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This document outlines the current state of the art in the understanding of gas in solution in shock absorber oils in unseperated shock absorbers. A literature review, overview of Henry's law, Henry's law coefficients for known gas and oil couples, in-service operational problems, lessons learned, and potential future work will be discussed in the document.

This document will outline existing best practices in the instrumentation of landing gears for in-service operation (including flight test, operational loads monitoring, etc.).

This document describes the approaches taken to define safe-life limits for the management of fatigue in landing gear structures, and the substantiation of those limits through full-scale fatigue testing. The safe-life scatter factors considered in a range of military and civil regulatory standards are also reviewed.

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) provides guidelines for the development of landing gear fatigue spectra for the purpose of designing and certification testing of Part 25 landing gear. Many of the recommendations herein are generalizations based on data obtained from a wide range of landing gears. The aircraft manufacturer or the landing gear supplier is encouraged to use data more specific to their particular undercarriage whenever possible.

The recommended practice establishes the requirements for lubricating oil filters for general aviation reciprocating engine applications with lubricating oil systems normally operating in a pressure range of 345 - 689 kPa (50 - 100 psig).

The intent of this document is to provide recommended practices for conducting shock absorption testing of civil aircraft landing gear equipped with oleo-pneumatic shock absorbers. The primary focus is for Part 25 aircraft, but differences for Part 23, 27, and 29 aircraft are provided where appropriate.

This document will contain guidance and considerations for the use of composite materials on non-primary structure for landing gear systems. Content to include design considerations, conditions and applications where composites are feasible/beneficial, high-level descriptions of various manufacturing processes, and certification/validation considerations.

This SAE Aerospace Recommended Practice (ARP) provides guidance on the definition, development, and establishing a LGIP.

This Aerospace Information Report (AIR) will examine considerations relative to the use of mechanical switches on aircraft landing gear, and present "lessons learned" during the period that these devices have been used.

This SAE Aerospace Standard (AS) covers an alternate gland design for the installation of scraper/ wiper rings in the lower end of landing gear shock struts for the purpose of contaminant exclusion. The defined scraper gland covered by this document, as shown in Table 1, is a variant of AS4716, the accepted gland standard for AS568, O-ring packing seals. Piston rod diameters, gland internal diameters, groove sidewall angles and the surface finish are all defined by AS4716, but the gland outer retaining wall diameter is changed. The traditional scraper design installed into the glands detailed in Table 1 typically utilize components made from PTFE, urethane, or nitrile materials. These scraper designs, while still acceptable, must be reviewed in consideration to deicing, cleaners and disinfectant fluids applied to or in contact with the landing gear, as the materials of construction for the installed scrapers may not be compatible to these fluids.

This SAE Aerospace Standard (AS) covers an alternate gland design for the installation of scraper/wiper rings in the lower end of landing gear shock struts for the purpose of contaminant exclusion. The defined scraper gland covered by this document, as shown in Table 1, is a variant of AS4716, the accepted gland standard for MS28775, O-ring packing seals. Piston diameters, gland internal diameters, groove sidewall angles and the surface finish are all defined by AS4716, but the gland outer retaining wall diameter is changed. AS4088 is similar to this document, but was developed by SAE A-6 for flight control and general-purpose cylinders. It differs from this document primarily by the clearance between the rod (piston) and outer gland wall. Since landing gears are more susceptible to dirt contamination, the additional clearance provides a larger path to allow excessive dirt accumulation to exit the gland.

This SAE Aerospace Standard (AS) covers an alternate gland design for the installation of scraper/wiper rings in the lower end of landing gear shock struts for the purpose of contaminant exclusion. The defined scraper gland covered by this document, as shown in Table 1, is a variant of AS4716, the accepted gland standard for MS28775, O-ring packing seals. Piston rod diameters, gland internal diameters, groove sidewall angles and the surface finish are all defined by AS4716, but the gland outer retaining wall diameter is changed. The traditional scraper design installed into the glands detailed in Table 1 typically utilize components made from urethane or nitrile materials. These scraper designs, while still acceptable, must be reviewed in consideration to deicing, cleaners and disinfectant fluids applied to or in contact with the landing gear, as the materials of construction for the installed scrapers may not be compatible to these fluids.

This SAE Aerospace Information Report (AIR) discusses the potential considerations for landing gear that may have to traverse arresting cables. This can be a consideration civil aircraft and aircraft without arrestor hooks that operate into dual use (military and civil) airfields.

This document defines the criteria used for the selection of landing gear shock strut upper and lower bearings (see Figure 1).

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.

Provide guidance and parameters on selection of a calendar based overhaul interval due to environmental exposure.

This project will convert MIL-L-8552 (including changes defined in Amendment 2, 10 December 1968) word-for-word into an SAE Aerospace Standard. The new document will be approved in accordance with SAE's "accelerated approval" process.