General Dynamics FX designs (Alternatives to the F-15)

[overscan (PaulMM)]

General Dynamics FX


[Edited - better scans posted below - Admin]

 

[overscan (PaulMM)]

http://bobcunningham.org/


Extremely small scans, I have tried to scale up enough to see something.

 

[overscan (PaulMM)]

Here is the General Dynamics VG & fixed wing FX designs in full glory (via Mark Nankivil).

 

[Stargazer]

Fabulous. Thanks Mark and Paul!

 

[codeone]

Those are from Bob Cunningham's last book. I'll see if I can dig up the original files--and drawings.

 

[overscan (PaulMM)]

Anyone have a copy of On Falcon Wings: The F-16 Story by Lindsay Peacock?

It has a picture of the General Dynamics FX design, can someone confirm if its one of the above pics or not?

 

[RAP]

Yes, the first 3 pics are in the book and described as GD Advanced Day Fighter (ADF) designs which lead to the FX competetion that was won by the F-15 (page 8).

 

[chuck4]

What are the benefits of a shock cone vs shock ramp intake design?

 

[Sundog]

What are the benefits of a shock cone vs shock ramp intake design?

Shock cones tend to be more efficient and lighter weight IIRC. However, the 2D ramps are better at high alpha than shock cones. Part of the disparity you see there, IIRC, is the early FX had more leanings towards an Interceptor with fighter abilities, rather then a pure fighter with interceptor abilities. In the early to mid 60's swing wings were in vogue. However, reportedly the FX changed as a result of Boyd's EM work and apparently the USAF was worried that if their fighter was too much like the F-14 they would be forced to merge the programs and end up with another Navy fighter and all of the attendant drawbacks that brings with it for a land based aircraft.

There is a really good report, I think linked earlier in this thread, on the history of the FX program. I've not had time to read it, just to glance through it, but I highly recommend you download it and read it. I plan to read it during vacation in a few months.

 

[circle-5]

What is known: this model came from General Dynamics Fort Worth.
What is speculative: this might be an FX study.

Any additional info is welcomed (3-views, renderings, photographs of the actual airplane in flight, etc.)

Thank you.

 

[overscan (PaulMM)]

What is known: this model came from General Dynamics Fort Worth.
What is speculative: this might be an FX study.

Any additional info is welcomed (3-views, renderings, photographs of the actual airplane in flight, etc.)

Thank you.

It seems to be identical to the General Dynamics Tailormate study "B3" configuration as noted in my F-16 Evolution article (page 4). That doesn't preclude it also being the final fixed wing FX design as well, in fact I think it is rather probable that it was.

https://www.secretprojects.co.uk/forum/F-16%20SPF%20Study.pdf

 

[hesham]

Nice find my dear Circle-5.

 

[circle-5]

It seems to be identical to the General Dynamics Tailormate study "B3" configuration as noted in my F-16 Evolution article (page 4). That doesn't preclude it also being the final fixed wing FX design as well, in fact I think it is rather probable that it was.

https://www.secretprojects.co.uk/forum/F-16%20SPF%20Study.pdf

Thank you Overscan –

I love your F-16 report. Just didn't think of looking at LWF material for FX data. As always, you nailed it.

These airplane models always look a lot better to me, when I can put them in their proper historical context. Now I need to find a model of the earlier GD FX study with VG.

 

[dan_inbox]

You see nothing on the right............

Allyson, Can you please tell us more about this MacAir 260 and her companion?
Please please please?

 

[allysonca]

I obtained a full set of the MacAir 260's that had posted on the forum a long time ago. The set I had was a Transport, Transport with AWACS dome, a make it build any version set, an attack, all weather, and the 3 engine that was adapatable. I sold the entire collection and miss these the most.....

As to the Northrop AX, had this in 3 different versions in 40th scale and one 10th scale. will look for the pictures.... I have a blank I am restoring and will post as soon as it is finished. It's down the list after a shelf decided it did not want to be supportive.

 

[overscan (PaulMM)]

Back to topic.

General Dynamics had not been funded to participate in the earliest concept exploration studies for Advanced Tactical Fighter / FX in 1965 and 1966, but in 1967 they won a contract for concept formulation studies alongside McDonnell-Douglas. While the air force was then still looking for a large, very complex, probably variable geometry fighter in the 60,000lb thrust class, as part of this contract General Dynamics worked on many variants including fixed-wing, variable geometry, single-engine and twin-engine, heavy and lightweight concepts. All the designs built on ideas already explored in the earlier 1965 ADF studies by Hillaker, most notably the blended fuselage tapering into a blunt edged leading-edge extension, mid wing and large bubble canopy, while the serious intake boundary layer issues encountered on the F-111 intakes might explain the unusual use of underslung axisymmetric engine pods on the General Dynamics’ large variable geometry design.

General Dynamics submitted their FX-132 design for the F-X contract definition phase in 1968 but they were unsuccessful, placing last of the four submissions. Former General Dynamics’ Control Systems Engineer Carl Droste said “many believed it to be the worst configuration we ever designed”, with variable geometry wings, podded engines, complicated cambered fuselage surfaces, hard core structure built inside the outer skin, and limited room for weapons. According to John H Watson, “General Dynamics had four FX designs going into the RFP time frame. They picked the wrong design and the wrong presenter. Also, it wasn’t their time to win a major program”. In fact, FX proved a humiliating third failure for General Dynamics following VFX (lost to Grumman, F-14) and AMSA (lost to Rockwell, B-1), which was partly why they subsequently went so hard on LWF.

Harry Hillaker was given the task of selling General Dynamics VG FX design to the Air Force (presumably, the “wrong presenter”?) and after failing to gain a contract was rather despondent, and was on the verge of quitting General Dynamics. He hadn’t believed in VG for the FX requirement, and had preferred the fixed-wing, lighter weight design, but having oversold VG on the F-111 the company felt a fixed wing FX design would reflect badly on the then-production F-111.

Out of the ashes of the FX debacle however emerged the F-16, via the FX-404, Model 401 design evolution.

 

[ExConfig]

I realize this is an old thread but I just found it. So if anyone is still here... At one time I worked in GD Advanced Design and have two FX models in 1/20 scale. One is a half model of a side inlet, twin tail F-16ish configuration. The other is a full model on stand of FX-121, the VG config shown above. The model's wings swing and are geared together.

 

[overscan (PaulMM)]

That's awesome! thanks for the information. I previously guessed this one was the final FX-132 config? Is this the FX-121?

 

[ExConfig]

I stand corrected! If I'd bothered to look for more than a few seconds I would have seen the differences. My model is marked FX-121 (with another character at the end that's mostly gone and unreadable), but differs obviously from the -132 artwork.

FX-121 has verticals that are not canted, an apparently longer wing (wing tip roughly in line with and parallel to the stab tip, when fully swept), no top-view curvature to the max-half-breadth in the forward fuselage, and the aft part of the nacelles would be visible between the stabilizer and vertical in the same view as your art.

I've looked for info on these models for years but have never found anything until now. This program was before my time, which was the late 80s. In my excitement I posted hastily. Sorry!!

 

[overscan (PaulMM)]

No worries! If you are able to post some smartphone / digital camera photos of the models I am sure lots of members here would be greatly interested in seeing the FX-121 and the other model.

There's some crossover with this topic on LWF:

https://www.secretprojects.co.uk/threads/adf-to-lwf-evolution-of-the-general-dynamics-f-16.1335/

 

[overscan (PaulMM)]

Related topics:

1965 - 1969 FX Competition (F-15 alternatives)
Fairchild FX fighter project (rival to the McDonnell-Douglas F-15)
North American Rockwell NA-335 fighter project (to USAF FX requirement)
McDonnell-Douglas Model 199 FX - design and development of the F-15
Lockheed FX / Tactical Fighter Designs (Alternatives to the F-15)
General Dynamics VG fighter from Allyson Vought collection

 

[overscan (PaulMM)]

{crosspost from General Dynamics VG fighter from Allyson Vought collection)

This is an unidentified VG General Dynamics design possibly FX related. Very similar to FX-132 in wing and tail, but different intakes.

 

[overscan (PaulMM)]

So - I have a correction to make. FX-132 may not be the VG design at all but rather a fixed wing one. From a famous report in the early design history of the F-16 comes this comparision drawing:



The context in which FX-132 was mentioned previously was that it was the final FX design. I assumed that meant it was the final VG submission. It might be that the "FX-132 with fixed wing" reference here means FX-132 (final FX design) was tested with both VG and fixed wings.