Abstract: An aircraft has a fuselage, an engine disposed within the fuselage, a rotatable wing disposed above the fuselage and selectively rotatable about a wing rotation axis, and a plurality of interconnect driveshafts disposed within the rotatable wing, and at least one drive system component that is connected between the engine and the interconnect driveshaft is disposed along the wing rotation axis.

Abstract: The present invention includes an air flow bypass for a tiltrotor engine comprising: a ram air inlet comprising bypass door(s) capable of at least partially or fully blocking a ram air flow through the ram air inlet; a barrier filter inlet positioned in a side, a bottom, and/or a top of a tiltrotor engine nacelle; a filter plenum; a selector duct comprising one or more openings; and one or more selector duct doors or covers over the one or more openings; wherein the barrier filter inlet, the filter plenum, the one or more openings in the selector duct, the selector duct, and an engine are in fluid communication and the bypass door(s) in the ram inlet are closed and the barrier filter inlet provides filtered air flow to the engine when the aircraft is in hover operations.