Aircraft Maintenance Records: What the Law Requires and Why They Matter After an Accident

What the Aircraft's Maintenance Records Can Tell You About Its Condition

Aircraft maintenance records are the entries, logbooks and forms that document the inspections, repairs, alterations and overhauls done on an aircraft and its parts. Aircraft logbooks are the bound or kept records in which those maintenance entries are made, usually separate books or sections for the airframe, the engine and the propeller.

If you are trying to learn what condition the aircraft was in before the flight, these are the papers that hold the answer. The federal rule that says what must be kept is 14 C.F.R. § 91.417. Under it, each registered owner or operator keeps two groups of records, except for certain altimeter and transponder work performed under §§ 91.411 and 91.413.

The first group covers the maintenance, preventive maintenance and alteration of each aircraft (including the airframe) and each engine, propeller, rotor and appliance, along with records of the 100-hour, annual, progressive and other required or approved inspections. Each record must include a description of the work, the date it was completed, and the signature and certificate number of the person approving the aircraft for return to service.

The second group tracks the aircraft's ongoing status: total time in service of the airframe, each engine, propeller and rotor; the current status of life-limited parts; time since last overhaul of items that must be overhauled on a set schedule; the current inspection status; the current status of airworthiness directives; and copies of the forms required for each major alteration.

Retention periods differ. Records in the first group are kept until the work is repeated or superseded by other work, or for 1 year after the work is performed. Records in the second group are kept and transferred with the aircraft when it is sold. A list of defects given to the owner after an inspection is kept until the defects are repaired and the aircraft is approved for return to service. For a family, this means some older work entries may no longer exist, while the status records should follow the aircraft.

These records exist to show airworthiness, meaning the aircraft is in condition for safe flight. Under 14 C.F.R. § 91.7, no person may operate a civil aircraft unless it is airworthy, and the pilot in command is responsible for determining whether it is in condition for safe flight.

Form 337 is the FAA form used for major repairs and major alterations. Section 91.417 requires the owner or operator to keep copies of those forms, and when a fuel tank is installed inside the passenger or baggage compartment, a copy of FAA Form 337 must be kept on board the aircraft.

Who Is Responsible for Keeping the Records

Two different people carry two different duties. The registered owner or operator keeps the records under section 91.417. The person who does the work makes the entry under 14 C.F.R. Part 43, the federal rules for maintenance, preventive maintenance, rebuilding and alteration.

Under 14 C.F.R. § 91.403, the owner or operator is primarily responsible for keeping the aircraft airworthy, including compliance with part 39 of the federal aviation rules, which governs airworthiness directives. Under 14 C.F.R. § 91.409, no person may generally operate an aircraft unless, within the preceding 12 calendar months, it has had an annual inspection under part 43 and been approved for return to service by an authorized person, or an inspection for the issuance of an airworthiness certificate.

The mechanic's side is set out in 14 C.F.R. § 43.9. Except in the cases that section excludes, each person who maintains, performs preventive maintenance on, rebuilds or alters an aircraft, airframe, engine, propeller, appliance or component part must make an entry in that equipment's maintenance record. Inspections follow a separate rule, 14 C.F.R. § 43.11. The person approving or disapproving the aircraft for return to service after an inspection under part 91, part 125, § 135.411(a)(1) or § 135.419 must record the type and extent of the inspection, its date and the aircraft's total time in service, and their signature, certificate number and kind of certificate.

For a family or an injured passenger, this split matters. The person who held the books and the person who wrote in them may be different, and each duty stands on its own. Knowing who did which is part of understanding how the aircraft came to be flying that day.

Flying With an Airline or Charter? How Part 121 and Part 135 Add a Layer

The rules above are the general Part 91 layer that applies to most private flying. Commercial operations sit under their own parts of the federal aviation rules.

An air carrier is a company that carries passengers or cargo for hire. Scheduled airlines generally operate under the federal aviation rules for air carriers, known as Part 121. A charter (Part 135) operator is a company that flies commuter or on-demand trips, such as charter, air taxi, many air ambulance flights and some sightseeing operations, under the federal aviation rules for those operations, known as Part 135. Each part carries its own maintenance recordkeeping requirements beyond the Part 91 rules.

Section 43.9 itself recognizes this layer. Each holder of an air carrier operating certificate or an operating certificate issued under Part 121 or 135 that is required by its approved operations specifications to provide for a continuous airworthiness maintenance program must make a record of the maintenance, preventive maintenance, rebuilding and alteration on the aircraft and parts it operates, under the applicable provisions of Part 121 or 135. A continuous airworthiness maintenance program is an operator's approved, ongoing program for keeping its fleet airworthy, rather than relying only on periodic inspections.

If you were a passenger on an airline, charter or air ambulance flight, a different and more detailed set of records may exist than for a private plane, kept by a company rather than an individual owner. Which layer governed a particular flight depends on how that flight was operated, and a conversation with an attorney can help sort out which set of rules applied.

What the Records Must Contain — and What Gaps or Falsifications Can Mean

When a family reads a logbook, each maintenance entry under section 43.9 should show four things: what work was done (or a reference to data acceptable to the FAA Administrator); when it was finished; who did it, if that person differs from the one approving it; and, if the work was done satisfactorily, the signature, certificate number and kind of certificate of the person approving it. That signature counts as approval for return to service only for the work performed. Major repairs and major alterations must also be entered on a form and handled as appendix B of part 43 prescribes.

Inspection entries carry certification language. Under section 43.11, except for progressive inspections, an aircraft found airworthy gets a statement such as "I certify that this aircraft has been inspected in accordance with (insert type) inspection and was determined to be in airworthy condition." If it is not approved because of needed maintenance, noncompliance with specifications, airworthiness directives or other approved data, the entry states that a list of discrepancies and unairworthy items has been provided to the owner or operator. The inspector must give the owner or lessee a signed and dated list of those discrepancies, and items allowed to stay inoperative must be placarded "Inoperative."

An airworthiness directive (AD) is a required safety action tied to part 39. Section 91.417 requires records of each applicable AD's current status, the method of compliance, the AD number and revision date, and, for recurring actions, when the next action is due.

A missing date, an unsigned entry, an AD with no recorded compliance, or a discrepancy list with no repair entry is a gap measured against these rules. For a family trying to understand what happened, an unsigned inspection or an AD with no compliance record raises a question about whether required work was done before the flight. Federal regulations also prohibit falsifying, reproducing or altering maintenance records. A gap is a fact to be understood, though, not proof of what caused an accident.

Why Maintenance Records Matter When Someone Is Hurt in an Aviation Accident

The National Transportation Safety Board (NTSB) is the federal agency that investigates civil aviation accidents. Section 91.417(c) requires the owner or operator to make all required maintenance records available for inspection by the FAA Administrator or any authorized representative of the NTSB. The NTSB may issue a preliminary report while an investigation is open and a final report later, which can state a probable cause, the agency's own conclusion about why the accident happened.

Federal law keeps that report out of a damages case. Under 49 U.S.C. § 1154(b), "No part of a report of the Board, related to an accident or an investigation of an accident, may be admitted into evidence or used in a civil action for damages resulting from a matter mentioned in the report." Section 1154(a) separately limits discovery of cockpit recorder recordings and transcripts.

The maintenance records are different documents. They were made before the accident, by mechanics and inspectors, under the rules described above. That is why aircraft logbooks evidence comes up so often: the entries can show whether required inspections were done, whether discrepancies were fixed before return to service, whether ADs were complied with, and where life-limited parts stood. How a court treats them depends on the rules of evidence and the facts.

If you were hurt, or are a family member after a death, the records that usually matter include the aircraft logbooks, inspection entries, discrepancy lists, Form 337 copies, and your own medical records and accident reports. Our site's pages on aircraft maintenance negligence and experimental aircraft crashes describe how these records connect to particular kinds of cases, and model pages such as Piper PA-28 accidents show how NTSB records are reported.

Civil claims for injury or death are decided under state tort law, not the federal aviation regulations, and the standard of care in a civil case is a question of state law.

How to Access Aircraft Maintenance Records

The logbooks and maintenance records described here are held by the owner or operator, because section 91.417 places the keeping duty on them. The status records in the second group stay with the aircraft and transfer to a buyer when it is sold. The FAA maintains the Civil Aviation Registry, which handles aircraft registration records, but the owner's logbooks are not kept there.

For an injured passenger or a family, this means the records are usually in the hands of the people whose conduct may be in question, not a public office. In a lawsuit, records held by an operator, owner or maintenance provider are generally sought through discovery, the court process by which parties request documents from one another. The aircraft may also have changed hands, been repaired or been leased, which affects who holds which records.

The practical questions are who owned and operated the aircraft, who maintained it, and whether the records were kept in one place. If you would like to talk through where the records in your situation may be held and what they could show, you can request a case evaluation.

Federal Regulations and State Tort Law: Two Separate Layers

Federal aviation regulations set what owners, operators and mechanics must do. Whether anyone owes damages for an injury or death is a separate question, decided under state tort law.

A negligence claim generally asks whether someone owed a duty of care, breached it, and caused harm that led to damages. A federal recordkeeping violation does not automatically establish civil liability, and complying with the regulations does not automatically bar a claim. For you, this means a gap in the logbook is one piece of a larger picture, and a clean logbook does not by itself close the question. Whether these elements are met depends on the facts.

Product liability is a claim that a defective aircraft or component caused an injury. It is distinct from a negligence claim against an operator or maintenance provider; our page on aircraft product liability explains it further. Wrongful death is a claim brought by surviving family members when a person dies, and wrongful-death rules differ from state to state.

Where the accident happened and where a claim is brought can shape the rules that apply to you: limitation periods, comparative-fault rules and damages rules differ by state, and no single state's rule applies everywhere. Whether federal law displaces a particular state claim, known as preemption, depends on the claim and the facts. State-specific rules are addressed on the site's state pages, and a conversation with an attorney can help sort out which rules govern a particular situation.