Results of Studies to Improve the Ground Flotation of Aircraft 670560
In recent years the AFFDL has actively attempted to develop improved techniques and criteria for providing aircraft with a capability for landing on substandard fields. A number of R&D programs have been conducted to this end. These programs have involved the participation of not only the AFFDL Landing Gear Test Facility, but also the Vicksburg Waterways Experiment Station, and various aircraft and landing gear contractors.
The scope of approaches investigated includes expandable tires, extra wide tires, low pressure tires, track gear, air cushion gear, and basic flotation criteria. This paper summarizes the significant results of these programs.
The paper briefly summarizes the presently available criteria for ground flotation on bare soil and indicates approaches for improving aircraft ground flotation characteristics. Also included are the results of AFFDL tests of conventional tires tested at high deflection, and of unconventional (expandable) tires which collapse for stowage. Finally, the advantages and limitation of unconventional gear such as the track gear and the air cushion are discussed.
The following conclusions are presented: Conventional 17.00–20 and 20.00–20 size tires may be operated at 50% deflection for at least 30 landings. An expandable tire which expands from 38 “diameter to 59” diameter performed satisfactorily per spec MIL-T-504l. The air cushion landing gear offers promise for providing a breakthrough in high flotation capability for aircraft.