Component Maintenance Without Approved Data and the EASA Form 1 Question
A CAR-145 organisation overhauls a landing gear actuator removed from a regional turboprop. The OEM's component maintenance manual is unavailable because the OEM has gone bankrupt and the manual is out of print. The shop supervisor proposes using a 'similar' manual from another actuator model, adjusting torque values by judgement, and issuing an EASA Form 1 on completion. The actuator is a critical component. The organisation's rating covers the component, but the approved data is the problem. The customer needs the aircraft back in service within a week. A used serviceable actuator of the correct part number is available as an alternative, but its traceability paperwork is incomplete.
1. Can the organisation overhaul the actuator using the 'similar' manual and issue a Form 1? Justify with reference to approved data requirements.
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No. Maintenance must be performed using approved data appropriate to the component. A manual for a different actuator model, with torque values adjusted by judgement, is not approved data for this part. Issuing an EASA Form 1 would falsely certify that the work was done to approved standards, which is a serious breach.
Key points:
- Approved data means data approved by the type certificate holder/design authority or the competent authority (e.g., CMM issued under the design approval, or an approved repair scheme).
- 'Similar' data and engineering judgement are not substitutes for critical components.
- A Form 1 certifies that maintenance was performed in accordance with approved data and that the item is airworthy; without approved data, that statement cannot be made.
Options: obtain the correct CMM (from the design authority, a successor, or the authority), obtain an approved repair/modification scheme, or replace the unit with a correctly documented serviceable part.
2. Evaluate the alternative of fitting the used serviceable actuator with incomplete traceability. What must be established before installation?
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A used serviceable component may be fitted only if its airworthiness status and traceability are established. Incomplete paperwork is a red flag.
Before installation, the organisation must confirm:
- The part number and serial number match the aircraft/component requirement.
- The unit's maintenance history and last shop visit are documented.
- A valid authorised release certificate (e.g., EASA Form 1 or equivalent) or acceptable traceability to a known source exists.
- Any life-limited or overhaul-interval status is known and within limits.
If traceability cannot be established, the unit cannot be assumed airworthy. The organisation should not fit it on a 'looks fine' basis. The correct action is to resolve the paperwork (contact the source, obtain records) or source a properly documented unit. Installing an untraceable critical component would undermine the aircraft's continuing airworthiness and could invalidate the maintenance release.