Aircraft with retractable auxiliary power unit

Claim 1

In a heavier than air aircraft of the type having an airframe including a fuselage supporting first and second wing members along the longitudinal axis of said fuselage and having first and second main power units disposed on opposite sides of said fuselage and generally above the longitudinal axis of said wing members, the improvement comprising: (a) an opening formed in the bottom of said fuselage said opening being located symmetrically about a line parallel to said longitudinal axis of said fuselage; (b) first and second door members shaped to conform to the surface of said fuselage in the area of said opening for normally covering said opening; (c) a hydrogen peroxide fueled thruster rocket engine auxiliary power unit; (d) a generally rectangular mounting plate connected to said auxiliary power unit; (e) first and second guide rails connected to said fuselage and extending transverse to said longitudinal axis of said fuselage and generally disposed within said fuselage and in proximity to said opening, said guide rails slidably engaging the edges of said mounting plate; and (f) hydraulically operable positioning means coupled between said fuselage and said mounting plate for selectively opening said door members and moving said auxiliary power unit from a normal position within said fuselage through said opening, to a position exterior to said fuselage and below the longitudinal axis of said first and second wing members prior to energization of said auxiliary power unit.