14 CFR Part 145 — Repair Station Certification and Operations

What Is a Part 145 Repair Station?

14 CFR Part 145 establishes the rules under which a domestic or foreign repair station may be certificated by the FAA to perform maintenance, preventive maintenance, and alterations on aircraft, airframes, powerplants, propellers, appliances, or component parts. Any shop that maintains or repairs aviation articles for compensation or hire—and wants FAA authorization to return those articles to service—must hold a Part 145 certificate, unless another regulation (such as an air carrier's own approved maintenance program under Part 121 or Part 135) applies instead.

A Part 145 certificate is not a one-time event. The FAA issues the certificate with specific ratings, and the station must continually meet the requirements tied to those ratings. The certificate is site-specific: it covers the location and facilities described in the application, so moving to a new building or adding a new work scope requires FAA approval.

Certificate Ratings

Part 145 organizes repair station work into rating categories. The main rating classes are:

• Airframe ratings — cover the entire airframe of a specific aircraft group or class.
• Powerplant ratings — cover engines, within specified aircraft groups.
• Propeller ratings — cover propeller systems.
• Radio ratings — cover communication and navigation equipment.
• Instrument ratings — cover flight, engine, and navigation instruments.
• Accessory ratings — cover components such as pumps, actuators, and fuel controls.

Each rating may be limited to a specific make, model, or series of article, or it may cover a broader class, depending on the station's capabilities. When a station wants to add a new rating, it must demonstrate to the FAA that it has the facility space, tools, equipment, technical data, and qualified personnel to support that additional scope before the rating is added.

Facility, Equipment, and Technical Data Requirements

A certificated repair station must have housing adequate for the work it is authorized to perform. That means sufficient floor space, proper environmental controls for precision work, segregated areas to prevent contamination or confusion between serviceable and unserviceable parts, and adequate lighting. Safety considerations are built into these requirements: flammable materials must be stored and handled in compliance with applicable fire codes, and work areas must be arranged to support safe practices including proper use of personal protective equipment (PPE) and lockout/tagout (LOTO) procedures when energy-isolating equipment or aircraft systems during maintenance.

The station must have, or have access to, all tools, equipment, and test apparatus necessary to determine whether the article is airworthy. Equipment must be calibrated and records of calibration maintained. Technical data—manufacturer's manuals, service bulletins, and FAA-approved data—must be current and available to technicians at the work site.

The Repair Station Manual (RSM)

Every Part 145 certificated station must prepare and follow a Repair Station Manual (RSM). The RSM is the governing document that describes how the station operates. It must address at minimum:

• The scope of work the station is authorized to perform.
• Procedures for maintaining and controlling technical data.
• Procedures for ordering and receiving parts and materials, including incoming inspection.
• Work order control and how maintenance records are created and retained.
• Procedures for contracting maintenance to outside parties (contract maintenance).
• How the station ensures that only properly trained and authorized personnel perform or approve work.
• Procedures for notifying the FAA of certain events, including accidents or incidents involving maintained articles.

The RSM must be approved by the FAA before the certificate is issued, and any significant change to it requires FAA approval before the change is implemented.

The Quality Control Manual (QCM)

Alongside the RSM, the station must have a Quality Control Manual (QCM) that describes the station's system for ensuring the airworthiness of work performed. The QCM covers inspection procedures, how discrepancies are discovered and resolved, receiving inspection criteria, final inspection and return-to-service steps, and how calibration of inspection equipment is managed. Together, the RSM and QCM form the backbone of the station's quality system and are the documents an FAA inspector will examine during surveillance and renewal inspections.

Personnel Requirements

Accountable Manager. Part 145 requires each certificated repair station to identify an accountable manager—an individual who has the authority and responsibility to ensure the station meets all regulatory requirements and to commit necessary resources to do so. The accountable manager is the primary point of contact with the FAA and is personally responsible for the overall compliance of the station.

Certificated Mechanics. Mechanics working at a Part 145 station and signing off maintenance must hold the appropriate FAA mechanic certificate with the applicable ratings (Airframe and/or Powerplant) as required by the work being performed. The mechanic who approves an article for return to service is certifying that the work meets the applicable standards—a significant legal responsibility. Non-certificated personnel may perform certain tasks under the direct supervision of an appropriately certificated person, but the certificated individual retains responsibility for the quality of that work.

Training Requirements. Part 145 requires the station to have a training program ensuring that personnel are qualified for the work they perform. Training records must be maintained.

FAA Oversight and Inspections

The FAA conducts initial certification inspections to verify that a station meets all Part 145 requirements before issuing a certificate. After certification, the FAA performs ongoing surveillance inspections. Stations must allow FAA inspectors access to facilities, records, and personnel at any time. Failure to maintain the required facilities, personnel, or documentation can result in suspension or revocation of the certificate.

Safety Culture in a Part 145 Environment

Part 145 compliance is inseparable from safety. Proper housekeeping, calibrated tools, controlled technical data, and qualified personnel all directly support airworthy maintenance. Mechanics should never return an article to service if there is any doubt about its airworthiness—the regulations require that doubt be resolved through proper inspection and approved data before sign-off.