Part 145 Contract Maintenance Requirements: What the FAA Expects

No repair station does everything in house. The prop goes out to a prop shop. The cylinder goes out for machine work. NDT gets called in. Every one of those handoffs is contract maintenance, and every one is your responsibility when the aircraft leaves your hangar.

Here is what the Part 145 contract maintenance requirements say and where shops come up short. As always, your repair station manual, quality control manual, and ops specs govern what your shop must do. This is not legal advice, and your PMI's reading is the one that counts.

Two kinds of outside source, two sets of rules

14 CFR 145.217 splits contract maintenance into two paths, and the difference decides how much lands back on you.

A certificated outside source

Another Part 145 station, or a person working under Part 43 authority, performs the function and signs for their own work. The function still has to be approved for contracting and listed, but their release is a real release and it travels with your file.

A noncertificated person

The machine shop, the plating house, the test lab, the vendor with no certificate. You can use them, but three things have to be true: they follow a quality control system equivalent to yours, you remain directly in charge of the work, and you verify by test or inspection that the work was done satisfactorily and the article is airworthy before approving it for return to service. Their paperwork is not an airworthiness approval. Yours is.

The list

A repair station has to maintain, and make available to its responsible Flight Standards office, the functions it contracts out, the name of each outside facility, and the type of certificate and ratings each one holds, if any. That list is a live document. Most findings here are not about a bad vendor. They are about the vendor who has done your NDT for two years and never made the list, or a list still naming a shop that closed in 2023.

One more limit: a repair station may not provide only the approval for return to service on a complete type certificated product after contract maintenance. You cannot be the signature at the end of work you had no part in.

What your quality control manual has to cover

Under 145.211, the quality control manual has to describe your procedures for qualifying and surveilling noncertificated persons who work for you. Write these down, then actually do them:

• How a vendor gets approved. What you reviewed, who signed off, when it expires.
• How you survey them. An audit, a site visit, a documented review at a stated interval. Whatever you wrote is what you owe.
• What incoming verification looks like. The test or inspection on the returned article, who is authorized to do it, where the result is recorded.
• How a vendor gets removed. Quality escapes, late work, a lapsed capability. Somebody has to be able to say no.

What an auditor actually asks for

It starts with a work order, not the vendor list. Pick a job, find the line where something went outside, and walk it: who did it, are they on the list, was the function approved for contracting, where is the inspection proving you verified it, who signed the release. If any link in that chain lives in an email folder, it is going to be a long afternoon. Same evidence trail as our Part 145 audit checklist, and the vendor's release belongs in the customer's return to service package as well.

Where shops lose the thread

The vendor list lives in a Word doc. Nobody updates a document outside the path of daily work. If purchasing can send a unit out without touching the list, the list is wrong.

Receiving verification is a signature on a packing slip. A signature saying the box arrived is not an inspection saying the article is airworthy. Two different records, and auditors know it.

The outside paperwork never reaches the work order. It sits in receiving and gets hunted down at release time.

Keeping the evidence with the job

None of this is hard. It is just scattered. The fix is one system holding the purchase, the vendor record, and the work order the article belongs to.

That is how Orion is built: purchasing and vendor and parts records tie to the work order that drove the outside repair, and the discrepancy stays open until the article comes back and gets verified. At close, the one button return to service package pulls the signed logbook entry, 8130-3s, CAMP and MSP cards, and service records into one file. Every signature is an FAA AC 120-78B compliant e-signature with re-authentication at signing and a SHA-256 tamper hash, and the audit log shows who touched what and when. Orion is modular on published pricing, so you build only the pieces you run.

Want to see an outside repair tracked from PO to verified receipt to signed release? Schedule a call.