Abstract: A self-propelled disk harrow apparatus having four gangs of disc members attached thereto which are rotated to propel the disk harrow and to thereby till the soil. Wheels are provided for allowing the disk harrow to travel on public roads and to aid in propelling the disk harrow. When the disc members extend too far into the soil or otherwise become ineffective in propelling the disk harrow, for example when in wet or sandy soil, the weight of the disk harrow transfers to the wheels and the wheels tend to primarily propel the disk harrow. A hydraulicly controlled pitch control is provided for controlling how deeply the discs extend into the ground. An automatic coupling structure is also provided for allowing each gang of discs to be folded for extending the effective length thereof and still providing power to all of the discs on each gang.

Abstract: An airplane fuselage of a type having a concave bottom for providing more lift and control at low speeds and with two strut members extending along and on each side of the concave bottom for providing skids for the purpose of emergency landings. The two bottom strut members are connected at the forward end thereof but are spaced apart at the rear end thereof to prevent an aircraft from turning to one side or the other due to direct contact with the ground or a body of water. A top and central strut member is also provided on the fuselage. Relatively short wings are attached to the fuselage portion, all parts of which are located above the two lower strut members. The landing gear is located in the wing structure.