571.What is the number of outflow valves and safety valves?

90.What is the purpose of the damper nitrogen bottole and Emergency Operation Cylinder?

89.What happens when the arming lever is set to the ARMED position ?

88.Which device blocks the outer control handle during inner control handle operation ?

87.How is the operator warned, when there is a residual pressure in the cabin?

86.The passenger door is maintained parallel to the fuselage by :

85.When is the drain tank emptied ?

84.On ground, in case of failure, how can you open or close the air intake flap ?

83.Normal APU shutdown is performed from ?

82.From where can an APU emergency shut down be performed ?

81.What is the main function of the APU ?