Abstract: A compartment based inlet particle separator system for an aircraft that includes an auxiliary power unit (APU) system compartment is provided. The system includes a separation barrier wall, a ram air inlet opening, a diffuser, and an inlet particle separator (IPS). The separation barrier wall is disposed within the APU system compartment and divides the APU system compartment into two compartments. The ram air inlet opening is formed one of the compartments. The diffuser receives ram air from a ram air inlet opening and discharges ram air into a compartment. The IPS is disposed within the a compartment between the diffuser outlet and the APU air inlet port.

Abstract: Monolithic acoustically-treated composite structures and methods for fabricating the same are provided. A monolithic acoustically-treated composite structure comprises an internal frame assembly comprising a unitary composite frame structure and at least one acoustic panel assembly. The unitary composite frame structure defines a shape of the monolithic acoustically-treated composite structure to be fabricated. A composite overlay covers the internal frame assembly. The method for fabricating the monolithic acoustically-treated composite structure comprises forming the unitary composite frame structure, including the at least one acoustic panel in the unitary composite frame structure, and covering the internal frame assembly with the composite overlay.

Abstract: A compartment based inlet particle separator system for an aircraft that includes an auxiliary power unit (APU) system compartment is provided. The system includes a separation barrier wall, a ram air inlet opening, a diffuser, and an inlet particle separator (IPS). The separation barrier wall is disposed within the APU system compartment and divides the APU system compartment into two compartments. The ram air inlet opening is formed one of the compartments. The diffuser receives ram air from a ram air inlet opening and discharges ram air into a compartment. The IPS is disposed within the a compartment between the diffuser outlet and the APU air inlet port.

Abstract: Monolithic acoustically-treated composite structures and methods for fabricating the same are provided. A monolithic acoustically-treated composite structure comprises an internal frame assembly comprising a unitary composite frame structure and at least one acoustic panel assembly. The unitary composite frame structure defines a shape of the monolithic acoustically-treated composite structure to be fabricated. A composite overlay covers the internal frame assembly. The method for fabricating the monolithic acoustically-treated composite structure comprises forming the unitary composite frame structure, including the at least one acoustic panel in the unitary composite frame structure, and covering the internal frame assembly with the composite overlay.

Abstract: Monolithic acoustically-treated composite structures and methods for fabricating the same are provided. A monolithic acoustically-treated composite structure comprises an internal frame assembly comprising a unitary composite frame structure and at least one acoustic panel assembly. The unitary composite frame structure defines a shape of the monolithic acoustically-treated composite structure to be fabricated. A composite overlay covers the internal frame assembly. The method for fabricating the monolithic acoustically-treated composite structure comprises forming the unitary composite frame structure, including the at least one acoustic panel in the unitary composite frame structure, and covering the internal frame assembly with the composite overlay.

Abstract: Monolithic acoustically-treated composite structures and methods for fabricating the same are provided. A monolithic acoustically-treated composite structure comprises an internal frame assembly comprising a unitary composite frame structure and at least one acoustic panel assembly. The unitary composite frame structure defines a shape of the monolithic acoustically-treated composite structure to be fabricated. A composite overlay covers the internal frame assembly. The method for fabricating the monolithic acoustically-treated composite structure comprises forming the unitary composite frame structure, including the at least one acoustic panel in the unitary composite frame structure, and covering the internal frame assembly with the composite overlay.

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.