LLP Tracking and Component Records: What M.A.305 Requires and What Transfers with the Aircraft
M.A.305 records for life-limited parts and time-controlled components, retention periods, what transfers with the aircraft, and an LLP status table to copy.
Dionysis Kefalas17 min readFor CAMO and Part-145 staff
Part 8 of 8 in EASA Continuing Airworthiness Show parts
- 1Continuing Airworthiness: Part-M and Part-CAMO
- 2Aircraft Maintenance Programme under Part-M
- 3EASA Reliability Programmes and Monitoring
- 4Airworthiness Reviews and the ARC
- 5CAMO and CAO Continuing Airworthiness Bodies
- 6Part-M: Release to Service and Records
- 7EASA Airworthiness Directives: AD Compliance Explained
- 8LLP Back-to-Birth Records and Component Tracking (M.A.305)
Quotes checked on against 2 sources. Show sourcesHide sources
- EASA Easy Access Rules for Continuing Airworthiness (Regulation (EU) No 1321/2014) — 2 Sep 2025 revision
- EASA Continuing Airworthiness frequently asked questions, FAQ 19043 (library document slug continuing-airworthiness, no version label), checked on https://www.easa.europa.eu/en/faq/19043
On this page
The LLP sheet that arrives with the engine
ExampleAir is fitting a spare engine, ESN-EXAMPLE-201, to XX-EXA. It arrives with an EASA Form 1 and a pack of LLP sheets: the high-pressure turbine stage 1 disk shows 8,662 cycles since new and 11,338 remaining. Before relying on them, the records team has to see how they were built: which engines the disk flew in, when, and at what counts.
That is what EASA asks for. M.A.305(d) puts the current status of every life-limited part (LLP) and time-controlled component (TCC) in the aircraft continuing airworthiness records. M.A.305(e) adds an in-service history record for each LLP and sets how long the supporting records are kept. M.A.307 moves the records when the aircraft is permanently transferred or the owner contracts a CAMO or CAO, and the retention periods carry on. Below: each rule quoted, a status table, and a worked entry.
Key facts
- The aircraft continuing airworthiness records include the current status of LLPs and TCCs (M.A.305(d)).
- For an LLP, the status shows the limit, the life accumulated and the life remaining in each applicable parameter (GM M.A.305).
- Each LLP needs an in-service history record. EASA's FAQ says the term "back to birth" is not used in European regulations.
- Installed LLPs and TCCs "shall not exceed the approved limitation as specified in the AMP and ADs" (M.A.503).
- Records of the last scheduled maintenance of LLPs and TCCs stay until superseded, covering not shorter than 36 months (M.A.305(e)).
- On a permanent transfer the records go with the aircraft, and the retention periods continue to apply to the new holder (M.A.307).
- A CAMO that ceases operations transfers its retained records to the owner, and should confirm in writing that they are complete and accurate (CAMO.A.220(a)(8) and its AMC1).
Which parts count: life-limited or time-controlled
The guidance material to M.A.305 defines both terms and the parameters.
[…]
(b)‘Applicable airworthiness limitation parameter’ and ‘applicable parameter’ refer to ‘flight hours’ and/or ‘flight cycles’ and/or ‘landings’ and/or ‘calendar time’, and/or any other applicable utilisation measurement unit, as appropriate.
(c)A ‘life-limited part’ is a part for which the maintenance schedule of the aircraft maintenance programme requires the permanent removal from service when, or before, the specified mandatory life limitation in accordance with Commission Regulation (EU) No 748/2012 if any of the applicable parameters is reached.
[…]
(e)The term ‘time-controlled components’ embraces any component for which the maintenance schedule of the aircraft maintenance programme requires periodically the removal for maintenance to be performed in an appropriate approved organisation for maintenance in components (workshop) to return the component to a specified standard, the replacement of sub-components of the assembly by new ones, or the inspection or test of component’s performance, after a service period controlled at component level in accordance with the specified airworthiness limitation defined in accordance with Commission Regulation (EU) No 748/2012, in any of the applicable parameters.
[…]
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
An LLP leaves service for good at its limit. A TCC goes to the workshop at its interval and comes back. Both count in whichever parameters apply, and the LLP limit is reached when "any" of them is. Part-ML aircraft use the term "service life-limited component", defined in ML.A.503.
What the record must show for each part
[…]
(d)The aircraft continuing airworthiness records shall include the current status specific to components of:
1.life-limited parts, including the life accumulated by each affected part in relation to the applicable airworthiness limitation parameter; and
2.time-controlled components, including the life accumulated by the affected components in the applicable parameter, since the last accomplishment of scheduled maintenance, as specified in the AMP.
[…]
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
The guidance material says what "current status" means.
[…]
(d)The ‘current status’ when referring to components of life-limited parts should indicate, for each affected part, the life limitation, the total life accumulated in any applicable parameter (as appropriate) and the remaining life in any applicable parameter before the life limitation is reached.
[…]
(l)The term ‘current status’ refers to the data which accurately establishes the level of compliance of an aircraft, engine, propeller or component thereof, with a requirement. Each status should:
(1)identify the aircraft, the engine, the propeller or the component it applies to;
(2)be dated; and
(3)include the relevant total in-service life accumulated in the applicable parameter on the date of the status.
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
Three numbers per LLP, in every parameter that applies: the limit, what it has used, what it has left. A TCC's count restarts at its last scheduled maintenance. Every status carries a date and the unit's total on that date, or nobody can check it against the aircraft.
The limit is not yours to choose. M.A.503 ties it to the programme and the directives.
(a)Installed life-limited parts and time-controlled components shall not exceed the approved limitation as specified in the AMP and ADs, except as provided for in point M.A.504(b).
(b)When the approved limitation expires, the component shall be removed from the aircraft for maintenance, or for disposal in the case of life-limited parts.
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
See the AMP guide for the programme side and the AD guide for directive limits.
Back-to-birth: what the rules actually ask for
In the trade, "back to birth" means an unbroken history from manufacture to today. EASA was asked whether Europe requires it.
FAQ 19043 — Back-to-birth traceability · EASA frequently asked questions, Continuing Airworthiness · easa.europa.eu/en/faq/19043
The term “back to birth” is not used in European regulations. The requirements that apply to a life-limited part or a service life-limited component (see definition in ML.A.503(a)) are basically stated in M.A.305 (d)&(e) or ML.A.305(e). All detailed maintenance records of a maintenance action (e.g. a restoration) must be kept until another maintenance action equivalent in scope (another restoration) is done, but never less than 36 months. […]
An FAQ is the Agency explaining its rules, not a rule (how to read EASA regulations). The rule is the in-service history record of M.A.305(e)(3)(i), quoted under retention below. The guidance material says what it holds.
[…]
(j)The term ‘in-service history record’ embraces records from which the current status of life-limited parts can be determined. The ‘in-service history record’ template could be adjusted to the relevant characteristics of the life-limited part, e.g. an engine disk being different from a fire extinguisher squib or landing gear sliding tube.
Such records document each time a life-limited part is placed in service or removed from service. They should clearly:
(1)identify the part by its part number and serial number,
(2)show the date of installation and removal (i.e. date on/date off),
(3)show the details of the installation and removal (i.e. type, serial number, weight variant, thrust rating, as appropriate, of the aircraft, engine, engine module, or propeller) at installation and removal of the part when this is necessary to appropriately control the life limitation.
(4)Show the total in-service life accumulated in any applicable parameter, as appropriate, corresponding to the dates of installation and removal of the part.
[…]
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
Those four items are the links of the chain: every date on and off, the host, and the life at that moment. If the limit depends on thrust rating or weight variant, record it at each installation.
Gaps happen: a log card lost between owners. The AMC allows a way through.
[…]
(b)Conservative methods to manage missing historical periods are acceptable to establish the current status of the life-limited part. In the case of use of a conservative method, the supporting documents should be endorsed. Recommendations from the design approval holder or the declarant of a declaration of design compliance on the procedures to record or reconstruct the in-service history should be considered.
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
The other side is a part whose history cannot be established. The AMC to M.A.501 is direct, and the AMC to 145.A.42 gives a Part-145 organisation the same test.
UNSALVAGEABLE COMPONENTS
The following types of components should typically be classified as unsalvageable:
[…]
(d)life-limited parts that have reached or exceeded their mandatory life limitation, or have missing or incomplete records;
[…]
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
[…]
(d)parts with mandatory life limitations that have reached or exceeded these limitations, or have missing or incomplete records;
[…]
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
A gap in an LLP's history is an airworthiness question, not a filing problem. If a conservative method is used, have the endorsed evidence before accepting the part.
An LLP and component status table you can copy
Each column answers a line quoted above. "Limit source" is practice: M.A.503 names the AMP and ADs, so say which.
ExampleAir's entries for the disk and a landing gear. Part numbers, references and limits are illustrative.
The disk's figures come from its history, not the engine's counter:
- The history record shows 4,300 cycles since new when the disk was fitted to ESN-EXAMPLE-201 on 12 March 2024, at 9,850 engine cycles.
- Engine cycles since then: 14,212 − 9,850 = 4,362.
- Cycles since new today: 4,300 + 4,362 = 8,662.
- Remaining: 20,000 − 8,662 = 11,338.
Every number traces to a document. The landing gear has two limits: keep both remainders, and never turn cycles into a date through an assumed utilisation rate.
The same data answers the Form 1 guidance for a serviceable part removed from an aircraft, where "time since overhaul" appears (AMC2 145.A.50(d)).
[…]
2.6.1. Serviceable aircraft components removed from a Member State registered aircraft may be issued with an EASA Form 1 by an appropriately rated organisation subject to compliance with this subparagraph.
[…]
(g)The flight hours/cycles/landings as applicable of any life-limited parts and time-controlled components including time since overhaul should be established.
[…]
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
[…]
(e)The owner or operator shall establish a system to keep the following documents and data in a form acceptable to the competent authority and for the periods specified below:
[…]
3.data specific to certain components:
(i)an in-service history record for each life-limited part based on which the current status of compliance with airworthiness limitations is determined;
(ii)the CRS and detailed maintenance records for the last accomplishment of any scheduled maintenance and any subsequent unscheduled maintenance of all life-limited parts and time-controlled components until the scheduled maintenance has been superseded by another scheduled maintenance of equivalent scope and detail but covering a period not shorter than 36 months;
[…]
4.Record-keeping periods when the aircraft is permanently withdrawn from service:
[…]
(ii)the last effective status and reports as identified under points (c) and (d) of point M.A.305 which shall be retained for at least 12 months; and
(iii)the most recent CRS(s) and detailed maintenance records as identified under points (e)(2)(ii) and (e)(3)(i) of point M.A.305 which shall be retained for at least 12 months.
[…]
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
For the disk, the March 2024 Form 1 stays until an equivalent shop visit supersedes it, subject to the 36-month floor (GM M.A.305(e)(2) explains the same wording where it appears in point (e)(2)). Part-ML: ML.A.305 points (e) and (h). The aircraft-level lines are quoted in Part-M: Release to Service and Records.
What transfers when the owner, operator or CAMO changes
(a)When an aircraft is permanently transferred from one owner or operator to another, the transferring owner or operator shall ensure that the continuing airworthiness records referred to in point M.A.305 and, if applicable the technical log system referred to in point M.A.306, are also transferred.
(b)When the owner contracts the continuing airworthiness management tasks to a CAMO or CAO, the owner shall ensure that the continuing airworthiness records referred to in point M.A.305 are transferred to that contracted organisation.
(c)The time periods for the retention of records set out in point (e) of point M.A.305 shall continue to apply to the new owner, operator, CAMO or CAO.
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
Point (c) bites: the same retention periods continue to apply to whoever takes the records over, so a gap you inherit is yours to manage. The AMC covers short leases; ML.A.307 is the Part-ML counterpart.
[…]
A ‘permanent transfer’ does not generally include the dry lease-out of an aircraft when the duration of the lease agreement is less than 6 months. However the competent authority should be satisfied that all continuing airworthiness records necessary for the duration of the lease agreement are transferred to the lessee or made accessible to them.
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
For the CAMO, CAMO.A.220 covers what it retains and hands on, and its AMC adds a written statement.
(a)Continuing airworthiness management records (1) The organisation shall ensure that records required by points M.A.305, ML.A.305 and, if applicable point M.A.306, are retained.
[…]
(8)When the organisation ceases operations, all retained records shall be transferred to the owner of the aircraft.
[…]
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
The records should be transferred to the aircraft owner when requested, or to the person or organisation that will manage the continuing airworthiness, if accepted by the aircraft owner. The CAMO transferring the records should provide a written statement confirming that all records
have been transferred and are complete and accurate.
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
A component pack for the incoming CAMO, built from the lines quoted here:
- Dated LLP status for each engine, APU and landing gear, with unit totals on that date.
- The in-service history record for each LLP, with any endorsed conservative-method evidence.
- TCC status, with life since the last scheduled maintenance.
- The CRS or Form 1 and detailed records of the last scheduled maintenance of each LLP and TCC.
- If the outgoing CAMO is ceasing operations, its written statement that all records have been transferred and are complete and accurate. In any other handover, asking for the same statement is good practice, not a quoted requirement.
Before accepting it, read two LLP serial numbers off the parts and trace each through its history to the status line.
A lease return adds a contract on top: return conditions are commercial terms, and none of the rules quoted here sets them. For the open-items side, see the redelivery article.
Keeping the working list in Avioverse
In Registries, the Aircraft component register starter gives you Aircraft registration and Aircraft MSN in the header, and rows with Part number, Serial number, Installed on and Installation status (Installed, Stored or Removed). The starter is offered on your first registry; a blank registry with the same fields works too, and Settings adds fields later.
Remaining life needs three additions:
- A Number header field for the current reading, such as "Engine cycles". Each calculated column reads one header counter, so the simplest layout is one register per engine, and one per aircraft for airframe and landing-gear parts.
- On each row, a Number column for the counter at installation, and an Interval column set to Counter — hours, cycles, distance… with the unit "cycles", holding the life left at installation.
- A Calculated column using Due and remaining, then Last done + interval, with the header reading as the current value and Show set to Next due, remaining & status.
For the disk: 9,850 at installation plus 15,700 left (20,000 − 4,300). The column shows next due at 25,550 engine cycles, 11,338 cycles remaining, and a status of Not due, Due soon (if you set a warning), Due now at zero or Overdue; a missing reading shows Unable to assess. In the screen's words: "Update this header once to refresh all rows."
A part with a calendar and a cycles limit gets two such columns. Overall due status combines up to 10 of them: any overdue column makes the row Overdue, and "Missing readings never produce an all-clear." Export CSV and Registry (PDF) produce a file.
The life limit, the history and the arithmetic behind "life left at installation" stay with you; the register does not check them. It is a working list, not the continuing-airworthiness record: rows take no attachments and keep no history, there is no import, and it sends no notifications.
Where to read it yourself
Every rule quoted here comes from the EASA Easy Access Rules for Continuing Airworthiness, 2025-09-02 revision, and links to its regulation-library page; the FAQ is EASA FAQ 19043. This guide closes the series the overview opens.
Educational content, not regulatory compliance advice. Verify against the current regulation text before relying on it.
In this series
Frequently asked questions
What records does EASA require for a life-limited part?
M.A.305(d) puts the current status of each life-limited part in the aircraft continuing airworthiness records, including the life it has accumulated against the applicable limitation parameter. M.A.305(e)(3)(i) adds an in-service history record for each life-limited part. GM M.A.305 says the current status should show the life limitation, the total life accumulated and the remaining life in each applicable parameter.
Does EASA require back-to-birth traceability for LLPs?
EASA FAQ 19043 says the term "back to birth" is not used in European regulations and points to M.A.305(d) and (e), or ML.A.305(e). What M.A.305 asks for is an in-service history record for each life-limited part, from which its current status is determined.
How long must LLP and time-controlled component records be kept?
M.A.305(e)(3)(ii) keeps the CRS and detailed maintenance records for the last scheduled maintenance, and any later unscheduled maintenance, until superseded by equivalent scheduled maintenance, covering a period not shorter than 36 months. After the aircraft is permanently withdrawn from service, M.A.305(e)(4) keeps the last effective status and the records it names for at least 12 months.
Which records transfer when an aircraft changes owner, operator or CAMO?
Under M.A.307, a permanent transfer moves the M.A.305 records, and the M.A.306 technical log where applicable, to the new owner or operator. When the owner contracts a CAMO or CAO, the records go to that organisation. The M.A.305(e) retention periods continue to apply to the new owner, operator, CAMO or CAO.
Can a life-limited part with a gap in its history still be used?
AMC M.A.305(e)(3) accepts conservative methods to manage missing historical periods, with the supporting documents endorsed and the design approval holder's recommendations considered. AMC1 M.A.501(a)(3) lists life-limited parts with missing or incomplete records among the components that should typically be classified as unsalvageable.
Related
Written by Dionysis Kefalas. Retired Hellenic Air Force Captain and founder of Avioverse. About the author
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