Page 10 (25) Choose the CORRECT answer
(a) Hydraulic and pneumatic systems work as back up to each other. When one system fails, the other is used to move the actuators.
(b) Hydraulic system is pressured by engine driven pumps or air driven pumps.
(c) Major subsystems of Auxiliary Power Unit (APU) System are: Gas turbine, Compressor for pneumatic power and generator for electrical DC power.
(d) APU is located at the tail end of aircraft and so its weight is very useful to keep a nose up tendency during the flight.

(26) Choose the CORRECT answer
(a) Some Avionics systems are: Displays and controls, Communication system, Navigation system, Cabin entertainment system, Weather radar and Flight management system.
(b) The hot air from the engine, called bleed air is used to heat the leading edge of the wing to prevent the formation of ice and so there is no anti-ice system needed for the engine itself.
(c) Design of complex systems of aircraft is not carried out by following ARP standards as they are only recommended practices.
(d) Emergency power system allows safe flight and landing in case of a total power loss that is when all Engines and APU are inoperative.