After the usual intense competition, McDonnell was chosen in 1969 to produce the fighter that would bring true dogfight superiority back to the West.

Nothing is ever simple in aviation and the F-15 Eagle, despite its acclaim as a super air-to-air fighter, performs excellently in a variety of other roles, as demonstrated by its ability to deliver no less than 23,600lb of offensive weapons. Because the F-15 was designed for one role only,it has an enormous fixed wing. At relatively low speeds, rolling manoeuvres are effected by aileron; as the F-15 reaches supersonic speed these manoeuvres are initiated by a combination of differental taileron and twin-rudder controlls.

The two big turbofans are fed by inlets which are not only fully variabe according to Mach number but which also tilt downwards in nose-high flight at low speeds. The massive power output is at sea level consderably more than the F-15's clean gross weight, and is a major factor in the F-15s amazing rate of climb and outstanding performance in the vertical plane. The Pratt & Whitney F-l00 was designed especially for the Eagle, and collossal funding was provided by the US Air Force. The engine was not without its problems, however, and for many years has suffered from 'stall stagnation' ano other problems. Competition from General Electric has spurred the new Fl00-220 version which is designed to fly 4000 combat missions without overhaul.

An important element of the design was to be the inclusion of a special 25mm Gatling-type gun which would use caseless ammunition. However, this was abandoned at an early stage in the project, and replaced by the well-proven 20mm General Electric M6 I, housed in the right wing root, with ammunition in a tank inboard of the engine duct. When the gun is fired, the rudders are automatically applied just enough to counteract the off-center recoil,

Visibility is excellent with full 3600 view through the bubble canopy. The Hughes APG-63 (now upgraded to APG-70) radar gives the pilot plenty of warning and is capable of detecting airborne and surface targets at long range with marvellous clarity, Initially this information is supplied on a head-down display mounted on the instrument panel. At closer ranges the radar picture is presented on the HUD (head-up display), with all radar controls on the stick and throttles, which enable the pilot to control the radar and all weapons while manoeuvring. He can select the weaponry using a throttle-mounted switch; as he does this, the radar automatically switches to the correct mode.

Normal missile armament is four AIM-7 Sparrows plus four AIM-9 Sidewinder missiles. The Sidewinder is, of course, well-proven, but the medium-range Sparrow was shown to be somewhat unreliable during the Vietnam war, That earlier AIM-7E version has now been replaced by a longer-range AIM-7L, with the monopulse-guided AIM7M version also entering service, This will be even more resistant to electronic countermeasures. The Sparrow's greatest 'scalp' to date came when an Israeli F-15 shot down a Syrian MiG-25 on 29 July 1980.

The F-15C has an internal fuel capacity of no less than 13,455lb. This can of course, be augmented by external tanks and air-to-air refuelling, The F-15C can also carry two FAST (fuel and sensor, tactical) conformal tanks along the sides of the fuselage which house an extra 9725 lb of fuel, and the total fuel capacity for ferry purposes is an amazing 35,075 lb - as heavy as three fully loaded P-51s!

The initial order for the Eagle was 729, but this number has risen to 1488, of which over 1000 have been delivered. The first versions were the F-15A and tandem dual-control F-15B, but in 1979 these gave way to the F-15C and F- I SD with many improvements. The USAF now plans also to buy 392 F-15E dual-role fighters, with APG-70 high resolution radar, a new computer and programmable armament control system, with avionics managed from the rear seat, and colossal capability in the attack mission. The F-15E will be able to operate at weights up to 81,000 lb, about twice as much as the wartime B-17 Fortress!

When one looks at the new F-15E it seems unbelievable that such a modest-sized conventional aircraft can have such capability. The main landing gears each have a single leg and a single wheel with a small-section tyre inflated to very high pressure. To take off at a speed exceeding 200mph at a weight in excess of 80,000 lb seems incredible, until one realises that this rests squarely on great engine power, superb structural materials and a great length of the best and smoothest concrete. On the other side of the Iron Curtain they have never stopped building aircraft which, on paper, are less impressive, with less weight and giant low-pressure tyres which often cause bulges in the aircraft when they are retracted. The difference lies in the fact that the Soviet warplanes do not need airfields, and in wartime this could be the difference between survival and destruction.

To date, no other aircraft in the Western world has been able to match the F-15's all-round performance. Its combination of excellent high power-to-weight ratio, light wing-loading and massive precision strike capability make it a difficult act to follow, eaven though the russian MiG-29 is said to be equal to the F-15.

 

SPECIFICATIONs

F-15C

Country of origin: USA.
Manufacturer: McDonnell Aircraft Company.
Type: Single-seat all-weather fighter.
Year: I 974.
Engine: Two 10,637kg (23,4501b) Pratt & Whitney F 100-220 turbofans.
Wingspan: 13.05m (42ft 10in).
Length: 19.45m (63ft 10in).
Height: 5.68m (18ft 7in).
Weight: 30,845kg (68,000lb).
Maximum speed: 2660km/h (1650mph).
Ceiling: 18,300m (60,000ft).
Range: 5745km (3570 miles) (with Fast packs).
Armament: One 20mm M6 I cannon, four AIM-7
Sparrows and four AIM-9 Sidewinder air-to-air missiles, plus centreline pylon stressed for 2313kg (5100 lb): total capacity with Fast pack conformal tanks 10,705kg , (23,600 lb) of weapons.