Landing gear systems are one of the more problematic subsystems on Naval aircraft. Landing gear failure can be caused by hard landings due to actual severe high sink rate with high enough GW to exceed the design strength, but are extremely rare. More common are fatigue and environmentally caused failures. Aircraft managers address this issue by making estimations of operational loads, and doing detailed fatigue analysis as appropriate to ensure safe landing gear operation. These estimations are conservative by nature, and frequently necessitate assumptions about landing, ground or braking conditions that may be different in actual operational service. The ability to measure, record, and possibly process the operational loads data for each aircrafts landing gear would give Aircraft Program Offices the ability to make more intelligent management decisions about operational limits, inspection intervals, and removal & depot overhaul cycle values. Additionally, landing gear failures can be caused by mis-servicing of the landing gear, resulting in much higher loads (even for a
Benefit: ES3 anticipates the results of Phase I work will validate the feasibility and need for immediate pursuit of Phase II efforts. ES3 anticipates that current SHM technology is available to design and prototype a system that will meet the objectives of the program. The immediate benefit will be the ability to warn operators of low fluid level and hard landings. Automated determination of C.G., weight and balance can follow this functionality. Measurement of landing gear strains/loads/accelerations and temperatures will lead to greater understanding of each aircrafts operating parameters. This, in turn, will allow for more intelligent maintenance requirements, or inspection and repair intervals. This will maximize the utilization of the landing gear components, without compromising their safe operation; which will ensure life cycle cost reductions. Other benefits will include: Ability to increase aircraft structural capacity or operational limitation Ability to decrease aircraft brake cooling times Ability to determine high load events, and notify operators for special inspections or removal
Keywords: weight & balance, weight & balance, Structural Health, Fatigue tracking, prognostic, structural health monitoring, fluid level, Landing Gear, hard landing indication, Center of Gravity, Diagnostic
