Abstract: This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet.

Abstract: A flight system capable of passively stable hover comprises an apparatus defining a vertical axis, and including multiple upright ducts spaced about the axis; fluid momentum generators in the ducts to effect flow of fluid downwardly in the ducts; and fluid flow deflector structure in the path of the downwardly flowing fluid, and angled to deflect the fluid flow away from the axis, in such manner as to provide stability in hover of the apparatus.

Abstract: A flight system capable of passively stable hover and horizontal translatory flight, comprises an apparatus defining a vertical axis, and including multiple ducts with substantially vertical axes in hover mode, spaced the axis; fluid momentum generators in the ducts to effect flow of fluid downwardly in the ducts in hover; and fluid flow deflector structure in the path of the flowing duct fluid, and angled to deflect the fluid flow away from the axis, in such manner as to provide stability in hover of the apparatus, as well as stability when the entire device is tilted through approximately 90.degree. to execute horizontal translatory flight.

Abstract: A terrain surveillance, powered aircraft is disclosed to have an on-board video camera that is not gimballed relative to the aircraft, the aircraft typically comprising multiple components; the method of the invention including: assembling the components into aircraft configuration at or near a launch site; launching the aircraft at that site with no human pilot on board same; remotely controlling the flight path of the aircraft by radio or cable link, to fly to a location for terrain surveillance; operating the on-board video camera to survey the terrain while varying yaw of the aircraft to provide sweep viewing of the terrain; and recovering the aircraft by controlling its flight to steeply descend to a landing zone.

Abstract: An efficient aircraft utilizes a stabilizer spaced from a fixed wing, and supported for controlled rolling about an axis extending generally in a forward direction, to control aircraft yaw. The stabilizer extends generally horizontally in straight forward flight. Pitch of the stabilizer is also controlled.

Abstract: An elongated protrusion extends adjacent and along a truck body corner in enveloping relation therewith, the corner located at the junction between the exterior side and top walls of a truck body, said protrusion having two rearwardly elongated edge portions respectively attached to the body exterior side wall and top wall, the protrusion having a rearwardly elongated mid-portion which is outwardly convex and which protrudes laterally throughout the major length of the protrusion.

Abstract: A drag reducing means for a truck includes a porous structure typically mounted on the cab roof to pass air into the gap between the cab and trailer body in rearward flowing streams that undergo deceleration. Eddies are formed in the gap and act as a barrier to airfow into the gap at its sides and top.

Abstract: Apparatus combined with or combinable with a vehicle body having a longitudinally elongated corner from which body surfaces extend at an angle, one of the surfaces presented forwardly toward oncoming air flow, and the other surface extending generally rearwardly away from that corner, the apparatus comprisingA. means for preventing, reducing, or delaying separation of the flow boundary layer from said other surface rearwardly of said corner at normal operating speeds of the vehicle,B. said means comprising a longitudinally elongated protrusion having a substantially smooth, arcuate outer surface projecting smoothly outwardly of a first of said body surfaces said protrusion surface having a first longitudinally elongated terminal extent merging toward said first body surface in spaced relation to said corner, and second longitudinally elongated terminal extent merging toward a second of said body surfaces proximate said corner.