The signature jet plane
whoosh guitar effect which was originally achieved by using two
tape recorders, each with a copy of the same recording. One recorder is slightly
delayed behind the other by dragging a finger along the "flange" of the
tape reel, creating
notches and
peaks in the signal which give flanging it's signature
sound. The advent of
solid state bucket brigade chips made
analog delay effects possible, which made flanging effects easier to create.
With the bucket brigade chips used in analog delay lines out of production (SADXXXX, MNXXXX from Panasonic, etc.), the much coveted sound of analog delay effects such as delay, flanging, and chorus may be a thing of the past. See also digital vs analog.
John Lennon is credited with coining the actual term "flanging".
The legendary guitar pioneer Les Paul is credited with first discovering the actual effect of flanging on his 1945 recording Mamie's Boogie. He used 2 disc recorders to create the effect. One was equipped with a variable speed control and a sync motor so it could be delayed slightly behind the other disc recorder.
See also comb filter, stomp box, guitar pedal, flange