Abstract: An insulation assembly for use with an APU having an exhaust muffler is disclosed herein. The insulation assembly includes, but is not limited to, a first insulating member that is configured for placement on a top portion of the exhaust muffler and a second insulating member attached to the first insulating member and configured for placement on a bottom portion of the exhaust muffler. The second insulating member is less resistant to heat transfer than the first insulating member.

Abstract: A ram door assembly is provided for an intake opening of an intake duct of an auxiliary power unit of an aircraft. The ram door assembly includes a ram door hingeably mounted adjacent to the intake opening and moveable between an open position to a closed position. The ram door has an interior surface and an exterior surface. The ram door assembly further includes a fairing positioned on the interior surface of the ram door.

Abstract: An inlet door system including an aft inlet duct mounted door actuator providing RAM air to an auxiliary power unit (APU) contained within an aircraft is provided. The inlet door system includes an inlet duct, the aft inlet duct mounted door actuator, and a door. The inlet duct is configured to extend from the auxiliary power unit to the aircraft housing and has a sidewall that defines a flow passage. The door actuator is mounted to an exterior surface of the aft portion of the inlet duct. The door is coupled to the actuator. The actuator is configured to selectively rotate the door between at least a first position and a second position.

Abstract: An adjustable and lockable bushing assembly includes a locking plate and a bushing. The locking plate has a bushing engagement opening that is defined by a plurality of first serrations, and a boss that extends axially therefrom. The bushing engages the locking plate and includes a concentric section, an eccentric section, a lock interface section, and an opening. The opening has a fixed diameter and extends along a longitudinal axis through the bushing. The concentric section has an outer surface that has a circumference that is concentric with the longitudinal axis. The eccentric section extends from the concentric section has an outer surface that has a circumference that is eccentric with the longitudinal axis. The lock interface section extends from the concentric section and includes an outer surface defined by a plurality of second serrations that engage the first serrations.

Abstract: An insulation assembly for use with an APU having an exhaust muffler is disclosed herein. The insulation assembly includes, but is not limited to, a first insulating member that is configured for placement on a top portion of the exhaust muffler and a second insulating member attached to the first insulating member and configured for placement on a bottom portion of the exhaust muffler. The second insulating member is less resistant to heat transfer than the first insulating member.

Abstract: A ram door assembly is provided for an intake opening of an intake duct of an auxiliary power unit of an aircraft. The ram door assembly includes a ram door hingeably mounted adjacent to the intake opening and moveable between an open position to a closed position. The ram door has an interior surface and an exterior surface. The ram door assembly further includes a fairing positioned on the interior surface of the ram door.

Abstract: An inlet door system including an aft inlet duct mounted door actuator providing RAM air to an auxiliary power unit (APU) contained within an aircraft is provided. The inlet door system includes an inlet duct, the aft inlet duct mounted door actuator, and a door. The inlet duct is configured to extend from the auxiliary power unit to the aircraft housing and has a sidewall that defines a flow passage. The door actuator is mounted to an exterior surface of the aft portion of the inlet duct. The door is coupled to the actuator. The actuator is configured to selectively rotate the door between at least a first position and a second position.