Door activated airborne stair structure

An airborne stair and door structure for installation in an aircraft fuselage comprising:

• a door opening in said fuselage defined by a top, a sill and sides;
• a door having a hinge means at its upper edge engaging said aircraft fuselage, said door adapted to close said door opening;
• stair means carried by a support means mounted for rotation about a pivot on a frame means attached to said fuselage at said sill said stair means adapted to rotate outwardly through said door opening to provide access to and from said aircraft;
• at least one operating rod engaging said door at a pivot point spaced inwardly of said fuselage from said hinge means and mounted for reciprocation induced by rotation of said door about said hinge means, first downwardly upon initial movement of said door from a closed position, then past an over-center point and then upwardly upon continued rotation of said door toward an open position;
• stair actuator means operated by said operating rod causing rotation of said stair means inwardly of said fuselage upon downward movement of said operating rod and outward rotation of said stair means upon upward movement of said operating rod;
• and
• yoke means engaging said support means and said operational rod adapted to convert reciprocative motion of said rod to rotative motion of said support means, said yoke means permitting continued upward reciprocation of said rod without continued rotation of said support means upon engagement of said stair means with the ground or other support surface;
• whereby initial outward rotation of said door from a closed position to an intermediate position whereat said stair can rotate outwardly without engaging said door is accomplished without substantial outward rotation of said stair means and continued outward rotation of said door toward an open position rotates said stair means outwardly and then downwardly of said fuselage toward a ground engaging position;
• the stair means and the door being mechanically interconnected to counterbalance each other whereby power necessary to operate the door and stair means is minimized.