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.
References in periodicals archive ?
Put the fat flap back down on the meat and score the fat, season with salt and pepper and brown on all sides.
Bearing grief in my heart I flap back to my abode each dawn in dejection,
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.
Pants feature button waist, belt loops, two button flap back pockets and two large cargo pockets with button flaps.
2> Bend the flap back and cover the inside of the flap with a piece of aluminum foil.
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.
I remember laying pounds 500 to pounds 200 and pounds 450 to pounds 100 at St Helens flap back in 1977 when there were no less than 12 layers one of whom was the late Pat Whelan, who eventually bet without the favourite until the track closed.
After the laser is used on the cornea, we put the flap back down and ideally there are no wrinkles or layers in it.
The infants were allowed to see the cardboard flap back and forth, through its full 180-degree arc.
The extra pressure exerted on the craft during its maneuvers caused the panel to flap back and forth.
Both gates opened and continued to flap back and forth onto Princess Ileana's hind legs, causing further upset and increasing her damaging kicking.
He cuts through the skin and folds the flap back to expose the thin membrane covering the skull, the periosteum, which is then cut through and a circle of holes is made in the skull itself with a burr drill.