A method of simulating an aircraft one-engine inoperative (“OEI”) event includes operating a supplemental power unit (“SPU”) at a first SPU power level less than an SPU contingency power rating, operating a primary engine at a first primary-engine power level, reducing the primary-engine power level to less than the first primary-engine power level, and maintaining a sum of the primary-engine power level and the SPU power level at a power level substantially equal to the SPU contingency power rating.

A manned or unmanned aircraft has a main body with a circular shape and a circular outer periphery. One or more rotor blades extend substantially horizontally outward from the main body at or about the circular outer periphery. In addition, one or more counter-rotation blades extend substantially horizontally outward from said main body at or about the circular outer periphery, but vertically offset from the main rotor blades.

A manned or unmanned aircraft has a main body with a circular shape and a circular outer periphery. One or more rotor blades extend substantially horizontally outward from the main body at or about the circular outer periphery. In addition, one or more counter-rotation blades extend substantially horizontally outward from said main body at or about the circular outer periphery, but vertically offset from the main rotor blades.

A torque transmission system having multiple torque transmission pathways from a driving shaft to a driven shaft. The driving shaft extends from a lower segment to an upper segment via an intermediate segment, the driven shaft extending from a first segment to a second segment. The transmission system includes a nominal spline coupling that is operational in a nominal operating mode, a backup spline coupling between the driving shaft and the driven shaft that is inactive in the nominal operating mode, and a backup radial guide device between the driving shaft and the driven shaft that is inactive in the nominal operating mode.

A rotor mast including an outer member defining a channel therethrough and an inner member disposed in the channel through the outer member, wherein the inner member is configured to apply a compressive force to the outer member.

A rotor mast including an outer member defining a channel therethrough and an inner member disposed in the channel through the outer member, wherein the inner member is configured to apply a compressive force to the outer member.

A lubricating liquid manifold for a crankpin of an epicyclic gear train. The epicyclic gear train is lubricated by a lubrication system conveying a first flow of a lubricating liquid towards the manifold and a second flow of the lubricating liquid towards a member to be lubricated. The manifold comprises a hollow body provided with an inlet port intended to receive the first flow and an outlet port designed such that the first flow is conveyed towards a guide device connected to the crankpin. The manifold comprises a barrier comprising a shoulder connected to the body and a deflector protruding radially outwards from the body so as to form, with the shoulder, a diversion space for diverting the second flow and preventing it from penetrating into the manifold.

A lubricating liquid manifold for a crankpin of an epicyclic gear train. The epicyclic gear train is lubricated by a lubrication system conveying a first flow of a lubricating liquid towards the manifold and a second flow of the lubricating liquid towards a member to be lubricated. The manifold comprises a hollow body provided with an inlet port intended to receive the first flow and an outlet port designed such that the first flow is conveyed towards a guide device connected to the crankpin. The manifold comprises a barrier comprising a shoulder connected to the body and a deflector protruding radially outwards from the body so as to form, with the shoulder, a diversion space for diverting the second flow and preventing it from penetrating into the manifold.

An aircraft structure protected from collisions with foreign objects includes a first support proximate to an aircraft structure root; first sheets attached to the first support to form a first leading edge portion of the aircraft structure; a second support proximate to an outer end of the aircraft structure; second sheets attached to the second support to form a second leading edge portion; and a door including one or more ribs disposed between the first and second supports and configured to give shape to a third leading edge portion of the aircraft structure; and third sheets, attached to the ribs to form the third portion of the leading edge; wherein the first support, the first sheets, the second support, the second sheets, the one or more ribs, and the third sheets are disposed to mitigate damage from a foreign object collision by absorbing kinetic energy from a collision.

Various implementations described herein are directed to an aircraft having a multi-engine configuration with multiple engines. The aircraft may have a flight control system coupled to the multiple engines with a multi-engine interface. The flight control system may be configured to shutdown at least one engine of the multiple engines during reduced-engine operation by continuously calculating altitude for the reduced-engine operation based on one or more of an aircraft descent rate of the aircraft and an engine restart time of the at least one engine.