Aircraft Technical Records Landing Gear and Engines – Life Limited Parts (LLP’s) Considerations

Sofema Aviation Services' Next Course will take place at Avenue Hotel Deira – Dubai, UAE:

Aircraft Technical Records Specialist Lessee Management for CAMO & TR Staff – 2 Days

The course will run from 9 am to 5 pm from February 2nd to February 3rd 2020

Sign up here

What is Back to Birth Traceability? (BTB) or (B2B)

Actually, it is not a term which EASA uses – however it is recognised within the leasing community as the basis of validating the integrity of Life Limited Components.

With the Introduction of Maintenance Steering Group 3 (MSG3) back in 1980 the number of Life Limited Components reduced with many “Hard Time” components being moved to “On Condition” classification.

However many components including many “Engine”, “Auxiliary Power Unit” (APU) and “Landing Gear” (LDG Gear) Components continued to be “life Limited” so it is important that we are able to track these components correctly within the Technical Records System.

In general, there are no deviations from manufacturer-imposed life limits even though Life Limits are based on “Safe Life” principles where the component is called within a considerable margin of its expected or anticipated failure.

During the life of the aircraft, it is normal for major components to be replaced a number of times, moreover, during overhaul and shop visits sub-components are often replaced.

The use of Re-Market Components

It is quite common to replace a removed component (Engine, APU Etc) with a pre-used one and in such cases care should be taken to manage the numerous “sub” LLP components which may have had numerous have been taken from a different unit, operated on different aircraft by different operators and under different authorities.

The task of managing all associated documentation back to birth is of critical importance not just to ensure flight safety but to also guarantee the maximum retention of asset value.

New Parts Certification

Typically, individual release certificates for the components installed on a “new” aircraft (including landing gear & engines) are not provided, however, they do exist as they are “manufactured” by a different company than the aircraft.

Data concerning the subparts of all LLP are provided as part of the master assembly status provided by the Type Certificate Holder with the new aircraft.

In-Service Back to Birth Traceability

During aircraft in service operations, the major assemblies containing several life-limited parts will be replaced, and during overhauls and refurbishment other LLP may also be replaced due to damage and deterioration.

To optimise the maintenance program there is an option to install used life-limited parts which have enough life remaining to meet the airline’s operational requirements.

As the aircraft matures, the parts can mix and match and the task of maintaining Back to Birth Traceability becomes ever more challenging.

Note – Failure to fully engage with this data can lead to costly exposures during lease return audits.

How can we Establish the Actual Life of the Component?

Whilst the process is straightforward it is by no means easy as we should trace every movement from when the component was manufactured. From its first release certificate or New Aircraft build evidence together with all fitment evidence and Hours, Cycles and Landings as applicable throughout the operation and use of the component in service.

It may be necessary to obtain statements from the previous operators confirming that while under their control, the engine (or aircraft, or landing gear) to which a given component has been installed has flown a given amount of cycles and has not suffered from any incidents or accidents.

What Documents are Required to Show Back to Birth Traceability?

Manufacturer Certification

a) Aircraft export certificate of airworthiness together with a fit list of all components installed.

b) Master assembly (engine or landing gear) release certificate (EASA Form One, FAA 8130 or equivalent).

c) Fit list of sub-components fitted at manufacture. This shows that the component has been factory fitted to a new master assembly.

d) Release certificate stating “manufactured” for the component itself – you will get this is the component has been manufactured as a spare part and was not originally installed on any engine or landing gear leg.

e) Removal / Installation Documentation from Previous Operators.

Shop Visit & Maintenance Documentation

It may be necessary to have the shop visit reports for the master assembly, including release certificates for master assembly and any given component.

It will be also necessary to have a copy of the CRS of all relevant maintenance checks. The Tech Log page does contain a CRS as well as Flight Hours / Cycles.

Note – typically task cards do not constitute a CRS.

Statements from Previous Operators

Statements confirming that the master assembly and/or the aircraft it was fitted to, was flown by the given operator within a given range of dates and for a given number of hours and cycles.

Non-incident statements. Those statements are mainly necessary for insurance purposes. They confirm that, while the component has been under the previous operator’s supervision, it has not taken part in any accident or serious accident, has not been subjected to saltwater or fire, etc.

What is an Export Certificate of Airworthiness?

The Export Certificate of Airworthiness (Export CofA) confirms that the particular aircraft complies with the list of type-certificate data (TCDS) and is suitable for safe use. The Export Certificate of Airworthiness does not imply that the aircraft could be already flown. To achieve this, a valid Certificate of Airworthiness (CofA) or Permit to Fly (PtoF) is needed.

The issue of such a certificate is not obligatory (in accordance with the ICAO Airw. Manual 9760). However, the applicant shall submit the following for its issue: Application for the issue of Export Certificate of Airworthiness (AIR.OBR-53).

In case that the aircraft is exported into a state with a valid agreement with EASA, the export certificate (EASA Form 27) is issued in accordance with the said agreement (for example: BASA). In other cases, in the absence of any agreement between the two countries related to the issuance of the export certificate of airworthiness – the national Export Certificate of Airworthiness shall be issued.

Sofema Aviation Service www.sassofia.com and Sofema Online www.sofemaonline.com offer CAMO Lessee Regulatory and Vocation training both online and within the classroom environment. for details or enquiries please email [email protected] or [email protected].