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Funny/Friendly Off topic discussion. Fail this test and threads will be migrated to Way Off Topic.

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User avatar
By waveview
#394902
It appears that moving the CG rear of design specifications can have catastrophic consequences on many aircraft , SR 71 included.

"The mission was intended to investigate procedures designed to reduce trim drag and improve high Mach cruise performance while the center of gravity (CG) was located further aft than normal, reducing the Blackbird’s longitudinal stability."

Looks like they were trying to reduce the amount of trailing edge reflex on a delta wing to improve high speed performance. Now where have I heard that before?
By blindrodie
#394915
It appears that moving the CG rear of design specifications can have catastrophic consequences on many aircraft , SR 71 included.
LOL, what a crazy thing to do.... :crazy: :wink: :twisted:

8)
User avatar
By magentabluesky
#394916
From the video:

"An investigation found that optimizing the planes performance had made it less stable. That led to a loss of control which put the airframe under catastrophic strain."

Yes, there are practical lessons in this story applicable to hang gliding, takeout reflex, lower your tips, move your cg aft to increase performance, all make your hang glider less stable. The Sr71 test was exactly that, less reflex and aft cg. They found the aircraft limit.

You could say the Sr71 was controlled by weight shift in pitch and trimmed with elevators. They moved the fuel fore and aft in different phases of flight, aft to go fast in cruise (less aero drag), forward for stability when landing and maneuvering.
blindrodie wrote:LOL, what a crazy thing to do....
Yeh, tell that to some hang glider pilots
#395785
magentabluesky wrote:No matter what the aircraft or who the pilots are, there is risk when pushing up against the limits.

An incredible story:

This SR-71 Pilot Free Fell from the Edge of Space

The amazing story of Bill Weaver: the Blackbird pilot who survived his SR-71 disintegration
I believe met this guy a few years ago. He was flying rc model airplanes at the local rc flying field. The guy I met had ejected from an SR-71 and there can't be too many of those and the name kind of rings a bell.

Steve
User avatar
By KTMPilot
#395792
Wills Wing in re: increasing pitch stability:
"Increase the amount of reflex (upward deflection at the tail) in the three most inboard battens on each wing. You can increase the reflex by up to an inch over what is shown on the batten pattern , the result will be an increase in pitch pressure, a slight improvement in high speed glide, and
a slight degradation in minimum sink rate performance. "
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