Re: Sighted a shock wave above airliner wing

Date:         13 Oct 98 02:48:17 
From:         "S.L." <look@the.sig>
Organization: Applied Research Laboratories - The University of Texas at Austin
References:   1 2 3 4
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Alan Browne wrote:
> Phil Dunn wrote:
> > Do you think this could be condensation instead of shock wave?
> >
> > I have flown lots of supersonic formation and you don't see shock waves.
> > You can feel them though.
> >
> > But as the pressure gets very low, you can see transient condensation of
> > water and this appears like shock wave.
>
> I agree: I have often seen condensation form in sheets over a wing, and
> occasionally in sharply defined patterns that could be interpreted as a
> shock wave.

Nope- two entirely different phenomena, and I've seen both enough times
that its quite easy to tell the difference. The condensation usually
occurs at low altitude and low speed (down where the moisture is). The
transparent (not translucent, or "foggy") shock wave is seen only at
high altitudes and at cruise speeds. There is NO mistaking the two at
all.

--
Stephen Lacker
Applied Research Laboratories, The University of Texas at Austin
slacker@arlut.utexxas.edu (Remove the extra 'x' to mail me)