FAA requirements for aircraft maintenance records fall into two tiers: routine entries that document each maintenance action and inspection, and a permanent set of records that follow the aircraft for its entire service life. Under 14 CFR 91.417, every registered owner or operator must maintain records of all maintenance, preventive maintenance, alterations, and required inspections for the aircraft and each of its major components.1eCFR. 14 CFR 91.417 – Maintenance Records Get either tier wrong and the aircraft can be grounded, its value can drop sharply, and the FAA can impose civil penalties per violation.
What Records You Must Keep
The regulation splits your recordkeeping duty into two categories. The first covers ongoing work: each maintenance action, preventive maintenance task, alteration, and required inspection gets its own dated entry. The second covers the aircraft’s permanent identity, the items that establish where it stands against every rule and life limit that applies to it.
The permanent items include:
- Total time in service of the airframe, each engine, each propeller, and each rotor.
- The current status of any life-limited part, such as certain turbine discs or landing gear forgings.
- Time since last overhaul for every installed item that requires periodic overhaul on a scheduled basis.
- The current inspection status, including when the last required inspection occurred and when the next is due under the aircraft’s inspection program.
- The current status of every applicable airworthiness directive, with the AD number, revision date, method of compliance, and the due date for any recurring action.
- Copies of FAA Form 337 for every major alteration to the airframe and currently installed engines, propellers, and appliances.
The regulation does not require three physical logbooks. Industry practice almost universally divides the records into an airframe log, an engine log, and a propeller log because engines and propellers frequently outlive the airframes they’re installed on and may be transferred between aircraft. Independent logs let a mechanic trace each component’s full history regardless of which airframe it’s currently bolted to.
How Long Each Record Must Be Kept
Retention timelines follow the two-tier split.
Routine maintenance and inspection entries recorded under 91.417(a)(1) must be kept until the work is repeated or superseded by other work, or for one year after the work is performed, whichever comes first.1eCFR. 14 CFR 91.417 – Maintenance Records A 100-hour inspection entry can be retired once the next 100-hour inspection is completed and recorded.
The permanent items listed under 91.417(a)(2), the total-time, life-limited, overhaul, inspection status, AD, and Form 337 records, must be retained indefinitely and transferred with the aircraft at the time of sale.1eCFR. 14 CFR 91.417 – Maintenance Records Losing or discarding a permanent record creates a gap that can be extremely expensive to fill and may be impossible to fully reconstruct.
All records must be made available for inspection by the FAA Administrator or any authorized representative of the National Transportation Safety Board upon request.1eCFR. 14 CFR 91.417 – Maintenance Records
What Every Entry Must Contain
Two regulations govern the content of maintenance record entries. 14 CFR 43.9 covers entries for maintenance, preventive maintenance, rebuilding, and alterations. 14 CFR 43.11 covers entries made after inspections. Inspection entries build on the basic content rules and add more.
Maintenance and Alteration Entries
Every maintenance entry must include a description of the work performed, written clearly enough that a mechanic who has never seen the aircraft can understand exactly what was done. The entry must record the date the work was completed. If someone other than the person approving the return to service actually performed the work, that person’s name goes in the record too.2eCFR. 14 CFR 43.9 – Content, Form, and Disposition of Maintenance Records
The most legally significant part of any entry is the approval for return to service. The person signing off the work must include their signature, certificate number, and kind of certificate held. That signature is what makes the aircraft legal to fly again, and it applies only to the specific work described in that entry.2eCFR. 14 CFR 43.9 – Content, Form, and Disposition of Maintenance Records An entry missing any of these elements is incomplete, and the aircraft is not considered returned to service until the entry is corrected.
For complex or extensive work, the FAA allows the entry to reference manufacturer manuals, service bulletins, advisory circulars, or other approved technical data rather than spelling out every procedure in longhand. Any referenced documents that are not in common industry usage must be retained as part of the maintenance records.3Federal Aviation Administration. Maintenance Records AC 43-9C CHG 1
Inspection Entries
After a required inspection (annual, 100-hour, progressive, or other program-based inspection), the person approving or disapproving the aircraft for return to service must record the type of inspection and the extent of the inspection performed, the date, the aircraft’s total time in service at that point, and the inspector’s signature with certificate number and certificate type.4eCFR. 14 CFR 43.11 – Content, Form, and Disposition of Records for Inspections
If the aircraft passes, the inspector must include a signed statement certifying it was inspected and found airworthy. If it does not pass, the entry must say so and reference a dated list of discrepancies and unairworthy items provided to the owner.4eCFR. 14 CFR 43.11 – Content, Form, and Disposition of Records for Inspections An aircraft with unresolved discrepancies from an annual inspection cannot fly except to a location for repairs under a ferry permit, and the discrepancy list is the document that proves what still needs fixing.
Airworthiness Directives vs. Service Bulletins
Two categories of post-manufacture instructions create ongoing recordkeeping obligations, and the legal line between them matters.
Airworthiness Directives are mandatory. They are legally enforceable regulations issued under 14 CFR Part 39 to correct an unsafe condition in a product. Operating an aircraft that does not meet the requirements of an applicable AD violates federal law each time the aircraft flies.5eCFR. 14 CFR Part 39 – Airworthiness Directives The permanent records must reflect the compliance status of every applicable AD, including the AD number, its revision date, the method used to comply, and, for recurring ADs, when the next action comes due.1eCFR. 14 CFR 91.417 – Maintenance Records Sloppy AD tracking is one of the fastest ways to create an unairworthy aircraft on paper even when the physical work was actually done.
Service Bulletins are different. Manufacturers issue them to inform owners about safety improvements, maintenance recommendations, or product enhancements. For Part 91 operators, compliance with a service bulletin is advisory and not mandatory unless the bulletin is incorporated into an airworthiness directive.6Federal Aviation Administration. Service Bulletins and the Aircraft Owner Ignoring relevant service bulletins can still cost you. Buyers and their mechanics scrutinize SB compliance during pre-purchase evaluations, and a long list of open bulletins often becomes a negotiating point even when none are legally required.
Major Alterations and FAA Form 337
Any repair or alteration that goes beyond routine preventive maintenance and significantly affects the aircraft’s structural strength, performance, flight characteristics, or other qualities that determine airworthiness requires the completion of FAA Form 337. The person who performs or supervises the work must prepare the form.7Federal Aviation Administration. AC 43.9-1G – Instructions for Completion of FAA Form 337 Common examples include avionics upgrades, engine swaps, wing modifications, and fuel system alterations.
Form 337 serves a dual purpose. One signed copy goes to the aircraft owner and becomes part of the aircraft’s permanent maintenance records. A duplicate copy must be forwarded to the FAA Aircraft Registration Branch within 48 hours after the aircraft is approved for return to service.7Federal Aviation Administration. AC 43.9-1G – Instructions for Completion of FAA Form 337 The FAA also accepts electronic submission through its online portal. Even if the owner’s copy is lost, the FAA’s copy at the Registration Branch can be retrieved to reconstruct the modification history. Form 337s are permanent records and must never be discarded.
Documents That Must Be On Board Every Flight
Separate from the maintenance logs, certain documents must be physically inside the aircraft for every flight. Pilots often remember them by the acronym ARROW, though the underlying rules span more than one regulation.
The Airworthiness Certificate confirms the aircraft met federal design and safety standards when it was manufactured or last inspected, and it must be displayed at the cabin or cockpit entrance where passengers and crew can read it. The Registration Certificate establishes the aircraft’s national identity and legal ownership. Without either document, the aircraft cannot legally fly.8eCFR. 14 CFR 91.203 – Civil Aircraft Certifications Required
A Radio Station License from the FCC is required whenever an aircraft flies to a foreign destination or communicates with foreign stations. Domestic-only flights within the United States do not require one. The license is valid for ten years. At least one crew member on an international flight must also hold a Restricted Radiotelephone Operator Permit, which is a separate personal credential.9Federal Communications Commission. Aircraft Stations
The Operating Handbook (the Pilot’s Operating Handbook or approved flight manual) contains the performance data, limitations, and emergency procedures specific to that aircraft model. Federal regulations prohibit operating a civil aircraft without complying with the operating limitations in the approved manual, and the manual itself must be available on board. Weight and Balance data ensures the aircraft is loaded within its structural and aerodynamic limits. Any time equipment is added, removed, or relocated, the weight and balance record must be recalculated before the next flight.
Electronic Records
The FAA does not require electronic recordkeeping, but it allows it. Advisory Circular 120-78B, issued in December 2024, provides guidance on acceptable methods for electronic signatures, electronic recordkeeping systems, and electronic manuals.10Federal Aviation Administration. AC 120-78B – Electronic Signatures, Electronic Recordkeeping, and Electronic Manuals The advisory circular is not itself a regulation but represents one acceptable means of compliance.
For an electronic system to meet FAA standards, it must provide data integrity, accuracy, and accessibility equal to or better than paper records. The system needs controlled access to prevent unauthorized changes, protection against data corruption, and safeguards ensuring that a signed record cannot be edited after the signature is applied.10Federal Aviation Administration. AC 120-78B – Electronic Signatures, Electronic Recordkeeping, and Electronic Manuals Electronic signatures must be unique to the signer, under the signer’s sole control, and must prevent the signer from later denying they signed the record.
For Part 91 owner-operators, digital records are increasingly common through third-party platforms. Keeping a parallel paper backup or verified digital backup remains a smart safeguard. If an electronic system fails and records cannot be retrieved, the owner faces the same reconstruction burden as any paper loss.
Transferring Records When You Sell
When a U.S.-registered aircraft changes hands, 14 CFR 91.419 requires the seller to transfer all maintenance records to the buyer at the time of sale. The buyer can choose to receive these records in plain language or in coded form. As a practical exception, the buyer may allow the seller to retain physical custody of the routine 91.417(a)(1) maintenance records, but doing so does not relieve the buyer of the obligation to make those records available for FAA or NTSB inspection.11eCFR. 14 CFR 91.419 – Transfer of Maintenance Records
Buyers and their mechanics conduct thorough logbook audits before any purchase, checking for complete AD compliance histories, unbroken chains of annual inspections, properly documented Form 337s, and consistent time-in-service entries. A single unexplained gap, such as a missing engine log covering an overhaul period, raises immediate red flags.
If Records Are Lost or Destroyed
Logbooks get lost. They are destroyed in hangar fires, misplaced during ownership changes, or occasionally stolen. When that happens, the records must be reconstructed from secondary sources. FAA guidance recommends starting with a signed and notarized statement of the known history, supported by whatever documentation you can assemble: aircraft rental receipts, instructor attestations, copies of prior FAA Form 8710-1 applications, repair station work orders, and Form 337 copies retrieved from the FAA Aircraft Registration Branch.
The first page of any new logbook should clearly identify it as a reconstructed record and list the specific sources used to build it. Any future mechanic or buyer will immediately recognize a brand-new logbook on an older aircraft, and a forthright explanation is far better than one that appears to hide gaps.
For the permanent 91.417(a)(2) items, some reconstruction is relatively straightforward. The FAA keeps copies of all Form 337s filed with the Registration Branch, so major alteration histories can usually be recovered. Total time in service can sometimes be pieced together from prior annual inspection entries filed with the FAA, engine overhaul records held by overhaul shops, or Hobbs meter readings from FBOs. AD compliance status is harder. Without original records showing when and how each AD was addressed, a mechanic may need to physically inspect for compliance or perform the AD work fresh to establish a clean baseline.
Penalties for Getting It Wrong
Record violations carry real financial consequences. Under 49 U.S.C. 46301, the FAA can impose civil penalties for violations of aviation regulations, including recordkeeping requirements. As of the most recent 2025 adjustment, the maximum civil penalties are:12Office of the Law Revision Counsel. 49 USC 46301 – Civil Penalties
- Individuals and small businesses, general violations: up to $1,875 per violation.
- Individuals and small businesses, specific violations including registration and recordation under Chapter 441: up to $17,062 per violation.
- Other persons (companies, operators): up to $75,000 per violation.
The FAA Reauthorization Act of 2024 substantially increased the administrative penalty caps for violations occurring after its enactment: up to $100,000 for individuals and up to $1,200,000 for entities other than individuals.12Office of the Law Revision Counsel. 49 USC 46301 – Civil Penalties These are ceiling figures. The actual penalty for a single missing logbook entry will be far less than the maximum, but violations tend to compound. If an inspector finds one recordkeeping problem, they usually find several, and each instance can be treated as a separate violation.
Fines aren’t the whole story. Incomplete records can result in the aircraft being found unairworthy. An airplane without documentation proving compliance with applicable airworthiness directives violates 14 CFR Part 39 every time it flies.5eCFR. 14 CFR Part 39 – Airworthiness Directives A mechanic who signs off work with an incomplete entry can face certificate action, including suspension or revocation of their mechanic certificate. For owners, the practical consequence is often worse than any fine: an aircraft grounded until its records are brought into compliance, burning hangar rent and lost flying time while the paperwork gets sorted out.