14 CFR Part 43 Maintenance Compliance Requirements

For an aviation operator or maintenance, repair, and overhaul business, 14 CFR Part 43 maintenance compliance requirements are the working rules behind aircraft maintenance. They address maintenance, preventive maintenance, rebuilding, alteration, return to service, records, life-limited parts, performance standards, inspections, and airworthiness limitations.

Schedule a consultation with an aviation attorney to discuss a Part 43 compliance concern, an FAA inquiry, or a maintenance-related business risk.

This article focuses on the compliance and legal obligations that matter to aircraft operators, certificate holders, Part 145 repair stations, and MRO leadership. It is not a substitute for reviewing the current regulation, an aircraft’s approved data, applicable operations specifications, or the facts of a particular maintenance event. For the broader relationship between operator classification and FAA obligations, see Aero Law Center’s FAA regulatory compliance and operator classification guide.

14 CFR Part 43 Maintenance Compliance Requirements for MROs

14 CFR Part 43 is the Federal Aviation Administration’s maintenance rule. Under section 43.1, it generally governs maintenance, preventive maintenance, rebuilding, and alteration of aircraft with a U.S. airworthiness certificate. As well as certain foreign-registered civil aircraft used in common carriage or carriage of mail under Parts 121 or 135. It also applies to the airframe, aircraft engines, propellers, appliances, and component parts covered by the rule.

The current eCFR text is the controlling starting point for determining scope. It also identifies limited exceptions, including certain experimental aircraft and aircraft operated under Part 107, subject to the regulation’s stated conditions. That means a company should not treat a general summary of Part 43 as a universal answer. The aircraft’s certificate, operation, maintenance program, component, and applicable operating rules all matter.

Part 43 matters because maintenance work is not complete merely when a technician finishes the physical task. The work must be performed by an authorized person, in accordance with applicable performance rules and approved or acceptable data. It must be documented in the required form and approved for return to service by a person with the required authority. A failure in any one of those steps can create operational, enforcement, contractual, insurance, or litigation exposure.

Who Must Follow FAR Part 43 Maintenance Requirements?

Part 43 obligations can reach several roles in an aviation business. The precise duties depend on the work performed and the regulatory framework governing the aircraft or operation.

The compliance analysis commonly includes:

• Aircraft owners and operators: They must ensure required maintenance is completed and records are preserved. They must also avoid operating an aircraft when it is not in an airworthy condition or when required maintenance documentation is missing.
• Maintenance personnel: A person performing maintenance, preventive maintenance, rebuilding, or alteration must fall within the authorization rules and perform the work in a manner consistent with Part 43.
• Persons approving return to service: Section 43.7 addresses who may approve an aircraft, airframe, engine, propeller, appliance, or component part for return to service after covered work.
• Part 145 repair stations and MROs: A repair station must consider both Part 43 requirements and the separate privileges, ratings, procedures, records, quality controls, and limitations that apply under Part 145.
• Air carriers and commercial operators: Parts 121 and 135 contain additional maintenance-program and inspection requirements. Part 43 still matters, but it does not replace those more specific operational rules.

A useful internal control is to identify, before work begins, who is performing each task and what authority permits that person to perform it. Identify who will approve return to service, what technical data controls the work, and what record entry is required. When a business cannot answer those questions consistently, the problem is often a process and governance issue rather than a single technician issue.

What Maintenance, Preventive Maintenance, and Alteration Does Part 43 Govern?

Part 43 separates several types of work that can have different authorization and recordkeeping consequences. Maintenance generally includes inspection, overhaul, repair, preservation, and replacement of parts, but the correct classification depends on the work and the regulatory definitions that apply. Preventive maintenance is a limited category of simpler tasks listed in Appendix A. Rebuilding and alteration involve their own requirements, including the treatment of major repairs and major alterations.

Appendix A is especially important for businesses assessing whether work qualifies as preventive maintenance. A task should not be treated as preventive maintenance simply because it appears routine, inexpensive, or familiar. The person performing the work must still be authorized, the task must fit the applicable list and conditions, and the work must be recorded and approved as required.

For major repairs and major alterations, Appendix A and Appendix B should be reviewed together with the approved or acceptable technical data. Depending on the work, a Form 337 or another required record may be involved. The fact that a modification is physically small does not, by itself, determine whether it is a major alteration. Classification should be made using the applicable regulatory criteria and technical context.

Part 43 also contains performance rules in section 43.13. In general terms, maintenance must use methods, techniques, and practices acceptable to the FAA and must use materials and tools that are appropriate for the work. The aircraft or product must be returned to a condition for safe operation, and the work must account for the manufacturer’s maintenance instructions and other applicable data. A compliance review should therefore connect the task card, work order, manuals, parts documentation, inspection steps, and final approval rather than treating each record as an isolated form.

What Are the Preventive Maintenance Requirements Under Part 43?

Preventive maintenance under Part 43 is limited maintenance that may be performed by a person authorized under the applicable rule. Including a pilot-owner in circumstances allowed by the regulation. The task must be one of the preventive maintenance items listed in Appendix A, and the person performing the work must follow the applicable instructions, limitations, and recordkeeping requirements.

Before returning an aircraft to service after preventive maintenance, the responsible person should confirm:

1. The task is actually within the preventive maintenance list and is not a repair, alteration, or inspection requiring a different authorization.
2. The person performing the task is authorized to perform it on that aircraft and under that operating context.
3. The work was completed using the appropriate methods, techniques, practices, materials, tools, and technical data.
4. The required maintenance record entry identifies the work, date of completion, person who performed it, and person approving return to service when the rules require separate approval.
5. Any operational or airworthiness limitations, inspection requirements, or related discrepancies have been addressed before the aircraft is operated.

For a repair station or MRO. Preventive maintenance questions may arise when a customer asks the facility to perform work that appears simple but falls outside the facility’s authorized process or the definition in Appendix A. Escalating an uncertain classification before work begins is generally safer than trying to correct an incomplete record after delivery.

Part 43 Recordkeeping Requirements: What Must Operators Document?

Recordkeeping is one of the most important parts of Part 43 compliance because the record is often the evidence that the work was properly performed and approved. Section 43.9 addresses the content, form, and disposition of maintenance, preventive maintenance, rebuilding, and alteration records. Subject to the inspection-related provisions that have separate treatment under section 43.11 and other referenced rules.

A typical maintenance record entry should be specific enough to show what was done and how the aircraft or product was returned to service. Depending on the work, the record may need to identify the date, a description or reference to acceptable data. The name of the person performing the work, the signature or approved identifier, and the approval for return to service. A vague entry such as “work completed” may not provide a defensible record of the actual maintenance.

Operators and MROs should also maintain a controlled process for several records tasks:

• Link work orders, task cards, inspection findings, and parts traceability to the final maintenance entry.
• Identify life-limited parts and preserve the information needed to establish their status.
• Record major repairs and alterations in the form and manner required by Part 43.
• Protect electronic records from unauthorized alteration, loss, or destruction.
• Retain records for the period required by the applicable rule, operating specification, maintenance program, or contract.
• Correct an error transparently rather than overwriting, backdating, or obscuring the original record.

The FAA’s AC 43-9D provides information about maintenance recordkeeping and FAA Form 8130-3. The FAA describes the circular as guidance, not as an independent source of legally binding obligations. And notes that it does not apply in the same way to air carrier maintenance programs under specified Parts 121 and 135 provisions. Use it as a compliance aid alongside the regulation and the operator’s approved programs, not as a replacement for them.

Contact Aero Law Center if a missing, inconsistent, or disputed maintenance record could affect an aircraft delivery, customer dispute, FAA review, or certificate decision.

How Do Return-to-Service and Inspection Rules Affect Compliance?

Return to service is a regulatory approval, not merely a statement that a mechanic believes the task is finished. Section 43.5 addresses approval for return to service, and section 43.7 identifies persons who may provide that approval for the relevant aircraft or component. The approval should correspond to the work actually performed and the authority held by the approving person.

Inspection work may trigger additional requirements. Section 43.11 addresses the content, form, and disposition of records for certain inspections conducted under Parts 91 and 125 and specified Part 135 provisions. The applicable inspection program, aircraft category, and operating rules determine which record format and approval language is required.

For an MRO, a sound release process should keep several actions separate:

• Completion of a maintenance task.
• Completion of an inspection or required functional check.
• Correction of a discrepancy.
• Approval for return to service.
• Delivery of the aircraft or component to the customer.

Separating those steps helps management identify who made each decision and what evidence supports it. It also creates a clearer response if an operator later receives an FAA request, a customer claim, or a question about whether the work met the applicable requirements.

Common Part 43 Compliance Problems and FAA Enforcement Risk

Part 43 problems often arise from process breakdowns rather than a single dramatic event. Common risk areas include:

• Performing work outside the authority, rating, or procedure available to the person or facility.
• Using technical data that is not applicable, current, or acceptable for the work.
• Failing to identify whether a repair or alteration is major.
• Omitting required information from a maintenance or inspection record.
• Approving return to service without completing the required inspection or discrepancy resolution.
• Losing traceability for life-limited parts or parts installed during maintenance.
• Altering, reproducing, backdating, or falsifying a maintenance record.
• Allowing customer pressure, production targets, or a rushed aircraft release to override a documented stop-work process.

Section 43.12 specifically addresses maintenance records involving falsification, reproduction, or alteration. Depending on the facts, a Part 43 issue may also affect an operator’s airworthiness determination, operations specifications, certificate status, customer contracts, insurance position, or exposure to civil claims. The legal consequences depend on the evidence, the applicable operating rules, the seriousness of the conduct, and the FAA’s enforcement posture.

If the FAA raises a concern, preserve the relevant work orders, records, personnel authorizations, training materials, manuals, parts documentation, communications, and quality-system records. Avoid making an unsupported admission or changing historical records without a controlled legal and technical process. An aviation attorney can help coordinate the response while the business continues its safety and reporting obligations.

How Can an Aviation Attorney Help MROs and Repair Stations Stay Compliant?

Legal counsel cannot replace a director of maintenance, quality system, accountable manager, or qualified technician. Counsel can, however, help a business translate regulatory requirements into defensible processes and respond when maintenance compliance becomes a legal issue.

For a Part 145 repair station or MRO, that support may include reviewing certificate and rating issues, evaluating maintenance contracts, preparing for an FAA audit. Assessing a disputed maintenance event, coordinating a response to a letter of investigation, and advising on the legal consequences of a record or release problem. It may also include helping leadership distinguish a correctable process gap from conduct that requires immediate reporting, containment, customer communication, or enforcement strategy.

Aero Law Center focuses exclusively on aviation-specific legal matters and serves aviation businesses nationwide. Its regulatory practice includes proactive compliance advisory, FAA audit preparation, operational reviews, certification maintenance, and enforcement defense. For broader context on how operator classification affects FAA obligations, review the firm’s FAA regulatory compliance and operator classification guide. The firm’s related aircraft repair shop litigation counsel and aircraft maintenance lawsuit guidance address the disputes that can follow an alleged maintenance error or documentation failure.

Request a consultation with Aero Law Center at the first sign of an FAA inquiry, disputed maintenance record, certificate concern, or significant MRO compliance issue.

Frequently Asked Questions About Part 43 Compliance

What are the requirements for preventive maintenance under CFR Part 43?

Preventive maintenance must fit the applicable list in Appendix A, be performed by a person authorized under the applicable rule. Follow the required methods and limitations, and be recorded and approved for return to service as required. A routine task is not automatically preventive maintenance.

What is required under FAR Part 43 before returning an aircraft to service?

The covered maintenance, preventive maintenance, rebuilding, alteration, or inspection must be completed using applicable requirements and acceptable methods. The required record must be made, and a person authorized under section 43.7 must approve return to service when the rule requires that approval.

Does Part 43 apply to a Part 145 repair station?

Part 43 requirements commonly apply to maintenance work performed by or for a Part 145 repair station. While Part 145 adds separate certification, rating, facility, personnel, quality, and procedural requirements. A repair station should evaluate both parts and any applicable approved procedures or operating limitations.

What should an MRO do after discovering a maintenance record error?

Secure the original record and related work evidence, stop any process that could compound the error, involve the appropriate maintenance and quality personnel. And obtain legal guidance when the issue may affect airworthiness, an FAA report, a customer dispute, or potential enforcement. Do not silently overwrite or backdate a historical record.

This article is provided for general informational purposes only and does not constitute legal advice. Aviation regulations, FAA guidance, and individual circumstances can change the analysis. Reading this article or contacting Aero Law Center does not create an attorney-client relationship. Prior results do not guarantee a similar outcome.