Evolution of the Eurofighter Typhoon: TKF-90, AST 396, AST.403 and more

uk 75 · 21 April 2020

On the BAe P103 given that the Bell XF109 and VJ101C had shown the risks of this tilt engine approach why did BAe think it was workable?

shedofdread · 21 April 2020

uk 75 said:
On the BAe P103 given that the Bell XF109 and VJ101C had shiwn the risks of this tilt engine approach why did BAe think it was workable?

IIRC, they weren't using it to achieve VTOL but more an extreme STOL so *maybe* some of the issues wouldn't be as extreme. Not really sure why but the P.103 has always appealed to me. Maybe I just like a challenge......

Bies · 7 August 2020

What was the reason behind resignation from double vertical stabilizers in Eurofighter?

Many EF prototypes had double stabilizers. And final EF has somewhat restricted high AoA regime due to having single vertical stab.
Plus canted stabs will give smaller radar reflection from the side.

It was due to financial reasons or there was some aerodynamics behind this decision?

overscan (PaulMM) · 7 August 2020

This decision was first explored on the ACA / EAP.

Warton (BAE) did extensive trade studies on one versus two tails in 1982 and felt the performance benefit to the ACA configuration was minimal and outweighed by additional weight and compexity. High alpha capability was an MBB obsession and not a major concern for BAE or the RAF.

For EAP the initial plan was MBB doing centre fuselage and vertical tails, and AIT the rear fuselage, but then BAE had to take these over when the other partner nations cut funding and went with largely Tornado rear fuselage including a single Tornado fin. It worked well enough on EAP.

When EFA design was finalised, two versus one tails was re-examined again, but the same conclusion was reached as before. For the given requirements, low drag and weight and adequate stability was the right solution.

F-2 · 7 February 2021

Hey! I don’t know if anyone knows, but I’m really interested in the 1986 farnborough mock up. It seems close to the final design, anyone know how it differs, does anyone have a three view? I’ve heard it might have been the P.120 but I’m not sure that’s the case. Since the EAP only first flew a month before and provided vital test data I assume it must have been revised in someway, but how?

F-2 · 9 February 2021

View: https://m.youtube.com/watch?v=SqOu0JuH_-g

View: https://m.youtube.com/watch?v=4oE2pc4hi-I&t=2107s

Some video of the 1986 mock up

The timing seems very odd generally from what I’ve seen is that you have a mock up either when your about to cut metal or about to sell someone on a configuration. Generally it’s three years or so from mock up to final. Yet I don’t think physical work on the eurofighter started till 1989, prototype done in early 1992 and almost two years before the first fight (which is also kinda odd) 1986-1989 seems like kind of a black hole.

also a web archive of an old article that had a dead link https://web.archive.org/web/2014052...ch='Bae P 120'&scrollbar=0&page=1&view=FitH,0

overscan (PaulMM) · 10 February 2021

F-2 said:
View: https://m.youtube.com/watch?v=SqOu0JuH_-g

View: https://m.youtube.com/watch?v=4oE2pc4hi-I&t=2107s

Some video of the 1986 mock up

The timing seems very odd generally from what I’ve seen is that you have a mock up either when your about to cut metal or about to sell someone on a configuration. Generally it’s three years or so from mock up to final. Yet I don’t think physical work on the eurofighter started till 1989, prototype done in early 1992 and almost two years before the first fight (which is also kinda odd) 1986-1989 seems like kind of a black hole.

also a web archive of an old article that had a dead link https://web.archive.org/web/20140520093941if_/http://www.flightglobal.com/FlightPDFArchive/1985/1985 - 1541.PDF#navpanes=0&search='Bae P 120'&scrollbar=0&page=1&view=FitH,0

I'm not really understanding your argument.

Mockups are made for various reasons at various times. Sometimes they are highly classified at the time, and presented only to the customer Air Force and never displayed in public. The EFA mockup in 1986 was a sales tool. EFA was going in circles, BAE in particular were trying to get something going. EFA mockup in 1986 showed roughly the then-current EFA config - I have an official drawing from May 1986 which exactly corresponds with this painting:

Its a stepping stone between EAP (originally "Experimental Aircraft for the Agile Combat Aircraft") and the later EFA configuration with "smiling" intake. It wasn't until contract award in November 1988 that any serious work started happening.

Archibald · 10 February 2021

High alpha capability was an MBB obsession

... and they certainly went to the deep end of it with X-31 - itself based on a rejected EFA design.

hesham · 11 September 2021

I don't remember the source.

F-2 · 13 October 2021

[edited - no links to Key Publishing publications except official website please - Admin]

boxkite · 23 November 2021

(Probably) an MBB design with a different canard layout than this one in # 105.

Source: Luftfahrtforschung in Deutschland (Die deutsche Luftfahrt, volume 30) by Hirschel/Prem/Madelung
ISBN 3-7637-6123-3

F-2 · 17 January 2022

The P.110 Project (Hansard, 29 June 1982)

api.parliament.uk

So parliamentary discussion on the p.110 in 1982 it talks about the design goals in some general terms. It seems though it was conceived to be equal or better then contemporary designs.

hesham · 18 April 2022

From Aviation magazine 1977,

is this Model belong to this topic?

Apophenia · 18 April 2022

hesham said:
is this Model belong to this topic?

Definitely an AST 403 connection.

Perhaps an MBB modular model from the high AOA wind tunnel tests? Paul post #105 shows a similar-looking model (albeit assembled with twin fins). Oddly, the model in your clippings looks very much like the BAe P.96.

F-2 · 4 August 2022

P.110 and TKF-90 where merged into the ACA when they decided on a collaboration, but why was the ACA configuration abandoned in favor of the EFA? I know the partnership between nations fell apart but when they got back together what prompted them to change course?

red admiral · 4 August 2022

Wing planform was because single sweep was less complex, lower risk

Fin was because EAP had to re-use Tornado aft fuselage on cost grounds, and it turned out that the single fin was adequate,

F-2 · 4 August 2022

red admiral said:
Wing planform was because single sweep was less complex, lower risk

Fin was because EAP had to re-use Tornado aft fuselage on cost grounds, and it turned out that the single fin was adequate,

So it just evolved it wasn’t a total redesign?

overscan (PaulMM) · 4 August 2022

red admiral said:
Wing planform was because single sweep was less complex, lower risk

Fin was because EAP had to re-use Tornado aft fuselage on cost grounds, and it turned out that the single fin was adequate,

I thought the cranked wing was better for subsonic agility but worse supersonically as well.

Typhoon went for transonic and supersonic capability rather than optimising the airframe for low speed / high AOA. A single fin gave adequate stability to 30 deg AOA and was lighter.

red admiral · 4 August 2022

F-2 said:
So it just evolved it wasn’t a total redesign?

I'd definitely represent it this way. Evolution on several fronts e.g. airframe, engines, avionics across multiple projects. ACA to EFA was pretty small changes to the airframe element

red admiral · 4 August 2022

overscan (PaulMM) said:
I thought the cranked wing was better for subsonic agility but worse supersonically as well.

Typhoon went for transonic and supersonic capability rather than optimising the airframe for low speed / high AOA. A single fin gave adequate stability to 30 deg AOA and was lighter.

There's always multiple trade offs; I was trying to describe what I believe were the key reasons from what I know and what people involved have described.

There's also a difference between what was predicted to be better at the time, and how it turned out in practice. I'm pretty sure some different decisions would have been made with hindsight based on what was found in trials / operations.

Should have had leading edge vortex flaps instead of the slats

hesham · 19 October 2022

From Aviation magazine 1979.

Mike Pryce · 19 October 2022

red admiral said:
overscan (PaulMM) said:

I thought the cranked wing was better for subsonic agility but worse supersonically as well.

Typhoon went for transonic and supersonic capability rather than optimising the airframe for low speed / high AOA. A single fin gave adequate stability to 30 deg AOA and was lighter.

Click to expand...

There's always multiple trade offs; I was trying to describe what I believe were the key reasons from what I know and what people involved have described.

There's also a difference between what was predicted to be better at the time, and how it turned out in practice. I'm pretty sure some different decisions would have been made with hindsight based on what was found in trials / operations.

Should have had leading edge vortex flaps instead of the slats

More vortex flaps!

Sat with Typhoon design team at Warton many moons ago I asked about the cranked wing. The RAE at Farnborough objected on the basis that 'it stalls twice'.

hesham · 21 October 2022

From Aviation magazine 1980.

hesham · 22 October 2022

From Aviation magazine 1981.

Voltzz · 24 December 2022

On the occasion of the Paris Air Show 79, Dornier presented its thoughts on the TKF 90 to a wider public for the first time. Our drawing above shows the basic design as proposed by Dornier for the tactical fighter 90. Key features of this design include:
- Conventional design
- Derivation of an existing engine, adapted to the required thrust class, performance, fuel consumption, operating characteristics and costs
- CCV to improve the glide ratio even during maneuvering
- Extensive use of carbon fiber composite construction to reduce structural weight
- Digital avionics with high mission flexibility
- Multi-purpose display units to reduce pilot workload
- Modern precision and scattering weapons
- Procedures for accurate weapon delivery even from greater distances (stand-off)
As an extension of the capabilities of the basic design, Dornier is currently studying various equipment options. As an example, the combined night vision system of FLIR and radar information for air-to-ground operations shown in our following figure, in which the high resolution capability of a thermal imager at close range is processed with the range information of the radar to produce a plastic-looking image of the overflown terrain or of the target. The TKF 90, which is to replace the F-4 Phantom fighters in our neighboring country to the north in the 1990s, is intended for air-to-air and air-to-ground roles with highly effective armament and appropriate mission flexibility. Its full development and series production are likely to be realized within the framework of a multinational program (similar to the "Tornado" and "Alpha Jet" projects). Corresponding negotiations are currently underway or planned with Great Britain and France.

Source

TsrJoe · 24 December 2022

Interesting, that 1979 TKF.90 proposal is reminiscent of the Hawker Siddeley HS.1207 / BAe. P.158 (itself based upon the Northrop F-17 Cobra)

Voltzz · 2 January 2023

overscan (PaulMM) said:
From 1991 AGARD CP 497

Interesting to see the Northropesque Diamond wing design.

i found a Dornier Post article (in german) on the 'Pitch Thrust Vector-/ Reverse Devices' mentioned in that graphic for the Diamond Wing.
Do-Post_85-2

hesham · 14 January 2023

MANTUS said:
AIT-320

In the first half of the '70s, Aeritalia (born November 12, 1969 by the merger of Fiat Aviation, Aerfer and Salmoiraghi) continued to evaluate various preliminary plans to replace the G 91R. The AIT 311 had a configuration quite similar to the AMX future, but powered by two General Electric J85, the same as the G 91Y. The compact AIT 315, powered by a General Electric TF34 turbofan, had two guns in the dorsal position. The most ambitious AIT 320, supersonic wing media would have to mount a Pratt & Whitney F404 or a Turbo-Union RB.199. (Archive Aeromedia) In the first half of the 1970s, Aeritalia (formed on November 12, 1969 by the merger of Fiat Aviation, Aerfer and Salmoiraghi) continued to evaluate a number of preliminary projects for an aircraft intended as a replacement for the IAF G 91R. AIT had an AMX-311 like general configuration, powered by two General Electric J85, the same engine unit as the G 91Y. The compact AIT 315, powered by one General Electric TF34 turbofan, was fitted with a pair of cannons in the dorsal position. The more ambitious AIT 320, a mid-winged supersonic aircraft, was powered by either Pratt & Whitney F404 or Turbo-Union RB.199. (Archive Aeromedia)

Click to expand...

Source:

http://www.aeromedia.it/lb2916.html

From Aviation magazine 1986,

the AIT-315.

hesham · 15 January 2023

From Aviation magazine 1986.

hesham · 16 January 2023

From Aviation magazine 1987.

F-2 · 24 January 2023

There are a large number of documents in the British national archives on the P.110 and EAP in the UK National Archives. I tried to get a copy of the top one over the summer but it was large enough to cost I think a little more than 200 USD. Is anyone interested in any of these, possibly get a pot going?

Controller of Aircraft: proposed advanced combat fighter, P110

Controller of Aircraft: proposed advanced combat fighter, P110 | The National Archives

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