Help needed with Mystery F5

Hi All,

Saw this modified F5 in the Museum at Titusville, Florida in April;

It is still in NASA colours, so was obviously used for some kind of research. Can anyone suggest what that large nose is all about?!

 

Cheers AWA

Yeah, I recall reading something about it being used for research into reducing sonic booms...either that or they've been feeding it fish (Pelican anyone?)

Can't remember how it worked though...

 

This is the F-5 Shaped Sonic Boom Demonstrator (SSBD), an F-5E modified by Northrop Grumman under the US Defense Advanced Research Projects Agency's Quiet Supersonic Platform. It was the first aircraft to demonstrate that the shockwave signature could be altered by shaping the aircraft - hence the wierd-looking forward fuselage.

Check these sites:

http://www.dfrc.nasa.gov/gallery/Photo/SSBD/HTML/EC03-0225-6.html

http://www.aiaa.org/aerospace/images/articleimages/pdf/croftseptember04.pdf

I believe its work was then taken on by NASA's "Quiet Spike" F-15.

 

Quiet Spike uses a different application of the same technique to shape the boom. It divides the bow shock into a series of smaller shockwaves, one generated by the tip and one by each of the ramps between the segments of the telescoping boom. The idea is that each of these smaller shockwaves stays separate all the way to the ground, instead of coalescing into one big overpressure spike, so that inside of a loud bang you get a more spread-out sound, like a muffled whoosh. A spike may also be needed on the tail to deal with the second pressure spike, theone that gives a sonic boom its characteristic N-wave signature and "double bang" sound.

 

Put all that boom shaping stuff together in a whole plane and you get this beauty of a beast - the Skunk Works-designed Quiet Supersonic Transport, or QSST...

http://www.saiqsst.com/