General Dynamics/Rockwell International F-16AF Agile Falcon

Started by CammNut, December 31, 2017, 02:08:11 PM

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CammNut

Mightily pleased with itself for having developed the premier lightweight fighter in the shape of the F-16, the US started having second thoughts when it saw the high-alpha high jinks of the Soviets' supermaneuverable Su-27.

The F-16 had what the US Air Force thought it wanted - low wing loading and high thrust-to-weight ratio for maneuverability - but the USAF became worried the Flanker in close-in combat would simply out-turn the F-16.

Where the F-16's angle of attack ("alpha") was deliberately limited by its fly-by-wire control system to prevent accidental departure from controlled flight in a dogfight, the Su-27 pilot could pull through wing stall to essentially stop and turn aircraft, defeating any missile or gun attack.

When it realized what the Flanker could do, the USAF sent General Dynamics back to the drawing board to produce a fighter that could outmaneuver the Soviet's best in a close-in fight.

GD approached Rockwell International, which had built the Highly Maneuverable Aircraft Technology (HiMAT) remotely piloted research vehicle for NASA. With the F-16A fuselage as the starting point, the team added the HiMAT's close-coupled canard configuration with its aeroelastically tailored wing. The result of the collaboration was the F-16AF Agile Falcon.

In the HiMAT configuration, the foreplane was always in clean air, providing the control power needed to freely move the aircraft into and out of post-stall flight. Powerful vortices shed by the foreplane interacted with airflow over the wing to prevent it turning towards the tips. This delayed stall. The wingtip fins remained in clean air to high alpha, providing directional stability.

The layers of carbon fiber in the laminated composite wing skins were aligned so as to make the wing twist leading-edge down as aerodynamic loads increased with angle of attack. This also delayed the stall, allowing the pilot to pull to higher nose-up angles when tracking at target. The result was instantaneous and sustained turn rates that allowed the F-16AF to outmaneuver the Su-27.         

by TheWoracle, on Flickr

This model has been more than 20 years in the making. Its origins are lost in the mists of time. I know the basis is a 1/72 Matchbox F-16A fuselage. And I think the wing and foreplane started out as the wing and tailplane of a Monogram box-scale A-5A Vigilante.

by TheWoracle, on Flickr

Through all the years that I did not do any modeling, I would still take this one out from time to time to do a little more fettling, putting and sanding. The wingtip surfaces were broken off, lost and replaced so many times, I no longer remember where they came from.

by TheWoracle, on Flickr

This model has a strong connection to my day job, as one of the first trips I did after changing careers from apprentice aircraft designer to apprentice aviation journalist, was to visit Rockwell International in El Segundo, California, early in 1980.

by TheWoracle, on Flickr

There I sat in a conference room in a small corner of what had once been a mighty North American Aviation plant, but had been since sold to Northrop, and I was briefed by Rockwell on HiMAT to the sound of Northrop mechanics riveting F-18 aft fuselages together.

by TheWoracle, on Flickr

The subscale HiMAT was designed to be a modular research aircraft, and there were grand plans to fly the aircraft with a forward-swept wing and two-dimensional thrust vectoring - but none of those materialized. The HiMAT flew in 1979 in the configuration modeled here.

by TheWoracle, on Flickr
by TheWoracle, on Flickr

HiMAT was the last aircraft Rockwell built before being acquired by Boeing. Somewhere in a box around here, patiently awaiting completion, is the competitor to the F-16AF - Northrop's F-20 fitted with the forward-swept wing from the Grumman X-29. Maybe it will emerge one day...

by TheWoracle, on Flickr

CammNut

For those of you who might not be familiar with it, here is the Rockwell HiMAT

NASA photo by TheWoracle, on Flickr

Here is the link to the Wikipedia entry: https://en.wikipedia.org/wiki/Rockwell_HiMAT

And here is the story from that visit to Rockwell: https://www.flightglobal.com/pdfarchive/view/1980/1980%20-%201643.html?search=rockwell%20himat

The Rat

"My mind is a raging torrent, flooded with rivulets of thought, cascading into a waterfall of creative alternatives." Hedley Lamarr, Blazing Saddles

Life is too short to worry about perfection

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Caveman

secretprojects forum migrant

Martin H

I always hope for the best.
Unfortunately,
experience has taught me to expect the worst.

Size (of the stash) matters.

IPMS (UK) What if? SIG Leader.
IPMS (UK) Project Cancelled SIG Member.

dwomby

Excellent .  Even if it was a very long gestation, it was worth the wait.

David

sandiego89

Looks great.  Thrust vectoring nozzle or paddles would put it over the edge!  Well done. 
Dave "Sandiego89"
Chesapeake, Virginia, USA

TheChronicOne

-Sprues McDuck-

Steel Penguin

that is a thing of beauty  :thumbsup:
another F16 based plane I can say I like the look of  .
the things you learn, give your mind the wings to fly, and the chains to hold yourself steady
take off and nuke the site form orbit, nope, time for the real thing, CAM and gridfire, call special circumstances. 
wow, its like freefalling into the Geofront
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chrisonord

Wow, that is really cool. Hats off to you sir. I will be studying this for sure :thumbsup:
Chris.
The dogs philosophy on life.
If you cant eat it hump it or fight it,
Pee on it and walk away!!

DogfighterZen

I have to admit i've never been much of a fan of the HiMAT design, although it was based on the F-16 and had impressive performance... Still, i think your model looks much better than the real one did. :thumbsup:
"Sticks and stones may break some bones but a 3.57's gonna blow your damn head off!!"

NARSES2

Do not condemn the judgement of another because it differs from your own. You may both be wrong.

PR19_Kit

Even I like that one, much though I detest the standard Lawn Dart.
Kit's Rule 1 ) Any aircraft can be improved by fitting longer wings, and/or a longer fuselage
Kit's Rule 2) The backstory can always be changed to suit the model

...and I'm not a closeted 'Take That' fan, I'm a REAL fan! :)

Regards
Kit


CammNut

Thanks folks. Good to get it finished, finally.

And Happy New Year to everyone on What If Modelers.