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Posts Tagged ‘performance’

Measuring fighter aircraft maneuvering performance

Posted by Picard578 on March 21, 2016

Maneuvering performance can be divided into several types. Those types are transient maneuverability, angular maneuverability, energy maneuverability and endurance. Transient maneuverability denotes aircraft’s ability to quickly switch from one maneuver to another. Energy performance measures aircraft’s ability to gain, lose or maintain energy (speed and/or altitude). Angular (turn) performance measures aircraft’s ability to achieve and sustain a certain turn rate. Endurance measures aircraft’s ability to stay and fight without refueling. All these characteristics are important for winning a fight, and thus measures should be found to reliably measure them. There is also a significant overlap: acceleration (energy gain/loss) is in nature energy maneuverability characteristic, but is also part of transient maneuverability. Similarly, pitch and turn onset rates, while transient in nature, also factor highly in turn performance (up to a point). And too short endurance can force the pilot to preserve fuel, thus negatively impacting aircraft’s actual energy and turn performance. Read the rest of this entry »

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A-10 effectiveness assessment

Posted by Picard578 on August 16, 2015

Introduction

A-10 is the premiere close air support fighter today, and one of the very few dedicated CAS platforms in existence. Close air support is one of the most important, and most difficult, missions that air force can be tasked with. However, it is part of a spectrum of missions which require cooperation with other services (army cooperation missions are close air support, armed reconnaissance, battlefield interdiction and tactical reconnaissance; navy cooperation missions are patrol surveillance, air defense and anti-ship attack; missions controlled by the air force are air-to-air, deep interdiction and strategic bombing). As such, close support is typically ignored by air forces in favor of missions that air forces control and undertake by themselves, without any involvement from other services.

Close air support is defined as attack against targets within combat (artillery) range, in direct combat contact with supported units. It has to be coordinated with both the artillery and supported units. Read the rest of this entry »

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Airborne IRST properties and performance

Posted by Picard578 on June 16, 2015

Introduction

IRST is a sensory device which uses IR (infrared) radiation for detection and targeting purposes. IR radiation has wavelength of 0,75 to 1.000 microns (micrometers), longer than wavelengths of color red in the visible spectrum (visible spectrum ranges from 0,39 to 0,7 microns, with violet at 0,4 and red at 0,7 microns). It is given off by all objects above absolute zero, though objects that are below average temperature of their surroundings will absorb far more IR radiation than they will give out. Unlike FLIR which is a targeting device, IRST can be used for initial detection as well. Read the rest of this entry »

Posted in technology | Tagged: , , , , , , , , , , , , , | 80 Comments »

Single vs twin engined fighters

Posted by Picard578 on August 9, 2014

Single engined fighters have typically been favored due to their low procurement and operational costs, ease of maintenance and assumed better air-to-air performance. Yet there is also a belief that single-engined fighters are inherently less survivable and lower-performance than twin-engined fighters. Read the rest of this entry »

Posted in weapons | Tagged: , , , , , , , | 47 Comments »

F-35 and its troubles

Posted by Picard578 on May 11, 2013

While people term F-35 a “multirole” aircraft, and Lockheed Martin stated that it is second-best air superiority fighter in the world, F-35 is primarly a dedicated ground attack aircraft. This can be seen relatively easily, as there are different requirements for fighters and for ground attack aircraft.

Primary requirement for ground attack aircraft is ability to fly low and fast. This means that gust sensitivity should be minimal, which is done by high wing loading; only exception are close air support aircraft, which have to be able to fly low and slow, and be agile at low speeds. Air superiority aircraft, on the other hand, has to be able to turn while maintaining energy, which is achieved through having low wing loading, low drag and high thrust to weight ratio.

F-35s EOTS IR sensor (not to be confused with EO DAS which is defense system) can only detect targets right in front of, and below, aircraft.

Eots-Angles

Wavelengths used by it are also optimised for detecting ground targets.

Even F-35s name says it all: “strike fighter”. Unlike multirole fighters, which are designed to operate primarly in air superiority role but can also carry out ground and (sometimes) maritime strike missions, strike fighter is designed to operate primarly in strike role, with air-to-air capability being secondary and usually limited to self-defense (even A-10 can carry Sidewinders for self-protection purposes).

At 50% fuel, thrust-to-weight ratio of all three fighters is below that of modern fighter aircraft at air-to-air configuration takeoff weight, with exception of Saab Gripen. For both F-35A and F-35B, wing loading at 50% fuel is above 400 kg per square meter, with F-35C achieving barely acceptable 340 kilos per square meter. While there is a degree of wing-body blending, amound of body lift is not comparable to air superiority aircraft like F-16, Gripen or Rafale. STOVL requirement also resulted in stubby, fat body, making F-35 a drag queen, especially when compared to clean F-16 – and for all three aircraft listed, clean configuration includes 2 AAM, either BVR or WVR, whereas Typhoon carries 4 BVR AAM in clean configuration. Result is that F-35 has rather sluggish acceleration, and looses energy quickly.

Its cockpit visibility is also good only to front, sides and above aircraft – and in these areas, it is still limited by bow canopy frame. Rearward visibility is nonexistent, thanks to STOVL requirements of B variant – and when pilot brought up that flaw, general Bogdan stated that he can always “put pilot in cargo aircraft where he won’t have to worry about getting gunned down”. Its high-tech HMD, counted at to adress problems of limited cockpit view, also experienced problems, making it possible that information to F-35s pilots will be limited to only what they can see directly through canopy – which is not much – and what can de displayed from sensors on screens within cockpit. This means that problems with canopy bow and ejection seat headrest impeding visibility might get F-35 gunned down in visual combat.

F-35 is also seriously flammable – fuel literally surrounds the engine, and fire protection measures have long since been deleted from the design in order to make it lighter. As result, hits from any kind of weapon which can penetrate its skin – basically anything from 20 mm cannon and above – will turn it into fireball.

Due to everything described above, it has to rely on stealth to survive. But stealth aircraft since SR-71 have been routinely detected by radars and IR sensors during and after Cold War; USSR luckily never chose to shoot any US aircraft, while Iraq did not have capability to do so, even if indications exist that Iraqis did detect F-117. But Serbs easily solved the VHF radar’s problem with low resolution, using it to guide IR SAM close enough to F-117 for missile to acquire and engage the target. Result are two F-117s taken out of action during Kosovo war, one shot down and one mission-killed.

Radar-based BVR combat has never been reliable either. Radar-guided missiles never achieved Pk of over 8% against capable opponent, and this is unlikely to improve, despite all USAFs self-deluding exercises where F-22s BVR missiles are assigned probabilities of kill of 90%. Even this “capable” should be taken with bit of salt, as it refers to North Vietnamese – but at very least, and unlike Iraqis, they did try to evade the missiles.

In fact, by using Air Power Australia report and fixing it with calculable data, it is possible to calculate likely BVR missile Pk against modern, 12-g capable fighter. As g forces pulled in tracking turn are square of speed difference, it can be calculated how much of forces required can modern missiles achieve. AIM-120 travels at Mach 4, and can pull 30 g within its NEZ, yet it would need 768 Gs to reliably hit a modern fighter which is maneuvering at corner speed of Mach 0,5, or 237 Gs if target is still at standard cruise speed of Mach 0,9. This results in Pk between 3 and 13% against fighter aircraft with no ECM, which fits perfectly with 8% Pk demonstrated against (mostly) maneuvering aircraft without ECM to date. If fighter is maneuvering at corner speed, but is still limited to 9 g by FCS (is not in override), BVR missile Pk is 5,2%. Thus, we have following kill-chain against modern fighter aircraft in g override (12 g capable) at M 0,5 (most likely scenario, as RWR will have warned pilot of radar lock):

Action – likelyhood of failure – hit probability

  1. Active missile confirmed on launch rail — 0.1% — 0,999

  2. Search and track radar jammed – 5% — 0,949

  3. Launch or missile failure – 5% — 0,902

  4. Guidance link jammed – 3% — 0,875

  5. Seeker head jammed or diverted — 30% — 0,612

  6. Chaff or decoys seduce the seeker — 5% — 0,581

  7. Seeker chooses towed decoy — 50% — 0,29

  8. Aircraft out-maneuvers missile — 97% — 0,00873

  9. Fuse or warhead failure — 2% — 0,00856

Total: 0,86%

Against 9 g capable fighter aircraft, it goes this way:

  1. Active missile confirmed on launch rail — 0.1%
  2. Search and track radar jammed – 5%
  3. Launch or missile failure – 5%
  4. Guidance link jammed – 3%
  5. Seeker head jammed or diverted — 30%
  6. Chaff or decoys seduce the seeker — 5%
  7. Seeker chooses towed decoy — 50% — 0,291
  8. Aircraft out-maneuvers missile — 94,8% — 0,015
  9. Fuse or warhead failure — 2% — 0,0146

Total: 1,46%

This can be compared to 0,36% probability of kill shown by modern SAMs against capable opponent (with 2 hits being a non-maneuvering VLO light bombers at low altitude and with no ECM; if only actual fighters are counted, probability of kill is 0,12%, as 1 F-16 was shot down out of 842 launches).

In WVR combat, if missile travels at Mach 3 and fighter aircraft travels at Mach 0,5 (corner speed of many modern fighters) and can pull 12 g maneuvers, missile needs to pull 432 g to hit fighter aircraft. This gives a Pk of 14% for WVR missiles, as even IRIS-T can “only” pull 60 gs. Against targets limited to 9 g, it has to pull 324 g, for Pk of 18,5%.

As such, for visual-range missiles, against aircraft maneuvering at corner speed, calculation goes this way:

  1. Active missile confirmed or on launch rail – 0,001 – 0,999
  2. Launch or missile failure – 0,03 – 0,969
  3. DIRCM effective – 0,00 (rarely fitted to fighters)
  4. Flare or decoys seduce the seeker – 0,05 – 0,921
  5. Aircraft out-maneuvers the missile – 0,86 – 0,13
  6. Fuse or warhead failure – 0,1 – 0,12

Total Pk: 12%

Against fighter aircraft limited to 9 g it goes this way:

  1. Active missile confirmed or on launch rail – 0,001 – 0,999
  2. Launch or missile failure – 0,03 – 0,969
  3. DIRCM effective – 0,00 (rarely fitted to fighters)
  4. Flare or decoys seduce the seeker – 0,05 – 0,92
  5. Aircraft out-maneuvers the missile – 0,81 – 0,17
  6. Fuse or warhead failure – 0,1 – 0,157

Total Pk: 15,7%

As such, BVR missiles will have Pk of 0,86% – 1,46%, and WVR missiles will have Pk of 12% – 15,7%. As F-35 can carry 4 missiles, combined Pk will be 3,44% – 5,84% for BVR missiles, or 48% – 62,8% for WVR missiles. Because F-35 is very expensive and maintenance-intensive, it will find itself outnumbered, and forced to engage opponents with gun. This will mean F-35s loss against most fighter aircraft, as it is performance-limited: only one version can regularly pull 9 g maneuvers, and other two are limited to 7 and 7,5 g, respectively – which also means that opponent’s IR missiles will have higher Pk against them (~20%) than other way around. They can’t run either, as maximum speed when clean is Mach 1,6 – theoretically, as current aircraft are unable to go past Mach 0,9. While all three versions likely have ultimate load limit of 13,5 g, it is unknown wether F-35B and C will be allowed to go into g override to same limit as F-35A.

F-35s technology, once thought to be best of the best, is now outdated. Its IRST is no better than European counterparts, and is actually worse for air-to-air work as it is designed – and uses wavelengths suited for – air-to-ground work; and by the time F-35 enters service, Eurocanards will have AESA radars.

As a ground attack aircraft, it is only somewhat better. It can carry only two 900-kg bombs in its bomb bays, making it a rather average bomber. It is unable to carry out close air support, as it is too vulnerable to get low enough to engage tactical targets, too fast to put weapons precisely on target even if it does come low, and too fuel-thirsty to loiter over ground troops in need of air cover.

In March 2013, F-35A was forbidden from doing following things:

  • descent rates of more than 30 meters per second
  • airspeed above Mach 0,9 (compare to advertised Mach 1,6)
  • angle of attack beyond -5 and +18 degrees (compare to advertised +50 degrees)
  • maneuvers beyond -1 and +5 g (compare to advertised 9 g for A version)
  • takeoffs or landings in formation
  • flying at night or in bad weather
  • using real or simulated weapons
  • rapid stick or rudder movements
  • air-to-air or air-to-ground tracking maneuvers
  • refuelling in the air
  • flying within 40 kilometers from lightning
  • use of electronic countermeasures
  • use of anti-jamming, secure communications or datalinks
  • electro-optical targeting
  • using DAS to detect targets or threats
  • using IFF interrogator
  • using HMD as “primary reference”
  • use of air-to-air or air-to-ground radar modes for electronic attack, sea search, ground-moving targets or close-in air combat modes.

It also had quite a list of other problems:

  • liable to explode if struck with lightning
  • F-135 jet engine exceeds weight capacity of traditional replenishment systems and generates more heat than previous engines
  • extensive damage will require returning aircraft to factory for repairs
  • fuel dump subsystem poses fire hazard
  • survivability issues (rumored to be about stealth)
  • airframe unlikely to last through required lifespan
  • using the afterburner damages the aircraft
  • poor radar performance

But this is hardly end of F-35s troubles list. Performance shortfalls are compounded by development problems: at one point, Lockheed Martin had to cannibalize LRIP production line for spares so prototypes can continue with testing.

F-35s costs are understated. Sometimes-heard 59 and 79 million USD values are those of early days of the programme, specifically from 2002. But even without inflation, costs have doubled by 2012, with flyaway cost being 197 million USD for F-35A, 237,7 million USD for F-35B and 236,8 million USD for F-35C. And these are unlikely to get any lower than they are for very simple reason: modern fighter aircraft are complex, and for them learning curve barely exists. And what of learning curve does exist has already been largely absorbed by reduction in cost which lowered F-35As unit flyaway cost from 207 to 197 million USD. One of reasons is that fighter aircraft get continuous upgrades which do not allow production to stabilize and invest in truly effective cost reduction measures. F-22s unit flyaway costs went backwards late in production: whereas flyaway cost mid-production was 200 million USD, last aircraft produced cost 250 million USD flyaway. Same happened with F-14, F-15 and F-16, due to increased complexity of new technology put in to make them “more capable”; F-16A would, today, cost 30 million USD, but F-16C costs 70 million USD.

F-35 is also very unreliable, which means that pilots won’t be able to fly it as often as required, and it is not meeting reliability growth targets. One in seven training sorties in late 2012 resulted in mission aborts. By late 2012, F-35 was barely achieving one sortie every 3 days. It had 4 flight hours between critical failures, and by 2013 mean elapsed time for engine removal and installation was 52 hours (system treshold being 120 minutes). Flights were also aborted due to battery problems whenever temperature dropped below 15 degrees Celzius, making F-35 utterly unsuitable to Canada, Great Britain or Scandinavian countries.

I have already mentioned HMD problems. These include misaligned horizons; inoperative or flickering displays; double, unfocused, jittery, washed-out and/or latent images. Due to all that confusion, HMD more hurts situational awareness than it helps – and F-35, due to STOVL requirement for Marine version, has nil rearward visibility.

While F-35 has met 7 out of 10 objectives, several objectives – like “begun lab testing” – were impossible to fail. But these do not show how well – or bad – programme is progressing. And in the end, it cannot be expected that dedicated strike aircraft can perform well in air superiority role; role which, despite wishful thinking by weapons designers, is still visual-range unless enemy is outmatched in every way imaginable. But if it is, F-15A and Tornado ADV are perfectly capable of handling him; there is no need for stealth fighters; and if it isn’t, F-35, with its disastrous visual-range performance, cannot be anything more than cannon fodder, soaking up enemy missiles so more capable fighters – be it F-22, F-15 or F-16 – can take out enemy aircraft without heavy losses. But F-35 is too expensive for that, which means that USAF will be in trouble as soon as F-16 is replaced by F-35.

Pig-that-ate-the-Pentagon.Lockheed-Martin flying-pig-325x275

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Usefulness of BVR combat

Posted by Picard578 on April 27, 2013

United States, as well as many of its allies, have always looked towards increasing range of combat as much as possible. Just as often, it failed, especially in the air, where technologists’ dream of destroying enemy air force before it reaches visual range remains unfulfilled to this day. Main reason for it is that BVR combat is, conceptually, operationally and technologically, massively complex affair. Exact extent of visual range depends on size of aircraft – while maximum visual detection range for MiG-21 is 8,5 kilometers, it is 15,37 kilometers for F-14. Smoke can extend that range by over 5,6 kilometers; while by other info, definition of BVR combat considers “BVR” to be anything beyond 37 kilometers. Optical devices such as IRST or TV cameras can extend range of visual identification of aircraft – PIRATE can identify enemy aircraft at 40 kilometers in ideal conditions.

BVR theory states that future air combat will be comprised of large “missile truck” aircraft flying at supersonic speeds, launching radar-guided missiles at targets that are way too far to be identified visually. This has resulted in development of aircraft that are very heavy (most weight little less or more than 15 metric tons empty – for example, Tornado ADV weights 14,5 metric tons, and F-22 weights 19,7 metric tons), carry large amounts of missiles, and are far more expensive and much less reliable than aircraft with bias towards visual-range combat. Yet BVR combat still has not taken lead role in air-to-air combat.

We can in fact draw paralels between modern air-to-air combat and modern infantry combat. While infantry has access to sniper rifles that allow ranges of around two kilometers, and old battle rifles had ranges of 500-1000 meters, most combat happens at ranges no greater than 100 meters, and never involves single shooters. In Vietnam, M-14 proved basically useless as basic infantry weapon when compared to AK-47. Reason for this is that, while large battle rifles were useful in static warfare of World War I, World War II and later wars saw mobile warfare develop with combat happening at low ranges, thus requiring lighter, faster-firing weapons. Result was development of sub-machine guns, as well as first assault rifles (such as German MP-44, renamed StG-44, which was world’s first assault rifle and provided inspiration for very successful AK-47; both were used by Vietcong).

In air-to-air combat, BVR missiles fill the niche of old battle rifles and modern sniper rifles, WVR missiles fill the niche of modern assault rifles, while gun fills niche of combat knife. While gun is most versatile weapon of the lot – it can be used for air-to-air work, close air support, firing warning shots towards aircraft violating forbidden airspace – it is not often used in air-to-air combat and is treated purely as fallback weapon in case missiles have been expended.

It is often forgotten is that g forces in tracking turn are a square of speed. Thus, in WVR combat, if missile travels at Mach 3 and fighter aircraft travels at Mach 0,6 (corner speed of many modern fighters) and can pull 9 g maneuvers, then missile needs to pull 225 g to match turn radius, or 100 g if fighter is travelling at Mach 0,9. If missile is fired outside ideal position, it has to maneuver in order to point its nose towards the target, thus lowering probability of kill; there is also a danger of targeted aircraft simply flying out of missile’s field of view. This danger is also present with active-seeker BVR missiles. In BVR, AIM-120 travels at Mach 4, and can pull 30 g within its NEZ, yet it would need 400 Gs to reliably hit a modern fighter which is maneuvering at corner speed of Mach 0,6, or 178 Gs if target is still at standard cruise speed of Mach 0,9.

Further, even though BVR missiles have maximum range of over 100 kilometers, their effective range against aircraft in attack is 1/5 of that – around 20 kilometers – and target beyond 40 kilometers can feel free to maneuver without even taking any possible missile shots into account, as only way these would hit is luck. One of reasons is that BVR missiles follow ballistic trajectories – AIM-120C-5 allegedly has motor burn time of 8 seconds, which gives range of around 10 kilometers before motor burns out. At ranges greater than 8 kilometers, attacking fighter can still choose wether to outmaneuver or outrun the BVR missile; at distances less than that is missile’s no-escape zone, where aircraft cannot outrun the missile, it has to outmaneuver it, but such distances automatically mean that combat is not longer beyond visual range. Ranges stated are also only true at high altitude against aircraft in attack; at low altitude, effective range of BVR missile is reduced to 25% of its range at high altitude, and range against aircraft in flight is 1/4 of that against aircraft in attack.

Missiles in fact can achieve either maximum range or maximum maneuvering capability – missile that pulls 40 g at sea level will only pull 13 g at 10.000 meters and 2,85 g at 20.000 meters, unless 40 g is a structural limit. AIM-9 for example can pull 40 g at SL and at 10.000 ft, and 35 g at 20.000 ft. Thus, it can be expected to pull single-digit number of g’s at 40.000 ft.  Meanwhile, F-16 for example can sustain 8,5 g at 15.000 ft, and Rafale can sustain 9 g at 40.000 ft.

Proximity fuses on missiles can trigger explosion of missile if anything (like a bird) flies nearby. Warhead itself has lethal radius of 10-12 meters for late AIM-120 variants.

Missiles are not the only problem with BVR combat. There are also questions of reliable IFF, penalties for using active sensors in combat, weight, cost and complexity penalties on weapons systems caused by systems required for BVR combat, as well as training penalties caused by aforementioned penalties on weapons system.

Training penalties are probably most damaging. In 1940, Germans – outnumbered 1,5 to 1, and using inferior tanks – overran France in three weeks because they had superior personnell – both commanders and soldiers. On the Eastern Front, German Panther and Tiger I tanks achieved favorable exchange ratios against more numerous – and in many aspects superior – Soviet T-34-85, IS-I and IS-II tanks, and General Guderian favored increased production of Panzer IV equipped with long cannon over production of more capable, but more expensive, less reliable and less strategically mobile Panther (for each Panther, Germany could have produced two Panzer IVs; for Tiger I, ratio was four Panzer IVs for each Tiger). After Gulf War I, General Schwarzkopf said that the outcome of Gulf War I would have been the same if the U.S. and Iraqi armies had exchanged weapons, a statement similar to one given by IAF General Mordecai Hod after 1973 war, in which he stated that IAFs 80-1 victory against Arabs would have remained the same if both sides had exchanged the weapons. Yet BVR-oriented aircraft, low in number and hugely complex, cannot be used for training often enough. While technologists typically counter this argument by pointing to increased ability of simulators, that argument is not realistic: simulation is never perfect, as quality of the end result is never better – and is often lot worse – than quality of data used to compute it. Simulators often misinterpret reality, and support tactics that would get pilots killed in real combat. Further, simulators cannot prepare pilot for handling of shifting g forces encountered during both dogfight and BVR combat maneuvering.

Meanwhile, using active sensors is outright suicidal in combat. Aircraft using active sensors will be quickly detected and targeted by modern defense and EW suites, and unique radar footprint may allow for BVR IFF identification. This can allow passive aircraft to launch BVR infrared or anti-radiation missile, and/or to use data acquired to achieve optimal starting position and speed for following dogfight. Only countermeasure is to turn radar off and rely solely on passive sensors. IRST is especially useful here, as while air temperature at 11 000 meters is -56 degrees Celzius, airframe temperature due to air friction can reach 54,4 degrees Celzius at Mach 1,6 and 116,8 degrees Celzius at Mach 2. It is also very difficult to impossible to jam, and offers greater angular resolution than radar. Result is that flying from cloud to cloud is still a viable combat tactic; but it is not perfect either, as clouds are not always present and may not be close enough for aircraft to avoid detection in the mean time.

As for IFF issue, only reliable IFF method is visual one, especially since pilots often turn IFF transponders off to avoid being tracked. Visual IFF, unless assisted by optical sensors (be it camera or IRST), usually requires two aircraft to approach within one mile or less (sometimes as close as 400 meters), whereas minimum range of AIM-120D is 900 meters. But even when assisted by visual sensors, it may not always be reliable, as opponent may be using fighters of same type or at least of very similar visual signature.

Aircraft designed for BVR combat are significantly more complex and costlier than aircraft designed for WVR combat; I will demonstrate this on examples. F-15 was designed for BVR, and F-16 for WVR, but with similar technology; F-15C costs 126 million USD whereas F-16A costs 30 million USD, a 4:1 difference. F-15s successor, and currently most capable BVR platform in the world is F-22, whereas Gripen C is F-16s successor (in idea and aerodynamics, not in lineage), though with far more BVR capability. F-22A costs 262 million USD, compared to Gripen C’s 44 million USD, or 6:1 cost difference (all costs are unit flyaway costs in FY-2013 USD). Aside from smaller number of units bought, increased complexity means that these units fly less often: F-22s maintenance downtime is 45 MHPFH, compared to Gripen’s 10. Thus for 1 billion USD, one will have 3 F-22s flying 11 hours per week, or 22 Gripens flying 336 hours per week. Even Gripen’s cost per flight hour is 1/13 of F-22s, 4 700 USD vs 61 000 USD. Older fighters also follow this outline, with F-5E costing 940 FY1980 USD per hour compared to F-4Es cost of 2 733 FY1980 USD per hour, a 3:1 difference. Weapons are more expensive too: while AIM-120D costs 1 470 000 USD per missile, IRIS-T costs 270 000 USD, a 5:1 difference.

Weight difference is also significant. Gripen C weights 6 622 kg empty, compared to 19 700 kg empty for F-22; F-16A weights 7 076 kg compared to 12 700 kg for F-15C. It can be seen that WVR fighters are significantly smaller and lighter than contemporary BVR fighters. And with cost of 6 645 USD per kg, Gripen C is significantly cheaper per unit of weight than F-22 which costs 13 300 USD per kg, whereas F-16A costs 4 240 USD per kg, which when compared to F-15Cs 9 921 USD per kg gives similar ratio to F-22/Gripen one.

Even if previous shortcomings are disregarded, BVR combat is not always possible. If fighters are tied in defending a fixed point, or if enemy attack is not noticed on time (distance between air fields is too low, enemy manages to sneak up by using the terrain) only option is engaging in visual-range combat.

Past air-to-air combat experience also suggests that days of BVR combat being primary form of air-to-air combat are still far away, if they ever come. First BVR craze happened in 1950s, when USAF procured the “century series” fighters, and USN bought F-6D Missileer and F-4H-1 Phantom II, latter of which carried Sparrow missile; former used huge Eagle missile, similar to F-14 with its Phoenix missile. Phantom was also adapted into USAF as F-4C Phantom II. Soon, other BVR fighters – F-111, F-14, F-15 – followed. Soviets, in an arms race that was actually more about prestige than about military capability, decided to counter this development with BVR fighters of their own: Yak-28, Tu-28 and MiG-25 as counters to 3rd generation BVR fighters, with F-15 being countered by Su-27.

These fighters all followed logic of “bigger is better”. Bigger radar – focus of the logic – required bigger airframe, which in turn required bigger engines. Both weight and complexity spiralled upwards, creating fighters that were costly, flew very few sorties and had maneuvering capabilities more typical of strategic bombers than of fighter aircraft – logic being that they will not have to maneuver, as they will destroy the enemy far before it comes to the merge. Exception to this as far as US fighters are concerned are F-15 and F-22, but even that was only due to influence of Boyd’s Fighter Mafia; Su-27, being designed to counter F-15 and built with same requirement of high BVR capability and high maneuverability, also follows basic logic of large but very agile aircraft with large radar. All aircraft mentioned as being agile were developed after Vietnam War, in which failure of BVR-only logic was aptly demonstrated; yet they all relied on using superior range and technology to defeat superior numbers of “less capable” WVR fighters.

But in practice, BVR promise fell short. During the entire Cold War, 407 kills were made with missiles in eight conflicts, with reliable data for ninth conflict, Iran-Iraq war, not being avaliable. Only four saw use of radar-guided BVR missiles: Rolling Thunder and Linebacker in Vietnam, Yom Kippur War, and conflict over Bekaa Valley. In total, 144 kills were made with guns, 308 with heat-seeking missiles and 73 with radar-guided missiles. What is interesting to notice is that, while percentage of gun kills in the latest conflict, Bekaa Valley, was lower than in any other, it also held second-lowest percentage of radar-guided missile kills, and highest percentage of IR missile kills. Out of 73 radar-guided missile kills, 69 were scored within visual range, with remaining four being carefully staged outside combat. Out of these kills, two were made by Israel under intense US diplomatic pressure to establish BVR doctrine, and two were made by US in Vietnam, with one of US kills being a freindly-fire incident, a F-4 mistakenly identified as MiG-21. As there were 61 BVR shots during entire Cold War, this results in Pk of 6,6%, compared to 15% for IR missiles, and to promised BVR missile Pk of 80-90%. Even though majority of BVR missile shots in Vietnam were made from visual range, Pk was still 9,6%. While F-4 and F-105 did score numerous aerial victories in Vietnam, all except two mentioned BVR kills were made within visual range, and of these, many were achieved by gun after Top Gun course was established, securing USAF an unquestionable pilot superiority. In fact, F-4 consistently underperformed until it was given gun and pilots were taught how to dogfight, and Navy F-8, with its far lower wing loading and mass, performed far better against MiGs. And even today, missile tests are carried out against drones with limited maneuvering capability, as these are usually rebuilt old aircraft (for example, QF-4 which is a rebuilt F-4).

Further, in these 407 kills, most targets were unaware and fired at from the rear, and there were almost no head-on BVR shots due to high closing speeds of aircraft involved. This shows that good rearward visibility from cockpit is still important despite all technological advancements.

Two post-Cold War wars in Iraq are offered as examples that BVR theory has finally reached maturity and that BVR combat now is prevalent form of aerial combat. Out of 41 kills in Desert Storm, 16 involved use of BVR shots, but only five kills are known to have been made at BVR. Even then, longest-ranged kill of these five certain BVR kills was made at distance of 29,6 kilometers, and one of remaining BVR shots was made at night from what would have been visual range in daytime. Desert Storm was first conflict where more kills were made by radar-guided missiles than by IR missiles – 24 vs 10. While 24 radar-guided missile kills out of 88 shots gives Pk of 27%, F-15s killed 23 targets in 67 shots with AIM-7 (Pk 0,34), while Sidewinder launches from F-15 resulted in 8 kills from 12 shots (Pk 0,67). While F-16s launched 36 Sidewinders and scored 0 kills, at least 20 launches were accidental due to poor control stick ergonomy; F-16s in question themselves were overweight F-16Cs, so-called “more capable” variant equipped with BVR capability and tons of electronics. Iraqi Freedom was likely similar in this aspect. AIM-120, meanwhile, demonstrated BVR Pk of 0,46 in Iraqi Freedom and Allied Force (6 kills out of 13 shots). It also achieved the longest ranged air-to-air combat kill ever, when a Dutch F-16 shot down a (malfunctioning and nonmaneuvering) Serb MiG-29 at 34,8 km.

Navy and USMC themselves achieved 21 Sparrows and 38 Sidewinders in the Desert Storm, achieving one kill with Sparrow (Pk=4,76%) and two with Sidewinders (Pk=5,26%). Reasons for such low Pk are unclear, though given F-16s problems it is possible that most launches from F-18 were accidental.

Claim that USAFs combat record proves maturity of BVR combat or even missiles in general is misleading, however. Targets that were fired at were in vast majority of cases unaware they were being fired at and thus did not take any evasive action; no targets had electronic countermeasures, support from stand-off jammers, nor comparable BVR weapon (be it radar-guided, IR or anti-radiation BVR missile). When targets were aware they were targeted and thus did take evasive action – such as when two Iraqi MiG-25s illuminated two F-15Cs with BVR radar in 1999 – BVR shots were ineffective (in example cited, US fighters made 6 BVR shots to no effect). There was also constant AWACS avaliability in both Gulf Wars, and in all wars US/Coalition aircraft had numerical superiority. Iraqi pilots also were badly trained, and most Iraqi jets did not have bubble canopy like F-16, but one that did not provide rearward visibility and was in many cases heavily framed, limiting pilot’s ability to acquire missile visually in addition to total lack of warning devices.

I will also note here a report by Air Power Australia group, found here. Some assumptions have to be fixed: missiles have demonstrated 0,34 – 0,46 Pk against non-maneuvering opponents with no ECM; 0,46 figure is for AIM-120 and is one I will use here. Thus 54% miss value is attributed to factors that have no connection to ECM or maneuvering. Out of remaining 46%, there is 93% for chance of miss. Thus BVR missile Pk against aware, maneuvering opponent using modern ECM suite is around 3%. Considering that most opponents shot at by BVR missiles during Cold War had no ECM, and some at least did not notice a missile, thus failing to take evasive action, this can be considered to be in line with demonstrated Pk.

Latest BVR craze has resulted in F-22 and F-35, both of which are utterly expensive and maintenance intensive, and latter of which is in its major characteristics more similar to century series than modern fighter aircraft. F-35 in itself is utterly incapable of handling itself in close combat due to large weight, high drag, high wing loading and low thrust to weight ratio. It can also carry at most 4 BVR missiles in internal bays. With this in mind, claims by manufacturer that F-35 is 4 times as effective in air-to-air combat as next best fighter in the air would require probability of kill for BVR missiles of 80-90%, and opponent’s complete inability to engage F-35 itself at BVR range. Track record of BVR missiles to date as well as development of infrared BVR missiles and long range QWIP IRST sensors mean that any such assumptions are nothing more than wishful thinking on part of sales department and high technology addicts.

Result is that eye remains most important sensor on the aircraft, and pilot who looses sight of the opponent during maneuvers is likely to be quickly shot down. Secondary are onboard passive sensors such as IRST and RWR, followed by offboard sensors – both passive and active – whereas onboard active sensors take last place. Human factors still trump technology, and higher cost does not mean more capability in a real world combat scenario – even with missiles, both BVR and WVR, pilot has to know how to achieve ideal firing solution, and more electronics means more weight, which hurts airframe performance.

Considering that BVR missiles generally cost 2-5 times as much as IR WVR missiles, yet are 44% as effective, it is easy to calculate that they are only 8,8-22% as cost-effective as IR missiles, while in most cases not offering noticeable advantage in engagement range, and at same time incurring cost and capability penalties on aircraft designed to use them.

For end, I will adress an argument that is obviously invalid but very often does come up anyway: one of exercises in which F-22 “dominates” against “legacy” fighters, with kill ratios between 10:1 and 30:1. But these exercises are bogus, as they depend on incorrect assumptions about air combat to produce results. In them, most kills are achieved at BVR as BVR missiles are assigned Pk of 90%, despite never achieving such performance; enemy anti-radar measures such as anti-radiation missiles or missile cueing with RWRs are not allowed; most F-22s opponents went without avionics upgrade for a very long time and thus likely don’t have ability to jam AESA radar; Red Force simply charges in, from known vector; and real fleet cost and fleet readiness are not represented, which means that F-22 doesn’t face force ratios it would face in real world. Due to that, exercises are only useful as a propaganda tool, having no connection to reality of air combat, and using them to argue for usefulness of stealth and BVR combat is nothing more than a circular logic.

EDIT 5. 5. 2013.:

There are more details about Serb MiG-29s:

http://www.acig.org/artman/publish/article_380.shtml

“even if from around 1996 they started suffering from a latent lack of spares, which severely impacted the capability of the service to maintain them.”

MiG-29s were badly maintained.

“Eventually, the cancellation of the development of Novi Avion resulted in MiG-29s remaining in service with the JRViPVO until the late 1990s, and well past their resources. To make matters worse, the corrupt regime of the Serbian dictator Slobodan Milosevic was more concerned with own survival and to reinforce riot-police and similar services, or finance the aggression war in Bosnia but with the maintenance of MiGs. Consequently, when Serbia found itself confronted with the NATO, in 1998, the condition of the MiGs with the 127.LAE was very poor, and its pilots were flying barely 20 hours annually.”

Pilots were not experienced in flying the aircraft.

“As only few aircraft were considered operational (they were actually merely flyable)”

Aircraft merely flyable, AKA not in condition for combat.

“Maj. Ljubisa Kulacin evaded several missiles fired at him while fighting to bring his malfunctioning systems back in working order”

Kulacin evaded several missiles despite equipment malfunction.

“Kulacin’s experience was not much different to that of his three other colleagues, all of which experienced immense problems with weapons and navigational systems on their aircraft: on the 18112, flown by Maj. Arizanov, both the radio and SPO-15 malfunctioned; on 18104, flown by Maj. Ilic, the radar failed; on 18111, flown by Maj. Nikolic, both the radar and the SN-29 missile guidance systems were inoperative, and apparently the
SPO-15 also did not function properly.”

At least 4 MiG-29s had equipment malfunctions, two cases of radar malfunction and two cases of RWR malfunction.

“The fifth and last MiG-29 to get airborne on that night was 18106, flown by Maj. Predrag Milutinovic. Immediately after take-off his radar failed and even the electrical generator malfunctioned. Shortly after, he was warned by SPO-15 of being acquired, but he evaded the opponent by several evasive manoeuvres. Attempting to evade further encounters and searching for an airfield where a landing was possible, he finally ended over Ribarska Banja, when his RWR warned him of acquisition by a ground-based radar. Seconds afterward the aircraft was hit and Milutinovic forced to eject. ”

Radar failure, electric generator malfunction. Evaded several enemy missiles and was shot down by friendly SAM.

“Once there, the GCI advised them that both were detected by the NATO aircraft, but would not indicate the kind of a threat. This was a tragic mistake: Maj. Peric led his wingman into a climb, and straight into three AIM-120 missiles fired by two USAF F-15Cs that were on a patrol over Tuzla. Two missiles hit home, destroying both MiGs: after evading one AIM-120, Maj. Peric’s aircraft was hit and he ejected safely, but Capt. Radosavljevic was killed.”

Apparently no missile or radar warner.

No quotes indicate existence of countermeasures, and many of MiGs had no radar warners either. At least two MiG-29 kills happened at visual range, too, as photos exist.

http://www.510fs.org/index.php/squadron/code-one-magazine/item/78-schlemming-with-the-fulcrum

“The JG73 has also retained a number of former East German MiG-29 pilots who have had to tailor their knowledge of the airplane to fit western style tactics. Most of the Fulcrum pilots have less than 300 hours in the aircraft. Only a few have over 400 hours. No one in the unit, including former East German pilots, has over 500 hours in the MiG29.”

Even Eastern German pilots had less than 500 hours in the MiG-29 by 1995.

“”The Fulcrum doesn’t have the crisp movements of an F-16,” Sparrow continued. ‘You need to be an octopus in the MiG29 to work the avionics. Those German pilots have it tough. Just to get a simple lock on and fire a missile may take a half dozen hands-off switches or so. We can do the same with a flick of the thumb while we are looking at the HUD. F-16 pilots also have a significant sight advantage. A couple of hundred feet advantage can make a difference in air-to-air combat; the actual difference is more significant than that. MiG29 pilots have a tough time checking their six o’clock. Their canopy rail is higher. They can lose sight of us even when flying BFM.””

MiG-29 has cockpit that is not user friendly and is great distraction from fighting, and does not have good out-of-cockpit view.

“”Besides visibility, I expected better turning performance,” McCoy continued. “The MiG29 is not a continuous nine-g machine like the F-16. I tried to do some things I normally do in an F-16. For example, I tried a high-AOA guns jink. I got the Fulcrum down to about 180 knots and pulled ninety degrees of bank and pulling heavy g’s I then went to idle and added a little rudder to get the jet to roll with ailerons. The pilot took control away from me in the middle of these maneuvers because the airplane was about to: snap. I use the F-16’s quick roll rate like this all the time with no problem.”

Bad turn rate, bad roll rate, design not tolerant to maneuvers.

“The aircraft was not built for close-in dog fighting, though it is aerodynamically capable of it,” Prunk continued. “The East Germans flew it as a point defense interceptor, like a MiG-21. They were not allowed to max perform the airplane, to explore its capabilities or their own capabilities. Sorties lasted about thirty minutes. The airplane was designed to scramble, jettison the tank, go supersonic, shoot its missiles, and go home.”

Not a maneuvering fighter.

EDIT 26. 7. 2014.:

When the 1973 war is compared to the Vietnam war, it clearly shows impact of training on missile Pk. While US fighters achieved radar missile Pk of 10,9% (276 shots / 30 kills) against NVAF fighters in a 1971-1973 period, in the 1973 Yom Kippur war, Israeli fighters achieved radar missile Pk of 41,7%, far closer to the 1991 Gulf War. This shows that opponent’s competence was a primary factor in missile performance. As a matter of fact, there was very little if any technological disparity between two sides in the Yom Kippur war, with Israel using F-4 Phantom jets against Arab MiG-21s and MiG-25s.

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On AviationIntel F-22 vs Typhoon article

Posted by Picard578 on November 24, 2012

http://aviationintel.com/2012/07/28/in-response-to-reports-of-simulated-f-22-raptor-kills-by-german-eurofighters/

 

While author is indeed correct that training sorties do not necessarily mean that one type of aircraft is superior, multiple sorties can, when analyzed properly and assuming that setup is known, provide some information about respective fighter’s capabilities.

Huge control surfaces and thrust vectoring are useful for high-altitude and low-speed maneuvers, not in types of maneuvers required for close-in combat (transsonic low-altitude maneuvers). In fact, thrust vectoring is dangerous as it bleeds off energy, leaving fighter defenseless if it does not manage to get a kill immediately upon using it Secondly, German Typhoons in the exercise had no helmet-mounted sights, and as such had to point nose at F-22s to get a lock.

Modern radar warners, such as those carried by the Typhoons, are very capable of detecting even newest LPI radars. In any scenario where IRST-less Typhoon and F-22 went against each other with no AWACS support, both sides would be limited to visual detection.

In the end, visual-range combat is more likely than not to be decisive between fully equipped 4,5-th/5-th generation aircraft. As such, while F-22 is a capable dogfighter, it cannot be counted on to have a major impact in a war due to high cost and low sortie rate.

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F-35 cheated on performance tests

Posted by Picard578 on October 18, 2012

Wired.com article is here:

http://www.wired.com/dangerroom/2012/03/jsf-test/

While F-35 has been stated to have met all performance criteria, I have been sceptical about statement – not only because performance criteria were less than impressive themselves, but because I was aware that money and reputation that went into F-35 meant that USAF and Lockheed Martin will fight tooth and nail to keep F-35s reputation untarnished, including favorite tool of all corporations: lying about their products (alternatively known as “marketing”, “promoting product” etc).

I have been proven right. As can be seen from the article, only reason F-35 has met criteria is that already-low criteria bar has been lowered even further. End result is about the same as you would expect from building a fighter with no performance requirements stated, and then writing performance requirements to be the same as said fighter actually achieved. Suffice to say, that is not how weapons are being designed.

But noone at USAF or Lockheed Martin will care as long as their pockets are full and their bribes regular.

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