b.  
aircraft operations, is defined in JAR–OPS;

c.  
type certification of aircraft, is defined in JAR–21;

d.  
maintenance, is defined in JAR–OPS Subpart M. 

‘Gate’ means a mechanical arrangement which provides positive stops at given positions of an operating control and is such that a separate movement of the operating control in another direction is necessary in order to initiate movement beyond one of the stops. (Applicable to JAR–25 only.)
‘Ground Idling Conditions’ (turbine engines) means the conditions of minimum rotational speed associated with zero forward speed and the maximum exhaust gas temperature at this speed.
‘Gyroplane’ means a rotorcraft the rotors of which are not engine driven except for initial starting, but are made to rotate by action of the air when the rotorcraft is moving, and the means of propulsion of which, consisting usually of conventional propellers, is independent of the rotor system.
‘Harness’ means the equipment, consisting of two shoulder straps and a lap belt, which is provided to restrain a member of the flight crew against inertia loads occurring in emergency conditions.
*‘Helicopter’ means a rotorcraft that, for its horizontal motion, depends principally on its engine-driven rotors.
*‘Heliport’ means an area of land, water, or structure used or intended to be used for the landing and take-off of helicopters. 
‘Icing Atmospheric Conditions’. The definitions of atmospheric conditions are given in this sub-paragraph and Figures 2 to 7:–