FH.XI.E.K6
KnowledgeDifference between low rotor rpm and blade stall.
From the FAA library
- Chapter 11: Helicopter Emergencies and Hazards › Retreating Blade Stall
some point as the forward speed increases, the low blade speed on the retreating blade, and its high AOA cause a stall and loss of lift. Retreating blade stall is a factor in limiting a helicopter’s never-exceed speed ... development can be felt by a low frequency vibration, pitching up of the nose, and a roll in the direction of the retreating blade. High weight, low rotor rpm, high density altitude, turbulence and/or steep, abrupt turns are all conducive…
- Chapter 11: Helicopter Emergencies and Hazards › Low Rotor RPM and Rotor Stall
Other causes of a power-on low rotor rpm condition include the pilot rolling the throttle the wrong way in helicopters not equipped with a governor or a governor failure in helicopters so equipped. As the rpm decreases, the amount ... horsepower the engine can produce also decreases. Engine horsepower is directly proportional to its rpm, so a 10 percent loss in rpm due to overpitching, or one of the other scenarios above, will result in a 10 percent loss…
- Chapter 11: Helicopter Emergencies and Hazards › Low-G Conditions and Mast Bumping
Recover from a low-G situation by first gently applying aft cyclic to restore normal G before attempting to correct any roll. If turbulence is expected or encountered, reduce power and use a slower than normal cruise speed. Turbulence (where ... high rotor flapping angles are already present), and higher airspeeds (where the controls are more sensitive) both increase susceptibility to low-G conditions. • Use a flight simulator to learn to recognize and experience low G conditions that result in mast…