In the early 1980s, air forces and manufacturers in Europe wanted a new fighter. Several studies, including the Agile Combat Aircraft, envisioned the aircraft as a canard delta design, specialising in air superiority. Collaboration between all the major nations seemed possible, but France split off on its own, to work on the ACX. France was now arch-rivals with its previous partners and leapt into the lead when its Rafale-A technology demonstrator flew on 4th July 1986, Britain soon fired back with the EAP.
The EAP first flew on 8th August 1986. The aircraft was built as a technology demonstrator for what would become the Eurofighter Typhoon. Though there was a small element of international collaboration in the EAP, it was essentially British, and as such was the last ever supersonic British aircraft. Its performance was very impressive, as one test pilot noted, “It goes like a ferret with a firework up its bum!”.
Hush-Kit interviewed EAP test pilot Dave Eagles to get the inside story.
What were you first impressions of flying EAP?
“First, delight at finally getting the aircraft into the air. We had had 3 days or so of delay due to gloomy weather. But then happiness with the control feel, — the response and harmonisation and the marked attitude stability — and the cockpit view.”
What was the best thing about flying EAP?
“The best thing was the realisation that, in spite of all the political odds, we had succeeded in producing this state of the art aircraft, in very short time from eventual order, and that it obviously had the makings of a superb fighter. See above on response and attitude stability.”
What was the worst thing about flying EAP?
“There was nothing about the aircraft that was disappointing. There were a couple of minor gripes involving nuisance warnings. When looking at individual engine handling – to confirm that there was no interference between engines due to that initially common intake – the system produced gear box drive warnings as one or other of the engines dropped away from driving the gear box. But this was explainable. Another nuisance warning was a fuel pump warning that came on as attitude was increased during a slow down; and throttle friction was found to be too low. All of these minor points were quickly fixed.”
Typhoon has enjoyed an unprecedented safety record for a fighter, why do you think this is?
“I am not privy to current RAF ops, but I would add that reliability levels of components and systems on Typhoon was for the first time, part of the specification (this was also partly the case on Tornado ). As well, Typhoon design was subjected to much higher levels of system safety scrutiny than previous programmes.”
Do you have a favourite aircraft and if so, why?
“It would have to be Tornado, because I spent so much of my career being deeply involved with it. But for sheer joy I must say that flying the Sea Fury with the Royal Australian Navy comes close.” Do you have a least favourite aircraft and if so, why?
“No. All pilots are in love with the aircraft they are currently flying. Even the Buccaneer Mk.1, which relied on the curvature of the earth to get airborne, was, at the time I flew it, delightful.”
The most repeated quote about EAP is that ‘it went like a ferret with a firework up its bum’, which is attributed to an ‘EAP test pilot’. Do you know the origin of this quote and would you agree with it?
“I don’t know where the ferret quote came from; I hadn’t heard it before. But I certainly agree with it! The EAP of course was quite light (17,000kg), and 2 x Mk 104 RB 199s gave it an impressive push. I see that in my report of the first take-off I described the acceleration as “brisk”! The Typhoon of course has the more powerful EJ200 and basically isn’t that much heavier. So I guess that is ‘very brisk’ ”
Which modern aircraft would you most like to fly and why?
“I would very much like to fly the Typhoon, to see how it eventually turned out. I would love to fly a Tornado again, purely to feed nostalgia and one aircraft I have always longed to fly is the SR-71. An American friend of mine who flew them with NASA said, “You ain’t never been lost ’til you’ve been lost at Mach 3!”
How important was EAP for the development of EFA/Typhoon?
“The research work done on EAP was enormously important to Eurofighter in developing Typhoon, in spite of the change in wing planform, which I believe was made in the interests of productionising.”
Did the actual EAP aircraft have a nickname, what did people on the project refer to it as?
“Not that I’m aware of. But I was pleased that it’s first few flights were made with ‘FLY NAVY’ stickers just behind the cockpit!”
Typhoon’s handling characteristics and cockpit receive a lot of praise, do you feel a sense of pride knowing that you directly contributed to this?
“Yes- I feel a great sense of pride in knowing I was involved in the build up to Typhoon, but I have to say that a very great deal of the handling characteristic tuning was done by test pilots like Pete Orme and Chris Yeo after I left Warton. The cockpit, too, was of course much changed in layout as Typhoon’s complicated weapon system was added, but I will claim some involvement. I make a much stronger claim to the Tornado cockpit design “.
Hush-Kit would like to express its thanks to Dave Eagles.
EAP: A photo-journal
Want to see more stories like this: Follow my vapour trail on Twitter: @Hush_kit
Thank you for reading Hush-Kit. Our site is absolutely free and we have no advertisements. If you’ve enjoyed an article you can donate here. At the moment our contributors do not receive any payment but we’re hoping to reward them for their fascinating stories in the future.
Have a look at 10 worst British military aircraft, Su-35 versus Typhoon, 10 Best fighters of World War II , top WVR and BVR fighters of today, an interview with a Super Hornet pilot and a Pacifist’s Guide to Warplanes. Was the Spitfire overrated? Want something more bizarre? The Top Ten fictional aircraft is a fascinating read, as is The Strange Story and The Planet Satellite. The Fashion Versus Aircraft Camo is also a real cracker. Those interested in the Cold Way should read A pilot’s guide to flying and fighting in the Lightning. Those feeling less belligerent may enjoy A pilot’s farewell to the Airbus A340. Looking for something more humorous? Have a look at this F-35 satire and ‘Werner Herzog’s Guide to pusher bi-planes or the Ten most boring aircraft. In the mood for something more offensive? Try the NSFW 10 best looking American airplanes, or the same but for Canadians.
The new European aircraft would choose the best features of the US teen fighters, improve them and add the canard delta arrangement. Both the ACA and the French ACX were originally schemed with compound-sweep wings. The advantages of a compound sweep were described by Ray Whitford:
“The high degree of inboard sweep promotes strong vortex formation at high AOA, and low wave drag at supersonic speed. The lower sweep of the outboard panels maximise manoeuvrability by lowering the span loading to reduce the induced drag which has been the drawback of simple deltas. Both projects (ACA and ACX) were designed with automatic leading-edge slats, those on the outboard panels being particularly powerful as a result of the lower sweep.”
EAP was built using carbon fibre composites and aluminium lithium alloy. The advanced construction techniques and materials kept the aircraft light and strong. The canopy is noticeably heavier in its use of framing, compared to the F-16 and F/A-18.
EAP enjoyed a shabazz public roll-out. BAe was keen to see show the aircraft off, partly as the rival Rafale-A was not only revealed earlier, but appeared to be closer to a production aircraft than the EAP.
EAP blasts off under the power of two Turbo-Union RB199 Mk 104D. As anyone who has ever flown a Tornado ADV above 30,000 ft will testify, the ‘199, with its high bypass ratio, is far from being a decent fighter engine.
One of the technologies Europe the EAP inherited from the late teen fighters was the glass MFD (multi-functional displays) cockpit. The cockpit was clearly heavily influenced by the F/A-18 Hornet, which had entered service in 1983. Europe’s first ‘modern’ fighter cockpit came when the Rafale entered service in 2000. Prior to this both the British Sea Harrier FA.2 and French Mirage 2000-5 had received MFDs. The wide angle HUD had first been seen on the F-16, which entered service in 1978. One genuine innovation was voice control, known as DVI (Direct Voice Input) which came with the Eurofighter Typhoon, and was first used operationally in 2005. Though a similar system was tested on the US F-16AFTI, the F-35 will be the first US fighter with DVI to enter service. The Hands On Throttle-And-Stick (HOTAS) configuration was seen in proto form on the English Electric Lightning, but was first seen in its modern form on the F-16. Unlike the F-16 the stick was centre-mounted on EAP, the relative merits of side- versus central-stick remain a matter of opinion.
The EAP was fitted with a modified Tornado fin, for the sake of cost and risk reduction. The gun muzzle position is different to Typhoon’s, which is in the wing-root.
EAP was designed without considerations of RCS-reduction. In 1986, stealth was still a highly classified area. Germany had built a stealth demonstrator, the MBB Lampyridae in 1980, but this was quickly hushed up and canned, when the US, world leaders in stealth got wind of it.
Though advanced in aerodynamics and materials, EAP was clearly behind the technology curve of the Advanced Tactical Fighter concepts being explored by US fighter companies of the time. EAP emphasised agility at high speeds, good man-machine interface and high combat persistence to excel in beyond-visual range and close-in combat. It was intended to outfight the emerging threat of ‘Flanker’s and ‘Fulcrum’s. Despite Eurofighter’s claims that it was designed from the outset as a multi-role fighter, ground attack was very much a secondary consideration. Some early artworks of EFA showed it armed with BL775 cluster bombs, a weapon that was banned before Typhoon entered service. The Typhoon was first used in anger in the air-to-ground role, in Libya in 2011.
There is surprisingly little footage of EAP online, but some scouting around revealed this:
The boxy intake of EAP gave way to the ‘smiling’ curved intake of Typhoon. Dummy ASRAAMS are carried.
Thanks to Nick Stroud from The Aviation Historian.