The BAe EAP ZF534 seen in the static display at the 1986 Farnborough Air Show.
The Experimental Aircraft Programme (EAP) brought together critical technologies and capabilities ahead of the EFA (later Eurofighter Typhoon) programme.
The EAP programme originated in 1982, and represented a risk reduction activity between the Agile Combat Aircraft (ACA) study conducted by British Aerospace (BAe), West Germany's Messerschmitt-Bölkow-Blohm (MBB) and Italian aircraft company Aeritalia and the product definition of the four-nation (UK, Germany, Italy and Spain) EFA programme.
The contract for EAP was signed on 26th May 1983, to be jointly funded by the MoD and Industry.
The BAe EAP ZF534 takes off at the start of its display at Farnborough 1986.
EAP was intended to demonstrate active, full-authority digital fly-by-wire controls, a significantly unstable (by 15% of mean chord) canard delta configuration. It would feature new manufacturing materials and methods (including carbon fibre composites, aluminium lithium alloys and super-plastically formed diffusion-bonded Titanium) and advanced digital electronic systems, including a glass cockpit with a wide field-of-view head-up display (HUD).
The flight control system, which was derived from that flown on the active control SEPECAT Jaguar (XX765), emphasised carefree ‘hands on throttle and stick’ handling with a high angle of attack , manoeuvrability and a departure prevention system.
An additional programme emphasis was placed on the ability to design and manufacture primary structures in advanced materials, using processes having a clear path to a full production capability.
Many companies in the supply chain (from the UK, Germany and Italy) contributed to the programme.
To reduce risk to the programme schedule, the EAP was powered by two Rolls-Royce RB199 Mk104D engines (the standard Panavia Tornado F.3 engine – less its thrust reverser) and was fitted with a modified Panavia Tornado fin.
As it was an experimental and technology demonstration aircraft, no weapons or military equipment was fitted, although dummy weapons were carried in a low-drag position.
An air-to-air photograph of the BAe EAP conducting trials in July 1988.
The programme ran to a tight schedule from the contract signature in Spring 1983, to the roll-out in April 1986, and the first flight of the only EAP aircraft (ZF534) on 8th August 1986. Impressively, this first flight lasted 67-minutes and included supersonic flight at Mach 1.1 and at altitudes up to 30,000 ft.
The aircraft flew nine further flights during its first week of operation and continued supporting the EFA / Typhoon programme with a series of test campaigns up until the beginning of May 1991. These test campaigns, in addition to the original EAP aims, provided data to validate load prediction modelling for the Typhoon / EFA programme.
The BAe EAP gave a spirited display of its carefree handling at the 1986 Farnborough Air Show.
When withdrawn from service, the EAP aircraft had completed 259 test sorties, totalling some 195 flying hours, during which it had exceeded Mach 2 and had flown at angles of attack of over 35 degrees.
The aircraft is now on permanent display at Royal Air Force Museum, Cosford.
Number built
One aircraft (ZF534)
Specification
| Powerplant | Two Turbo-Union RB.199-104D engines of 17,000 lb thrust with afterburner |
| Span | 38 ft 7.4 in |
| Maximum Weight | 32,000 lb |
| Capacity | Pilot only with carriage of dummy weapons |
| Maximum Speed | In excess of Mach 2.0 |
Survivors
| EAP (ZF534) | RAF Museum, Cosford www.rafmuseum.org.uk/cosford |
