blade stall

blade stall

blade stallclick for a larger image
Flow through the helicopter rotor during power settling.
As it refers to rotorcraft, it is the condition of the retreating rotor blade when in forward flight and when operating at an angle of attack greater than the maximum angle of lift. This occurs at high forward speeds and when settling with power.
References in periodicals archive ?
At high speed the main rotor is slowed to delay compressibility effects on the advancing tip, and unloaded by the wings to avoid retreating blade stall.
By unloading the rotor from its lift and propulsion responsibilities, you can delay the onset of retreating blade stall, which limits the speed of helicopters," said Piasecki.
This tip injection decreases the blade loading at the tip, allowing increased loading at lower blade spans before the blade stalls.