Document
April 1975 B75-10055
NASA TECH BRIEF
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Ames Research Center
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage commercial application. Tech Briefs are available on a subscription basis from the National Technical Information Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546.
Low-Profile Landing-Gear Assembly the truck is rotated horizontally by means of rotation The problem: six gears which are driven by dual actuators. The hor- To stow two landing-gear trucks, each with izontal lock is reengaged and the truck is rotated ver- double wheels, in the shadow of the main engine in- tically by retracting the hop damper actuators to their take ducts of a supersonic transport aircraft without minimum length. The jury strut is unlocked by a adding to the frontal area of the aircraft or appre- built-in actuator and the entire assembly is retracted ciably. increasing total aircraft drag.
about the main trunnion by an upper reaction actuator.
The solution: An assembly of cylinders, links, actuators, and Note: gears that permits the landing-gear unit to be retracted Requests for further information may be directed into a low profile for stowage in the aircraft.
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to: Technology Utilization Officer How it's done: The diagram illustrates the gear retraction se- Ames Research Center quence. At the lower left corner is a side view of the Moffett Field, California 94035 Reference: TSP 75-10055 truck and landing-gear assembly in the extended posi- tion (near sidewheels not shown). The landing-gear Patent status: unit is attached to the body of the structure by ball NASA has decided not to apply for a patent.
bearings; the truck assembly consists of conventional truck beams with wheels, axles, and brake reaction Source: Philip M Harper and Frank D. Neumann of links, and includes dual-truck-rotation hop damper Boeing Commercial Airplane Company actuators. Torque links and the hop damper control under contract to the pitch and yaw of the assembly and hold the truck Ames Research Center in a horizontal position until the aircraft is airborne.
(ARC-10786) Then, a horizontal rotation lock is disengaged and
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Government assumes any liability resulting from the use of the This document was prepared under the sponsorship of the National information contained in this document, or warrants that such use Aeronautics and Space Administration. Neither the United States will be free from privately owned rights.
Government nor any person acting on behalf of the United States II .
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B7510055 Category 06