Most DER-repair guidance focuses on the repair. This one focuses on the source. Two providers can both offer to restore the same component under approved engineering data and still be very different to buy from — in what their approval actually covers, in who performs the physical work, and in the paper that arrives with your returned unit. For a procurement or quality team, the task is qualifying the provider, not just confirming a repair exists. Here is a checklist for doing that, built on the same logic as our PMA supplier-vetting checklist.

Start With the Approval Basis

Before anything else, understand what approves the repair and whether it applies to your part. A DER repair rests on engineering data that a Designated Engineering Representative has found compliant with the airworthiness standards, documented on FAA Form 8110-3. That form is the approval of the technical data — it does not by itself authorize production, grant operational approval, or serve as a work order. So the first question to a source is precise: what is the 8110-3 basis for this repair, and does its applicability cover your specific part number and the specific damage or condition you have?

This matters because 8110-3 repair approvals come in different shapes. A one-time (single) approval covers one component. A serial-number-specific approval is tied to particular units. A multiple-use approval can support a Repair Specification — standardized, repeatable instructions for a recurring major repair. A source who can name which form applies to your job, and show that the applicability envelope matches your part and defect, understands their own product. Vagueness here is a signal. Our walkthrough of how a DER repair gets approved explains these forms in more depth.

Confirm Who Performs the Physical Work

Approved data is only half the story. The 8110-3 approves the engineering; the physical repair is performed and returned to service under 14 CFR Part 43 by an appropriately rated repair station or mechanic. So a real vetting question is whether the entity doing the hands-on work holds the ratings for your component and runs a quality system you would trust with it.

Under 14 CFR Part 145, a certificated repair station operates against a defined scope — ratings by class, a quality system, trained personnel, calibrated tooling, and controlled processes. Ask what ratings the station holds and whether they cover your part class. Ask how they control the specialized processes a repair depends on, how nonconformances are recorded, and who holds release authority. A source that draws a clean line between the DER data and the rated station executing it — and can speak to both — is one whose repairs will look the same in twelve months as they do today.

Check the Documentation You’ll Actually Receive

A returned part is only as acceptable as the paper that arrives with it. Confirm up front what the document package will contain: a reference to the governing 8110-3 approval (and, where relevant, the Repair Specification it supports), the Part 43 maintenance records for the work performed, and — where the released article carries one — an FAA Form 8130-3 airworthiness approval tag. Each of these does a distinct job, and the receiving-inspection headache almost invariably traces back to one of them being missing, mismatched, or incomplete.

Ask for a sample document package before your first order. Reviewing it cold tells you more than any capability statement: whether the 8110-3 reference is traceable, whether the Part 43 records describe the actual work, and whether the tags and part markings agree with each other and with the unit in hand. We lay out the full paper trail in DER repair paperwork and documentation — use it as the yardstick for what a complete package looks like.

Verify Traceability End to End

Documentation and traceability are related but not the same. Traceability is the unbroken thread that connects the physical unit on your dock to the approved data that governs its repair and the rated facility that performed it. Confirm that part and serial numbers on the article match the records, that the records cite the correct 8110-3 approval, and that nothing in the chain requires you to take an undocumented step on faith. A source that keeps this thread intact is protecting you from the receiving problem no buyer wants — a part whose eligibility can’t be established on the paperwork alone.

Assess Track Record and Continued Operational Safety

Approval is a starting condition, not a performance record. Ask how long the source has performed this repair, what its in-service history looks like, and how it monitors field performance. There is a regulatory dimension here worth naming: holders of major-repair approvals carry Continued Operational Safety obligations — ongoing monitoring and response responsibilities for the repairs they put into service. A source that treats COS as a live discipline, tracks how its repaired units behave in the field, and has a clear path when a question arises is demonstrating exactly the reliability you are trying to buy. Steady, boring consistency is the goal.

The Checklist, in Short

Qualify a DER repair source against five things: a clear approval basis — the 8110-3 data or Repair Specification, and its applicability to your part and damage; the repair station doing the physical work, its Part 145 ratings, and its quality system; the documentation you will receive, including the 8110-3 reference, Part 43 records, and any 8130-3; traceability that holds end to end; and a track record backed by real Continued Operational Safety monitoring. A source strong on all five is one you can build a program around. For the wider context of where restoration fits alongside replacement, see our repairs overview.

How AviaFix Approaches Being the Source

We wrote this checklist because it is the standard we want to be held to. AviaFix aims to make vetting clear: a stated 8110-3 approval basis with applicability we can show against your part, physical work performed under the right ratings and quality controls, receipt-ready documentation, and traceability that clears your inspection on the first pass. Where a repair can’t be substantiated to the approval standard, we decline it rather than defend it later. If a source makes any of those hard to verify, that itself is the answer.

Frequently Asked Questions

What should I check before buying a DER repair? Five things: the approval basis (the 8110-3 data or the Repair Specification it supports, and whether its applicability covers your part and damage), the repair station performing the physical work and its 14 CFR Part 145 ratings and quality system, the documentation you will receive (the 8110-3 reference, Part 43 records, and any FAA Form 8130-3), end-to-end traceability, and the source’s track record and Continued Operational Safety monitoring.

Does the FAA Form 8110-3 mean the repair is fully approved? The 8110-3 documents a DER’s finding that the engineering data complies with the airworthiness standards. It does not authorize production, grant operational approval, or serve as a work order. The physical repair still has to be performed and returned to service under 14 CFR Part 43 by an appropriately rated station or mechanic. So confirm both halves: the approved data and the rated facility that executes it.

Why does the repair station’s rating matter if the data is DER-approved? Because approved data and approved work are separate steps. The 8110-3 covers the engineering; Part 43 governs the physical repair and return to service. A Part 145 repair station operates against defined ratings, a quality system, and controlled processes — so confirming the station holds the ratings for your component’s class, and runs a quality system you trust, is as important as confirming the DER data exists.

What documentation should arrive with a DER-repaired part? Expect a reference to the governing 8110-3 approval (and the Repair Specification where one applies), the Part 43 maintenance records describing the work performed, and — where the released article carries one — an FAA Form 8130-3. Part and serial numbers should match across the records and the unit itself. Ask for a sample package before your first order and treat any gap as a question to resolve, not overlook.

Sources & Further Reading

Related reading: DER Repair Paperwork · Vetting a PMA Supplier · Repairs overview

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