A nacelle for an aircraft engine comprising a first fan cowl and a second fan cowl, each fan cowl comprising a hinged end and a closing end, each fan cowl being mobile between a closed operating position and an open maintenance position, the first fan cowl having a larger angular coverage than the second fan cowl, the first fan cowl comprising an upper part connected to a lower part by an intermediate hinge so as to allow the lower part to fold towards the upper part.

A thrust reverser for an aircraft propulsion assembly includes a movable structure provided with external covers connected to hinges through a pivot connection allowing the external covers to rotate between a closed position and a maintenance position. The hinges are connected to secondary rails rigidly attached to an engine pylon through a sliding connection allowing the external covers to move in translation between a direct thrust position and a reverse thrust position. The hinges and the secondary rails are independent of beams to which the parts of the movable structure other than the external covers are connected. A method for maintaining an aircraft propulsion unit is also disclosed. The method includes positioning of the external covers in maintenance position followed by a placement of the beams and of the parts of the movable structure other than the external covers.

A thrust reverser for an aircraft propulsion assembly includes a movable structure provided with external covers connected to hinges through a pivot connection allowing the external covers to rotate between a closed position and a maintenance position. The hinges are connected to secondary rails rigidly attached to an engine pylon through a sliding connection allowing the external covers to move in translation between a direct thrust position and a reverse thrust position. The hinges and the secondary rails are independent of beams to which the parts of the movable structure other than the external covers are connected. A method for maintaining an aircraft propulsion unit is also disclosed. The method includes positioning of the external covers in maintenance position followed by a placement of the beams and of the parts of the movable structure other than the external covers.

A propulsion system assembly includes a variable area inlet and an inlet duct. The variable area inlet includes an outer airflow inlet passage, an inner airflow inlet passage, an inlet structure and a center body structure. The outer airflow inlet passage is between the inlet structure and the center body structure. The inner airflow inlet passage is formed within the center body structure. The center body structure includes a valve configured to regulate air flow through the inner airflow inlet passage. The valve includes a first door configured to pivot between a closed position and an open position. The inlet duct is configured to receive air from the outer airflow inlet passage when the first door is in the closed position. The inlet duct is configured to receive air from the outer airflow inlet passage and the inner airflow inlet passage when the first door is in the open position.

A propulsion system assembly includes a variable area inlet and an inlet duct. The variable area inlet includes an outer airflow inlet passage, an inner airflow inlet passage, an inlet structure and a center body structure. The outer airflow inlet passage is between the inlet structure and the center body structure. The inner airflow inlet passage is formed within the center body structure. The center body structure includes a valve configured to regulate air flow through the inner airflow inlet passage. The valve includes a first door configured to pivot between a closed position and an open position. The inlet duct is configured to receive air from the outer airflow inlet passage when the first door is in the closed position. The inlet duct is configured to receive air from the outer airflow inlet passage and the inner airflow inlet passage when the first door is in the open position.

An actuator assembly for a cowl door is provided. The actuator assembly includes a housing, an actuator configured to drive cowl door extension and cowl door retraction and to support the cowl door during the cowl door extension and the cowl door retraction and a clutch assembly interposed between the actuator and the housing. The clutch assembly is configured to engage a capability of the actuator to drive the cowl door retraction when the cowl door loads the actuator.

An actuator assembly for a cowl door is provided. The actuator assembly includes a housing, an actuator configured to drive cowl door extension and cowl door retraction and to support the cowl door during the cowl door extension and the cowl door retraction and a clutch assembly interposed between the actuator and the housing. The clutch assembly is configured to engage a capability of the actuator to drive the cowl door retraction when the cowl door loads the actuator.

A seal arrangement includes a first outer skin and a second outer skin disposed about an axial centerline. The second outer skin is adjacent the first outer skin and includes at least one door. A bulkhead extends substantially radially at least a portion of a distance between the axial centerline and one of the first outer skin and the second outer skin. A first outer frame includes a first portion, a second portion, and a third portion. The first portion of the first outer frame is mounted to the bulkhead. A seal is mounted to one of the at least one door and the second portion. The at least one door is rotatable between a first position and a second position. In the second position the seal contacts the at least one door and the second portion. The third portion is configured to limit a compression of the seal.

A seal arrangement includes a first outer skin and a second outer skin disposed about an axial centerline. The second outer skin is adjacent the first outer skin and includes at least one door. A bulkhead extends substantially radially at least a portion of a distance between the axial centerline and one of the first outer skin and the second outer skin. A first outer frame includes a first portion, a second portion, and a third portion. The first portion of the first outer frame is mounted to the bulkhead. A seal is mounted to one of the at least one door and the second portion. The at least one door is rotatable between a first position and a second position. In the second position the seal contacts the at least one door and the second portion. The third portion is configured to limit a compression of the seal.

A wear resistant composite material includes a first thickness of material, a second thickness of material, and a thickness of wear indicator located between and engaging the first thickness of material and the second thickness of material. The thickness of wear indicator has a colorant therein.