e.  
‘Containment’ means retention within the APU of all high energy rotor fragments resulting from the failure of a high energy rotor.

f.  
‘Critical rotor stage’ means the compressor and turbine stages whose rotors have the smallest margin of safety under the conditions of speed and temperature shown in Appendix 1, paragraph

7.10 of JAR–APU.

g.  
‘Demonstrate’ means to prove by physical test under the conditions specified in Appendix 1 of JAR–APU.

h.  
‘Essential APU’ means an APU which produces bleed air and/or power to drive accessories necessary for the dispatch of the aircraft to maintain safe aircraft operation. 

i.  
‘High energy rotor’ means a rotating component or assembly which, when ruptured, will generate high kinetic energy fragments.

j.  
‘Major part’ means a part of whose failure might adversely affect the operational integrity of the unit.

k.  
‘Maximum allowable speed’ means the maximum rotor speed which the APU would experience under overload or transient conditions and is limited by installed safety devices. 

l.  
‘Maximum allowable temperature’ means the maximum exhaust gas temperature (EGT) or turbine inlet temperature (TIT) which the APU would experience during overload or transient conditions and is limited by installed safety devices.

Change 5  1–2 15 July 1996
m  ‘Minor part’ means a part which is not a major part.
n.  
‘Non-essential APU’ means an APU which may be used on the aircraft as a matter of convenience, either on the ground or in flight, and may be shut down without jeopardising safe aircraft operations.

o.  
‘Output provisions’ means any drive pad or compressed air output flange intended for aircraft use to extract usable shaft or pneumatic power from the APU.