable] strike aircraft with ATC radar, you can’t kill it without a fire control system”. The problem with VHF and UHF band radars is that with long wavelengths come large radar resolution cells. That means that contacts are not tracked with the required level of fidelity to guide a weapon onto a target. These limitations can be overcome with signal processing in Phased array radars — particularly high-powered active electronically scanned arrays (AESA).
“The target engagement radar or control radar has a very narrow scope, so enemy defenses are trying to search the sky. We are making enemies search the sky looking through a soda straw. When the only aperture of the world is through a soda straw, we can force them into a very narrow scope so they will never see aircraft going in to deliver ordnance”
The F-35 in particular has shocked the defense industry into a new reality. Beyond its merits and failings, the F-35 aims to replace the majority of tactical fighters in the U.S. inventory with one type, sold by one contractor. Not only does this mean that there will be no future fighter aircraft competitions potentially for decades, but it also means all those sustainment and upgrade dollars will be migrating away from a diversified fleet supported by many manufacturers and right into the pockets of a single major contractor. Like the B-2, the F-35 has became too big to fail near past of no return, sending the program into what is now deemed a Pentagon death spiral; a feedback loop where a weapon is too expensive to buy because you don't buy enough of them and you don't buy enough of it because it is too expensive to buy. (In the end, the $45B Advanced Technology Bomber project that took well over a decade to field ended up producing just a measly 21 air-frames. The cost of each of those airframes, with the price of development amortized across the small fleet: About $2.2B each.)
If a fighter can turn faster than its opponent, it will find it easier to get into a favourable position, -- generally, behind that opponent. An air-plane's ability to turn can be roughly gauged by its wing loading. This is the mass of the aircraft divided by the area of the wings. The bigger the wings, the easier it is for them to push the aircraft in a direction other than that in which it is currently travelling. Note that some aircraft use thrust vectoring, where the jet exhaust from the engines doesn't always go straight backwards but can be tilted up or down (and sometimes also left to right) to increase maneuverability.
Engine power also confers advantages in air combat. Most simply, high overall speed can allow a pilot to choose to disengage an opponent by simply outrunning it. This ability to disengage may also apply to incoming missiles, allowing escape from what would be a fatal shot to a slower air-plane.
A high-powered fighter is also more likely to maintain a crucial overall energy advantage over its opponent. All air combat manoeuvres (ACM) require a certain amount of physical energy, most simply thought of as airspeed plus altitude. When fighters perform the high-g manoeuvres common in air-to-air combat, they must sacrifice one or both of these qualities, and there are fundamental limits to how much of each can be sacrificed. Altitude can obviously not go below the ground level, and airspeed can not fall below the stall speed of the fighter. If a pilot attempts a maneuver at too low an initial total energy level, he/she will likely stall the air-plane and become an easy target for a missile or gun kill. The fighter's engines add energy at a certain rate; the higher this rate, the greater can be considered the fighter's ability to manoeuvre. Higher engine power allows the air-plane to maintain a high energy level and therefore engage in more aggressive ACM.
Conventional thinking in the planning of air campaigns, empirically observable from the Blitzkrieg campaigns of the 1940s through to the recent United States led air campaigns since 1991, places a heavy emphasis on the defeat of opposing airfields by aerial attack, to deny an opponent the opportunity to contest airspace. To achieve this effect, an attacker needs the capability to repeatedly penetrate defended airspace to shut down airfields, keep them shut down, and inflict attrition upon opposing aircraft on the ground.
Basically the Russians built the MiG-23 to fight F-105s, F-104s, F-4s, Mirage IIIs and as a technological response to the USAF`s needs for a variable geometry fighter in the form of a cheap soviet F-111sky. The Americans responded with the F-15 and F-14 and much later with the F-16 and F-18, this prompted the development of the Su-27 and MiG-29 and the west then designed the Eurofighter, Rafale Gripen and F-22 to counter the MiG-29 and Su-27 threat.
The F-22A may get ‘first look’ with the APG-77, the Advanced Infra Red Search and Track (AIRST) sensor having been deleted to save money, but the PAK-FA may get ‘first look’ using its advanced infra-red sensor. A radar cross section of only -20 dBSM would deny early Beyond Visual Range (BVR) missile shots using the AIM-120C/D AMRAAM to all current and planned US fighters. Doing any better, like -30 dBSM or -40 dBSM, simply increases the level of difficulty in prosecuting long range missile attacks. The consequence of this is that missile combat will be compressed into shorter distances and shorter timelines. A larger portion of engagements will be at visual range, and most BVR engagements will end up taking place inside 30 nautical miles. Then, the engagement becomes a supersonic equivalent of the Battle of Britain or air combat over North Korea. The outcome will be difficult to predict and will depend on missile capabilities zone and the pilots.
Information superiority aims at reducing one’s own observation to action loop (Observation-Orientation-Decision-Action) while elongating the enemy’s loop.
ps: Noshir Gowadia and others, whom the US convicted in 2010, provided China with the lock-on range for infrared-guided missiles against the B-2 and information that allowed China to develop a low-signature cruise missile exhaust system.
During Operation Focus of the Six Day War, Israeli pilots flying the French built Mirage III interceptors were able to routinely dominate the formidable MIG 21's of several Arab air forces. When the pilot training advantage is taken away, dogfights between Western and Soviet/Russian aircraft becomes much closer. In several of the Indo-Pakistan conflicts, the Soviet equipped Indian Air Force kept toe to toe with the American supplied Pakistani Air Force.
The “package” of fighters and support aircraft using SEAD to reach a target is led by aircraft Wild Weasels. These have radar detection and jamming equipment which can either hide the group from enemy radar or prevent the enemy from making accurate use of their ground-to-air missiles. You will need fighters to deal with enemy interceptors. Thus the battle can range from 10,000 meters up down to ground level. The Wild Weasels carry missiles that home in on enemy ground radars. The most dangerous opposition comes from enemy guns, which often can fire without radar in clear weather. For this reason, raids at night and in bad weather are often preferred. If all goes according to plan, the Weasels will protect the electronically less sophisticated strike aircraft to the targets, where they release their loads. Everyone then fights their way home past a thoroughly alerted enemy. The stealth aircraft are well suited to perform the Wild Weasel role and have done so.
Air-Superiority (F - fighter)
Flat vs round nozzle
The F22 stealth fighter costs as much as $678 million per copy. Plus the F-22′s small production run of under 200 planes make it the Me-262 Sturmvogel of its time. The Me-262 was the world’s first production jet fighter, with performance that could dominate any allied propeller plane. Yet the 200 or so Me-262s produced were swept from the World War 2 skies, by 2,000+ P-51 Mustangs, P-47 Thunderbolts, etc.
The F-22 employs planform shaping and faceting with blended facet boundaries, in the shape of the nose, the fuselage sides about the inlets and engines, and the upper forward fuselage. It used serrated edges extensively. Another important feature of the F-22's stealth characteristics is the new low-RCS air system. This system uses 4 ports distributed along the forward fuselage to reduce emission control. In addition, the F-22 is the first fighter aircraft to include a completely frameless canopy. This eliminates RCS reflections from the windshield arc without compromising structural integrity.
"Presently, the flat nozzle has two inherent snags which, in principle, have not been dealt with yet. Firstly, the turbine is round but the nozzle is flat with a distance between them being small. The distance cannot be increased because this would lead to an increase in the overall length of the aircraft, a loss of thrust, etc. While transforming the circular gas stream into the flat one, the nozzle, developed by Mr. Ryzhov, was losing 14-17% of thrust. Unfortunately, the gas stream cannot be "bent" as we would like it to. It has its own laws too. So far, no one has managed to transform the circular gas stream into the flat one without losing thrust. The very same snag was hit by the Americans in developing their F-117 featuring a non-afterburning engine. Such engines lose approximately 15% of thrust too. However, the F-117 is a specialised Stealth aircraft with the main requirement of ensuring "invisibility". It does not need a real good thrust/weight ratio. That is why the Americans put up deliberately with an unavoidable loss of thrust but benefited from reduced signatures.
Secondly, the other primary problem is weight. The circular TVC nozzle produces only tensile stress while the flat one exerts bending stress as well. Those stresses require special measures to be taken to ensure the nozzle strength in order to avoid deformation of the nozzle. Those measures mean additional weight. The flat nozzle made of metal is heavier than the circular one by approximately half a tonne. The problem can be circumvented through the use of the "carbon-carbon" materials which have low specific weight and can stand high temperature. To preventing carbon-carbon units from burning they are covered by a thick layer of fire-resistant ceramics are used only in manufacturing the control surfaces of rocket engines. The latter are actually disposable since their operation never exceeds 40-50 seconds while an aircraft engine service life amounts to 1,000 hours or more. This requires advance material technology."
F/A-22 or F-22 'Raptor' is a single seat, twin-engine, all-weather fighter fifth-generation fighter aircraft that uses stealth technology. It's designed primarily as an air superiority fighter which has super agility at all speeds, altitudes and angles of attack. During exercises, it is fitted with a special radar reflector to appear on the radar screens of friendly aircraft.
The Air Force declared the F-22 stealth fighter operational in 2006, but waited eight years to finally send the jets into combat. Its the first operational stealth fighter built in aviation history that combines super-cruise, super-maneuverability, stealth, ground attack, electronic warfare, signals intelligence and sensor fusion in a single weapons platform. However, the F-22 Raptors can’t do without AWACS support. To stay invisible, they attack with their radar switched off, relying entirely on targeting data provided by the “flying eye,” that has to fly within 400 kilometers of the combat area.
As adversaries build new fighters, the F-16 and F-15 fighters will soon be tactically obsolete. The F-22 was envisaged to penetrate high and fast, deep into Soviet held airspace and have the energy performance advantage to outperform the new Soviet designs in BVR and close combat, and engage and disengage at will, so that strike aircrafts can demolish Soviet ground-based air defences and defended assets.
A single Raptor during one of its first training sorties was able to kill eight F-15s in a mock air-to-air engagement, well before they could see it. The Raptor's high operating altitude is also a significant tactical advantage over prior fighters.
In its first Red Flag (in which F-15s and F-16s played as enemy air forces during exercises) participation, in 2007, the Raptor was able to establish air dominance rapidly and with no losses. However, in close range (50 kms), its large and hot engines are a disadvantage when facing large number of advanced 4th gen fighter jets.
Both the AN/APG-77 AESA featured in the F-22A and the AN/APG-81 AESA featured in the F-35 are equipped with low probability intercept modes. Without low probability intercept modes, the aircraft is incredibly vulnerable to being jammed and tracked by enemy radars. Radars equipped with LPI modes are much more difficult to jam and track. The APG-77 is said to have a range of about 250 km which enables it to detect its adversaries long before they even know what’s happening. It can also provide fire control for the AIM-120 which would allow it to shoot down a hostile aircraft 100 km away, without the F-22 even revealing itself to enemy radar. This radar can also act as a jammer by overloading sensors of hostile aircraft and missiles. The APG-77 will be upgraded to enhance its detection range to 400 km using narrow beams. The Raptor will achieve first look and first shoot capability against stealthy opponents including the PAK FA. This will give the Raptor a tremendous advantage against the PAK FA and other future stealthy opponents.
One of the most vital but rather unknown sensors are the AN/ALR-94 radar warning receiver (RWR) and the AN/AAR-56 Infrared and Ultraviolet Missile Launch Detector (MLD). The RWR, which is distributed around the aircraft, is a passive radar detector which enables the F-22 to detect hostile radar emissions without revealing itself. It has a range of over “432 km”.
It is widely known that the F-22 stealth aircraft is stealthy in X-band and upper S-band. VHF radar can't do fire-control, but they can see you. With low-frequency radars, they can tell which way to look, and they can scramble their super-cruising aircraft out to you. F-22 will only be able to fire at BVR with help from other assets as it complete lack of optical sensors, unless refitted with imaging IRST or video camera. Even if it does prove able to fire from BVR, at such ranges missile’s kill probability will be low, and it will still be giving itself away. It also has also has inferior rearward visibility.
The Air Force operates mostly Block-10 and Block-20 aircraft. The Block 10s are used for training at Tyndall AFB. Increment 2 also helped fix some previous operations and maintenance issues.
F-22 has trouble communicating with other aircraft including the F-35, and relies on voice radios to relay battle-space information. It can receive but not transmit information via Link 16, the most common coalition data-link. F-22 does not have a helmet mounted cueing system (HMCS), which some consider as being essential. This poses a potential problem for F-22 pilots should they get into a dog fight within visual distance. The F-22’s advanced radars does give the Raptor such an advantage over other fighter aircrafts, however, the fact the F-22 can’t carry the AIM-9X Sidewinder air-to-air missile only makes this harder for F-22 pilots.
Increment 3.1 upgrade will:
•Add synthetic aperture radar.
•Add the ability to drop Small Diameter Bombs.
•Add electronic attack capabilities.
•Adds a Synthetic Aperture Radar (SAR) mapping feature along with an Electronic Attack (EA) capability to aircraft which will also afford Raptor pilots the ability to designate their own ground targets on the fly and attack enemy radar.
This enhanced ground attack capability is part of the F-22's 'increment 3.1 software upgrade,' along with improved mapping and ground targeting capabilities, as well as being able to initiate electronic attacks using its powerful APG-77 AESA radar.
3.2A will see additional electronic protection measures and upgrades to the Link-16 data link system and its ability to work with the jets sensor suite.
3.2B will see the software and hardware upgrade to allow the Raptor to use the AIM-120D and AIM-9X air-to-air missile system, which allows pilots to target enemy aircraft off axis to the aircraft’s direction of flight. Block II The integration of the new AIM-9X Block II variant will remedy the current lack of a high off-bore sight (HOBS) missile capability in the Raptor’s arsenal. Integrating the helmet-mounted cueing system will allow the F-22 to exploit the high off-boresight capability of the Raytheon AIM-9X Block II Sidewinder missile.
Air Force officials had intended to offer the Vision Systems International Joint Helmet-Mounted Cueing System to F-22 pilots. This is the same system used in the F-15, F-16 and the F/A-18. The helmet should integrate symbology and colour imagery with enhanced night vision systems. The Raptor’s problem is that its Increment 3 set keeps changing, with items being added and subtracted while cost climbs, and the schedule lengthens.
Other capabilities planned in the Increment 3.2 upgrade includes:
•The ability to independently re-target eight SDBs at eight separate targets.
•Further improvements to the electronic protection system and an upgrade to the aircraft geo-location system.
The tooling and equipment needed to produce the F-22 fighter, which was barred from export because of its sophistication, remain in storage along with video instructions for various assembly processes.
While F-22 is a capable dogfighter for its size and weight, its low production run and high maintenance downtime mean that it will likely find itself outnumbered in any war. Flight control surfaces include leading and trailing-edge flaps, ailerons, rudders on the canted vertical stabilizers, and all-moving horizontal tails; these surfaces also serve as speed brakes. Through 2008, F-22s averaged 2.0 hours Mean Time Between Maintenance (MTBM). The latest delivered F-22s, known as Lot 6 jets, are exhibiting an MTBM of 3.2 hours.
The F-22 takes 42 man-hours of maintenance for each hour in the air. About half of those maintenance hours are taken with repairing its radar-absorbent-material (RAM) coating. But the F-22's surfaces are made of aluminum, which are covered in top-coat of RAM that must constantly be reapplied. Those costs tend to rise as aircraft get older, and the F-22′s extensive use of uncommon materials like titanium and composites adds some new variables to the ageing curve. However, the ceramic-matrix RAM is applied sparingly on the F-22 airframe when compared to the F-117 entire airframe. This is because designers have incorporated curves on crucial surfaces and edges, which lessens the need for RAM. The F-22 has a warning system, called "Signature Assessment System", which presents warning indicators when routine wear-and-tear have degraded the aircraft's radar signature to the point of requiring more substantial repairs.
However unlike the B-2, which requires climate-controlled hangars, the F-22 can undergo repairs on the flight line or in a normal hangar. Availability has risen from 40% to 63% by 2004 (68% by 2009). F-22 pilots are restricted to 10 to 12 hours in the air per month due to an operating cost of $58,000 per hour, the Air Force simply can’t afford more than that. Ideally pilots would get at least twice that amount of flying time in order to be fully proficient in their weapon system. However, F-22 in 2008 cost per flying hour was $19K while for the F-15 was $17K. But only 123 F-22 are ‘combat-coded.’ Arguably, the F-22 has wiped out half of the U.S. fighter fleet even before the Russians or Chinese have had a chance to attack it. Simply due to its cost. Flaying beyond Mach 2.0 can also risks delamination.
The US has gone with the trapezoidal configuration whereas the Russians have gone with a tailed delta wing configuration just like with their MiGs. With aerodynamic design and introduction of the Gen 4 R-73 (AA-11 Archer) missile and the Shchel series helmet mounted sights in the MiG-29 and especially the Su-27 made them more than half a generation ahead of the US fighters.
Pratt & Whitney won the F-22's engine contest with its F119 —which while not as powerful, was far more reliable than General Electric’s novel variable-cycle YF120. It features 2 Pratt & Whitney F-119 PW-100 turbofans which individually produce around 120 kN of dry thrust and >160 kN of afterburning thrust. This exceptional level of thrust, combined with its aerodynamic design, allows the F-22 to supercruise at speeds greater than Mach Mach 1.7 or 1.8 without afterburner—but its endurance is limited.
The F-22's thrust-vector control system cannot provide roll or yaw control because the engines are too close together. The engine installation leaves no place for weapon bays in the same plane as the engines—they have to be installed around and below the inlet ducts. Missiles with non-folding fins limits the total amount of missiles it can carry to 8. The serpentine inlet ducts add length and weight. Post-stall recovery is problematic if TVC fails, and the fixed fins and rudders are large.
Supercruise is the capability of an aircraft to fly at supersonic speeds by using the engine’s dry thrust only. Afterburning thrust is needed for other aircrafts to fly at supersonic speeds for short intervals. But the F-22 can fly at supersonic speeds for long periods as it doesn’t need to use fuel draining afterburners.
The Air Force-funded think tank RAND 2008 study looked at 588 air-to-air shoot-downs since the 1950s and counted just 24 that occurred with the attacker firing from beyond visual range. Historically, American long-range air-to-air missiles have been 90% less effective than predicted, RAND asserted. It remains to be seen if AMRAAM missiles can reverse these trends. The F-22’s long-range air-to-air missiles might not be able to hit an enemy aircraft, thanks to new enemy radar-jamming techniques. The Raptor carries six AMRAAMs and two shorter range AIM-9 Sidewinder missiles inside its weapons bays.
AMRAAM’s had some great upgrades over the years, but at the end of the day, it’s old technology and wasn't really designed with today’s significant electronic attack in mind. The problem is that many potential adversaries, such as the Chinese and the Russians, have developed advanced digital radio frequency memory (DRFM) jammers. The F-22’s long-range air-to-air missiles might not be able to hit an enemy aircraft, because of these new enemy radar-jamming techniques. These new jammers essentially blind the small radars found onboard air-to-air missiles like the Raytheon AIM-120 AMRAAM, which is the primary long-range weapon for all U.S. and most allied fighter planes.
These jammers, which effectively memorize an incoming radar signal and repeat it back to the sender, seriously hamper the performance of friendly radars. Worse, these new jammers essentially blind the small radars found onboard air-to-air missiles like the Raytheon AIM-120 AMRAAM, which is the primary long-range weapon for all U.S. and most allied fighter planes. That means it could take several missile shots to kill an enemy fighter, even for an advanced stealth aircraft like the Raptor. “While exact Pk [probability of kill] numbers are classified, let’s just say that I won't be killing these guys one for one,” the senior Air Force official said. The Pentagon could also develop a new missile that combines multiple types of sensors such as infrared and radar into the same weapon—which has been attempted without much success in the past.
The E/A-18 Growler has successfully jammed the F-22 in various exercises with its powerful built in jamming equipment and APG-79 radar. Since the Russians know that they can’t compete with the US in stealth technology, they have concentrated in putting a wide variety of radars, sensors and advanced jamming equipment in their 5th gen fighter. The Su-50 will house multiple AESA radars in its nose, L-band wing radars and rear looking AESA radars and jammers. It will also feature the latest Himalaya Electronic Warfare Suite and Jammers which are said to be the most powerful of its kind to be mounted on a fighter.
Thrust Vectoring can contribute to create certain advantages but only in a limited portion of the flight envelope at velocities well below “corner speed”, wasting valuable time in manoeuvring the aircraft to achieve a suitable condition . In WVR (Within Visual Range) arena, the large F-22 tends to lose too much energy when using thrust vectoring during a sharp turn when naturally the energy it loses makes the then slow moving stealth combat plane quite vulnerable for a short time. The F-22's thrust-vector control system cannot provide roll or yaw control because the engines are too close together. According to some, F-22 allegedly has sustained turn rate of 23-24 degrees per sec. As 28 degree per sec sustained was made by an USAF colonel, it most probably was a mistake – possibly intentional; thus, second figure is more reliable (28 degrees per second is probably instantaneous turn rate).
Months of investigation costing millions of dollars failed to definitively solve the jet’s oxygen woes, removed faulty filters from all 180 or so F-22s. In 2012 the USAF contracted Lockheed Martin to upgrade 40 F-22 Raptor oxygen systems, and installed backup oxygen generator systems just in case the main system malfunctions. While, he added, the USAF is "certain the F-22 cockpit is a safe and effective workplace to operate", the new secondary oxygen supply systems are but one part of a suite of measures intended to improve the Raptor flight experience for all. By the end of 2012, for example, USAF Raptor pilots will also start to receive upgraded pressure G-suits vests to help them counter the vast G-forces generated as these highly agile fighters shift about the sky. The Air Force claims its has a handle on the in-flight blackouts. new backup oxygen generators installed.
But the Air Force says the alterations won’t do anything to fix the so-called “Raptor cough,” a chronic condition afflicting almost all F-22 pilots. The coughing — which, to be clear, is a totally separate issue from hypoxia — is due to a condition known as “acceleration atelectasis,” Maj. Gen. Charles Lyon, who headed the Air Force’s Raptor investigation, wrote in response to questions submitted following a September testimony before a House subcommittee. “Acceleration atelectasis results from pilots breathing high concentrations of oxygen (above 60 percent) while wearing anti-G trousers, and exposure to G-forces,” Lyon explained.
The coughing, Lyon continued, results from the closure of the lungs’ alveoli as oxygen-rich air is absorbed, leaving insufficient gas such as nitrogen behind to keep the alveoli open. “The normal physiologic response to re-open the alveoli is to cough,” Lyon wrote adding that an F–22 feeds its pilot higher concentrations of oxygen compared to other jets. The Air Force has ruled out any adverse health effects from toxic fluid leaks, hazardous particles from the Raptor’s stealth coating and the possible impact of breathing the F-22′s engine exhaust. If the maintainers really were sick, as they claimed, the Air Force is “confident that factors other than the life support system or the aircraft caused the ground incidents”.
The best way to prevent a service-wide warplane-grounding is to operate lots of different kinds of planes that don’t all suffer the same technical problems at the same time. No over-reliance on any single type of aircraft so we have a single point of failure. However, cuts in the number bought have raised fixed costs per plane, and also contributed to a shrinking industrial base that makes parts more expensive.
F-22′s fuel:weight ratio, wing loading, and acceleration are inferior to existing fighters. Adding that the unreliability the F-22′s stealth own radar IFF (Identification, Friend or Foe) will give it away when used.
Forward-swept wing design (failures due to cost, material & engine tech)
Polish Z-17 to Z-47 "Sep" types
New Delhi has suggested to Moscow that 65 T-50 fighter jet can be supplied off-the-shelf deal, while $11 billion R&D contract to improve upon the aircraft can carry on simultaneously for 8 years. Moscow is allegedly demanding $7 billion from India as part of a work-sharing agreement currently under negotiation includes the transfer of highly-sensitive Russian defense technology. India is not in a position to pay this kind of money. Before moving on, India wants a guarantee that it will be able to upgrade the fighter jet in the future without Russian support, which would require Moscow to share T-50 fighter's source codes.
The 34 ton T-50 is a blended wing-body design, resembling the Su-27 in one key respect: the core of the structure is the “centro-plane,” a long-chord, deep-section inner wing to which the rest of the air-frame components—the forward fuselage and widely separated engine nacelles, wings and tail surfaces—are attached. Compared to the Su-27, however, the centro-plane is deeper between the engines, to accommodate weapon bays. Its fuselage and nozzle shaping in the prototypes shares the same deficiencies as the F-35.
The main shortcoming of the project MiG design bureau was higher technical risk. The preliminary design phase was completed over two years ago in June 2013. The T-50 undertook its first flight in 2010. Russian air force is only planning to buy about a dozen PAK-FAs until the more powerful "second stage" Izdeliye 30 engines are developed. The engine will have a much higher fuel efficiency and specific thrust than the "product 117" has, and its structural and technological performance. Instead of buying PAK-FA, Russia is planning to continue production of advanced Su-30 and Su-35 Flanker variants. Russian development and manufacturing problems indicate the T-50 will not be a lot cheaper than the F-22. Few F-22s were built because of the high cost. American developers are now seeking to apply their stealth, and other technologies, to the development of combat UAVs.
Its radar systems “are capable of surveillance functions and active radio-location also serving as a tool of electronic warfare.” While the Russians have made enormous leaps in their sensor capabilities, U.S. warplanes still hold the edge in terms of sensor and true data-fusion, especially critical software in advanced mission computer (AMC) that provides coordinated enhanced situation awareness. Russia is planning to use the jointly-developed 5G fighter as an export variant of the T-50. The fighter is expected to enter IAF service by 2020. Malaysia won't get their T-50s until 2035 at the earliest.
There is still no definitive information about the T-50's internal weapons capability, but it seems likely that there are four separate weapon bays. Two bays outboard of the inlets each accommodate a single RVV-MD. Tandem bays between the engines each hold two missiles, but it is likely that the forward bay is deeper to house weapons such as the Kh-58UShKE, with the aft bay dedicated to air-to-air missiles in the R-77 family.
A mature production PAK-FA design has the potential to compete with the F-22A Raptor in VLO performance from key aspects, and will outperform the F-22A Raptor aerodynamically and kinematically. The PAK FA uses planform alignment to get invisible to radar. Therefore, from a technological strategy perspective, the PAK-FA renders all legacy US fighter aircraft, and the F-35 Lightning II Joint Strike Fighter, strategically irrelevant and non-viable. The T-50 is not meant to be a direct rival for the F-22 or B-2 because the Russian aircraft is not as stealthy as either. But if the maneuverability and advanced electronics live up to the promises, the aircraft would be more than a match for every fighter out there other than the F-22. PAK-FA makes a clear statement, which diverges fundamentally from Western thinking, that the idea that the Within-Visual-Range (WVR) and Beyond-Visual-Range (BVR) air combat are much alike. The principal difference is that the latter relies more heavily on long range sensors and its ability to defeat countermeasures and low observability.
The average value of this indicator for the PAK FA fighter is between 0.1 and 1 square metre, whereas the visibility of the American fifth-generation F-22 fighter is 0.3-0.4 square meters. In order to achieve this level of stealth, designers moved all weapons to the inside of the plane and also changed the shape of the air intake channels, also lining its walls with a material that absorbs radio waves, it said. While the T-50 is the stealthiest aircraft the Russians have, it is not nearly as stealthy as the F-22, or even the F-35 or B-2. The Russians are apparently going to emphasize maneuverability instead of stealth. India wants more stealthy airframe and would prefer a two-seat aircraft.
With the Indian participation (Code-named Project 79L) under the Perspective Multi-role Fighter (PMF) programme, Russia now has the billions of dollars it will take to carry out the T-50 development program. The preliminary testing program conducted by Sukhoi has so far involved 6 prototype airframes, including four flying, one static and one systems test airframe. More than 450 flights have been carried out to date under the program. The Indians are, by a contract signed in 2001, supposed to pay 25% of the development cost of the fighter, and for this they do not only get PAK FAs, but also their own especially made HAL FGFA, which is an upgraded version of the T-50, featuring more than 43 improvements from the PAK FA, among others better avionics, better stealth, and the capability to mount Indian missiles and rockets on the hardpoints. At least, that was the plan. India has already spent about $5 billion. Sources said the investment of USD 6.7 billion (Rs 44,800 crore) would give India only 4 prototypes of the FGFA aircraft and it will have to pay another USD 1 million (Rs 7 crore) for each plane which we would be ready for induction only after the year 2027-28. The overall cost of the project for the IAF is likely to come out to USD 24 billion (Rs 1,60,000 crore) which is almost the double the amount the force had planned. India is willing to induct only 12 of these planes into the IAF.
"Russia has already given the draft R&D contract to Sukhoi & HAL. It will include the cost of designing, infrastructure build-up at Ozar, prototype development and flight testing. So, India will have scientists and test pilots based both in Russia and Ozar during the R&D phase up to 2019. HAL will subsequently begin manufacturing the fighters,"
“Let's be clear: the HAL-Sukhoi program isn't a joint effort,” says an air force officer with Bengaluru-based Training Command. “The airframe will be identical to the ones the Russians currently have in flight-test. Our decision to go with a single-seat configuration is principally to avoid potential time overruns that will almost certainly be part of designing such a configuration. The maximum that HAL will do is insert a few systems of our choice and play lead integrator for the 'MKI,'. India's work-share in the FGFA project had been reduced to just 13% from the earlier envisaged one of 50%. HAL will contribute only tyres, basic navigational instrument VOR-DME, coolant for the radar, laser designation pod and heads-up display. India has conveyed its deep concerns to Russia about being denied "full access" to the FGFA project despite the fact that it is supposed to be an equal partner in financing it.
So vital is the FGFA to the IAF’s future that Defence Minister AK Antony has publicly rejected any prospect of buying the American fifth generation F-35 Joint Strike Fighter, declaring that the FGFA would suffice for India. In 2007, New Delhi and Moscow highlighted the fighter’s criticality in an Inter Governmental Agreement (IGA) for the project. Indian scientists say the expertise gained from the FGFA will provide crucial momentum for developing an all-Indian fifth generation fighter, designated the Advanced Medium Combat Aircraft (AMCA). Unfortunately India's work share will not involve development of stealth coating or stealth airframe design aspects.
Yet, with so much riding on the FGFA, the IAF has taken aback the MoD with its complaint that it would not be good enough. The IAF’s three top objections to the FGFA were: (a) The Russians are reluctant to share critical design information and work share with India; (b) The fighter’s current temporary AL-41F1 engines are unreliable and do not provide sufficient thrust for the airframe, leaving the aircraft at a significant disadvantage (Russian officials have already clarified that the Sukhoi T-50’s current engine, the AL-41F1, is a temporary solution to allow the flight-test programme to continue); and (c) It is very expensive.
A new engine, Izdeliye-30, that is currently being developed in Russia will eventually power both the FGFA and PAK-FA. The cold section will have a 3-stage compressor and a single-stage turbine; the hot section (the engine core) has a 5-stage compressor (instead of 9 stages) and a single-stage turbine. Apart from dramatically reducing the rate of fuel consumption, it will also have reduced IR signature by around 75%. They would be 30% lighter and feature higher thrust and 30% lower life-cycle costs than the Product 117 engine and provide the fighter a thrust to weight ratio of 1.41 – a huge number. Like the F-22A Raptor, the PAK-FA will provide a significant capability for the kinematic defeat of inbound missile shots. IAF wants iron-clad assurances on the stealth capabilities, engine performance, sensors and weapons fit of the aircraft.
AL-41 F1 engine (runs far hotter than the original Sukhoi-30MKI’s AL-31 engines) is currently under trials and thus the aircraft will initially be powered by ‘Saturn-Lyulka 117S’. The 117S themselves are an upgraded product achieved by clubbing AL-31F and improvising the technologies of AL-41F in the system. The high-temperature core components used in the Al-41F supercruising engine was modelled on the Pratt & Whitney F119 series that powers the F-22A.
117S engine can produce 142 kN and 87 kN of thrust with the afterburners engaged and disengaged respectively. The engine is equipped with circular thrust vectoring nozzles and has incorporated infrared and RCS reduction measures. The engine is equipped with state-of-the-art FADEC (Full Authority Digital Engine Control) Nerve centre to the FADEC system is the ECU or Engine Control Unit.
The NIIP AESA radar built for the T-50 worked very well as a prototype but the manufacturer found that the hand-built prototype NIIP was difficult to mass produce. It’s easy enough building prototypes, but developing a truly capable revolutionary aircraft — all during a major economic recession — isn’t so simple. If there are technical problems, Russia hasn't disclose them. Known problems with the T-50 are its engines and its defensive electronics which are proving difficult to solve. This puts the T-50 at a big disadvantage against the F-22 or F-35, which try to detect enemy aircraft at long distance, without being spotted, and then fire a radar guided missile (like AMRAAM). These problems are apparently the main reason for the delays. Now the T-50 program appears to be in serious trouble, and Russia Air force has cut back the 52 fighters down to a mere squadron (12 examples for testing). Apparently, Russia has already told its air force generals to prepare for a future full of Su-30s instead.
Commonly used RAM technology to date is the iron ball paint which contains tiny spheres coated with carbonyl iron or ferrite. World’s first purpose built stealth aircraft F-117A used electrically isolated carbonyl iron balls of specific dimensions suspended in a two-part epoxy paint. Foam absorber, Jaumann absorber, Carbon nano-tube and Split-ring resonator absorber systems and are the other known stealth coatings known and in use till date.
The Russians want to sell their "Fifth Generation Fighter" (which they admit is not true 5th Gen) to India and other foreign customers. Russians and Indians have been doing a lot of tinkering since the first T-50 flew. While the T-50 is the stealthiest aircraft the Russians have, it is not nearly as stealthy as the F-22, or even the F-35 or B-2. The Russians are apparently going to emphasize maneuverability instead of stealth. India initially wanted around 30 or 40 twin-seat aircraft to be used as trainers. But since PAK-FA was a single-seater, the Russians sought an additional $8 billion for the trainer version. The move was scrapped as India settled for training on simulators.
On January 15, 2014, at a MoD meeting to review progress on the FGFA, the deputy chief of air staff (DCAS), the IAF’s top procurement official, said the FGFA’s engine was unreliable, its radar inadequate, its stealth features badly engineered, India’s work share too low, and the fighter’s price would be exorbitant by the time it enters service.
The problems with the T-50 engines and its defensive electronics are proving difficult to solve. This puts the T-50 at a big disadvantage against the F-22 or F-35, which try to detect enemy aircraft at long distance, without being spotted, and then fire a radar guided missile (like AMRAAM). These problems are apparently the main reason for the delays. There were more short-falls put forward by the IAF like the problems encountered with the quality control, the un-patched wings that may fall apart in cases of stressed manoeuvres and the delay in the commencement of the architecture. When all these points are put together, the entire amount of the $6 Billion is relatively huge to pay up. The delay in resolving technical issues has meant that the IAF will not have 5th generation fighters even by the next decade.
If such a T-50 was sold for under $100 million each there would be a lot of buyers. But it looks like the T-50 will cost at least $120 million each. It also costs at least 50% more than the Su-27. That would be some $60 million, about what a top-of-the-line F-16 costs. Only 187 F-22s were built because of the high cost. American developers are now seeking to apply their stealth, and other technologies, to the development of combat UAVs. Thus, by the time the T-50 enters service at the end of the decade it may already be made obsolete by cheaper, unmanned, stealthy fighters. The United States, Russia, and China are all working on applying stealth technology to combat UAVs.
Russia announced in late 2015 that it would only induct a squadron (18-24 aircraft) of PAK FA fighter aircraft, and procure additional Sukhoi Su-35S aircraft instead. The original deal involved Russia procuring 250 and India 144 aircraft at a cost of around $30 billion by 2022. As a result, India threatened to abandon the project in its entirety. Russia in turn made a number of concessions including an offer to cut down its financial contribution from $6 to $ 3.7 billion for three PAK FA T-50 prototypes and substantial technology transfers.
A fundamental part of a fighter's avionics is its radar. All fighters are generally equipped with a passive device that "listens" for radars targeted at them. The F-22 and F-35's radar is designed to be difficult to detect (given the acronym Low Probability of Intercept - LPI), while maintaining superior ability to find other aircraft to conventional designs. Neither the Rafale (PESA RBE2) or Eurofighter have the advanced radar AESA which is a highly secret technology, and it is unlikely to be exported. Another factor to consider is the sophistication of other sensors, such as passive infra-red and passive radar detectors, as well as radar jamming capabilities. The 2004 exercise with USAF F-15 Eagles proved this despite the Indians winning "90% of the mock combat missions" since the F-15's were not permitted to use their inboard radar, also not to simulate the full range of the AMRAAM (restricted to 32 km when the full range is claimed in the report to be over 100km), nor to use the AMRAAM's own radar systems to guide itself in. After all the USAF F-15s have never lost an air-plane.
Zhuk-AE is the first non-american AESA radar for fighter jets ready for use. The latest incarnation of the Zhuk radar family featuring an Active Electronically Scanned Array (AESA). Russian industry has crossed the key hurdles of designing and integrating viable GaAs MMICs and performing the overall integration and design of an AESA. From this point we will see increasingly convergence with Western technology for AESAs, as new technologies like Gallium Nitride HEMT transistors are incorporated. The radar is stated to provide a detection range of 130 km for a head on target with up to 30 targets tracked and 6 of those engaged at any one time. As an AESA the radar is liquid cooled, with each transceiver capable of being switched off to prevent damage from overheating and switched on again when cooled. Two variants of the Zhuk-A exist: the FGA-29, and the follow on FGA-35 which will boast an improved detection range of 200 km with 60 targets tracked, the radar will also support a maximum mapping resolution of 1x1m in air to surface mode. The FGA-35 will feature a 700 mm antenna with an increased number of transmit and receive modules to between 1000-1,100, a 20 degree incline and a peak power of 6 kW.
The Zaslon is a Pulse-Doppler radar with a passive electronically scanned array (PESA) antenna and digital signal processing. The NATO codename for the radar is Flash Dance with the designations "SBI-16", "RP-31", "N007" and "S-800" also being associated with the radar.
The antenna used by the Zaslon is actually a multi-channel system comprising two separate electronically controlled arrays, an X-band radar with 1700 emitters and a L-band transponder with 64 emitters brought together into a single antenna. The radar was a landmark in aviation since it was the first time a PESA radar (previously found only on ground based systems) had been installed in a jet fighter. The Zaslon radar was publicly unveiled at the 1991 Paris Airshow with its associated MiG-31 interceptor, the Russians even removing the radome of the fighter to allow the Zaslon's revolutionary antenna to be seen. Also at Paris was the US F-117 Nighthawk (revolutionary for its use of stealth technology) which the Russians suggested should take to the air with the MiG-31 to see if the Zaslon could detect the F-117. Unfortunately no such contest was ever conducted though Russian experts were confident that Zaslon would have been able to detect the F-117 during flight.
It has IRST/laser ranger finder (à la MiG-29/Su-27)- something the Russians very much appreciate, and there seems relatively little effort to reduce this sensors radar cross section.
The two J-20s arrived at low level, one jet sped off to the horizon and left the other to perform a series of simple turns. The brief display, lasting only around a minute, did not involve low-speed passes and the pilots did not open the weapon-bay doors. The routine offered few clues about the jet’s engine, mobility and radar evading properties.
The J-20 is a single-seat, high-speed, twin-engined fighter with long-range AA missiles. It has divert-less supersonic inlets (DSI) on both sides, an all-moving vertical tail and a canard wing configuration. At the moment, it's just a flying shell with a hint of low observable capabilities. They are clearly not ready for combat and wouldn't be operational at least before 2019.
J-20 purpose is to push back USN tankers and AEW&C beyond 1000 miles. Neither the F-35 nor the slow F/A-18 Super Hornet have the operating range to reach the beaches beyond 1000 miles. F35 with external drop tanks are not stealthy and drop tanks mean you will trade off payload big time. There is an historic precedent for this. The most successful USAAF fighter in the Pacific, during WWII, was the very-long-range (if vulnerable) P-38.
China for the first time, this project relied on their own resources, or whether use of technology and consulting assistance to other countries, particularly Russia. However, it lacks the capable sensors to see targets at long range, which Russian do not possess. At present, each of the four released prototypes of the J-20 have differed substantially, as the Chinese continue to manage the steep learning curve of manufacturing stealth technology. It does represent a major leap for Chinese stealth airframe design. Because J-20 afterburner consumes so much fuel you can't use more than a few minutes at a time.
It is estimated that the fighter will weigh 16-19 tonnes empty with a maximum takeoff weight of 36 tonnes. It is estimated that it can carry a weapons payload of 10 tonnes. It has four hardpoints on internal weapons bay and six external hardpoints plus one gun. It is thought to have a body length of 21 meters, a wingspan of 13 m and a maximum flight speed of Mach 2.2. Its cruise speed will likely be around Mach 1.6. It will likely have a maximum altitude of 20,000 m and a range of 4,500 km (carrying two subsidiary fuel tanks). It will have a combat radius of 1,500 km. Its main weapon systems will be the PL-21 long-range active radar air-to-air missile, the PL-12 medium-range active radar air-to-air missile, the PL-10 radar-homing medium-range air-to-air missile and the PL-8 infrared-guided air-to-air missile, as well as homing weapons and free-fall general purpose bombs. It is piloted by one person.
It's a relatively conservatively designed twin-engined machine with trapezoidal wing, two markers and two tilting the horizontal tail. J-20 canards are coplanar to wing, which in combination with their distance from wing leading edge makes them ineffective as lift-enhancing surface. The angle of inclination of vertical tail surfaces and their connection to place trunk full copy leaning sides of the fuselage, giving the front view form one continuous line. This solution simplifies the calculations of radar reflectivity and is used in all modern stealth aircraft. The back end of the J-20 looks awfully like the non-stealthy Mig 1.44, as does the overall layout with delta canards. A major surprise is covered with a one-piece cockpit, similar to that of an F-22. Surprising because the Russians with similar and even smaller dimensions for the design quite a fighter PAK FA plagued for more than a year too, they fail at that. The 3rd prototype J-20 has something worth a mention: a revised nose section, similar to that of the F-35, with an IRST/EOTS – used to hunt low observable aircraft, and a metal finish that loosely reminds the radar absorbing Haze Paint first used on F-16s. According to several reports it has a new air intake design and shorter engine nozzles.
Perhaps the most obvious differences were the new nose design with a dielectric radome for an AESA radar featuring a sawtooth joint with the main fuselage, and the addition of an electro-optical targeting system in a fairing beneath the forward fuselage. The tailfins featured cropped tips; the inlets and DSI (diverter-less supersonic intake) bulges had been redesigned around the nozzles to improve rear-aspect radar cross-section; the leading-edge root extensions between wing and foreplanes were reshaped; the canopy had gained a stiffening bow frame and a slightly more pronounced hump; and the cumbersome main-wheel door design of the initial aircraft had been replaced by a much neater installation. Other changes included enlarged fairings to either side of the engine nozzles. Diamond-shaped windows around the fuselage suggest that a distributed aperture infrared vision system is installed. The sensor suite includes an electro-optical targeting system (EOTS) and a large-array AESA radar, which was developed by the 14th Institute at Nanjing Research Institute of Electronics Technology (NRIET, 14th Institute).
However, What the J-20 fighter lacks a is a bigger, reliable super-cruising engine, which the Russians will be probably hesitant to supply for fear of it being reverse engineered. Hence, a Chinese indigenous one is in need. An aircraft with supercruise should theoretically have a huge advantage in pursuing or avoiding a non supercruise-capable plane, in that the supercruise-capable aircraft will have a higher speed and thus a higher amount of manoeuvring energy. Super-cruise will also allow these planes to spend more time in combat, particularly at longer ranges, rather than in transit. At the moment the J-20 is believed to use the same engines that the Su-27/30 series of aircraft use – the Russian Saturn AL- 31. Further, there is no evidence of an Active Electronically Scanned Array Radar (AESA), without which its performance would be meaningless. Until these technologies fructify, he feels that the J-20 would just be a hollow threat. As in the rest of the world, and there will be a phase of EMD (engineering and manufacturing development) take at least ten years, and serial machines can hardly get to the real surgical operation before 2020. J-20 also lacks any IR signature reduction measures.
Stealth essentially means designing an aircraft so that it remains undetected by radar, infra red or visual means. It also includes technologies for reducing noise and smoke. Why stealth? With increases in radar detection ranges, higher power radars and more sophisticated signal processing, it became practically impossible for aircraft to avoid radar detection. One solution was to fly below the radar horizon. However that required special training. Further, the increased fuel consumption at low level dramatically reduced operating ranges. One solution was to use jamming – decoying the enemy radar into believing that the threat was coming from another direction. This required dedicated and expensive equipment and training. Moreover the enemy too was developing countermeasures and jamming was therefore not always effective.
One of the earliest methods used was to coat the surface with radar absorbent material (RAM). The Germans used this on their U-boats to avoid detection by allied aircraft in WWII. However, such materials are not durable and are maintenance heavy. Some form of RAM is still used today. Really significant RCS reduction requires a radical redesign of airframes. Curved surfaces usually reflect only a portion of the incident energy back in the direction of the transmitter, while flat surfaces reflect a major portion of the incident energy. Sometimes the incident energy is trapped in cavity formed by aircraft surfaces or ducts. This causes resonance and more energy reflections in all directions - obviously undesirable. One of the solutions to avoid radar detection is to cant the reflecting surfaces away from the perpendicular and direct the incident energy in other directions. This is called faceting. Here the aircraft surface is broken up into a number of differently angled planes, thus breaking up the incident energy and reflecting only a small portion back to the radiating source. This is used in the F-117, which looks very unlike any other fighter. Its surfaces are heavily faceted, somewhat like a cut diamond. Due to its design the F-117 pays a heavy drag penalty. It manoeuvres poorly and has a low top speed. If ever detected, it would be a sitting duck. These aircrafts is not cheap – a B-2 costs about two billion USD. The US stopped procurement at 26.
Further, all weapons have to be carried internally. So internal space has to be liberated. This rather obviously limits weapon carriage capacity. Engine inlet ducts are shielded with the engines located well inside the aircraft. This is because incident radar energy can bounce off the rotating blades and give away the aircraft’s presence. In order to avoid detection from the ground, the exhaust nozzles are located on the upper surface of the wing. Further, the aircraft’s hot exhaust gases are mixed with cooler air thus reducing the infrared signature useful to infrared seeking missiles. In order to cool the hot exhaust nozzles, different materials are also used. Going the stealthy way means a lot of compromises.
On 27th March 1999, the downing of an F-117 'Nighthawk' over Serbia only highlighted to the United States the importance of stealth. The pilot ejected and was rescued. It was the first time one of the much-touted "invisible" fighters had ever been hit. "At the time, our intelligence reports told of Chinese agents criss-crossing the region where the F-117 disintegrated, buying up parts of the plane from local farmers," says Adm. Davor Domazet-Loso, Croatia's military chief of staff during the Kosovo war. We believe the Chinese used those materials to gain an insight into secret stealth technologies ... and to reverse-engineer them," Domazet-Loso said in an interview.
A drugs bust conducted by undercover agents in the US has uncovered a plot to export sensitive military technology to China. Taiwanese nationals Hui Sheng Shen and Huan Ling Chang were both suspected of attempting to smuggle drugs and counterfeit goods through a port in New Jersey, US, but have since been accused of conspiring to export technology relating to F-22 fighter jets and several US-built UAVs. The pair were recorded in taped conversations claiming to be working with an adviser to a high-ranking Chinese government official looking for technology relating to Global Hawk, Reaper and Raven drones, as well as stealth technology relating to the F-22 fighter jet. Shen and Chang later revealed that their contacts were connected to a Chinese version of the Central Intelligence Agency and that Chinese government money would be used to make acquisitions of the sought-after technology.
Ming Suan Zhang was charged in Federal Court for “attempting to illegally export aerospace-grade carbon fiber“, and faces up to 20 years in prison. Allegedly, Zhang and unnamed accomplices tried to obtain the carbon fiber and have it exported out of the US to China. Luckily for the US, the company that Zhang contacted was actually a front business for Homeland Security and the “buyer” Zhang talked with was actually a US agent.
Duck tail is surprisingly vyklonené upwards as the machine J-10. While this is partly to help improve maneuverability and buoyancy (generation airborne viruses), but on the other hand, the significantly increased radar reflections. Not only from the front view but also from sides and angles that are typical for ground radar radiation. This would again suggest links between the project Yakovlev MFI as comparable American JAST concepts made by Lockheed Martin built just for that duck tail from the front view in the same plane as the angle of the wing leading edge.
The US has long suspected China of attempting to copy sensitive information relating to technological advances, particularly in the field of stealth technology. In 2005, a former Northrop B2 design engineer was arrested for selling highly classified data about the B-2 and its stealth design to China. The development of China's Chengdu J-20 fighter jet has been met with claims of stolen stealth designs from the B-2 Spirit programme, while China has also been accused of cyber espionage after a number of hacking attempts on Lockheed Martin computers.
China's J-20 programme is seen as a direct rival to Lockheed Martin's F-35 fifth generation fighter jets, but has been troubled by reported problems in its development. Stealth technology has been hard to develop and several sources have cited that catastrophic failures in potential engines for the aircraft have seriously affected the development of the fighters. The J-20 appears to be less than an F-35 clone, and more of an F-35 type aircraft with pretensions to being an F-22. In any event, the J-20 is an attempt to develop some kind of 5th generation aircraft, complete with stealth.
Increasingly, the U.S. military has made stealth one of its highest priorities, both in terms of new acquisitions and the retrofit of older aircraft. In short, stealth is the centre-piece of the U.S. air superiority strategy. Faced with the prospect of aerial stealth proliferation, states in the 21st century are looking for anti-stealth defence options.
One such alternative, passive radar, appears a cost-effective counter to stealth. Passive radar is a receive-only system that uses transmitters of opportunity. Integrating a system of netted receivers, passive radar can detect, track, and target piloted and un-piloted stealth systems and provide cuing for anti-air weapons systems. A passive radar system emits no radio energy and can be well camouflaged in both urban and rural landscapes. One of the most significant counters to stealth, namely conventional very high frequency (VHF) and ultra high frequency (UHF) radar, has been around since World War II and is still in use today for long-range air surveillance. Most LO techniques are designed to defeat acquisition and fire control radar in the X band, which uses centimeter wavelength. Poor resolution in angle and range, however, has historically prevented these radars from providing accurate targeting and fire control.
These J-20 fighters can then intercept the F-35 fighters and push them out of Chinese airspace. Given the severe drop in RCS with fourth-generation fighters, adding concentrated deployment of early warning aircraft and radar is a bottomless pit, as no country has been able to make up for the shortfall in their early warning and anti-aircraft defense systems. The US only has 187 F-22 fighters. With China’s J-20 fighters in development, as well as the sheer numbers of third-generation fighters, forming its main strategic combat force, along with early warning aircraft, electromagnetic interference systems and airborne warning and control systems, China will have a clear advantage over Japan in any potential air battle. If the J-20 is equipped with China’s fourth generation active electronically scanned array radar, and this equals the APG-77 with which the F-22 is equipped, the aircraft will be able to detect an F-35A head on at a distance of 50 km, whereas a F-35A will only be able to detect a J-20 head on at a distance of 20-40 km, giving the J-20 the advantage. The J-20 has similar capabilities to the F-22, including supercruise, electronic countermeasures (ECM) and super-maneuverability, giving it an advantage over the F-35A under all battle conditions.
There are eight prototypes of the J-20 and several pre-production models. 2011 “Black Ribbon”; 2014 “Galacticos”. 2101 and 2017 are the ninth and eighth J-20 fighter respectively. Chinese officials have stated that final requirements could be between 500 and 700 aircraft.
Although the Russian military had stopped the development work of the world's first supersonic V / STOL fighter aircraft - Jacques -141, but the R-79 -300 engine which developed for the aircraft has not been abandoned. Recently reported that China had already received the technical information of this type of engine & R-79-300V vector control engine nozzles, related production technology and an engine products. Russia has already sold hundreds of AL-31 series of turbofan engines to the China.
The prototypes will finish tests by 2018 and at least a decade away from the first production aircraft. The experimental X-2 is expected to make its maiden test flight in 2015. It will began service in 2035. The firing systems on the prototype still require a substantive amount of code deciphering in order to function correctly–and the task has proven to be abysmally complex, even for the world’s top engineers and researchers in Japan. The aircraft is to replace the fleet of F-2 fighters as early as 2028.
Japan admits that it will take about a decade to get the X-2 into service, assuming all the technical and fiscal obstacles can be overcome. Japan’s Technical Research and Development Institute is still looking into, infrared stealth, fiber optics, self-repairing flight control technologies, building air-to-air radar into the actual skin of the aircraft itself, and battlefield data networking in order for the fighter to be considered complete. Something that will set the new Japanese Fighter apart from the previous fighters are the thrust vectoring paddles. These game-changing paddles extend from the engine exhausts. This will enable the flying machine to allow the pilot to control the direction of the exhaust. Japan has already developed the Mitsubishi AAM-4B, a long-range air-to-air missile with an active electronically scanning array (AESA) radar as a seeker complete with homing functionality.
The 2011 design, 23DMU, looked somewhat like a scaled up ATD-X. As is common in stealth aircraft, snaking inlet ducts shielded the engine faces from radar energy, which they would otherwise reflect strongly. The tail of 23DMU had the usual four surfaces, with the fins angled outward. The result of the 23DMU design effort was quite a deep fuselage and a lot of radar-reflecting side area, which the designers sought to reduce in 24DMU by flattening the aircraft. They moved the engines outboard and fed them with straighter ducts, relying on blockers—radial baffles mounted ahead of the engines—to help obstruct radar energy. Just two stabilizers were mounted as a V-tail much like that of the Northrop YF-23, the aircraft that the U.S. Air Force rejected when it chose the F-22.
It is a twin-engine design which will utilize two Ishikawa Heavy Industries low-bypass turbofan engines for optimal thrust. Engineers are well into preliminary development of a surprisingly powerful turbofan for the twin-engine fighter, which would enter service around 2030 as the F-3. Key aims of the engine project are to achieve the extremely high temperature of 1,800C (3,272F) and to keep the powerplant slim in order to reduce airframe frontal area. The latter point is one of several features that suggest an intention to build a supercruising fighter, which now looks doubtful amid the emphasis on range over speed.
ATD-X stands for ‘Advance Technology Demonstrator - X’ & “DMU” stands for “digital mock-up”.
Interceptor & Striker (A - attack)
It was judged that having a single engine would create too much drag, but the two lift engines were dead weight in cruise, and the small cruise engine gave a poor thrust to weight ratio. It also had very small highly loaded wings. By contrast, the Harrier had a much higher thrust-to-weight ratio, it was effective as a dogfighter, and had larger wings which were put to good use in rolling short takeoffs.
The designers settled on an aircraft that combined pivoting wingtip engines with fixed vertical-lift engines buried in the fuselage. It was a simpler solution than the one used in the British Harrier. But like today’s F-35B, it possessed a disadvantage in that the fuselage lift power plant—a lift fan in the case of the F-35B—amounted to dead weight during cruise flight. This badly hurt its performance.
The blazing hot afterburner was also too close to the ground in vertical flight. A similar “downwash” problem has caused problems for the F-35B when taking off from the decks of amphibious assault ships. Tests revealed that the wingtip jets were troublesome in VTOL mode. While the VJ 101 came to naught, the engine apparently inspired the Soviet R-79V-300 used years later in the Yakovlev Yak-141 V/STOL fighter project. The same concept of an afterburning turbofan with vectoring nozzle is now powering the F-35B
I’m going to have some F-35s doing air superiority, some doing those early phases of persistent attack, opening the holes (by destroying enemy air defences), and again, the F-35 is not compelling unless it’s there in numbers,” the general says. “Because it can’t turn and run away, it’s got to have support from other F-35s. So I'm going to need eight F-35s to go after a target that I might only need two (F-22) Raptors to go after. But the F-35s can be equally or more effective against that site than the Raptor can because of the synergistic effects of the platform.
Trends from the database of air combat since 1965 show the rise of long range missiles which can now often outperform most traditional fighter aircraft, although stealth and electronic warfare help even the score. Attributes such as speed, thrust-to-weight ratios, and turn radius are even less important to success today and in the future. The advantage is on enhanced sensor performance, signature control, networks to achieve superior SA [situational awareness]. Some elements of the new battle force could be unmanned as well to take better advantage of the big aircraft’s endurance. Combatants will rely on Infrared Search and Track Systems (IRST) because Digital Radio Frequency Memory (DRFM) jammers will disrupt search radars. So enemies will be looking for heat with those IRST sensors and fast planes will be easier to spot because higher speeds mean higher heats from engines and along leading edges and other aircraft surfaces.
According to French and Edgren, the American plan to use the F-35 as a long-range combat platform – using BVR missiles – is fatally flawed because US air-to-air missiles do not have a splendid record in war. Despite the F-35’s designers’ preference for long-range combat, avoiding dogfights may prove difficult. The F-35 is a large aircraft but most of its internal space is taken up for fuel. There’s precious little internal space for carrying bombs and missiles. Secondly, if the missiles are carried on external hard-points, it nullifies whatever little claimed stealth it has. This problem will be exacerbated by the F-35’s limited ability to generate sorties, i.e., fly missions, to repeatedly deliver its weapons to targets over the duration of a campaign. This is a huge advantage for Flanker pilots because they can fire repeated salvos to achieve an air-to-air kill. Compared with the armoury of short-, medium- and long-range missiles that Flankers are known to carry, the F-35 has been virtually disarmed. Despite plans for the F-35 to replace most of America’s fighter and attack aircraft, the platform is ill-suited to cost-effectively counter near-peer foreign militaries. Given the critical failings of the F-35 programme and its exorbitant costs, the aircraft should be regarded as a bad bet. By staying fully committed to the F-35 programme, the United States is investing unprecedented resources in the wrong aircraft, at the wrong time, for the wrong reasons.
If the F-35 were to carry the high off-boresight missiles like the AIM-9X Sidewinder, it would have to so externally, negating its stealth since it cannot go internally while the F-35 is in its stealthy buttoned up configuration. Also, AMRAAM is dated technology and is quite vulnerable to digital radio frequency memory jammers, hence the U.S. must eventually develop a new air-to-air missile to replace it. Also, excessive vibration of missiles and bombs carried in the internal weapons bay on all three F-35 variants has force the plane to reduce speed to 550 knots for safe operation.
Pilots will need to slow down from the F-35's max speed of Mach 1.6 to Mach 1.2 to deploy weapons or defensive countermeasures. The F-35's weapons bay can overheat if the plane is maintaining high speeds at an altitude of under 25,000 feet and an atmospheric temperature 90° F or greater. The F-35 is also unable to pull more than 3.8 Gs with a fully loaded fuel tank, due to known problems with with the fuel tank siphon. The plane can only pull its maximum of 7 Gs once its fuel tanks are at least 45% empty.
DOT&E report states that the F-35 still has 276 “Critical to Correct” deficiencies—these must be fixed before the development process ends because they could “lead to operational mission failures during IOT&E or combat.” Of the 276, 72 were listed as “priority 1,” which are service-critical flaws that would prevent the services from fielding the jets until they are fixed.
The F-35 uses its fuel for cooling its electronics. The aircraft won't start if its fuel is too warm. Also there is a “low-risk potential” that air in the fuel system could over-pressurise an F-35’s fuel tanks. The design flaw impacts all three F-35 variants operated by the US service and international buyers. It also has (vibration and acoustic) stresses affecting the weapons bay.
As of October 2014 F-35 was only able to achieve 61% of planned sorties (51% for F-35C, 55% for the F-35 A and 72% for F-35B) due to maintenance issues. Each variant of F-35 has fallen short of its reliability and maintenance targets set for the current stage of development and the Government Accountability Office (GAO) has characterized engine reliability as “very poor”.
Largely because of the Marines “jump jet” demands, even the best-manufactured JSF is a second-rate dog fighter despite its vaunted ability to evade detection by radar.
Convinced by Lockheed and DARPA that the universal STOVL jet concept could work, in 1996 Congress directed the Pentagon to organize a contest to build the new plane. General Dynamics, Boeing and Lockheed drew up blueprints. The main idea was to develop a fighter with just one swappable component — the downward-blasting second engine — a single airplane design could do the jobs of the Marines’ vertical-launching Harrier and of the faster, farther-flying conventional planes of the Navy and Air Force.
Fundamentally, the problem is one of lift. A plane taking off vertically gets no lift from the wings. All the flight forces must come from the downward engine blast. Forcing the motor to do all the work results in three design drawbacks: a big, hot engine with almost no safety margin; an unsafe airframe that must be thinly built with tiny wings in order to keep the plane’s weight less than the down-thrust of the engine; and minimal fuel and weapons load, also to save weight.
A complicated system of shafts, gears and doors activates to reveal the horizontal lift fan installed in the center of the aircraft just behind the cockpit. Together the fan and nozzle produce more than 40,000 pounds of thrust, enough to lift the nearly 20-ton aircraft straight up off the ground. In vertical mode the Harrier carries far fewer bombs than conventional fighters and also lacks their flying range. And the concentrated downward blast of the Harrier’s vertical engine nozzles melts asphalt and kicks up engine-destroying dirt, making it impossible to operate from roads or even manicured lawns.
The original X-35 from 2001 had the advantage of being strictly a test plane with no need to carry weapons. But the frontline F-35 needs weapons. And to maintain the smooth shape that’s best for avoiding detection by radar, the weapons need to be carried inside internal bomb bays. Bomb bays would normally go along an airplane’s centerline, but the F-35's center is reserved for the 50-inch-diameter lift fan. Hence STOVL and stealth are incompatible. The extra width violates an important aerospace design principle called the “area rule,” which encourages narrow, cylindrical fuselages for best aerodynamic results. The absence of area rule on the F-35 increases drag and consequently decreases acceleration, fuel efficiency and flying range.
The bulky lift fan, fitted into the fuselage just behind the pilot, blocks the rear view from the cockpit — a shortcoming that one F-35 test pilot said would get the new plane “gunned every time.” That is, shot down in any aerial dogfight by enemy fighters you can’t see behind you. The video resolution (scanning 360 degrees) is far worse than the naked eye and completely inadequate for picking up the distant, tiny, minimal contrast dots in the sky that represent deadly fighter threats ready to kill you.
Ironically, the fan and other vertical-launch gear threatened to make the new plane too heavy to take off vertically. Lockheed poured more people, time and money (billed to the government) into a redesign effort that eventually shaved off much of the extra weight — basically by removing safety gear and making fuselage parts thinner and less tough. But the redesigned JSF, while somewhat lighter and more maneuverable, is also less durable and less safe to fly.
Due to the complexities of designing such a fighter and due to the weight problem, Boeing had decided to use two delta-wing aircrafts (which were extremely maneuverable). The Boeing efforts were dubbed the X-32A and X-32B. For VTOL characteristics the X-32B was used. It made use of a similar direct-lift engine function to that of the Harrier II. The engine was a conventional derivative of the F-22 reheated turbofan, designated F119-PW-614C. It required the engine to be moved from it's conventional rear position to just behind the cockpit. This was done to balance the weight of the aircraft to make it controllable when hovering. The supersonic and conventional takeoff and landing demonstrations were performed by the X-32A. This made use of the engine in it's conventional position. By contrast, the Lockheed Martin X-35 concept demonstrator aircraft were capable of transitioning between their STOVL and supersonic configurations in mid-flight. However, the Lockheed Martin STOVL team used a more complex and riskier alternative, known as the F119-PW-611, which comprised a remote shaft-driven lift fan powered by the main engine, but it generated more lift thrust.
To help pay for the overruns, between 2007 and 2012 the Pentagon decommissioned nearly 500 existing A-10s, F-15s, F-16s and F/A-18s — 15 percent of the jet fighter fleet — before any F-35s were ready to replace them. To add insult to strategic injury, one of the most modern Chinese prototype warplanes might actually be an illicit near-copy of the F-35 — albeit a more intelligent copy that wisely omits the most compromising aspects of the U.S. plane. The J-31 does not have a lift fan or even a space for a lift fan. The omission apparently allowed Chinese engineers to optimize the new plane for speed, acceleration, maneuverability and flying range — and to add good pilot visibility and a second rearward engine. It’s possible that in some future war, America’s JSFs could be shot down by faster, deadlier, Chinese-made JSF clones.
F-35 Lightning II Joint Strike Fighter is a tactical, multi-role capability semi-attack fighter-bomber aircraft, meaning they are capable of strike missions and enemy intercept in high-tech and high-intensity environment. As it stands, F-35 has 276 deficiencies which needs to be corrected.
An F-35 strike force under AWACS cover would be able to detect and engage non-stealthy Russian kinematic performance fighters like MiG-35, Su-30, Su-35 - well before the Russian fighters detects its presence and strike the first shot. With its networking stealthy ISR abilities, groups of F-35s or armed drones can coordinate their tactics and share data—which is an advantage. F-35 has the capability to send a focus beam down a computer virus to any kind of receiver (enemy's radio and radar) and effectively blind it or shut it down. It does not have to be connected to the Internet. Additionally, F-35 has very high acceleration and "Angle-of-Attack". It has "instantaneous turn rate" ability at different speeds optimized for performance.
The F-35’s issue is that it essentially failed to come out as a joint service aircraft. "The reasoning behind this was that it would ultimately be cheaper to build one Jack-of-all-trades rather than several specialists. Not only would one fighter design replace most of the USAF's, USN's, and U.S. Marine's fighter fleet, but it would become the prevalent fighter for many nations around the world as well. So great was the allure, that "partner nations" invested millions of dollars just for the privilege being included in on the program. Only the two largest bankroll contributors, the U.S. and U.K. would actually have say in the final design. All the other partner nations were simply go "along for the ride"."
The dream of a universal fighter proved to be a fantasy. The F-35 was designed as a ground attack aircraft with secondary air to air capabilities. It was sold on the idea that it could to do all the missions of several aircrafts (F-15s and F-16s air-to-air combat, A-10 ground-attack planes, carrier-launched like F/A-18s, Harriers like vertical-takeoff). History suggests turning “bombers” into “fighters” is hard. Currently the three versions of F-35 are essentially different airplane designs—the very thing the Joint Strike Fighter program had, at its outset, endeavored to avoid. In 2013 Gen. Mike Hostage, then the top officer in Air Combat Command, had to make a choice—either give the developers an extra couple of years to work on the F-35 or water down the official definition of “operational” in order to suit the new plane’s condition.
The X-35 demonstrator was missing 2 very important fighter components; a weapon system and radar. Since weapons need to be carried internally on a stealth aircraft, the entire air-frame needed changes, weapons bays and doors needed to be added, resulting in added bulk. Adding new capabilities to F-35 is difficult since its already densely packed with electronics, not to mention the added weight. Even if re-designed for a new engine, F-35 fuel consumption is already high, adversely impacting range. Several more years will pass before the aircraft has the full capabilities originally sought.
Lockheed Martin sold the idea of the F-35 Lightning II to the U.S. Air Force as a stealth fighter jet costing just $35 million a copy (the lower cost came from projected volume of 1,700 of F-35A). “It’s unbelievable, first it was $40 million to $50 million, and then they [the IAF] told us $70 million to $80 million. Now, we’re looking at nearly three times that amount, and who’s to say it won’t continue to climb?” It is Pentagon's costliest arms program, estimated to cost nearly $400 billion for 2,443 aircraft. Each plane was originally projected in 2014 to cost between $40m to $50m million, but the final cost is anywhere between $100m and $140m. Keeping the planes flying over the next half-century may cost another $1 trillion in sustainment. "To put it bluntly, the Pentagon's new trillion-dollar fighter jet doesn't go a fast as it should, doesn't turn as sharp as it should and doesn't handle as nimbly as it should." Now its new promised price reduction is $85 million per plane by 2018.
The interchangeability of parts of the three versions is limited to 20%, less than the 70% expected in initial designs. A study released this year by the Pentagon’s Director of Operational Test and Evaluation suggested that the proposed block buy may be premature because of ongoing software and maintenance issues.
The F-35’s power system and engine frequently failed. Its pilots’ high-tech helmets were bulky and buggy. The F-35 is the first combat fighter to eschew a traditional HUD (head's up display) in favour of HMD (helmet mounted display). For a while, it couldn’t fly near thunderstorms because it lacked the equipment for channeling lightning strikes. The new plane’s gun wouldn’t be fully operational until 2019. Its software was taking too long to write. Its radar often had to be rebooted mid-flight. And sometimes the F-35 just caught on fire while on the ground.
An F-35 squadron can carry inherent within it an electronic attack force, a missile defense tracking capability, a mapping capability for the ground forces, ISR and C2 capabilities for the deployed force and do so in a compact deployment package. In addition, an F-35 fleet can empower Air Defense Artillery (ADA), whether Aegis afloat or Patriots and THAAD Batteries, the concept of establishing air dominance is moving in a synergistic direction. An F-35 EW capability along with it’s AA and AG capability will introduce innovate tactics in the SEAD mission.
F-35 can cut down the distance at which it can be detected by radar from 100 km to 20-40 km. If the stealth F-35 Lightning II jets perform as envisioned, the next generation of pilots might never see targets with their own eyes and might never fly close enough to adversaries to become involved in one-on-one dogfights. It's designed to be the new catch-all, a performer of all but master of none. But as the most modern aircraft on the production line it can do things its predecessors can't, and it shows how the USAF is changing the way it fights. It was developed to counter the advanced sophisticated radar and lethal surface-to-air defence systems which is why it has a lot of advanced electronics and stealth capabilities, making it it extremely expensive even for rich countries. The planes are designed to engage in electronic warfare using sophisticated airborne computer systems that tie into their sensors and communications systems.
F-35's vertical launch fan, coupled with the jet engine, weighs more than two tons - more than the jet engine. The fan works only during take-off and turns into useless "dead weight" in level flight. Turn performance for the US Air Force's F-35A was reduced from 5.3 sustained g's to 4.6 sustained g's. The F-35B had its sustained g's cut from five to 4.5 g's, while the US Navy variant had its turn performance truncated from 5.1 to five sustained g's. Acceleration times from Mach 0.8 to Mach 1.2 were extended by eight seconds, 16 seconds and 43 seconds for the A, B and C-models respectively.
The F-35 is stealthy, but it's not as stealthy as F-22. It won't be able to dip into enemy airspace unnoticed like the B-21 Raider will, so the focus is how to make it more effective from further away. The F-35 is susceptible to detection by radars operating in the VHF bands of the spectrum. The fighter’s jamming is mostly confined to the X-band, in the sector covered by its APG-81 radar. These are not criticisms of the program but the result of choices by the customer, the Pentagon. F-35 has the world’s hottest running engine, and has no IR signature reduction measures, which were deleted to save weight; F-35s inability to supercruise makes this even worse since F-35 will have to use afterburner to fly supersonically, producing very visible afterburner plume.
The radar is designed to share detailed targeting information via data-link with other aircraft -- one F-35 can hang back and turn on its radar, which gives its position away to the target but keeps it far from danger, while another can sneak in and fire a missile without giving itself away. Pilots from the U.S. and allied countries flying F-35s 25 to 30 miles apart will be able to stitch together real-time maps that all of them will be able to use. They also will be able to direct their own missiles — or weapons from other planes, ships, submarines or ground stations — to targets they've selected while airborne.
To use jamming, also known as “electronic attack,” or EA, you have to be certain that the radar has detected you. Otherwise, jamming is going to reveal your presence and identify you as a stealth aircraft, since the adversary can see a signal but not a reflection. It also has an expandable radar decoy—BAE Systems’ ALE-70. Both are last-ditch measures to disrupt a missile engagement, not to prevent tracking. F-35 can emit frequencies which can confuse and disable Russian anti-aircraft systems such as the advanced S-400, which uses radar to lock onto enemy aircraft.
More recently, it has emerged that the U.S. Navy is worried because new Chinese warships carry the Type 517M VHF search radar. VHF radar can't do fire-control, but they can see you. With low-frequency radars, they can tell which way to look, and they can scramble their super-cruising aircraft out to you. Stealth is not dead but excessive reliance on a single-point design is not a good idea too.
The F-35 can carry two AIM-9X missiles on its wings. More and more, those missiles are going to be smarter and capable of new things, not just blowing things up. Rather than risk people and valuable air-planes, why not just let the missile do the work? It's getting easier to pack missiles full of fuel and electronics, making them more like miniature drones than the old dumb-bombs. Some missiles, like Raytheon's new MALD-J, contain small radar jammers and can be fired almost 600 miles from the target.
Future versions could have electronic surveillance equipment, sending data back home, or even the means to inject viruses into computer networks. Also look forward to things like the Israeli IAI Harop, a hybrid missile/UAV that can circle overhead for long periods of time, waiting for a whiff of electronic scent and guiding itself in.
One promising development is the High-Speed Strike Weapon, a hypersonic ground attack missile, capable of launching from thousands of miles away and streaking towards the target too fast for anyone to hit. The problem is that these aircrafts capabilities are decreasing faster than new designs can be realised. With Technical problems, cost overruns, and schedule slippages; the F-35 in on track to be the most expensive program in the history and is comparable to the Pentagon’s super-costly, deep strike missions only, F-111 and it orders were cut from 1,500 to 500. Does the cost justify given the performance? The answer is bound to be a controversial one.
"The problem was that each service had very different requirements. The Air Force wanted 1,763 cheap bombing trucks to replace F-16s and A-10s; the Navy wanted 480 "first day-of-the-war" deep-strike stealth bombers to compete with the Air Force in strategic bombing; and the Marines, still haunted by the ghosts of Admiral Frank Jack Fletcher and Guadalcanal, wanted to replace ageing Harriers and conventional F/A-18s with 609 short take-off vertical landing (STOVL) JSFs that will operate from big-deck amphibious assault ships if need be."
For example, the plane needs stealth technology for deep-strike bombing missions, where planes must remain unobserved while going into enemy territory. But stealth may actually inhibit the marines’ ability to carry out their primary mission – close air support. To remain low-observable – military-speak for stealthy –the JSF must carry large amounts of fuel and ordnance internally. However that capability, in turn, impacts how long it can loiter over the battlefield for the Marines. The last time the Air Force, Navy and Marines had the same jet fighter was back in the 1960s when they all adopted the F-4 Phantom II fighter-bomber.
At the end of the day, Air Force planners are justifying their decision as a national security one, not an economic one. "The need to strike distant targets and return safely did not emerge during the Cold War, nor did it end when the Berlin Wall fell," a group of Air Force Association officers recently wrote in a letter to the Senate. "While the U.S. was engaged in Iraq and Afghanistan, other nations were busy designing, fielding and proliferating new weapons that have the potential to curtail our freedom of action throughout major regions of the world."
Like the F-22, which had production capped at less than 200 aircraft, the capabilities, as superior as they are, may not justify the much higher costs. The F-35, at least for the navy, is headed in the same direction. The navy calculated that it would cost 63 percent more to operate the F-35C (which will replace the F-18C) and the F-35B (which will replace the AV-8). The navy can go ahead with the more recent F-18E and keep refurbishing, or even building, the AV-8. The navy recently began examining the possibility of buying fewer F-35s, in the long run, and replacing them with combat UAVs, like the X-47B.
Politics, and lobbying by the F-35 manufacturer, will probably keep the F-35 headed for fleet service, no matter what the cost. The F-35 Lightning II is still months away from its IOC, yet the USAF is already looking into future upgrades. Not just minor upgrades, like additional weapons, but major upgrades like radar and engines. While the F-35's P&W F135 is impressive in terms of raw power, it has not exactly gotten off to a great start. An engine fire resulted in the grounding of the entire fleet. This makes the idea of an entirely new engine for the F-35 especially attractive.
In the 1980s, the Soviets were hungry for a versatile carrier jet, one that could go beyond the role of simple interception and fleet defence. Alexander Sergeyevich Yakovlev put at least 10 of his chief designers on what the military had originally called the Yak-41.
Yakovlev never thought it had a lasting fighter aircraft in its Yak-38, the Soviet Union’s first fixed-wing carrier jet and the only production Soviet VTOL aircraft. More than 50 designs would be looked at before the team set its sights on a single-engine design with a vectoring nozzle and thrust jets behind the cockpit. The extreme temperatures that came with thrust vectoring and VTOL meant the plane had to be built with materials that could stack up, so titanium, graphite, and composites were chosen. Even so, the plane was not meant to hover for more than 2.5 minutes because of overheating worries.
Four prototypes were funded, and the Yak-41 made its first flight in 1987 at Zhukovskii. Two years later, the first successful hover flight test took place. The Soviets used the Yak-141 designation to throw off observers, as the program was classified a the time. In September 1991, the first successful vertical landing on a Soviet aircraft carrier took place. The Yak-41 would become the first VSTOL aircraft to achieve sustained supersonic flight. The program was a success except for one incident where a fuel tank ruptured during a hard landing in October, resulting in a fire and the ejection of the pilot.
Despite the successes, funding ran out for the program, and the government-in-flux did not order the Yak-41 into production. The problem was the Yak-38’s lack of combat capability. Yes, it could take off and land vertically, and transition between vertical to horizontal flight, a significant achievement. Unfortunately, its payload was derisory and its range pathetic, its air-to-air capability virtually non-existent. One reason was the Forger’s VTOL concept – while the Harrier had a single engine and could use all its thrust for horizontal or vertical flight, the Yak-38 had to lug two lift engines, dead weight at all other times than in vertical flight. In hot and high conditions (such as the combat evaluation it endured in Afghanistan), the Forger could carry less than 500lb of munitions. As a proof of concept vehicle, the Yak-38 only managed to ‘prove’ that VTOL combat aircraft were impractical. If only the Harrier had not disproved the point over the Falklands, Bosnia, Kosovo, Afghanistan.
What happened after the collapse of the Soviet Union? An American company came around in 1991 and was able to glean valuable insight from a proposed Russian fighter jet for what would one day become the F-35. In 1991, facing the end of the “Freestyle’s” program run, Yakovlev approached several foreign aircraft companies for help funding and developing the airplane. A similar tactic worked with Aermacchi with the Yak-130 trainer leading to the successful Alenia Aermacchi M-346 “Master.”
Lockheed Martin, unable to obtain the British short take-off/vertical landing (ASTOVL) technology used in the “Harrier” because of British Aerospace’s long-standing partnership with McDonnell Douglas, was already researching ideas for what would become the X-35. Lockheed Martin knew the Yak-41 technology was good, so the company signed a $400 million pact with Yakovlev to built three more Yak-141 prototypes. (By this time, Yakovlev had committed to using the 141 designation instead of Yak-41.)
The Yakovlev team was contracted to provide design consulting services, technological assistance, wind-tunnel and other testing support, and Yak-41/41M design and test data to Lockheed Martin. The greatest interest was shown in Yakovlev’s insights into exhaust gas recirculation, engine nozzle design (the R-79) and flight control during take-off and landing (as Gordon Yefim notes). Rolls-Royce Allison’s 3 Bearing Swivel Nozzle (3BSN) was developed from the “lobsterback” design used on the Yak-141 V/STOL prototype and licensed from Yakovlev.
(While Yakovlev didn’t invent the swiveling nozzle concept, it was the first to develop a flight-proven design. The Pratt & Whitney 3BSD nozzle was designed in 1960s and predates the work done on engine design by the Russians.) Following its debut on the X-35, the 3BSN nozzle was further evolved by Rolls Royce into the variable-area vane box nozzle (VAVBN), which is integral to the aircraft’s structure, for the F-35B.
In the end the Lockheed Martin X-35 beat the Boeing X-32 to become the US’s largest weapons program of all time.
The PW1000G geared turbofan engine (GTF) has gained market attention and acceptance for its innovative game-changer gear-drive system, which enables the fan and low spool of the engine to turn at different speeds to optimize the performance in each section. Scalability of the new core enables Pratt & Whitney to offer a variety of thrust ranges for various applications. The engine has excellent stall recovery.
The U.S. was embarrassed when it first discovered that the new MV-22 and F-35B created "heat management" problems, which means the F-35B can’t use its vertical landing capability in most places. At first there was an effort to redesign the exhaust but that did not reduce the heat enough for the F-35B. That was enough to cause heat resistant concrete to spall (come apart in flakes) and the heat resistant portable matting the U.S. Navy developed did not always prevent spalling when installed over concrete. Moreover the special matting was expensive and time-consuming to install. This turned into another multi-billion dollar "oops" moment as the melting deck problem was never brought up during the long development of either aircraft.
Pratt engineers were already in the midst of a redesign to the first stage fan in the IBR, embracing a solid bladed design over the hollow design. A ground-based test engine “blew” late last year, Bogban said, owing to cracking in the hollow blades. The second and third stage fans –- the area in question for the June 23 fire -– are both constructed of solid blades. Separately, the rubbing between the blades in the third-stage fan of the integrally bladed rotor (IBR) in the low pressure turbine section and the cowl surrounding them put increased stress on the blades; one failed catastrophically, prompting an engine fire. The rubbing was far more severe than normal and led to higher temperatures, microcracking and fatigue failure. The incident is the second in less than a year to affect a part of the engine known as the integrally bladed rotor, or IBR. The component contains three sets of fans to help compress air into the engine. A first-stage fan made of hollow titanium blew apart during ground testing in December and is undergoing redesign, while a third-stage fan made of solid titanium disintegrated during the June takeoff.
Also the engine has no infrared suppression or shield and so is vulnerable to IRST detecting aircraft and missile launches at ranges of 70 nmi or greater.
A new engine program, known as Adaptive Engine Technology Development (AETD) looks to bring adaptive-cycle engine design to the next generation of combat aircraft.
The complex Marine Corps’ version of the F-35 was, as of December, flying 47 hours on average between engine failures, instead of the 90 hours expected by this point in the development process, GAO officials said. Air Force and Navy models’ engines flew about 25 hours instead of a projected 120. The design changes and retrofits to already-produced jets — along with a slew of other problems, like flawed software systems — means the Pentagon’s “procurement plan may not be affordable,” the report suggests. STOVL design basically guarantees the F-35B is a fighter with a small weapons load, short fuel range, unreliable single engine fighter.
At this point the Pentagon has planned to spend nearly $400 billion on 2,443 planes — three variations of which will be produced for the Air Force, the Marines and the Navy. Estimates are that, with maintenance costs down the road, the program could top $1 trillion.
Lockheed Martin has been awarded two F-35 contracts totaling about $41.5 million, including one to "correct deficiencies" on the U.S. Marine Corps F-35B. Under a $10.5 million modification to a separate contract, Lockheed is to provide 61 retrofit kits to correct deficiencies that preclude aircraft mission readiness in support of the Marines' F-35B aircraft initial operating capabilities.
The Navy has identified the shaking of F-35C as a “must-fix deficiency’’ but “the program waited so long to take action that it is unlikely a solution can be implemented within” the development phase.
The Pentagon asked Lockheed to re-engineer the plane's design to change certain components. There are US laws, regulations, and policies which are diametrically opposed to such a strategy. The eight foreign partner nations are separated into three tiers defined by their financial commitment. The UK is the only tier one partner. The other partner nations can attend program reviews but are not allowed access to non-disclosure related content. There are various reasons for these restrictions, including foreign capability limitations, and the risks of a rogue nation and information exploitation. Also there are other foreign buyers which are not partners. They will probably know nothing about the peculiarities of the airplane they are procuring, and their loss of capability. There are very strict controls on U.S. tech and all foreign partners will not have full access to software codes on the plane, particularly those to maintain and upgrade the aircraft.
- Block 1A/1B – Block 1 comprises 78 percent of the more than 8.3 million source lines of code required for the F-35’s full warfighting capability. Block 1A was the ready for training configuration while Block 1B provided initial multi-level security.
- Block 2A – Block 2A is currently released to the F-35 fleet. It provides enhanced training including functionality for off-board fusion, initial data links, electronic attack and mission debrief. With Block 2A, nearly 86 percent of the required code for full warfighting capability is flying.
- Block 2B – Block 2B provides initial warfighting capabilities, including but not limited to expanded data links, multi-ship fusion and initial live weapons. The U.S. Marines will declare IOC with Block 2B. With Block 2B, more than 87 percent of the required code for full warfighting capability is flying.
- Block 3i – Block 3i provides the same tactical capabilities as Block 2B. The principal difference between 2B and 3i is the implementation of new hardware, specifically the updated Integrated Core Processor. The Air Force will declare IOC with Block 3i. With Block 3i, 89 percent of code required for full warfighting capability is flying.
“The F-35A in the Block 3i configuration has numerous limitations which make it less effective overall at CAS than most currently-fielded fighter aircraft like the F-15E, F-16, F-18 and A-10.”
- Block 3F – Block 3F provides 100 percent of the software required for full warfighting capability, including but not limited to data link imagery, full weapons and embedded training. Mission Systems Block 3F software development is 98% complete.
When the code is working, it takes 24 hours to upload data from each plane into a new ALIS ground computer. So when an F-35 deploys to a new base, an entire day is lost as the data is passed to the new ALIS. And only one plane at a time can upload. So if the 12 F-35’s of Hill Air Force Base’s first “operational” squadron deploy to combat, it will take nearly two weeks to start maintaining the full squadron with ALIS.
The code delay is the latest—and possibly most damaging—setback for the Pentagon’s ambitious and controversial plan to replace almost all of its Air Force, Navy and Marine Corps fighters with three different versions of the F-35 at a cost of more than a trillion dollars over the next 50 years. If the F-35’s code doesn’t work, then neither does the F-35. To complicate matters even further, the program is losing testing personnel right at this critical juncture.
Saddled with thousands of dysfunctional F-35s, the Pentagon could lose command of the air. One possible solution is to strip some features from the Block 3F software—say, compatibility with certain high-tech weapons—and wait to add those capabilities back to the F-35 on later software blocks. It’s no exaggeration to say that the future of U.S. air power rests on these 8 million lines of code.
It will be powered by two smoky Russian-made RD-93 turbofan engines. It has a long bay for weapons and can carry a lot of fuel. However, Russia has rejected the idea of providing China with a radar system because of India's involvement in its development.
The FC-31 first flew in 2012 and debuted at Zhuhai in 2014. The FC-31's flight routine shows that it "bleeds" too much energy -- so when it enters into a turn it begins to lose altitude. Even during straight and level flight the pilot has to engage the engine's afterburners in order to keep the aircraft from sinking to a lower altitude. These are defects in the aircraft's aerodynamic design that a Russian design team would not have made.
Fighter Experimental Projects - India, S. Korea, Turkey
MCA strike aircraft finally evolved into multi-role AMCA later when IAF came up with much more stringent requirements and further optimization for enhanced stealth and special coatings for its polycarbonate canopy. It also needed further treatment to reduce its IR signature through nozzle design and better bay cooling along with reduction on exhaust temperature from the engine nozzles. It will also feature edge matching, body conforming antennae and a low infrared signature through nozzle design, engine bay cooling and work on reduced exhaust temperature.
The Indian Navy wants ADA to develop a carrier deck version of the Advanced Medium Combat Aircraft (AMCA), an indigenous, twin-engine, fifth-generation, stealth fighter that is unlikely to enter service before 2030. The ADA chief has argued to the defence ministry, the need for a step-by-step incremental and realistic approach to naval first designing an optimised naval Tejas Mark II fighter design, rather than attempting a huge technology jump by designing a fifth-generation Naval AMCA.
First look at the aircraft was only available in 2009 when a wind tunnel model was displayed in Aero India 2009 for the first time. It featured two surface aircraft layout with serpentine air intakes with reduced radar cross-section (RCS) for reduce radar exposure to the fan blade and internal weapons bay. The weapons bay is placed on the underside of the fuselage between the nose and main landing gear. This was completely new design based on low observability design elements and with a diamond shaped trapezoidal airframe. The aircraft featured a tricycle landing gear configuration with a nose landing gear leg and two main landing gear legs. It will use stealthy radar-absorbent materials in its construction, including baked in fiber mat.
In the Paris Air Show 2013, ADA revealed that the AMCA will have Network-centric warfare, vehicle management (including weapons), data fusion, Cooperative Engagement Capability, decision aids, integrated modular avionics, internal carriage of weapons, signature control with sharpening for low observability, AESA radar, IR search-and-track, supersonic persistence, high-speed weapon release and thrust vectoring. The aircraft will use Integrated modular avionics for real time computing, Dr. Saraswat confirmed the use of Photonic crystal fibres.
On 7 February 2014 Dr Tamilmani told reporters on the sidelines of the three-day international meet on Product Life Cycle Modelling, Simulation and Synthesis (PLMSS) at VIT university on Monday,’ he said the aircraft would be equipped with twin engines with super cruise power and for the first time it would be using the stealth technology.
At Aero India 2015, DRDO Director Dr.Tamilmani Confirmed that nine prototypes are confirmed and will go ahead with construction of the first prototype when funds are allocated in the later part of 2015.He also confirmed that the work on three major technological issues which includes thrust vectoring and with supercruise capable engines without the use of afterburners, AESA radar which will use Gallium nitride (GaN) , IRST and advance situational oriented electronic warfare systems and all-aspect radar warning receiver (RWR), Self-Protection Jammer(SPJ), CMOS, Laser warning receiver (LWR), missile warning suite.
While the aircraft is slated to equipped with the Gryazev-Shipunov GSh-301 cannon. The aircraft will Cary missile varying from Beyond-visual-range missile Air-Air missile like DRDO Astra, Derby and close combat Missile like Vympel R-73, Vympel R-27, Python 5 and Helina missile which is under development, depending on the mission, AMCA is also designed to Launch Air-Air and Air-Surface Variant which includes BrahMos A, Brahmos M, Brahmos NG and Nirbhay cruise missile. The aircraft may be used to launch Brahmos 2 mid-range hypersonic missile and HSTDV long-range hypersonic missile which are under development. For bombing mission, it will carry possible configuration of Sudarshan laser-guided bomb, KAB-500L laser-guided bomb, and OFAB-100-120 Gravity bomb.
AMCA will be integrated from the cockpit to accompanying UAV's and UCAV's which will include DRDO AURA, DRDO Rustom through encrypted datalink connections.
The AMCA will features a full-panel-width glass cockpit touchscreen, panoramic cockpit display" (PCD), with dimensions of 60 by 24 centimeters designed by DARE and manufactured by Samtel Group or 44 by 18 centimetres by Elbit Systems with both systems supporting cockpit speech-recognition system (DVI) provided by Adacel which has been adopted on the F-35. A Helmet-mounted display system is under development with Head up display. Control system includes HOTAS Sidestick.
In 2015, 700 ADA employees were working on the project with 2,000 employees of DRDO and 1,000 employees of HAL supported by over 500 employees of subcontractors of both Indian and foreign firms. AMCA design team led by D.r A.K Ghosh had completed Low-speed Wind tunnel test, High-speed Wind tunnel test and Radar Cross-Section(RCS) test from 2008-2014.
AMCA will boost capabilities such as Self-protection and self-repair with the help of self-diagnosing and self-healing by distributing the work load to other system from affected to non-affected system. Protection would be provided with the use of Nanotechnology to produce advance composite materials to withstand higher resistance to damage and therefore reducing the damage surface area. Chairman of DRDO D.r. V.K Saraswat confirmed that aircraft will use Self Repairing Flight Control Capability", will be used in the aircraft to automatically detect failures or damage in its flight control surfaces, and using the remaining control surfaces, calibrate accordingly to retain controlled flight.
Air Staff Requirements (ASR):
- AMCA will not exceed 25 tons weight.
- Twin engine powered aircraft with higher thrust.
- AESA Radar
- Fully stealthy aircraft with low RCS
- More of indigenously developed technology and less imported technology (radars, engines, and avionics)
Saab would help ADA develop its planned fifth-generation (Gen-5) fighter, the Advanced Medium Combat Aircraft (AMCA). In this, Saab’s capability is untested, since Europe has no Gen-5 fighter programme. Instead, Saab is part of a European consortium working on an unmanned stealth aircraft, called the nEUROn.
Next Gen ISR, Bombers & Weapon Systems
(to counter modern enemy anti-access systems, that are becoming common)
"Unmanned aircraft also have no life support systems, no canopy, no ejection seat, no cockpit armour – all things designed to let the human pilot do his or her job and survive the experience. As a result, a UCAV with payload equal and performance superior to existing fighters will come in at about 10,000 pounds – one third to one quarter the weight of a conventional plane."
New digital adaptive cognitive electronic warfare (EW) system technologies use machine-learning algorithms to protect aircrafts against communications jammers, by measuring a variety of data — the power level, frequency and bandwidth of radio signals; and adopt different never-before-seen frequencies, signal characteristics and waveform to avoid being jammed. Essentially, the military’s approach has been to study enemy systems for vulnerabilities, figure out ways of disrupting them and then building a “playbook” filled with different EW tactics.
Meteor operates in three phases; first, it accelerates to cruising speed and altitude, then in its mid-course phase, the missile optimises its speed and direction in readiness for the final intercept phase. In the intercept phase, by virtue of its propulsion system, Meteor can accelerate to minimise the chances of the target escaping. It is this ability to retain energy and accelerate in the ‘end game’ that gives Meteor its unique advantage.
In each phase, the secure data link allows the missile and launch aircraft, or indeed, other aircraft, to control the approach and terminal guidance for maximum effectiveness. Although it can be a fire and forget missile, Meteor can also be as the sales blurb goes, ‘fire and think’.
Characterized by a solid fuel variable flow-ducted rocket (ramjet) and a navigation and guidance system, including an inertial mid-course with a two-way data link, active RF seeker derived from Aster and MICA models providing all together, according to MBDA, the largest No-Escape Zone and all-weather capabilities compared to other BVRAAMs.
In the early 90s there was an European requirement to replace the Skyflash missile but given the emerging threat, there was a defining requirement for longer-range, ECM resistance and extreme agile missile. (Russian fighters with IRST can see weapon launches at long-range and defeat them either with ECM or simple physics. The ramjet-powered R-77 also complicated matters.) BAE offering, now including Matra, Daimler-Benz LFK, Saab, Alenia and GEC Marconi, became Meteor in 1996. In 1999, France joined the Meteor project with 20% funding. After pulling out in 1998, Sweden re-joined in 1999. In 2000, the UK had selected Meteor. (Aerospatiale joined MBD and MBDA was formed.)
Its ASEA seeker may benefit from Japanese technology they have incorporated on the AAM-4B. The fact that Meteor fits inside an F-35 bay and the AAM-4B does not may also have a bearing on the Japanese enthusiasm for Meteor.
The missiles are ten times more expensive than a JADM bomb of the same weight. But the aviators make the argument that many aircraft and pilots would be lost if the air defenses of nations like, perhaps Russia or China, were attacked without using JASSM. If there were a war with North Korea, for example, JASSM would be essential to taking out enemy air defenses. This capability is apparently what attracted the South Koreans and also Poland.
Hypersonic cruise missile
Blended wing-body (BWB) aircraft
The A-12 Avenger II concept was a two-seater, all-weather, long range, very low observable, high payload, carrier-based stealth bomber; the result of the Navy's Advanced Tactical Aircraft (ATA) program, which aimed to replace the aging fleet of A-6 Intruders by 1994. this triangular shape that earned the A-12 the nickname of "Flying Dorito” after the Frito-Lay brand triangular corn chip. The program was cancelled in 1991 after the expenditure of approximately $5 billion and the aircraft never reached production. And while the A-12 itself is no more, much of the plane's advanced avionics systems made their way into the later F-117 bomber. You will also note the striking similarities between the A-12 and the Northrop Grumman B-2 Spirit and the Northrop Grumman X-47B.
H-0229 developed by Horton Brothers for Nazi’s during 1942
German’s coated the snorkels and periscopes of their submarines with RAM such as Sumpf and Schornsteinfeger
However, the BWB shape poses significant challenges that could not be overcome by early attempts to make such an aircraft, including by Northrop in the 1940s. One is low-speed control, which in the absence of a tailfin becomes a complicated issue that can only be addressed by a sophisticated, computer flight-control system. The Northrop Grumman B-2 stealth bomber is an example of a successful BWB design, but as the crash on take-off in 2008 of one example of that $2 billion type apparently demonstrated, any failure of the flight-control system is catastrophic. Cabin pressurisation will pose a problem in the flying wing's much larger cabin. It will require the development of a new pressurisation system.
NASA work in the 1990s found that a stitching technique it calls Perseus - protruded rod stitched efficient unitised structure. Collier's project will flight-test a scale-model variant of a BWB concept called X-48C. NASA previously flew the scale model X-48B that was powered by small turbojets at its Dryden Flight Research Center in California.
From 2003 to 2005 Noshir Gowadia made six trips to China, conspiring to conceal some of his visits by getting border agents to leave immigration stamps off his passport. The city of his interest was Chengdu, the same city home to the Chengdu Aircraft Industry Group and also the company that developed Chengdu J-20 stealth fighter. He’s also accused of attempting to sell classified stealth technology to the Swiss government and to businesses in Israel and Germany. On several other occasions, Gowadia provided “extensive amounts of classified information” to individuals in a third unspecified country while teaching a course on “low observable technology.” In 1999, Gowadia taught a course to foreigners in a second unspecified country, including information deemed “secret” that he had access to while working for Northrop and as a subcontractor for Los Alamos. In 2002, Gowadia faxed a proposal to develop infrared-suppression technology on military aircraft to a representative in an unspecified foreign country. The information included in the document was classified at the “top secret” level and made specific mention of the classified defense system in the United States.
The inherent survivability of the PLA's impressive underground airbase infrastructure has not been a major consideration in the ongoing debate in the United States on the utility, and indeed intended design, of the replacement heavy bomber aircraft. This aircraft will need heavy “earthquake bombs” that can destroy “super-hardened” deep underground bases built below 500 meters and the ability to repeatedly penetrate what is becoming the most capable Integrated Air Defence System in existence. Nothing less can close such bases down and China has more than 40 of them with unique and indeed exceptionally robust capability to withstand a large scale counter-air campaign.
Lower-frequency surveillance radar allows enemy air defenses to know that an aircraft is in the vicinity, and higher-frequency engagement radar allows integrated air defenses to target a fast-moving aircraft. These frequencies include UHF, VHF and X-band, among others. The concept with the new bomber is to engineer a next-generation stealth configuration able to evade both surveillance and engagement radar technologies.
As such, to defeat low frequency radars operating in the L, UHF and potentially the VHF bands (this is easier said than done—and could in fact be impossible), a flying wing design is in effect, mandatory. Electronic attack capability is necessary to counter low frequency radars operating in the VHF band, which are nearly impossible to defeat with airframe shape and low observable materials alone.
Air force officials also have said the new B-21 bomber, will enter service as a manned aircraft with a target unit price of $550 million. Its designed to beat the enemy’s AD/A2 capability. As the first new US bomber launched since the Northrop Grumman B-2A, the B-21 is expected to replace a fleet of 76 Boeing B-52H and possibly a portion of the supersonic Rockwell B-1B fleets (not the younger B-1B Lancer though). However under current plans, these B-52 and younger B-1B will be in service until approximately 2037. The B-52s may fly to 2045. A fleet of 20 B-2As will also remain and fly alongside the B-21.
Two concepts under consideration are: Multi-mission & Deep Strike.
It is likely to be an evolution of existing technology — not a revolution — in order to keep costs down to about $US564 million each. A preliminary comparison of the B-21 and B-2 bomber images suggests a very similar overall design. The most apparent difference is that the B-21 has a clean diamond-shaped center body section in contrast to the B-2’s more jagged rear center wing outline. The angles that intersect the crew cabin and the fuselage to the wings have become much smoother. A single point at the end of the fuselage replaces the three that bracket the engines on the B-2.
Engine exhaust is an important source of detectable heat. The indents in the B-2’s rear center wing were created by the engine exhausts. B-21's air-intakes of the two engines have been extended forward and the edges angled, presumably to further reduce the aircraft’s radar signature. It appears that the B-21 engines have been integral to the wing and the exhaust is spread out to the edges of the trailing wing but is unknown if the engine exhausts have been moved below the body, integrated better into the edge of the wing, or omitted from the drawing because it is still a secret.
Fuel efficiency and longer range are important features, because they reduce dependency on the Air Force's in-flight refuelling tankers - most of which are approaching 50 years in service. Also, because bomber forces aren't typically based in theater, long-range bombers fly long distances to deliver their weapons and thus face much longer flying hours. Modularity is a strictly enforced Pentagon requirement for the new program.
The B2 Spirit’s stealth comes from a mix of its low-profile shape and a variety of radar-absorbent materials. The B-21 Raider has to have allowances for two feet or more of radar absorbent material coatings on every surface or the designers are forced to make trades as to which frequency bands they optimize the aircraft to operate in. It both reflects radar away, and soaks radar into its skin. The F-117 attack jet, famous for its role in breaking Iraq’s air defences in 1990, took a different approach. Its faceted surface panels did a better job at scattering radar waves. But it needed a tail to keep it controllable — undoing some of the good of its ungainly angles. The B-21 will probably need a blend of both, as each approach has its strengths and weaknesses. And the aircraft’s ability to remain unseen must last 50 years.
Northrop Grumman not only has a factory designed to build B-2 bombers but that factory has an award-winning automated assembly line. Furthermore, the Air Force has announced that the initial buy will be in five lots for a total of 21 aircraft, or about four aircraft per lot. Northrop Grumman is uniquely qualified to drive efficiencies out of similar production rates. From the E-2D, to Global Hawk, and Triton, Northrop Grumman is very comfortable producing at that rate. Northrop Grumman has orders to have the first B-21 prototype examples of the new bomber rolling off the production lines in 2025.
The F-35 is stealthy, but it's not that stealthy. It won't be able to dip into enemy airspace unnoticed like the stealthy B-21 will, so the focus is how to make it more effective from further away. The radar is designed to share detailed targeting information via data-link with other aircraft -- one F-35 can hang back and turn on its radar, which gives its position away to the target but keeps it far from danger, while another can sneak in and fire a missile without giving itself away.
More and more, those missiles are going to be smarter and capable of new things, not just blowing things up. Rather than risk people and valuable airplanes, why not just let the missile do the work? It's getting easier to pack missiles full of fuel and electronics, making them more like miniature drones than the old dumb-bombs. Some missiles, like Raytheon's new MALD-J, contain small radar jammers and can be fired almost 600 miles from the target. Future versions could have electronic surveillance equipment, sending data back home, or even the means to inject viruses into computer networks. Also look forward to things like the Israeli IAI Harop, a hybrid missile/UAV that can circle overhead for long periods of time, waiting for a whiff of electronic scent and guiding itself in.
One promising development is the High-Speed Strike Weapon, a hypersonic ground attack missile, capable of launching from thousands of miles away and streaking towards the target too fast for anyone to hit.
The X-47B Unmanned Combat Air System Demonstrator (UCAS-D) program will demonstrate the capability of an autonomous, low-observable unmanned aircraft to perform carrier launches and recoveries.
4.7% B2 bombers have crashed & another 4.7% had engine fires.
Hypersonic Bomber aircraft
China is developing two hypersonic flight vehicle programs – one believed to be of a post-boost vehicle designed to be deployed from a missile that pursues its target from near space, or some 62 miles from earth. Pentagon’s assessment of Chinese capabilities suggested that China built the world’s largest shock-wave hypersonic wind tunnel capable of generating test flying conditions of up to Mach 9 speeds.
“The beauty of the HGV is that it can perform hypersonic precision strikes while maintaining a relatively low altitude and flat trajectory, making it far less vulnerable to missile defenses,” Rick Fisher, an analyst at the International Assessment and Strategy Center, told the Washington Free Beacon.
Current American hypersonic research is being conducted through the FALCON program in association with the Pentagon and Air Force. The US is in the process of perfecting Lockheed HTV-2, an unmanned, missile-launched aircraft capable of gaining speeds of up to Mach 20, or 13,000 miles per hour. The US Air Force is also testing the X-37B Space Plane, which has been orbiting earth since December 2012.
At the same time Boeing is working on the X-51 WaveRider, a jet-fueled, air-breathing hypersonic rocket developed for the Air Force to be used for hypersonic attack and reconnaissance missions.
Russia too has confirmed the development of similar ultrasonic technology.
The new plane offered game-changing capabilities to the military - and a twin-engine demonstrator jet that could reach any target in an hour could be developed for under $1 billion in five to six years. A hypersonic plane does not have to be an expensive, distant possibility. One key factor in keeping the new project affordable was a decision to limit speed to Mach 6, rather than reaching for higher speeds that would require more expensive materials such as those used on the space shuttle.
New Engine Tech
The idea is to compress the air in the LiquidPiston X2 engine to a very high ratio as in the diesel cycle and then isolating it in a constant volume chamber. When fuel is injected, it’s allowed to mix with the air and it auto-ignites as in a diesel engine, but the fuel/air mixture isn’t allowed to expand. Instead, it’s kept compressed in a constant volume so it can burn over an extended period, as in the Otto cycle. When the burning fuel/air mix is allowed to expand, it’s then overexpanded to near-atmospheric pressure. In this way, all the fuel is burned and almost all of the energy released is captured as work. Shkolnik calls this use of constant volume combustion “the holy grail of automotive engineering.”
Constant volume combustion and overexpansion provide an HEHC engine like the X2 with a number of benefits. Shkolnik points out that the X2 engine is exceptionally quiet because it burns all of its fuel. In current ICE engines, an alarming amount of fuel goes out the tailpipe. This not only cuts down on fuel efficiency and pollutes the air, it also makes the engine noisy. Since the X2 engine burns its fuel completely, there’s no need for complicated silencing apparatus.
The X2 engine is a rotary because piston engines aren’t suitable for the HEHC and a rotary engine provides much more flexibility. Also, the use of a rotary design greatly simplifies the engine with only three moving parts and 13 major components required. That allows the X2 to be one-tenth the size of a comparable diesel engine.
X2 engine is almost the inverse of a Wankel. It’s almost like the Wankel engine flipped inside-out. The X Mini is essentially an upgrade in design and efficiency of the compact Wankel rotary engine, invented in the 1950s and used today in sports cars, boats, and some aircraft.
The X2 engine has a better surface to volume ratio, it doesn’t have the thermodynamic limitations of the Otto cycle and it doesn't have the emissions problems of the Wankel. The Wankel has apex seals that are carried around with the rotor and need to be lubricated. The X2 engine, on the other hand, moves the seals from the rotor to the housing, so no special lubrication is required. Another way that the X2 engine differs from the Wankel is that Shkolnik has no intention of it sharing the same fate as the Wankel, which turned into an automotive also-ran when put head to head with the ICE or hybrid electrics to power motor cars, (though he admits that the X2 engine would be an excellent range extender for hybrids).
One place where the X2 engine may have an advantage is in auxiliary power units (APUs). Shkolnik said that an enormous amount of diesel fuel is wasted by lorry drivers for “hotel” purposes. That is, when they stop overnight they leave their engines idling to provide power for the living amenities of their long-distance rigs.
Another area is military applications. The U.S. military has a need for APUs that can run on heavy fuels, which the X2 engine can. Also, the Pentagon is very keen on developing robots. The military has need of APUs for tanks, which suffer from extremely bad fuel efficiency from idling to run electronics.
The next generation of unmanned vehicles to be able to work autonomously and together, in packs that can attack or defend a ship or outpost and cooperatively take on an attacker. Control Architecture for Robotic Agent Command and Sensing system (CARACaS) on the James River in Virginia, used up to 13 vessels—operating both autonomously and by remote—to escort a high-value ship and “swarm” an approaching vessel. CARACaS can be tacked onto just about any kind of boat, turning it into an unmanned vessel for the cost of several thousand dollars. Recently the Defence Department issued a call for technologies that could enable drones to hunt like a pack of wolves, as part of its Collaborative Operations in Denied Environment (CODE) program.
The drone has a low drag fiberglass fuselage, attached to spring loaded carbon fiber wings designed with custom airfoils. The outer-mold of Perdix is created with 3D printing to both allow for rapid production and lower costs. The rear wings have winglets and elevons for flight control. The drone uses a miniature electrical engine driving a custom pusher propeller to keep the drone airborne for the duration of the mission. The drone draws power for propulsion and on-board systems and sensors from a pack of lithium polymer batteries located in up front
Micro-drone showed “prodvinutye” behaviors “Roy”, such as the collective development of solutions that adapt (the environment) system in the air and “self-medication”. The operator on the ground is not required to control each of the UAV included in “Roy”.
During tests in 2014, 20 drones were packed into a chaff tube and released from the F-16s chaff and flare dispenser on a high-speed pass from an F-16 at an altitude of 2,000 ft. over Alaska. And roughly 90 Perdix missions were undertaken. In 2017, its was reported that 3 seperate F/A-18 Super Hornet fighter-bombers held a successful demonstration of one of the “world’s largest “swarms” of miniature unmanned aerial vehicles (UAVs) using 103 Perdix micro drones. The micro-drones demonstrated advanced swarm behaviors such as "collective decision-making, adaptive formation flying, and self-healing.
“Due to the complex nature of combat, Perdix are not pre-programmed synchronized individuals. They are a collective organism, sharing one distributed brain for decision-making and adapting to each other like swarms in nature,” said SCO Director William Roper. “Because every Perdix communicates and collaborates with every other Perdix, the swarm has no leader and can gracefully adapt to drones entering or exiting the team.”
Miniature Self-Defense Munition to be dispensed from a fighter jet, hone in on an incoming missile, kinetically engaging and destroying it. It is a hit-to-kill weapon, and so lacks a warhead. It would replace chaff, flares and directional infrared lasers. One project is a miniature, radar-guided missile called CUDA and the other programme is “KICM”.
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Although there is very little information the weapon used what was called pulse theory, and used two opposing magnets and electrical energy to accelerate projectiles to extreme velocities. This system pulls the bullet down the barrel, the opposite of gas from an explosion pushing it out.
Rail-guns do not require powders or explosives to fire the round. Addition, electro-magnetic guns provide a highly consistent and uniform explosive charge that gives much greater accuracy. It has higher muzzle velocity at speeds of Mach 5 or higher and so is less susceptible to bullet drop and wind shift. This means they are more accurate to a larger range. The massively increased speed also means there is no reason to use explosive rounds, as the sheer impact force of a solid metal rail-gun round would cause as much or more damage than a conventional explosive one. With no gunpowder and no explosive in the round an electromagnetic weapon is much safer to operate or mount as a vehicle, as there is no risk of an ammunition explosion through misfire or enemy attack.
This presents problems for a traditional battleship because power cannot be diverted from the ship's propulsion system. In the Navy's next-generation battleship, the all-electric DD(X), producing this kind of current will be possible. To launch a rail gun projectile, power would be diverted from the ship's engine to the gun turret. The gun would be fired, up to six rounds per minute, for as long as required. Then power would be shifted back to the engine.
The heat generated from the propulsion of the projectile is enough to erode the rails rapidly. Under high-usage conditions, rail guns would require frequent replacement of the rails until high grade rails capable of producing the same effect without frequent replacement are introduced.
Kali has also been used by the DRDO scientists for testing the vulnerability of the electronic systems of the Light Combat Aircraft (LCA) and for x-ray photography. It has also helped in designing electrostatic shields to "harden" the LCA and missiles from microwave attack by the enemy as well as protecting satellites against deadly Electromagnetic Impulses (EMI) generated by nuclear weapons and other cosmic disturbances, which "fry" and destroy electronic circuits.