An aircraft engine includes an air inlet duct and at least one strut having a leading edge and a trailing edge. The at least one strut extends across at least part of the air inlet duct and has a strut passage. The trailing edge has one or more edge contours, each defining a contour edge wall recessed from a baseline surface of the trailing edge. The one or more edge contours have a recessed tap in fluid communication with the strut passage.

An unmanned aircraft system having a flying wing orientation includes an airframe having leading and trailing edges, a two-dimensional thrust array coupled to the leading edge, a power system and a flight control system operable to independently control the speed of each propulsion assembly of the two-dimensional thrust array. In the flying wing orientation, the two-dimensional distributed thrust array provides airspeed control responsive to collectively changing the speed of each propulsion assembly, pitch authority responsive to differentially changing the speed of the propulsion assemblies above the airframe relative to the propulsion assemblies below the airframe, roll authority responsive to differentially changing the speed of the propulsion assemblies rotating clockwise relative to the propulsion assemblies rotating counterclockwise and yaw authority responsive to differentially changing the speed of the propulsion assemblies on a port side of the airframe relative to the propulsion assemblies on a starboard side of the airframe.

A strut assembly for a vibration isolation device is disclosed, comprising a piston spindle; a first elastomeric member and a second elastomeric member bonded to the piston spindle and in contact with an upper housing and a lower housing, respectively; a first strut support and a second strut support attached to or integral with the upper housing and the lower housing, respectively; a first strut spindle and the second strut support configured to be placed in the first strut support and the second strut support, respectively; and one or more removable struts configured to be engaged to the first strut spindle and to the second strut spindle, wherein at least one of the first or second strut spindles is removable such that the one or more struts can be replaced without breaking a bonding of the first elastomeric member, the second elastomeric member, or both.

A disclosed propulsion unit includes a pylon having a blade presenting a chord Cx and a downstream arm having a structural arm. The pylon has a first distance D between a trailing edge of a fan blade and a leading edge of the fan blade, a second distance d between said trailing edge of the blade and a leading edge of the structural arm, and a third distance L between the trailing edge of the blade and a mark located at a maximum thickness of the downstream arm. The pylon is dimensioned according to: a first quotient between D and Cx between 2.2 and 2.6, a second quotient between d and Cx between 1 and 1.2, and a third quotient between L and Cx between 4 and 7.

An assembly of parts assembled with one another by a shaft passing through orifices formed in the parts is disclosed. The shaft has a base diameter (DB) and a thickened diameter (DE) over diametrically opposed arcs at two different sections. The orifices are aligned with one another and each have a periphery having a first diameter (D1) on first diametrically opposed portions, the first diameter (D1) corresponding to the thickened diameter (DE), and a second diameter (D2), greater than the first diameter (D1), on second portions of the periphery. This allows the shaft to be fitted easily even when the orifices are only approximately aligned, and also makes removal easier.

An unmanned aircraft system includes a flying wing airframe having leading and trailing edges with respective sweep angles. A thrust array is coupled to the airframe and includes first and second motor mounts each rotatably coupled to the leading edge. Each motor mount has first and second propulsion assemblies coupled to respective first and second distal ends thereof. A power system is operably associated with the thrust array and is operable to provide power to each propulsion assembly. A flight control system is operably associated with the thrust array and is operable to independently control the speed of each propulsion assembly. In a flight configuration of the system, each motor mount is substantially perpendicular with the leading edge such that the thrust array forms a two-dimensional thrust array. In a compact storage configuration of the system, each motor mount is substantially parallel with the leading edge.

A control system and methods for controlling the position of one or more engine-mounting links of an engine-mounting linkage system are provided. In one aspect, an engine-mounting linkage system includes one or more engine-mounting links that each have an adjustable inclination angle. An inclination angle of a link may be adjusted by an actuator of the control system. One or more controllers of the control system can control the actuator and thus the inclination angle of the link by determining a control command based at least in part on an output received from one or more sensors of the control system. The controllers can then cause the actuator to change the inclination angle of the link based at least in part on the determined control command.

A system and method of converting engines on a turboprop aircraft, including removing an existing engine and associated propeller from an aircraft fuselage, installing an engine mount adapter assembly to the fuselage, and installing a replacement engine to the engine mount adapter assembly, whereby at least some portions of the replacement engine are attached to the engine mount adapter assembly for structural support.

A gas turbine engine arrangement includes an accessory gearbox which is mounted so as to be aligned in an axial direction along the engine. The accessory gearbox may be recessed at least partly into a casing of the engine.

A turbofan engine may comprise an inlet and a fan case coupled to the inlet. An engine case may be coupled to the fan case via a vane extending between the fan case and the engine case. A strut apparatus may extend from the fan case and limit deflection of the fan case. The strut apparatus may comprise a first end proximate the fan case, and a second end coupled to at least one of the engine case or a structure for mounting the turbofan engine to an aircraft.