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Critical Tracking of Life-Limited Aircraft Parts

September 2011

All make model aircraft have life-limited aircraft parts that need to be replaced. For example, the elevator control cable on a Learjet 35 requires replacement every 2400 hours and a Hawker 800’s outer flap synchro cables must be replaced at 5000 flights. Most operators are aware of these limits and track their time and usage to schedule replacement when required. But what about the life-limited parts contained WITHIN aircraft assemblies?

Life-Limited Parts within Aircraft Assemblies

The nose landing gear strut on your Challenger is leaking and has just been replaced with one with approximately the same total cycles and time. On the surface it appears that you are good to go until the next scheduled maintenance comes due. But what about all the life-limited parts contained inside? These parts are often overlooked or mis-documented as having the same time/cycles as the whole unit. This is true only when the unit had life-limited parts replaced with new or serviceable higher cycle parts during rework. No matter when these parts were installed, they have very high life limits of their own and must be tracked individually and separate from the assembly.

If the assembly requires work/inspection further down the road and the individual piece part times/cycles is unknown, then those piece parts must be replaced in order for the assembly to be returned to service.

Duncan Aviation recommends you utilize a component life-limited tracking log to document not only the assembly times and cycles, but the individual piece parts as well. These piece parts should be separated out and documented with their part number, serial number and associated times and cycles. This document must be keep permanently with the log book to avoid unnecessary replacement and accompany the unit during exchange, inspection, repair or rework.

The tracking of life-limited aircraft parts is very important; not just for the safety of the passengers and crew, but to safeguard your expenses as well. A little time spent tracking and documenting today will avoid potential failure of these parts and the possibility of financial repercussions in the future.

Duncan Aviation is one of a few Maintenance, Repair and Overhaul (MRO) companies that can provide a customer with comprehensive aircraft maintenance service, thorough logbook research and maintenance tracking services. For more information contact, Penny Smith with Duncan Aviation’s Maintenance Tracker Services.