2.2.7 Stall warning system
A stall is the situation where the air flow can no longer follow the profile of the wing due to an increase of the angle of attack of the wing. The wing will then lose its lift to a large extent and, therefore, the aircraft will soon lose altitude should the pilot not intervene. The stall warning system is used to generate the required warning before a stall starts. This warning (hereafter to be referred to as stick shaker) is emitted by vibration of the control columns. The operations of the system produces a distinctive noise which is audible to the flight crew. The pilot applying the prescribed recovery procedure must, subsequently prevent that the aircraft actively ends up in a stall situation. It should be noted that a full stall is different than a stick shaker warning situation. The aircraft can continue to fly normally at an angle of attack at which the stick shaker is activated. When the angle of attack is increased more the aircraft will stall and loose altitude rapidly.