Release to Service After an Unapproved Repair Scheme
You are the certifying B1 engineer on a CAR-66 approved maintenance organisation. A Boeing 737-800 arrives for a scheduled C-check. During inspection you find a 40 mm circumferential crack in the lower wing skin access panel doubler, within the allowable limits of the Structural Repair Manual (SRM) only if a repair scheme is approved. The operator's engineering department emails a repair drawing referencing a 'similar repair previously accepted on another aircraft type', stamped by a DER from a foreign authority, but the drawing is not listed in the aircraft's Type Certificate data sheet or the approved design data held by the organisation. The aircraft is due to fly a revenue sector in 14 hours. The accountable manager asks you to sign the Certificate of Release to Service (CRS) on the basis of the email and drawing.
1. Can you sign the CRS based on the emailed repair drawing? Justify your decision with reference to CAR-66 privileges and approved design data.
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No. As a B1 certifying staff member, you may only certify maintenance that has been carried out in accordance with approved design data and within the scope of your authorisation. The DER stamp from a foreign authority is not, by itself, approved design data for this aircraft type. The repair must be either:
- covered by the SRM/approved repair scheme, or
- approved by the State of Design (or the Type Certificate holder) and incorporated into the approved data set.
Signing the CRS would be a false certification and a breach of CAR-66 privileges, potentially exposing you to licence action and the organisation to enforcement. The correct action is to refuse to certify and escalate to the Part-145 quality/engineering function for design approval, or raise a concession/deviation through the proper channel.
2. What immediate actions should you take, and how do you communicate this to the accountable manager?
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- Quarantine/document the finding - record the crack and the unapproved drawing in the maintenance record and NCR system.
- Do not release - the aircraft remains unserviceable; place an 'Aircraft on Ground' (AOG) status in the technical log.
- Escalate - inform the Part-145 quality manager and engineering, requesting formal design approval (or a repair scheme from the TC holder).
- Communicate factually - explain to the accountable manager that the CRS is a legal statement of airworthiness, that the drawing lacks approved-data status, and that releasing would be unlawful regardless of commercial pressure.
- Offer options - expedited design approval, ferry permit under a specific flight condition if permitted by the NAA, or repair per an alternative approved scheme.
3. If a ferry flight is later considered, what conditions must be satisfied before any certification?
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A ferry flight requires a specific flight permit / ferry authorisation from the National Airworthiness Authority (GCAA), not a standard CRS. Conditions typically include:
- a documented engineering assessment showing the defect is within safe limits for the intended flight envelope;
- flight restrictions (altitude, speed, pressurisation, no passengers);
- a maintenance release endorsed for the ferry condition;
- approval by the operator's continuing airworthiness management organisation (CAMO).
Only after these are in place may certifying staff sign the ferry release. The original CRS for revenue service remains invalid until the repair is approved and accomplished.