Abstract: In conjunction with a system and method for optimizing mission conditions of a vehicle, one or more control surfaces movably mounted on a buoyancy-influenced vehicle and configured to maintain stable vehicular movement through a corresponding medium being navigated by the vehicle are individually, controllably and differentially displaced until an optimal position for each of the control surfaces that is collectively suitable to achieve optimum mission conditions is established. In one embodiment, a method for reducing drag induced by a propeller of a propeller-bearing aircraft during forward flight comprises rotating a propeller having one or two blades, when inactive, to an optimal drag-minimizing stowing angle which is angularly spaced from a forward direction of flight of the aircraft.

Abstract: A rotor lock mechanism is disclosed. The mechanism includes a pair of arms at a chosen offset angle # with respect to a long axis of a pair of rotor blades; an arm engagement device configured to restrain rotary motion of the arms; and a rotor drive shaft to which the pair of arms and the pair of rotor blades are attached. A method of use is also disclosed.

Abstract: A hybrid aerial vehicle (HAV) comprising: a fuselage of the HAV; a first mechanism within the fuselage for accepting a plurality of wings of the HAV, the first mechanism allowing coordinated contraction of the plurality of wings essentially into the fuselage such that tips of the wings are position in proximity of the fuselage and coordinated extension of the wings such that tips of each wing are positioned away from the fuselage; a first wing extending from the port side of the fuselage and connected to the first mechanism; a second wing extending from the starboard side of the fuselage and connected to the first mechanism; a second mechanism placed within the fuselage in proximity to its front end, the second mechanism allowing motion of propellers of the HAV affixed there to between a first plain and a second plain; a first set of propellers affixed at the port side of the fuselage to the second mechanism; a second set of propellers affixed at the starboard side of the fuselage to the second mechanism; a t