Abstract: Methods and systems for starting aircraft turbofan engines are disclosed. A system in accordance with one embodiment includes an electrically-powered starter motor coupled to a turbofan engine to provide power to the turbofan engine during an engine start procedure. The system can further include an on-board, deployable, ram air driven turbine coupled to an electrical generator, which is in turn coupled to the starter motor to provide electrical power to the starter motor. In other embodiments, the ram air driven turbine can be replaced with a fuel cell or a battery. In still further embodiments, a single controller can control operation of both the engine starter and other motors of the aircraft.

Abstract: An air inlet mechanism having a housing and a door structure, and being particularly well adapted or supplying a ram airflow to an auxiliary power unit (APU) of an aircraft while minimizing the aerodynamic drag created by the mechanism. The housing includes a body portion with a fluid conduit formed therethrough. The body portion also includes a wall member that defines an end wall with at least a portion of the endwall being concave in shape such that a recessed cavity is formed in the fluid conduit. The door structure is pivotably coupled to the housing and movable between a closed position substantially closing the fluid conduit and an open position wherein the door structure is disposed within the fluid conduit. The recessed cavity receives at least a portion of the door structure when the door structure is moved between the closed position and the open position.