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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.

Steel alloys, such as AF1410 (AMS 6527, UNS K92571) and AerMet 100 (AMS 6532), have been developed which have improved Fracture Toughness characteristics compared to the current landing gear steel alloy, 300M (AMS 6419 and AMS 6257, MIL-S-8844, UNS K44220). The 300M steel is the most widely used material in current landing gear designs. It has been successfully used in thousands of applications. The use of the 300M material necessitates a safe life design criterion where components are retired after one-fourth to one-sixth the laboratory test life. This criterion was established in part due to the relatively low fracture toughness of low-alloy steel in the 260 to 300 ksi strength range. The high fracture tough alloys give comparable strength levels with an increase in fracture toughness and better resistance to stress corrosion cracking. These alloys may make possible the consideration of new procedures for operation, maintenance, and inspection.

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 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 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 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 Information Report (AIR) discusses the nature of landing gear stability, describes many common landing gear stability problems, and suggests approaches and methods for solving or avoiding them.

This document outlines the most common repairs used on landing gear components. It is not the intention of this AIR to replace Overhaul/Component Maintenance or Technical Order Manuals, but it can serve as a guide into their preparation. This document may also be used as a template to develop an MRB (Material Review Board) plan. The recommendations in this document apply to components made of metallic alloys. These recommendations are intended for new manufactured components as well as for overhauled components. The extent of repair allowed for new components as opposed to in-service components is left to the cognizant engineering authorities. Reference could be made to this document when justifying repairs on landing gears. For repairs outside the scope of this document, a detailed justification is necessary. It must be understood that all the repairs listed in this document are not to be applied without the involvement of the cognizant engineer.

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).

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.

The scope of this document is to discuss the differences between electromechanical and proximity position sensing devices (sensor or switch) when used on landing gear. It also contains information which may be helpful when applying either type of technology after the selection has been made. The purpose is to help the designer make better choices when selecting a position-sensing device. Once that choice has been made, this document includes information to improve the reliability of new or current designs. It is not intended to replace recommendations from sensor manufacturers or actual experience, but to provide a set of general guidelines based on historic infromation of what is being used.

This document is intended to give advisory information for the selection of plain bearings and bearing materials most suitable for aircraft landing gear applications. Information is given on bearing installation methods and fits that have given satisfactory performance and service life expectancy. Corrosion is a major cause of problems in bearing installations for landing gears. Therefore, methods of corrosion prevention are outlined. Effort is directed toward minimizing maintenance and maximizing life expectancy of bearing installations. Lubricated and self-lubricating bearings are discussed. There are wide ranges of bearing load and motion requirements for applications in aircraft landing gears. For this reason, it is the responsibility of the designer to select that information which pertains to his particular application. Anti-friction bearings, defined as rolling element bearings generally used in wheel and live axle applications, will not be discussed in this document.

This document is intended to give advisory information for the selection of plain bearings and bearing materials most suitable for aircraft landing gear applications. Information included herein was derived from bearing tests and service experience/reports. Airframe/landing gear manufacturers, commercial airlines, the U.S. Air Force and Naval Air Systems Command provided input for the document. Information is given on bearing installation methods and fits that have given satisfactory performance and service life. Base metal corrosion is a major cause of problems in bearing installations for landing gears. Therefore, methods of corrosion prevention are discussed. Effort is directed toward minimizing maintenance and maximizing life expectancy of landing gear bearings. Lubricated and self-lubricating bearings are also discussed. There are wide ranges of bearing load and motion requirements for applications in aircraft landing gears.

This document provides recommended practices for the design, development, and verification testing of aircraft nosewheel steering (NWS) systems.

This information report provides general guidance for the design considerations, qualification in endurance, strength and fatigue of landing gear using composite components as principle structural elements. The information discussed herein includes the development and evaluation of design data considering: the potential for imbedded manufacturing defects, manufacturing process variations, the component operating environment, potential damage threats in service, rework and overhaul, and inspection processes. This AIR mainly discusses the use of thick composites for landing gear structural components. Considerations and recommendations provided in this AIR may therefore differ greatly from considerations and recommendations found in widely accepted composite design references such as CMH-17 and Advisory Circulars such as AC 20-107(B).