Safe Life Items / Life Limited Parts / Back to Birth – Aircraft lease requirements and data sources.

Safe Life Items / Life Limited Parts / Back to Birth – Aircraft lease requirements and data sources.

An aircraft will contain many LLP Life Limited Parts which can also be known as Safe Life Items SLI parts; typically, these are in components such as the engines and landing gear, although these items may be present in the cabin also depending on your configuration.

An LLP/SLI part was designed to have a defined “life” and after this “life” is complete it will be destroyed regardless of condition.

Another important term associated with Life Limited Parts or Safe Life Items is the term BTB “Back to Birth”; which means to ensure that we have an accurate trace of the exact life remaining of an LLP/SLI we need to know its every function since manufacture.

Where we get this LLP/SLI Data from can vary depending on OEM and the component.

The data that we are looking for will originate from an ICA “Instructions for Continued Airworthiness”.

The section of the ICA we are interested in is the Airworthiness Limitations where it should then detail any LLP data for the ICA requirements.

What can be a little challenging initially is locating the information as it can be located in Chapter 5 in an AMM (Aircraft Maintenance Manual – Time Limits / Maintenance Checks) or it might be in a CMM (Component Maintenance Manual); it can also be noted in several other different documents and or drawings.

With the initial certificate for the part and then any details of installation / removal / overhaul / modification’s etc detailing the hours/cycles/date can begin to form a history for the part.

It is particularly important to remember that the LLP/SLI status must be correct when the aircraft is handed over so always consider demo or ferry flights and their impact on utilisation.

Why not learn more about the considerations of these parts on our Engines and Landing Gear course and follow us to learn more.