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A landing gear system comprises the most compelling assembly of engineering skills. Its importance to the successful design of an aircraft can be favorably compared with that of the aircraft's wings and engines. A landing gear system consists of several different engineering disciplines, and is continually in the public eye especially with regard to safety. The primary objective of AIR4846 is to present a record of a variety of interesting gears, gear/aircraft systems and patents, and to discuss wherever possible the lessons learned, and the reasons for the design. Thus, the document is not only a historical account, but a means of recording technical knowledge for the practical benefit of future landing gear designers. Commendable efforts have been made over the years by several individuals to make such recordings, and AIR4846 will make continual reference to them. This applies to all books, papers, or specifications that have the approval of the SAE A-5 Committee.

This document covers the field of civilian, commercial and military airplanes and helicopters. This summary of tail bumper design approaches may be used by design personnel as a reference and guide for future airplanes and helicopters that require tail bumpers. Those described herein will consist of simple rub strips, structural loops with a wear surface for runway contact, retractable installations with replaceable shock absorbers and wear surfaces and complicated retractable tail landing gears with shock strut, wheels and tires. The information will be presented as a general description of the installation, its components and their functions.

This SAE Aerospace Information Report (AIR) covers the field of civilian, commercial and military airplanes and helicopters. This summary of tail bumper design approaches may be used by design personnel as a reference and guide for future airplanes and helicopters that require tail bumpers. Those described herein will consist of simple rub strips, structural loops with a wear surface for runway contact, retractable installations with replaceable shock absorbers and wear surfaces and complicated retractable tail landing gears with shock strut, wheels and tires. The information will be presented as a general description of the installation, its components and their functions.

This SAE Aerospace Information Report (AIR) covers the field of civilian, commercial and military airplanes and helicopters. This summary of tail bumper design approaches may be used by design personnel as a reference and guide for future airplanes and helicopters that require tail bumpers. Those described herein will consist of simple rub strips, structural loops with a wear surface for runway contact, retractable installations with replaceable shock absorbers and wear surfaces and complicated retractable tail landing gears with shock strut, wheels and tires. The information will be presented as a general description of the installation, its components and their functions.

This recommended practice covers the fixed structure, or independent energy absorbing system affixed to the airframe to afford protection to the control surfaces, engine and other portions during ground handling, take-off and landing.

This recommended practice covers the fixed structure, or independent energy absorbing system affixed to the airframe to afford protection to the control surfaces, engine and other portions during ground handling, take-off and landing.

This recommended practice covers the fixed structure, or independent energy absorbing system affixed to the airframe to afford protection to the control surfaces, engine and other portions during ground handling, take-off and landing.

This recommended practice covers the fixed structure, or independent energy absorbing system affixed to the airframe to afford protection to the control surfaces, engine and other portions during ground handling, take-off and landing.

This SAE Aerospace Recommended Practice (ARP) provides recommendations on cavity design, the installation of elastomer type spare seals in these cavities, and information surrounding elastomer material properties after contact with typical shock absorber hydraulic fluid(s) or grease. This ARP is primarily concerned with the use of spare seals on shock absorbers where only a single dynamic seal is fitted and in contact with the slider/shock absorber piston at any one time. These shock absorbers typically have a spare (dynamic) seal gland located on the outer diameter of the lower seal carrier. This spare seal gland is intended to house a spare elastomer contact seal. Split Polytetrafluoroethylene (PTFE) backup rings can also be installed in the spare seal cavity. During operation, if the fitted dynamic shock absorber standard seal begins to fail/leak, then the aircraft can be jacked up, allowing the lower gland nut of the shock absorber to be dropped down.

This specification covers definition of landing impact tests which are to be conducted on landing gear assemblies including shock absorbers, suggested instrumentation for the tests and required data of the resulting test report. It is intended to standardize impact test procedures on landing gear shock absorbers and to provide sufficient data to allow evaluation of the design with respect to requirements of MIL-L-8552 and MIL-S-8959 as applicable.

This specification covers definition of landing impact tests which are to be conducted on landing gear assemblies including shock absorbers, suggested instrumentation for the tests and required data of the resulting test report. It is intended to standardize impact test procedures on landing gear shock absorbers and to provide sufficient data to allow evaluation of the design with respect to requirements of MIL-L-8552 and MIL-S-8959 as applicable.

The purpose of this SAE Aerospace Recommended Practice (ARP) is to provide a practical definition of external hydraulic fluid leakage exhibited by landing gear shock absorbers/struts. The definition will outline normal (acceptable weepage) and excessive leakage (unacceptable leakage) of shock absorbers/struts that is measurable. The definition of leakage is applicable to new gear assemblies, refurbished/remanufactured (overhauled) shock absorbers/struts, leakage of shock absorbers/struts encountered during acceptance flights, newly delivered and in-service aircraft. This ARP is intended to provide guidelines for acceptable leakage of landing gear shock absorbers/struts between the ambient temperatures of -65 °F (-54 °C) and 130 °F (54 °C) and to outline the procedure for measuring such leakage. The specific limits that are applied to any particular aircraft shall be adjusted by the aircraft manufacturer before inclusion in the applicable maintenance manual.

The present document addresses gas and hydraulic fluid servicing required on commercial and military aircraft landing gears, for both single and dual chamber shock struts.

This SAE Aerospace Standard (AS) offers gland details for a 0.364 inch (9.246 mm) cross-section gland (nominal 3/8 inch) with proposed gland lengths for compression-type seals with two backup rings over a range of 7 to 21 inches (178 to 533 mm) in diameter. The dash number system used is similar to AS568A. A 600 series has been chosen as a logical extension of AS568A, and the 625 number has been selected for the initial number, since 300 and 400 series in MIL-G-5514 and AS4716 begin with 325 and 425 sizes. Seal configurations and design are not a part of this document. This gland is for use with compression-type seals including, but not limited to, O-rings, T-rings, D-rings, cap seals, etc.

This SAE Aerospace Standard (AS) offers gland details for a 0.364 inch (9.246 mm) cross-section gland (nominal 3/8 inch) with proposed gland lengths for compression-type seals with two backup rings over a range of 7 to 21 inches (178 to 533 mm) in diameter. The dash number system used is similar to AS568A. A 600 series has been chosen as a logical extension of AS568A, and the 625 number has been selected for the initial number, since 300 and 400 series in MIL-G-5514 and AS4716 begin with 325 and 425 sizes. Seal configurations and design are not a part of this document. This gland is for use with compression-type seals including, but not limited to, O-rings, T-rings, D-rings, cap seals, etc.

This SAE Aerospace Recommended Practice (ARP) applies to landing gear structures and mechanisms (excluding wheels, tires, and brakes) for all types and models of civil and military aircraft applications. All axles, wheel forks, axle beams, links, arms, mechanical and air-oil energy absorbers braces, lock assemblies, trunnion beams, etc., that sustain loads originating at the ground, and that are not integral parts of the airframe structure should be designed in accordance with this document. Hydraulic actuators (retraction, steering, positioning, and/or damping) should also be included in this coverage. It should be the responsibility of the airframe manufacturer to determine the compatibility of these needs with the aircraft and to specify requirements in excess of these minima where appropriate.

This ARP applies to all types and models of civil aircraft for landing gear structure and mechanism excepting wheels, tires and brakes. All axles, wheel forks, axle beams, links, arms, mechanical and air-oil energy absorbers, braces, lock assemblies, trunnion beams, etc., that sustain loads originating at the ground and that are not integral parts of the airframe structure shall be in accordance with this practice.

This SAE Aerospace Recommended Practice (ARP) applies to landing gear structures and mechanisms (excluding wheels, tires, and brakes) for all types and models of civil and military aircraft including all aircraft with vertical landing and crash attenuation requirements. All axles, wheel forks, axle beams, links, arms, mechanical and nitrogen/oil energy absorbers, lock assemblies, braces, trunnion beams, and truck beams etc., that sustain loads originating at the ground, and that are not integral parts of the airframe structure, should be designed in accordance with this document. Hydraulic actuators (retraction, main and nose gear steering, positioning, and/or damping) should also be included in this coverage.