Rapid Descents
Rapid descents relate to dramatic changes in cabin air pressure—even pressurized aircraft—and can result in discomfort in the middle ear. Relief is achieved by decreasing relative pressure by equalizing the middle ear with ambient pressure ("popping ears") through swallowing, yawning, chewing, or the valsalva maneuver.
Helicopters which lose power do not simply fall out of the sky. In a maneuver called autorotation, the pilot configures the rotors to spin faster driven by the upward moving air, which limits the rate of descent. Very shortly before meeting the ground, the pilot changes the momentum stored in the rotor to increase lift to slow the rate of descent to a normal landing (but without extended hovering).
Read more about this topic: Descent (aircraft)
Famous quotes containing the word rapid:
“It now appears that the negro race is, more than any other, susceptible of rapid civilization. The emancipation is observed, in the islands, to have wrought for the negro a benefit as sudden as when a thermometer is brought out of the shade into the sun. It has given him eyes and ears.”
—Ralph Waldo Emerson (1803–1882)