Re: Sighted a shock wave above airliner wing

Date:         13 Oct 98 02:48:15 
From:         gbraun@mitre.org (Gary Braun)
Organization: The MITRE Corporation
References:   1 2 3 4
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I've also seen this effect, and it was not condensation.  I have a
Master's degree in Aeronautical Engineering and several of my professors
have seen the shock wave (or rather the effects) as well.  In order to see
it, the sun has to be at your back (on the other side of the aircraft) and
you have to be sitting directly over the wing in line with the transonic
shock wave location.  It's rather hard to see, but if you watch closely a
thin "shadow" will appear along the length of the wing, moving slightly
fore and aft with the local changes in angle of attack or velocity.  It
appears similar to viewing a shock wave with a Schlieren system on a
supersonic wind tunnel.