Repair approval
Boeing 737NG repair and alteration approval records review
This review examines the repairs and alterations recorded on a specific Boeing 737NG to confirm each carries an approved-data basis and a clean disposition. It is run by or for the party taking on the aircraft, where an unsubstantiated repair can force removal or re-substantiation. It maps each repair to its damage report, its approved or acceptable data, and the return-to-service entry that closed it, and locates repairs against the airframe. You receive a repair map with an approval basis per item, a list of repairs with weak or missing substantiation, and the alterations that need engineering attention.
When this review is needed
- A 737NG is transferring and its structural repairs must show an approved-data basis the receiving side accepts.
- A repair was carried out but the file does not hold the data that substantiates it.
- An alteration is recorded without the STC or approved basis it should reference.
- A repair map is needed to locate accumulated repairs against the airframe before a heavy check.
The problem
A repair record can note the work and the sign-off while saying nothing about the data that made the repair acceptable. On a 737NG that has taken structural damage and alterations across operators, repairs pile up, and the approved-data basis behind each one is easy to lose track of. A repair without substantiation is not just a paperwork gap, because if the basis cannot be shown, the repair may have to be re-substantiated or removed, and that decision competes with a heavy-check schedule.
What gets reviewed
- Each recorded repair matched to its damage report and disposition
- The approved or acceptable data basis for every repair and alteration
- Alterations reconciled to the STC or approved basis they rest on
- Return-to-service entries closing each repair and alteration
- Repairs located against the airframe so their positions and interactions are known
- Repairs and alterations with missing, weak, or mismatched substantiation
Scope this review
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What gets validated
- Each repair cites approved or acceptable data appropriate to the damage and location
- An alteration references the STC or approved basis it was carried out under
- The return-to-service entry follows from the repair or alteration record
- Repair locations on the map reconcile with the damage reports and the airframe history
- No repair sits in the file without a traceable substantiation basis
Evidence normally required
- The repair and alteration records and any existing repair map
- Damage reports and dispositions for the recorded repairs
- Approved or acceptable data referenced for each repair
- STC and approval references for the alterations
- Return-to-service entries closing the repairs and alterations
Common discrepancies
- A repair recorded and signed off with no approved data behind it in the file
- An alteration missing the STC reference it should have been carried out under
- A repair whose location does not reconcile with the damage report on file
- A return-to-service entry that does not follow from the repair record it closes
What is at stake
A repair with no traceable approved data can force re-substantiation or removal, which is far more expensive than confirming the basis when the work is fresh. An alteration recorded without its STC reference can stall a transaction until the basis is reconstructed, and repairs that were never mapped against the airframe make the next structural inspection slower and riskier because their interaction is unknown.
Move from findings to resolution
Move from findings to a documented resolution path.
How the work runs
Assemble the repair map
Locate every recorded repair and alteration against the airframe and its damage reports.
Trace the substantiation
Match each repair and alteration to the approved or acceptable data it rests on.
Confirm the closures
Verify each return-to-service entry follows from the repair or alteration record.
Flag the weak items
List repairs and alterations with missing or mismatched substantiation and those needing engineering.
What the buyer receives
- A repair map with the approval basis identified per item
- A list of repairs and alterations with missing or weak substantiation
- The alterations that need engineering attention before they can be relied on
Who uses the output
- Asset managers pricing the substantiation exposure across the aircraft's repairs
- Engineering deciding how to treat a repair with no traceable approved-data basis
- Records teams recovering substantiation before a heavy check or a transfer
How the work fits into the transaction or program
The repair review feeds the structural and configuration read on an incoming 737NG, and its repair map is what the next heavy check works from. Where it finds a repair without approved data or an alteration missing its STC basis, that item moves into remediation before the aircraft's structural condition has to be signed off under a new program.
Aircraft-specific considerations
The 737NG accumulates structural repairs and cabin and avionics alterations across a long service life, and successive operators add STC modifications whose approval basis has to be traceable. Structural repair mapping matters more on this type than on a lightly modified airframe, because repair interactions drive the scope and the risk of the next heavy check.
Jurisdiction-specific considerations
A repair approved under FAA acceptable data may need its basis restated when the aircraft moves to an EASA operator, and an alteration under a foreign STC can require validation on the receiving register. The review notes where a substantiation accepted on the current register will be questioned by a receiving authority.
Regulatory limits
The review assesses the substantiation and disposition of recorded repairs and alterations. It does not approve repair data, develop substantiation, grant an STC, or make an airworthiness determination on any repair or alteration.
What this review does not cover
- Developing or approving repair or alteration data
- Performing or re-performing any repair or alteration
- Any airworthiness determination on the installed repairs
Specific to this review
- A repair without traceable approved data may have to be removed or re-substantiated, which costs far more than confirming the basis while the work is fresh.
- An unmapped repair makes the next heavy check slower and riskier, because a repair whose location and interaction are unknown cannot be planned around.
- An alteration recorded without its STC reference reads as complete until a transaction asks for the basis it was carried out under.
Sources
U.S. Government (eCFR). Maintenance recordkeeping content and approval-for-return-to-service requirements, including 43.9, 43.11, and Appendix B.
U.S. Government (eCFR). Records an owner or operator must keep, including total time in service, current status of life-limited parts, and AD compliance.
European Union / EASA. Continuing airworthiness, maintenance records, CAMO responsibilities, and the airworthiness review process in the EASA system.
Frequently asked questions
The repairs are recorded and signed off, so why check the approval data?
A sign-off records that work was done, not that it rested on approved data. If the substantiation cannot be shown, the repair may have to be re-substantiated or removed. This review confirms the approved-data basis for each repair and alteration and maps them against the airframe so the next heavy check can plan around them.
Relevant glossary terms
Related pages
Where this fits
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We will walk through your current state, the records or evidence involved, and a scoped first engagement.
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