NASA's LFAX ( Langley Fighter/Attack Experimental) designs - the real story?

hesham

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Hi,

the LFAX-8 with strut-braced wing.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19780008057_1978008057.pdf
 

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overscan (PaulMM)

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NASA histories claim that NASA's VFAX-4 (VG) and VFAX-8 (fixed wing) were major influences on the F-14 and F-15. Is this supported by evidence? The timing is tight - LFAX studies start in 1968.

Nasa claims:

The LFAX-4 and LFAX-8 embodied features that would subsequently be evident in the McDonnell Douglas F-15 and Northrop Grumman F-14 aircraft. The LFAX-8 design made an indelible impression on the McDonnell Douglas design team, which embraced the fundamental layout of the NASA configuration. The cranked-wing design of the LFAX-8 had to be modified by McDonnell Douglas as the requirements for transonic maneuvering became more important. Another modification to the LFAX-8 involved the installation of a larger radar dish in the nose than the NASA team had allowed for in their design. The installation required a larger diameter nose cone, and although the NASA researchers deplored the increased supersonic drag caused by the larger nose, the final design incorporated the larger dish.

The earliest LFAX model I've found is this 1968 LFAX-4 model which is clearly an F-111 with the rear fuselage butchered. The "big concept" of LFAX seems to be the rear fuselage with twin tails on booms with ventral fins.

http://crgis.ndc.nasa.gov/historic/20-Foot_Spin_Tunnel_(645)_Models_and_Tests_A-M#Langley_Fighter_Study
 

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overscan (PaulMM)

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1970, we have this developed LFAX-4 design. But the F-14 flew in 1970.
 

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overscan (PaulMM)

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LFAX-8 from a 1972 test.


I guess these models might all come from 1968, we just don't have photos from that time, only from subsequent tests reusing the models.
 

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hesham

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Hi,


I can't ID this fighter aircraft,the report said it was a development of vectored thrust nozzles,
and the study done by NASA and Boeing,but was that aircraft MD F-15 or a Boeing design ?.


http://arc.aiaa.org/doi/abs/10.2514/3.58715
 

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Mark Nankivil

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NASA is taking credit, or wanting to share it at the least, and doesn't deserve it. The F-15 configuration was frozen in '68 and after that, fine tuning was the order of the day. Talking to a McAir engineer who was heavily involved with the F-15 development, NASA was NOT a major player in fostering the design. They were used later for some work and as a baseline for fine tuning of the design. As you can see in the attachment, NASA's design work left something to be desired on the drag front....

Enjoy the Day! Mark
 

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overscan (PaulMM)

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Here's original NASA photos.


http://crgis.ndc.nasa.gov/historic/Test_249:_LFAX-4
 

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overscan (PaulMM)

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National Aeronautics and Space Administration has briefed the Air Force on its technical recommendations for USAF’s proposed FX advanced tactical fighter. The NASA configuration would employ a variable-geometry wing with a transonic air foil (AW&ST July 24, p. 25) and twin tail booms and would have a high-lift capability at altitude.

Aviation Week & Space Technology 20 November 1967
 

Dynoman

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LAX-10 AKA Foxbat Langely wind tunnel study
 

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