Effective translational lift (ETL) is when the lift generation from the rotor disc is more efficient due to increased aircraft speed or wind.
Translating tendency is the movement of the helicopter to the right due to the combination of main rotor torque and tail-rotor anti-torque.
Transverse flow is the decreased lift at the rear of the rotor disc due to an increase in induced flow as the disc moves through the air, producing a roll to the right.
Blow-back is the rearward tilt of the rotor disc during the transition to forward flight.
At high airspeed, the airflow from the helicopter’s forward movement may exceed the rotational speed of the retreating blade.
A retreating blade stall is when the retreating blade flaps down so significantly that the blade reaches its critical angle of attack and stalls.
Ground resonance is a vibration that can be destructive to a helicopter.
A dynamic rollover is a catastrophic event where rotor thrust pulls the helicopter sideways around a pivot point, such as from catching a skid on an object.
A vortex ring state is when the helicopter’s downwash recirculates into the induced flow and the helicopter descends while under power.
Loss of tail rotor effectiveness, commonly referred to as LTE, is when the ability to provide anti-torque thrust from the tail rotor is ineffective or highly unreliable.