flow field studies on scaled F-15 models show velocity fluctuations that
amplify and become more narrow-band at down steam locations. At the
top of the vertical tail, nearly periodic fluctuations are the dominant
flow feature. This is has been shown to be true with and without
tails present. The frequency corresponding to this spectral peak
is seen to vary with angle of attack and freestream velocity. This
implies that at certain flight conditions, the velocity fluctuations will
tune to a tail structural mode; thus causing tail buffet.