Aerodynamics

Question 1

Retreating blade stall - cause, symptoms & recovery

Answer 1

High FWD airspeed. Due to dissymmetry of lift, the rotor blades need to flap to equality, the higher the speed the greater the flapping required & eventually gets to point where the blades can no longer flap to equality causing the nose of the helicopter to pitch up & roll towards the treating blade. Recovery slow down, adjust cyclic and collective as necessary