flap back

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blow back

blow backclick for a larger image
Side view of blowback due to change in wind from the front.
The movement of rotor blades away from the relative wind without any control input. Also called flap back or flapback.


flapbackclick for a larger image
Side view of flapback due to change in wind from the front.
The changes in the helicopter disc attitude that occur without any control movement by the pilot. In forward flight, the rotor disc has a natural tendency to tilt back (longitudinally) because of the dissymmetry of lift that would be produced if the advancing blade was not allowed to reduce its angle of attack and the retreating blade increased its angle of attack. Also called blow back and flap back.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved
References in periodicals archive ?
'The surgeon first uses a suction ring to flatten the eye to cut a flap in the cornea, folding the flap back to reveal the middle section, called the stroma.
NEW ORLEANS -- It's daylight outside, but with indoor lights simulating a full moon, hundreds of bats flap back and forth.
Non-absorbable sutures were used to anchor the bone flap back into place following a craniotomy but they were associated with unwanted outcomes including functional and cosmetic defects as well as non-union and failure postoperatively.1 The craniofacial region is the most important part of the body with regards to harmony and symmetry and associated with self-image of the patient and modern day craniofacial surgery includes in itself the standard practice of maintaining this harmony and restoring the normal appearance for every patient to every possible degree.
Bend the flap back along the side that you did not cut.
Put the fat flap back down on the meat and score the fat, season with salt and pepper and brown on all sides.
Perhaps the most prevalent jig trailer today is the wide-clawed crawfish style, one that adds bulk and vibration as the paired claws flap back and forth, creating a thump you can easily feel through the rod.
Bearing grief in my heart I flap back to my abode each dawn in dejection,
FLAP BACK!: Our story on Tuesday and, left, falconer Paul Reeves on the trail of Stan the sea eagle FLYING HIGH: Stan the sea eagle who escaped from Warwick Castle has been seen near Kenilworth Road, Leamington
After Happy Feet and March Of The Penguins, everyone's favourite flightless birds flap back into cinemas in a good-natured Jim Carrey comedy based on the book of the same name.
It was Nani's direct running that got Arsene Wenger's side into a flap back meeting in January as United extended an unbeaten run against Arsenal to four games.