Visual guide 3 of 6
Maintenance records at a glance
Three different rules, three different jobs: 43.9 is what the mechanic writes after doing work, 43.11 is what the inspector writes after an inspection, and 91.417 is what the owner must keep, and for how long. Major repairs and alterations add Form 337.
The three rules side by side
43.9(a) — work entry
- Description of the work performed (or reference to data acceptable to the Administrator)
- Date of completion
- Name of the person performing the work, if other than the person approving it
- If satisfactory: signature, certificate number and kind of certificate of the person approving the work
The signature is approval for return to service only for the work performed. Major repairs/alterations also go on a form per Appendix B. 43.9(a)(4), (d)
43.11(a) — inspection entry
- Type of inspection and brief description of its extent
- Date and aircraft total time in service
- Signature, certificate number and kind of certificate
- If airworthy: "I certify that this aircraft has been inspected in accordance with (type) inspection and was determined to be in airworthy condition."
- If not: same, "…and a list of discrepancies and unairworthy items dated (date) has been provided for the aircraft owner or operator."
- Progressive: routine/detailed statement; program inspections: identify the program and the part accomplished
Discrepancy list: signed and dated, to the owner or lessee; items allowed inoperative under 91.213(d)(2) get an "Inoperative" placard and go on the list. 43.11(b)
91.417 — owner's records
(a)(1) Work & inspection records — description, date, signature and certificate number of the person approving RTS.
(a)(2) Status records:
- Total time in service — airframe, each engine, propeller, rotor
- Current status of life-limited parts
- Time since last overhaul of items with a required overhaul interval
- Current inspection status (time since last required inspection)
- Current AD status: method of compliance, AD number and revision date; next due time/date if recurring
- Copies of the 43.9(d) forms (Form 337) for each major alteration to airframe and currently installed engines, rotors, props, appliances
Retention clock (owner/operator)
| Record | Keep it… | Cite |
|---|---|---|
| Maintenance, PM, alteration, 100-hour, annual, progressive and other required inspection records — 91.417(a)(1) | Until the work is repeated or superseded by other work or for 1 year after the work is performed | 91.417(b)(1) |
| Status records — total time, LLP status, TSO, inspection status, AD status, 337 copies — 91.417(a)(2) | Retained and transferred with the aircraft when sold (permanent) | 91.417(b)(2); 91.419 |
| List of defects furnished under 43.11 | Until the defects are repaired and the aircraft is approved for return to service | 91.417(b)(3) |
| Form 337 for a fuel tank in the passenger or baggage compartment | On board the aircraft | 91.417(d); 91.203(c) |
| Repair station work records | At least 2 years from approval for return to service | 145.219(c) |
| Repair station work order used instead of a 337 (major repair per acceptable manual) | Duplicate kept at least 2 years; signed copy and maintenance release to owner | Part 43 App. B(b) |
Records required by 91.417 must be made available to the FAA or NTSB on request; the Form 337 for a cabin/baggage fuel tank must also be shown to any law-enforcement officer on request. 14 CFR 91.417(c) Exception: the altimeter/transponder tests of 91.411/91.413 are outside 91.417(a). 91.417(a)
When is a Form 337 required?
Logbook entry only
43.9(a) entry. No 337.
Form 337 + logbook
- Person performing the work executes the 337 at least in duplicate
- Signed copy to the aircraft owner
- Copy to the FAA Aircraft Registration Branch, Oklahoma City, within 48 hours after approval for return to service
43.9(d); App. B(a)
Work order option
For major repairs made per a manual or specifications acceptable to the FAA, a repair station may instead use the customer's work order, give the owner a signed copy plus a maintenance release, and keep a duplicate 2 years. App. B(b)
No 337 needed
Form 337 and Appendix B recording are not required for products not produced under an FAA approval. Record the work under 43.9 with the manufacturer's authorization. 43.1(d)(1)–(2); 91.327(b)(5)
Extended-range fuel tank in the cabin or baggage compartment: 337 in at least triplicate — one on board, one to the owner, one to the FAA within 48 hours after the work is inspected. Part 43 App. B(d) Also before return to service: if a repair or alteration changes operating limitations or flight data in the approved flight manual, revise them as 91.9 requires. 14 CFR 43.5(c)
Sample entries (practice templates)
These illustrate the required elements. Wording beyond the regulatory statements is illustrative. For experimental aircraft, use the exact language in the aircraft's operating limitations.
43.9 maintenance entry
description/data · date · name if different · signature, cert. no., kind
43.11 annual — approved
type & extent · date · total time · signature, cert. no., kind · statement
43.11 — disapproved
43.11(a)(5) + signed, dated list to owner (43.11(b))
Words that change the answer
| Term | Meaning | Cite |
|---|---|---|
| Overhauled | Disassembled, cleaned, inspected, repaired as necessary, reassembled, and tested per approved standards/data (or current data acceptable to the FAA from the TC/STC/approval holder) | 43.2(a) |
| Rebuilt | Same steps, but tested to the same tolerances and limits as a new item, using new parts or used parts within new-part (or approved over/undersize) limits | 43.2(b) |
| Zero-time engine | Owner may use a new record, without previous history, for an engine rebuilt by the manufacturer or an agency it approves; new record shows rebuild date, AD changes, and requested SB changes | 91.421 |
| Time in service | From the moment the aircraft leaves the surface until it touches it at the next point of landing | 1.1 |
| Life-limited part | Any part with a mandatory replacement limit in the type design, ICA or maintenance manual. On removal, control it by records, tag, marking, segregation or mutilation; transfer the record with the part | 43.10 |
| Operation after maintenance | Approved for RTS by a 43.7 person and the 43.9/43.11 entry made. If flight characteristics may have changed appreciably: a private-or-higher pilot flies an operational check and logs it before passengers are carried — unless ground tests/inspection show conclusively there's no change | 91.407 |