In brief
Part 91 separates maintenance records into records retained until the work is repeated or superseded, or for one year, and status records retained and transferred with the aircraft. Sound asset stewardship usually preserves a broader, source-linked history because configuration, valuation, warranty, and future maintenance depend on evidence beyond minimum retention periods.
Aircraft records do more than document regulatory compliance. They establish configuration, accumulated time, maintenance history, component identity, damage and alteration history, and the evidence behind future due calculations.
The central Part 91 rule is 14 CFR 91.417. It creates different retention periods for different records and requires specified status records to transfer with the aircraft. This guide explains that framework; it does not replace the current regulation or requirements that apply to a particular operator, repair station, product, or transaction.
The two Part 91 record groups
Section 91.417(a) separates records into two broad groups.
| Record group | Typical content | Baseline retention under Part 91 |
|---|---|---|
| Work records under 91.417(a)(1) | Maintenance, preventive maintenance, alteration, and required or approved inspections | Until the work is repeated or superseded by other work, or for one year after the work is performed |
| Status and permanent-history records under 91.417(a)(2) | Total time, life-limited-part status, overhaul status, current inspection status, current AD status, and specified major-alteration forms | Retained and transferred with the aircraft |
The exact language matters. A record should be classified by what it proves, not by the binder, file name, or system in which it happens to sit.
Records retained until repeated, superseded, or one year
The first group covers records of:
- Maintenance.
- Preventive maintenance.
- Alteration.
- 100-hour, annual, progressive, and other required or approved inspections.
The record must include the description or reference acceptable to the Administrator, completion date, and signature and certificate information required by the rule.
The “repeated or superseded” concept is contextual. A later event does not erase the value of an earlier record merely because it involves the same component. Teams should establish a controlled legal-retention interpretation and a separate business-retention policy.
Records retained and transferred with the aircraft
The second group carries the aircraft’s current status and enduring technical history. It includes records of:
- Total time in service of the airframe, each engine, and each propeller.
- Current status of each life-limited part for the airframe, engine, propeller, rotor, and appliance.
- Time since last overhaul for items required to be overhauled on a specified time basis.
- Current inspection status, including time since the last required inspection.
- Current status of applicable Airworthiness Directives, including method of compliance, AD number and revision date, and next recurring due time or date when applicable.
- Copies of forms prescribed by 14 CFR 43.9(d) for each major alteration to the airframe and currently installed engines, rotors, propellers, and appliances.
These are not merely old documents. They are the current, supportable statements used to operate, maintain, inspect, finance, and sell the aircraft.
A retention matrix that works
Create a matrix before deciding what may leave the active record set.
| Record type | Regulatory baseline | Operational reason to preserve |
|---|---|---|
| Routine maintenance entry | Repeated/superseded or one year, as applicable | Reliability, warranty, recurring defect, resale |
| Inspection record | Repeated/superseded or one year, as applicable | Inspection continuity and finding history |
| Total-time status | Retain and transfer | Due calculations, value, life status |
| Life-limited-part history | Retain and transfer | Installation eligibility and remaining life |
| Current AD status | Retain and transfer | Airworthiness and recurring compliance |
| Major alteration Form 337 | Retain and transfer as specified | Configuration and continued airworthiness |
| Work package and task cards | Depends on applicable rules and procedures | Proof behind summary entries and findings |
| Release certificates and trace | Depends on context | Component eligibility and commercial diligence |
| Damage and repair evidence | Multiple requirements may apply | Safety, configuration, insurance, valuation |
| Weight and balance / equipment list | Current approved information required in context | Aircraft configuration and operation |
Treat the legal minimum and the asset-history policy as separate columns. That prevents a minimum rule from being mistaken for a destruction instruction.
Record transfer at sale
When an aircraft is sold, section 91.417(b) requires the records specified in paragraph (a)(2) to transfer with it. A disciplined closing process should:
- Define the aircraft, engines, propellers, APU, landing gear, and installed serialized assets.
- Produce current status reports.
- Reconcile each material status to source evidence.
- Inventory physical and electronic record sets.
- Identify gaps, open discrepancies, and records held by third parties.
- Document delivery, access credentials, media, and file manifests.
- Obtain an acknowledgment without using it to waive unresolved facts.
- Preserve a controlled closing copy according to legal and contractual advice.
A box handoff is not enough. The buyer needs usable, intelligible, and traceable status.
Different rules may apply
Part 91 is not the only source of retention duties. Review:
- The aircraft’s operating rules and operations specifications.
- Approved aircraft inspection or maintenance programs.
- Part 135 or Part 121 requirements when applicable.
- Part 145 repair-station obligations.
- Manufacturer and program requirements.
- Instructions for continued airworthiness.
- Lease, loan, insurance, warranty, and maintenance-program contracts.
- Export, import, registry, and jurisdiction-specific requirements.
- Litigation holds, tax rules, and company document policies.
Use the strictest applicable requirement after qualified review. Do not assume a Part 91 summary governs every record in a commercial operation.
Electronic aircraft records
The FAA’s active AC 120-78B addresses electronic signatures, electronic recordkeeping systems, and electronic manuals for appropriate users.
An electronic system should provide:
- Authenticity and attribution.
- Protection against unauthorized alteration.
- Version and revision control.
- Legibility and faithful reproduction.
- Retrieval for FAA inspection.
- Access controls and role separation.
- Audit history.
- Backup, recovery, and continuity.
- Export in a durable, nonproprietary form.
- A controlled migration process when systems change.
Scanning a page is only the first step. Preserve the source image, searchable text, indexing, relationships, and verification status.
Original, copy, and source hierarchy
For each record type, document:
- Whether an original, duplicate, electronic original, or reproducible copy is required or accepted.
- Which system holds the authoritative record.
- Who may enter, correct, approve, or delete data.
- How a correction preserves the original entry and audit history.
- How attachments remain connected to the certification or maintenance entry.
- How received third-party records are validated.
Do not silently overwrite a serial number, time, or compliance value. Correct the structured field while preserving the source and reason for the change.
Access for inspection
Section 91.417(c) addresses making required records available for inspection by the Administrator or authorized representatives. The system should let an authorized user retrieve:
- The current status.
- The governing requirement.
- The supporting entry.
- Related work-package pages.
- Article and aircraft identity.
- Approval and signature evidence.
- Revision and supersedure history.
Speed matters, but provenance matters more. A fast answer without evidence is not a complete answer.
Common retention failures
Treating every document alike
One blanket period can discard permanent-status evidence or retain noise without usable organization.
Preserving a status report but not its evidence
A spreadsheet can state that an AD was complied with. The entry and work record show how, when, and on which configuration.
Destroying records at the minimum date
The record may still carry commercial, technical, warranty, tax, or litigation value.
Losing context during digitization
Pages detached from aircraft, component, work order, sequence, or signature context become difficult to trust.
Leaving records with vendors
Third-party portals close, accounts change, and shops are acquired. Obtain controlled deliverables and verify completeness.
Failing to migrate audit history
A system conversion that imports only current values can erase who changed a field and why.
Retention governance
A mature program assigns:
- A named record owner.
- A regulation and contract inventory.
- A record classification and retention matrix.
- Legal-hold and deletion controls.
- Vendor-return and transaction-transfer procedures.
- Electronic-system validation and access reviews.
- Scheduled completeness audits.
- Backup and recovery testing.
- Approved disposition with evidence.
Review the matrix whenever operating authority, fleet type, jurisdiction, maintenance program, lender, lessor, or records platform changes.
Audit checklist
- [ ] Current rules and operator requirements identified.
- [ ] Each record class mapped to a retention rule.
- [ ] Permanent/status records separated from routine work records.
- [ ] Total-time and life-limited-part status source-supported.
- [ ] AD status includes method and next recurring due.
- [ ] Major-alteration forms connected to configuration.
- [ ] Electronic records reproducible and auditable.
- [ ] Vendor-held records inventoried and retrievable.
- [ ] Backups restored in a test.
- [ ] Sale-transfer package and manifest defined.
- [ ] Disposition requires authorization and preserves a log.
Sources and further reading
Common questions
Frequently asked questions
How long must aircraft maintenance records be kept?
Under 14 CFR 91.417, specified maintenance records are generally retained until the work is repeated or superseded, or for one year after the work, while current status and other specified records are retained and transferred with the aircraft. Other operating rules, programs, contracts, and facts may require more.
Which aircraft records must transfer to a buyer?
The records identified in 14 CFR 91.417(a)(2) must be transferred with the aircraft at the time it is sold. These include specified total-time, life-limited-part, inspection, AD, and major-alteration status records.
Can aircraft records be stored electronically?
Electronic record systems may be acceptable when applicable requirements are met and the records remain accurate, accessible, secure, reproducible, and controlled. FAA AC 120-78B provides current guidance for electronic signatures, records, and manuals.
Should records be destroyed when the minimum retention period ends?
Not automatically. The regulation sets minimum retention duties, not a records-destruction schedule. Records can remain important to configuration, damage history, warranty, tax, valuation, maintenance planning, and resale.
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