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

[Grey Havoc]

Reverse polish notation. That brings back a few memories.

 

[uk 75]

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]

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]

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)]

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]

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]

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)]

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]

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.