The subject matter of this specification can be embodied in, among other things, a system that includes a flexible structure, a power inverter, a first electromechanical device configured to urge movement of a first portion of the flexible structure based on power received from the power inverter, a second electromechanical device configured to urge movement of a second portion of the flexible structure based on power received from the power inverter, a feedback sensor configured to provide a feedback signal indicative of alignment between the first portion and the second portion, and a controller configured to control operation of at least one of the first electromechanical device and the second electromechanical device based on the feedback signal.

A pressure relief valve assembly comprising a valve housing within which is provided a primary pressure relief valve having a valve ball and a valve spring, the valve spring biasing the valve ball in a first direction into a valve seat to prevent the passage of fluid from a fluid line through the valve, and wherein the spring force is selected such that a fluid force above a predetermined set point acting against the ball in a second direction opposite the first direction causes the ball to move out of the valve seat against the spring force to allow fluid to flow from the fluid line through the valve seat and through the valve, and wherein a secondary valve is positioned relative to the primary valve to retain fluid around the valve spring of the primary valve at a fluid force below the predetermined set point.

An aircraft turbojet engine nacelle includes a rear section without a lower bifurcation, the rear section including a thrust reverser system, and the thrust reverser system including a movable cowl. The nacelle includes a guide system including a movable portion and a fixed portion, the movable portion being secured in translation to the movable cowl and cooperating with the fixed portion and the fixed portion being fixed relative to the nacelle. The guide system is disposed proximate to a position called the “6 O'clock” position. In one form, the length of the fixed portion of the guide system is larger than or equal to 50% of the length of the movable portion.

An aircraft turbojet engine nacelle includes a rear section without a lower bifurcation, the rear section including a thrust reverser system, and the thrust reverser system including a movable cowl. The nacelle includes a guide system including a movable portion and a fixed portion, the movable portion being secured in translation to the movable cowl and cooperating with the fixed portion and the fixed portion being fixed relative to the nacelle. The guide system is disposed proximate to a position called the “6 O'clock” position. In one form, the length of the fixed portion of the guide system is larger than or equal to 50% of the length of the movable portion.

An engine pylon for mounting a jet engine beneath a wing of an aircraft, the engine pylon having a primary structure having two internal lateral fittings that face one another and a rib that is fastened between the two internal lateral fittings and a primary box that at least partially surrounds the primary structure and comprises a first part made from a composite material.

An engine pylon of an aircraft having a rear portion, two rear cowls around the rear portion, each rear cowl having an upper fixed cowl and a lower movable cowl mounted articulated on the rear portion, wherein in the closed position the two lower movable cowls are moved close to one another, such that their lower edges are contiguous, wherein in the open position the two lower movable cowls are tilted such that their lower edges are moved away from one another, for each lower movable cowl, a hinge system fixed between the lower movable cowl and the rear portion, and at least one locking system which locks the two lower movable cowls to one another in the closed position. The presence of the lower movable cowls ensures, among other things, easy access to the interior of the engine pylon.

An engine pylon of an aircraft having a rear portion, two rear cowls around the rear portion, each rear cowl having an upper fixed cowl and a lower movable cowl mounted articulated on the rear portion, wherein in the closed position the two lower movable cowls are moved close to one another, such that their lower edges are contiguous, wherein in the open position the two lower movable cowls are tilted such that their lower edges are moved away from one another, for each lower movable cowl, a hinge system fixed between the lower movable cowl and the rear portion, and at least one locking system which locks the two lower movable cowls to one another in the closed position. The presence of the lower movable cowls ensures, among other things, easy access to the interior of the engine pylon.

A turbofan propulsion assembly includes a thrust reverser with movable flaps. The propulsion assembly further includes an engine and a nacelle surrounding the engine, and the nacelle includes a thrust reverser with sliding cowls and thrust reverser flaps, and an inner structure. The portion of the inner structure positioned perpendicular to the thrust reverser flaps includes two halves that can open toward the exterior of the nacelle cowls.

A turbofan propulsion assembly includes a thrust reverser with movable flaps. The propulsion assembly further includes an engine and a nacelle surrounding the engine, and the nacelle includes a thrust reverser with sliding cowls and thrust reverser flaps, and an inner structure. The portion of the inner structure positioned perpendicular to the thrust reverser flaps includes two halves that can open toward the exterior of the nacelle cowls.

Guide systems for installing aircraft structures are disclosed. An example apparatus includes a first guide system structured to removably couple to a first aircraft structure having a first hinge component. A second guide system is structured to removably couple to a second aircraft structure having a second hinge component. The first guide system is to engage the second guide system to enable alignment between the first hinge component and the second hinge component during assembly of the first aircraft structure and the second aircraft structure.