While Gullio Douhet’s theory that bombardment of the enemy heartland can win the war has dominated USAF (USAAF during WWII) procurement ever since its formation has been thoroughly discredited (more about that in another article), Western air forces still procure far too many strategic bombers and deep strike fighters, while procuring insufficient number of close air support fighters; this often results in a situation where all ground attack aircraft, regardless of their suitability for the role, have to be used for close air support.
But Close Air Support is a very hard mission with strict requirements, which aircraft designed for other missions (“multirole” fighters, most tactical bombers with exception of aircraft designed specifically for CAS, any strategic bombers) do not meet. It is therefore paramount for these requirements to be well understood if CAS fighter is to be effective.
First concern is that crew of a CAS aircraft has to think of themselves and their mission as a ground soldiers, and understand infantry, armor and/or mechanized tactics. From this follows the requirement for CAS squadrons to be assigned to specific battallions and be colocated with them, but also a requirement for pilots to study ground combat – tactics, visual specifics of different vehicles. All of this means that “multirole” pilots are psychologically incapable of carrying out effective CAS, and that complex “multirole” aircraft are similarly incapable of satisfying basing requirements. In exercises, observers should sometimes swap places with ground troops and participate in them as infantrymen or otherwise members of ground units they are assigned to. Whenever CAS crews train, it should be with the unit they are assigned to, and observers should eventually reach the level where they will be capable of taking command of ground units.
Second problem is that Close Air Support is a very demanding mission. It is carried out at low altitude, so pilot will have a lot of trouble avoiding anti-air fire and avoiding to fly into the ground. This means that there should be a separate observer who will also command the aircraft, freeing up pilot to focus on flying.
Third concern is a coordination with both supported unit and the artillery. This means that ground unit should have attached ground FAC. Also, CAS aircraft should be survivable enough so as to be able to fly slow and low enough to identify targets.
It should also be noted that Close Air Support, while extremely useful, is an emergency procedure. Care should be taken to avoid situations where CAS is required; thus a CAS aircraft should also do a battlefield interdiction (every CAS aircraft can do interdiction, but not every aircraft capable of carrying out interdiction can perfom CAS); when CAS is requested, somebody has failed. In COIN operations, however, destruction of enemy before its contact with one’s own ground troops is often not possible. Battlefield interdiction, along with destruction of enemy ground formations on the move, includes destruction of communication lines – bridges, ship traffic etc.
Yet another mission well done by CAS fighters is the armed reconnaissance, when aircraft patrols in front of or at flanks of escorted unit(s), as designated by ground commander, and provides visual reconnaissance information directly to the ground commander. It also attacks detected enemy forces when appropriate.
In World War I, CAS consisted of attacking enemy ground positions before a major ground attack. Attacking was done by strafing, or by tossing small bombs over aircraft’s side.
Major performers of CAS in World War II were Germans with their Stuka units. Stuka was used primarly for Close Air Support, and its never produced successor (Hs-129B) was optimized for CAS, with two widely spaced engines, an armored cockpit and a 30 mm cannon carrying enough rounds for 18 tank-killing attacks compared to 6 for Stuka. Stuka could be considered a first dedicated CAS aircraft: it achieved low dive speeds below 200 kts, while carrying bombs weighting up to 500 kg. It was very maneuverable, and heavy armor meant that 20 mm AAA was considered an insignificant threat by Stuka pilots. While dive accuracy of ~10 meters was achieved, it was insufficient for tank killing; as a result, special tank-killing Stukas using 37 mm cannon were deployed to the Eastern front in 1943.
In the Battle of France, Guderian refused to stop his armored divisions after successful Ardennes offensive, resulting in first true “blitzkrieg” campaign. This also meant that he had to rely on “Stuka” units to replace usual artillery support. Later on, encirclement of Dunkirk proved that air power by itself cannot destroy dug-in enemy army.
At the Eastern Front, Stuka units performed CAS and battlefield interdiction. Hans Rudel, Stuka ace, flew 2.500 sorties on the Russian front, using his 37 mm cannon, and more rarely bombs, to destroy well over 500 tanks, some locomotives, two battleships and 12 Soviet fighters. In process, he lost 30 aircraft to accidents and AAA, a loss rate of 1,2%. Stuka itself cost about same as tanks it destroyed – 40.000 USD in 1943. Tank strafing attacks were executed either from almost vertical dive or from direct rear of the tank at altitude of around 10 meters. In presence of air defenses, vertical attacks were preferred with part of group attacking AAA, and remainder attacking assigned targets (usually tanks). They also informed ground troops of any enemy movement or deployment in their assigned areas. Thanks to their mobility – Stukas could easily take off from muddy fields – they could be colocated with ground troops. Whenever Russian tank columns were attacked, they would get off roads and start weaving maneuvers or disperse and try to hide. Rudel has also commented that high speeds are “poison” for finding tanks.
Neither RAF or USAAF were willing to develop specialized close air support aircraft. However, they did have some fighters which excelled in the close air support. US P-47 which failed as an air superiority fighter was eventually employed as a Stuka-equivalent. While high-altitude bombers dropped tons of bombs without any effect during Normandy landing, missing target area by miles, general Quaseada’s 1.500 P-47s running battlefield interdiction delayed 23 German divisions so much that their 3-day travel time took six weeks, and even those that did make it eventually were heavily mauled. Multi-engined bombers were also often tasked with providing CAS and battlefield interdiction, but were nowhere as effective. UK chose to create an armored and upgunned Hurricane model specialized for CAS; however, it was still a modification of an existing aircraft. Quaseada’s and Patton’s acceptance of close cooperation between Army and Air Force, their mutual trust, and Quaseada’s acceptance of importance of close air support, allowed Patton to go on his drive across France by relying on Quaseada’s P-47s to protect his right flank against attack from German ground forces, and thus concentrate full weight of his forces on the main attack. Towards the end of the war, Forward Air Controllers were attached to ground troops at the battallion level. USMC did that as early as 1943, and evolved a requirement for all aviators to serve at least one year in the infantry. F-4U turned out to be as suitable as P-47 for the same reasons: air-cooled engine and heavy armor.
Allies flew B-25s in low-altitude attacks. While not CAS aircraft, lessons gained are important for CAS fighter. Favorite speed was 250-300 knots. Pilots also considered survivability to be the best at altitudes below 50 and above 50.000 feets (below 15 and above 15.000 meters). While aircraft did get hit by small-arms fire during low altitude attacks, it was not dangerous.
In the Korean War, USAF originally had no CAS capability at all; B-29s delivered 13 CAS sorties per day, which were useless to troops they were supporting as they were delivered 3 miles forward. Interdiction missions were not a success either, as B-29s and B-26s dropped 4.000 bombs on railroad bridges on Yalu river, achieving 33 hits and blocking target bridges for one week. When bombardment of North Korean cities commenced, 90% of electric power was shut down – not by bombers but by fighters. Thus CAS fighter can also do a strategic bombardment when needed, though just like in Gulf Wars, knocking out of electic power in cities did not result in any impendement to enemy’s military activity. Another thing that Korean war demonstrated was ineffectiveness of the 450 knot jet fighters in the CAS role; this plus disbandment of all FAC capability in the interwar between WWII and Korean war meant that early USAF “CAS” was useless to troops on the ground. US Marine Corps have luckily created a strong tradition of close air support in their combined division/air wing teams during peacetime; as a result, they had very good CAS capability and dedicated majority of their sorties to the mission, using prop-driven Corsairs. Later on, USAF created a robust system of CAS aircraft coupled to airborne FACs as well as ground FACs. P-51 was first aircraft used in that role by USAF; while it proved an excellent fighter during World War II, exact same qualities that made it good fighter caused it to be unsuitable for Close Air Support: a rifle bullet through coolant radiator could destroy it. F-84 performed poorly as a CAS aircraft (once F-86 displaced it as an air superiority fighter) due to being too fast. Once trench warfare began, USAF placed strict altitude limits, only allowing survivable Marine Corsairs and Navy A-1s to fly below it; they however did not find many targets as both sides were well dug in. 50-cal (12,7 mm) machine guns, 20 mm cannons and 3 in rockets were used for attacking troops, vehicles, buildings, automatic weapons emplacements and combustible storage dumps; fragmentation bombs were used against these same targets; 500 lb (225 kg) general-purpose bombs and 5-in (127 mm) rockets were used against tanks, bridges, railway tunnels, artillery and AAA pieces and positions; 1.000 lb (450 kg) bombs were used against major bridges and tunnels, and napalm was jack-of-all-trades weapon, used against everything except railroad tracks. Rockets and bombs proved too inaccurate against the T-34, and .50 cal machine guns could not penetrate its armor. And while pilots rated napalm as most devastating, followed by rockets and then strafing, prisoners (actual subjects of these attacks) rated strafing as most devastating, followed by rockets and then napalm (simply lying down protects from effects of napalm since heat rises).
In Vietnam, high-speed jet fighters proved unsutiable for both battlefield interdiction and Close Air Support, with ordinary difficulties being compounded by the fact that missions were flown in heavily forrested areas. Old Navy A-1 propeller attack aircraft, used by Special Air Warfare forces, proved successful for night and day close air support due to its low speed maneuverability, survivability and extraordinary loiter performance. A-37, F-100 and F-4 were also used. A-37 had good maneuverability but lacked armament and loiter performance; F-100 was maneuverable but too fast, while F-4 and F-105 proved entirely unsuitable due to speed and lack of maneuverability. Navy A-4 was best CAS jet, A-7 was similar to F-100 and F-4 was used only when nothing else was avaliable. Due to complex control system, only aircraft loitering directly above troops requiring support acheved acceptable response time. Neither laser guided or electro-optical bombs were used in CAS, mostly due to the high percentage of “wild bombs”; weapons release computers were banned for the similar reason, and gun was preferred CAS weapon, though dumb rockets and bombs were also used. A-1s were only aircraft flying under 1.000 foot ceillings and providing support on cloudy nights when all other aircraft were grounded. During Ashau Valley helicopter assault, A-1s were the only aircraft that could operate under low ceillings in face of defenses that accounted for 30 helicopters lost. Marine CAS quality declined due to usage of F-4 and A-6 radar bombers, and cessation of requirement for pilots to serve a tour with infantry; it was still better than Navy or USAF one. Helicopters were also tested as a CAS platform, but it turned out that they were limited to area fire due to their inherent instability and inaccuracy of airborne swiwelled or turreted guns. They were also extremely vulnerable to all forms of air defenses due to lack of maneuverability (even AH-64 can’t pull more than +3,5/-0,5 g, compared to +11/-3,5 g for Rafale C and +7/-3 g for F-4). Only pros of helicopters were slow speed and the fact that they were owned by the Army. TOW missiles fired by helicopters did achieve good accuracy, but only against static undefended targets. Similarly, high-altitude “strategic” bombardment of North Vietnamese cities only demonstrated to them the US lack of resolve.
In the Gulf War, high-altitude “precision” bombing by B-52s and F-16s against dug-in Republician Guard failed. But in the war’s second week, Saddam sent significant military force towards the Saudi city of Khafji. Two A-10s and an AC-130 gunship destroyed 58 targets in a 71-vehicle convoy. Later, 20 Scud launchers were destroyed by two A-10s, using their 30 mm cannon. While air strikes made ground war possible at lower cost, they would have failed without said ground war. A-10s were just as survivable as the F-117s when operating in the same environment – at night, above heavily defended areas; all A-10 losses happened during the day, and F-117 was painted black to prevent some “smart” heads in USAF from sending it during day. Neither night flying A-10s, night flying F-111Fs or night flying F-117s suffered any losses. In Gulf War and Kosovo F-117 suffered 2 losses in 2.600 sorties, and A-10s 4 losses in 12.400 sorties – loss rates of 0,08% for F-117 and 0,03% for A-10. Thus it follows that radar stealth is not a survivability requirement, as the A-10 was nearly 3 times as survivable as the F-117. If only aircraft that were shot down, as opposed to written off due to damage, are counted, F-117 suffered 1 loss and A-10 3 losses – loss rates of 0,04% for F-117 and 0,02% for A-10; by this measure, A-10 was twice as survivable as F-117, and its slow speed was not detrimental despite claims made by USAF generals and often mindlessly repeated by general public. STOVL Harrier suffered heavy losses due to IR missiles as it has nozzles in middle of the body; F-18 with its nozzles located far back fared far better (5 hits and 1 loss). It should be noted that A-10s in the Desert Storm were far less survivable than they would have been when used competently – USAF ordered A-10s to retain their dark green color which made them stand out against both sky and the sand. In Kosovo war, high-altitude bombing – both of military and of civilian targets – proved useless, and Milosevic was one dictating the terms. NATO destroyed 13 tanks, 18 APCs and 20 artillery pieces; this was in part due to effectiveness of rather primitive countermeasures employed by Serbs (such as metal-lined-paper models). Later Corley’s survey claimed 246 tanks and APCs destroyed, but it actually only counted wether bombs detonated, counting decoys and misses into successful attacks and using evidence such as blurry cockpit videos and satellite recordings of munition detonations.
It should also be noted that A-10s were far less effective in the Gulf War than they could have been: they were assigned to “kill boxes” instead of acting as a free “jaeger air” and were jerked from “kill box” to “kill box” without any reason; often they could not finish the job in one “kill box” before being moved to uselessly loiter in the entirely empty “kill box”. Altitude restrictions helped cause some friendly fire incidents (such as attack on Mc LAV armored cards) and prevented A-10s from flying low altitude column cover and armed reconnaissance.
When fast jets operated on their own, they produced neglible results, dropping expensive ammunitions on decoys or previously destroyed targets, while having trouble finding well camouflaged and/or dug-in targets. They were not given the authority to descend to altitudes that would allow them to visually spot the enemy, nor did they have capability to loiter while looking for targets.
In Afghanistan, high altitude bombing also proved useless; A-10s, with their high-calibre cannon, low speed maneuverability and excellent, rugged construction, proved invaluable for providing Close Air Support. At least once it was provided without any radio contact with troops attacked, and A-10s provided cover for entire 6-hour return trip. On another occasion during Anaconda, Navy SEALs were pinned down by mortar fire; SEALs had to talk F-15E pilots into gun strafing runs since pilots never trained for that task, and F-15E is unsuitable for it since it is too fast. F-15Es were eventually successful, but it took several hours; this in turn meant several casualties that would not have happened had the A-10s been present. In 2007, an F-16 crashed while providing CAS: pilot had to perform gun strafing runs against Taliban to help ground forces in peril, but F-16 was too fast to come out of last low-level pass; unable to pull up, it crashed along with pilot (Maj. Troy Gilbert) inside. In mountain terrain, PGMs are not effective since such terrain offers ample cover and readily absorbs firepower. At Roberts Ridge, 12 Al Quaeda have been pounded by PGMs for hours; they suffered no casualties. PGMs are ineffective against moving targets; even when bombing static targets, bombs regularly bump into each other and into aircraft when dropped, bending fins – a problem which increases with airspeed (for this reason alone, any claims of 90% accuracy by PGMs are most likely bull); since any PGM is a complex system, guidance errors are also likely (AAMs failure rate is 50% for radar-guided BVR and 30% for IR WVR missiles). Caves that serve as hideouts remain invisible to high-altitude aircraft and satellites, and it is usually ground troops that discover them. Very often fire has to be delivered close to friendly troops; bombs are simply too destructive for that, especially precision ones which tend to be more destructive. Cannon is also very useful for suppressive fire. All of this lead to RAF Eurofighter Typhoons being equipped with guns despite original decision not to buy guns in order to save cost. There is another story which confirms usefulness of the gun: in Afghanistan, a Special Forces team attacked the compoind of the Taliban leader. Taliban reacted with heavy fire and the Air Force combat controller present was severely wounded; Predator overhead could not get a shot, while the F-16 ran low on fuel and departed. Finally, two A-10s arrived and controller asked them to make runs “danger close”; shells impacted 20 meters from the team – were this PGMs, both Special Forces team and Taliban would have been within kill zone, with only quality and quantity of avaliable cover deciding who will live and who will die. Taliban broke up the attack. Every member of SF team returned to the base alive, even the combat controller who had almost bled to death – and would have bled to death had attack lasted little longer (see previously described CAS mission carried out by F-15Es in support of SEALs for reference on how the fast jets have performed in similar circumstances).
In 2003 Operation Iraqi Freedom, few hundred SOF and airborne paratroopers effectively coordinated with airborne FAC-directed CAS to tie up entire Iraqi divisions.
Arabs never displayed interest or capability for Close Air Support, in primarly due to chronic incompetence of their pilots, but also due to unsitability of high-speed jets. Israel also never displayed interest in CAS, and in 1973 war IAF failed to have any impact on Sinai campaign. Only air forces that had aircraft unsitable for any mission other than Close Air Support displayed interest in that mission; for this reason alone argument for fast jets (such as F-35) as CAS platforms falls flat on its face. There is no way to deliver effective CAS without getting low and slow; high speed is likewise not required to survive extensive air defenses. CAS is not effective in dug-in warfare. For this reason, CAS fighters have to be commanded by the Army and flown by the Army pilots.
Due to requirement for a good situational awareness and quick reaction times, UAV is unsuitable for this role, as it is for the air superiority (and for the same reasons). Quick reaction times also require a broadcast control by ground FACs and direct cooperation between loitering CAS aircraft and ground troops, which means cuttning out a central command. In part due to these problems, NATO has lost 46 UAVs in Yugoslavia. UAVs also have weather limitations: they cannot fly if cloud ceilling is 2.000 meters or less, headwind is 35+ knots, tailwind is 2+ knots or crosswind is 20+ knots, lightning is within 10 nm or there is a danger of ice formation on the airframe. Fast fighters also encounter similar limitations as they have to be below clouds to effectively operate in air-to-ground role – and they are too vulnerable for that if clouds are low.
Modern networked defenses can be very lethal when static – radar SAMs are nearly-useless, but IR MANPADS and especially anti-aircraft guns are dangerous and are main causes of losses amon CAS aircraft. Dug-in enemy is also less vulnerable to attack (while low-altitude CAS fighters can harm even dug-in opponents their effectiveness is very low, and dug-in forces are essentially invulnerable to high-altitude bombing). Modern electronic-heavy defenses are however very susceptible to the breakdown when moving, which means that CAS aircraft must be capable of dealing them heavy damage on these occasions. Also, known presence of CAS aircraft can force the enemy to remain static, leaving him very vulnerable to being outmaneuvered by one’s own ground troops. But to be truly effective, CAS aircraft must fly at very low altitudes, measured in hundreds and often in tens of meters.
While some say that modern sensors have made low-altitude CAS aircraft obsolete, even most modern sensors and weapons are often defeated by simplest of countermeasures. Criteria for effective CAS have changed little: air superiority, suppression of enemy air defenses, target marking, favorable weather, prompt response, terminal controller and aircrew skill. “Favorable weather” requirement means that high-altitude aircraft are impotent on days of heavy overcast; even so-called “all-weather” capability does little to help – USAF in Desert Storm faced major problems and even sortie cancellations due to unfavorable weather conditions. Due to this, relying on thin-skinned, high-altitude, high-speed jets means that ground troops will be left without any air support during bad weather days. Most importantly, ground troops do not think much of fast jets doing CAS as evidenced by statement by Army Sgt. First Class Frank Antenori: “Fast moving aircraft are not designed to support ground troops, as much as the Air Force and Navy would like to think that, fighter aircraft that travel at speeds can’t slow down to identify the targets.”
From above, a list of basic requirements can be made: low cost, high sortie rate, long loiter time, rough field operating capability, basing mobility, low speed maneuverability (<300 meter turn radius at 140-300 kts; 45° attack speed of 225-275 kts), survivability (fast climb rate, rugged construction), high number of kills on board (20+ attack passes with gun and missiles, 15 attack passes with gun alone), high-calibre fast-accelerating cannon with fragmentation and AP rounds, iron bombs with delayed fuses.
Basing mobility is required for aircraft to remain close to the supported troops. Requirements that follow from it are rough field and road operating capability, easy maintenance, low fuel requirements.
Low speed maneuverability and survivability at low altitude are paramount since even most modern sensors will not help in heavily forrested areas, or indeed any area except for open desert. Camouflaged targets are very hard to find, and CAS fighters must have tight turn radius at low speed and altitude. Even modern imaging sensors cannot effectively distinguish actual targets from decoys, or find camouflaged targets – for these purposes, Mk.I eyeball is still the best sensor. It also needs to be slow so that pilot can detect smoke or hydrogen baloon markers.
Low-speed maneuverability requires low wing loading and thrust-to-weight ratio above 1 halfway through the mission. This means that thrust-to-weight ratio at takeoff will likely be around 0,8-0,9.
Survivability requires either separated, external twin engines or armored single engine; engine exhaust should be shielded, and engine nozzle(s) should be located at extreme rear end of the aircraft. Wing tip fuel tanks are a possibility; aside from keeping amount of violatile fuel away from crew, they could be used for keeping airplane afloat if forced to land on water. Further, tracking time should be reduced to minimum; gun requires tracking time of 2-3 seconds, while PGMs require tracking time in excess of 10 seconds, rendering aircraft extremely vulnerable. Unguided bombs and rockets fall somewhere in between. As aircraft must not remain above mask for more than 10-12 seconds, it is clear that PGMs have very limited utility. Fuel tanks will be separated from each other and surrounding equipment by foam. Another characteristic required to maximize survivability is ability to fly below 15 meters at speeds of 250-300 kts (460-560 kph).
Reasonable lethality against all possible targets is achieved only by large-calibre, high-velocity cannon with AP, SAP and HE rounds. IIR, electro-optical and especially radar-based weapons require far too long lock-on time, and former require absence of smoke and dust – features rarely found on the battlefield. That is not to say, that they are useless; however, their complexity and resultant risk of missing the target (while they have great CEP, many GPS and laser guided munitions malfunction, and sometimes go miles off the target) mean that they have very limited employment possibilities, mostly from low altitude against static targets. Even if 90% accuracy is achieved, remaining 10% is too dangerous – and higher the altitude, more dangerous it becomes.
Survivability, lethality, cost and situational awareness requirements eliminate UAV as an option.
Best of both worlds shold thus combine two relatively small engines, separated, armored and with exhaust nozzles at or near the extreme rear of the aircraft; shielded engine exhaust; inner skin and outer armored panels, spaced from inner skin; small overall size; low wing loading; single GIAT-30 cannon with 200-500 (middle point 350) rounds; low, straight wings with external wheels; body-mounted external skiis; bubble canopy; fuel tanks separated from both engines and cockpit; separated bath tube for crew.
To fulfill requirements, aircraft will have to either use commercial engines or not use jet engines at all, opting instead for piston engines. Piston engines are several times more fuel efficient than jet engines, and can thus offer extended loiter time. However, turbofan engines offer higher thrust. Pusher propellers, while avaliable, are highly susceptible to debris kicked up when taking off or landing and suffer performance penalties during maneuvers due to the air flow disturbance during maneuvers. Turboprop engines are most efficient at 320 to 640 kph; turbofan engines are most efficient at 500 to 1.000 kph. Attack speed is at 420-510 kph, search speed is around 350 kph, though 800 kph may still be slow enough for both search and attack.
Engines will thus be commercial turbofan, CF700. Single CF700 weights 730 lbs (331 kg) and offers 4.500 lbs (2.041 kgf) of thrust; specific fuel consumption is 0,67 lb/lbf-hr, for a per-engine fuel consumption of 3.015 lb/h, or 1.367,6 kg/h (3,4 times less than that of M88 used in the air superiority fighter). Two engines will thus give 4.082 kgf of thrust and fuel consumption of 2735 kg/h.
Cannon will be French GIAT-30; as it is smaller than Gattling guns of same calibre, it will allow aircraft to be smaller, and thus cheaper and more survivable. It will be angled 2 degrees downwards. Possible modifications include higher muzzle velocity (stronger charge) and ammo that will include HE, HEAT and tungsten rounds. Secondary weapons will be dumb bombs, rocket launchers and pods containing 12,7 mm (.50 cal) machine guns. Linkless ammo feed will be used.
To achieve acceptable rough field operating capability, it will use large, wide, soft tires. Wheels should be only half-submerged when in flight, and widely separated, so as to allow aircraft to land even with wheels up; another possibility is for them to be fixed as on Stuka, though it adds drag. Yet another possibility is using wide, external skiis to allow operations from muddy fields, snow or ice.
It will ideally have a 40% fuel fraction, identical to the FLX, though anything above 35% is acceptable.
Survivability, as noted, requires armored engine, shielded engine exhaust, nozzles at extreme rear end of the aircraft; but also a small visual, acoustic and IR signature (thus small size), good situational awareness and countermeasures. As no practical amount of armor can ensure that engine will not be hit, two engines will be required; still, aircraft should be kept as small as possible to keep cost low, as well as to achieve low detectability and good basing performance. Aircraft should also have spaced armored skin, and engines should be spaced from each other. Another possibility is to reduce number of hits to minimum, which can be achieved by small size and good agility (low wing loading, high TWR), thus using single engine or two smaller engines. To provide protection from ground fire, engines can be mounted on top of the wings. Primary weapons will be gun, iron bombs and unguided rockets; only extraordinarily will it carry IR missiles.
Situational awareness will be achieved by a good cockpit visibility. It will be two-seat, with a pilot and a separate observer; observer is needed to leave pilot concentrated on flying, and to have someone who will study how various vehicles look and help avoid friendly fire incidents (it is not a new concept: French T-6 CAS/FAC aircraft in Algeria were two-seat). For night operations, both pilot and copilot will be provided with night-vision googles. This will also enable it to act as a forward air controller if prop-driven FAC is unavaliable for any reason.
Small size, long loiter time and good survivability will also make it a good SEAD aircraft; for this purpose, ALARM missile will be used. Aircraft will use terrain masking, using RWRs to find SAM sites and only going above terrain for brief periods of time in order to destroy SAMs before they manage to lock on to it.
Data is as follows:
Length: 12,04 m (12,6 m with tail)
Wingspan: 12,97 m
Height: 3,2 m
Wing area: 26,5 m2
Empty weight: 6.500 kg
Fuel capacity: 4.900 kg
- Rear tank: 160x110x199 cm = 16x11x19 dm = 3344 l
- Forward tank: 220x110x110 cm = 22x11x11 dm = 2662 l
- 1 l = 0,82 kg
Fuel fraction: 0,43
Weight: (30 mm GIAT-30 round: 530 g, AGM-65: 300 kg)
With 100% fuel + 600×30 mm rounds: 11.718 kg
With 50% fuel + 600×30 mm rounds: 9.268 kg
With 100% fuel + 600x30mm rounds + 4 AGM-65: 12.918 kg
With 50% fuel + 600x30mm rounds + 4 AGM-65: 10.468 kg
With 100% fuel + 600×30 mm rounds: 442 kg/m2
With 50% fuel + 600×30 mm rounds: 350 kg/m2
With 100% fuel + 600x30mm rounds + 4 AGM-65: 487 kg/m2
With 50% fuel + 600x30mm rounds + 4 AGM-65: 395 kg/m2
Thrust: 4.082 kgf
Fuel consmption: 2735 kg/h
With 100% fuel + 600×30 mm rounds: 0,35
With 50% fuel + 600×30 mm rounds: 0,44
With 100% fuel + 600x30mm rounds + 4 AGM-65: 0,32
With 50% fuel + 600x30mm rounds + 4 AGM-65: 0,39
Cruise: 600 kph
Time in the air:
107 minutes (1,79 hrs) on the internal fuel
151 minute (2,52 hrs) with 2 1.000 kg drop tanks
on internal fuel: 537 km
with 2 1.000 kg drop tanks: 757 km
1 GIAT-30 with 600 rounds (rate of fire of 2.500 rpm, 0,05s to full rate of fire = 15 1-second bursts)
6 wing hardpoints (AGM-65, ALARM, advanced anti radiation missile, or unguided munitions: rockets (15 70 mm or 5 127 mm rockets per pod), bombs (112 kg, 225 kg, 450 kg), recoilless rifles (75/90/105 mm); outermost hardpoints can hold IRIS-T for self-defense)
1 centerline hardpoint (jamming pod)
radar warner receivers
missile approach warners
jamming pods (if terrain masking is judged insufficient)
Unit flyaway cost: 9.000.000 USD
Cost per flying hour: 1.000-1.500 USD
Sorties per day per aircraft: 3
Sorties per day per billion procurement: 333
Unit flyaway cost is calculated with assumption that AXs cost per kg is same as that of the A-10 (1.413 USD per kg).
Comparision with other fighters
AX’s weapons loadout allows it 21 attack pass; A-10 for comparision has 22 firing passes of gun ammo and 6 missiles, for total of 28 attack passes. A-10s unit flyaway cost of 16 million USD and 3 sorties per day per aircraft however mean that while A-10 can fly 186 sorties per day per billion USD, AX can fly 333 sorties per day per billion USD; a 1,8:1 sortie generation advantage; this means that ALX offers 6.993 attack passes per billion procurement USD per day, compared to 5.208 for the A-10. AX is also far less visible and more maneuverable, resulting in greater survivability.
Comparing it with other fighters that are supposed to perform CAS is nowhere near being a fair play: aside from being completely incapable of performing actual CAS, fast jets are also too costly. F-16C costs 70 million USD flyaway and can fly 1,2 sorties per day, resulting in 16 sorties per day per billion USD (a 21:1 advantage for AX); F-35A costs 184 million USD flyaway and can fly 0,3 sorties per day, resulting in 1,5 sorties per day (a 222:1 advantage for AX).
F-16C has 4,7 1-second bursts from gun and can carry up to 12 bombs, for a total of 17 attack passes; F-35A has 2,6 1-second bursts and can carry up to 10 bombs, for a total of 13 attack passes. Thus per billion procurement USD, F-16C offers a total of 272 attack passes, and F-35A offers a total of 20 attack passes. From this it can easily be calculated that, for equal procurement cost, F-16C offers 13 times as many attack passes as the F-35A, A-10 offers 260 times as many attack passes as the F-35A, and AX offers 350 times as many attack passes as the F-35A.
It is also interesting to compare it to several proposed CAS fighters. First one is Pierre Sprey’s CAS fighter (America’s Defense Meltdown, pg 161). Sprey’s fighter has 30 mm cannon, 8.000 kgf of thrust, 6.350 kg empty weight, 4.500 kg of fuel (fuel fraction of 0,41), 11.300 kg combat takeoff weight. Another Fighter Mafia’s proposal, “Blitz Fighter” by James Burton (made into concept at LTV Vought Company), an airplane with empty weight of 2.300-4.500 kg, using 4-barreled 30 mm Gattling gun and a minimum of sensors; it would have cost 7,4 million USD (adjusted for inflation to 2013 USD). AX has 30 mm revolver cannon, 4.100 kgf of thrust, 6.500 kg empty weight, 4.900 kg of fuel (fuel fraction of 0,43), 11.700 kg combat takeoff weight, and while it can carry guided AT missiles, it relies primarly on its gun and dumb weapons; it costs 9 million USD. It can be seen that while AX is not as radical concept as other two fighters, it offers most of the same advantages.
EDIT 28.11.2013.: Camo designs