How Albatrosses and Fulmars prevent a Crash Landing

Albatrosses and Fulmars are seabirds that have wing spans of over
3 m, which are amongst the largest of extant birds. Such a large wing
span is better suitable for gliding flight than for flapping, and real
flapping flight is therefore hardly observed in these birds. However,
especially during slow speed flight such as take-off and landing,
the static lift production of gliding flight does not suffice to provide
enough lift to get or keep the bird airborne. Many smaller birds that
use gliding flight as their main flight mode, e.g. gulls, switch to a
short period of flapping during high lift demand. Since the long
and slender wings of Albatrosses and Fulmars hardly allow for
flapping due to the high inertia of the long wings, these birds show
a different behaviour during take-off and landing instead, which
may be associated with a different lift production mechanism. In
this study we show that the oscillatory wing-tilting behaviour of
Albatrosses and Fulmars during take-off and landing causes periodic
lift enhancement by invoking periodic unsteady flow over the wing,
providing a significant increase in average lift.