Aviation Forum / General / Aviation / July 2009

It looks to me like differential wing strokes caused the turn

On Jul 16, 1:20 pm, "atl...@gmail.com" <atl...@gmail.com> wrote:

On Jul 16, 1:20 pm, "atl...@gmail.com" <atl...@gmail.com> wrote:

Not that I'm the Audubon expert around here by a long shot :-)) but I
had occasion to study quite closely the film shot by Art Scholl of
seagulls for the film Johnathon Livingston Seagull.
Art shot a ton of high speed film as his helper was hand feeding gulls
off the transom of a boat to get shots to be used in the film. The
film was a beautiful study of bird aerodynamics.
Watching the gulls hover and turn almost in place I believe 2a is
right. The birds use their entire bodies to face into these turns sort
of like an ice skater twisting into a jump, then use differential
strength with their wings with a stronger stroke on the outside wing
to make the turn. The tail seems to help with general balance and
causing a lean back toward the desired turn direction that helps the
outside wing.
They are indeed beautiful to watch, and I have to admit that without
high speed film like that shot by Art, I never would have had an
inkling of the exact dynamics involved it's so complicated.
Dudley Henriques