FAA Part 145 Repair Stations: The Backbone of U.S. Aviation Maintenance
FAA Part 145 certification under Title 14 of the Code of Federal Regulations is the federal standard that authorizes maintenance, repair, and overhaul (MRO) facilities to work on U.S.-registered aircraft, engines, and components. With approximately 4,850 certified stations operating domestically, these facilities form the infrastructure that keeps commercial, cargo, and general aviation fleets airworthy.
Rating Classes and What They Mean
Each Part 145 certificate specifies ratings that define what a station can legally work on. The six primary rating categories are:
| Rating | Scope |
|---|---|
| Airframe | Structural and system maintenance on complete aircraft (Classes I–IV by weight) |
| Powerplant | Engine teardown, inspection, repair, and overhaul (Classes I–III) |
| Propeller | Propeller overhaul and repair (Classes I–II) |
| Radio | Avionics and communication equipment (Classes I–III) |
| Instrument | Flight instruments and gauges (Classes I–IV) |
| Accessory | Mechanical, electrical, and electronic accessories (Classes I–III) |
A station may hold limited ratings restricted to specific aircraft models, engine types, or manufacturer product lines—common for OEM-authorized service centers.
Market Structure
The U.S. MRO market is dominated by a mix of airline-affiliated shops and independent providers. Delta TechOps, the largest airline-owned MRO in North America with over 9,600 employees, services both Delta’s fleet and third-party customers from its Atlanta hub. Independent providers like AAR Corp and StandardAero compete on flexibility, offering quick-turn engine shop visits and heavy airframe checks across multiple locations.
Business and general aviation MRO is served by specialists such as Duncan Aviation, which operates under a single FAA certificate covering all its facilities—a first in FAA history—and provides full-service maintenance for Bombardier, Dassault, and other business jet platforms.
Dual Certification Advantage
Many U.S. Part 145 stations also hold EASA Part-145 approval, allowing them to service European-registered aircraft. This dual certification is increasingly important as global fleet operators seek MRO providers that can handle mixed-registry fleets without repositioning aircraft overseas.
Choosing the Right Repair Station
- Verify the certificate
- Confirm the station’s ratings and limitations on the FAA’s facility dashboard before contracting work.
- Match capabilities to need
- A Class IV airframe rating covers aircraft over 12,500 lbs—essential for commercial operators, but unnecessary for light GA aircraft.
- Check turnaround commitments
- Engine shop visit lead times vary widely; shops with dedicated test cells and parts inventory typically deliver faster.
- Evaluate geographic proximity
- Ferry flight costs add up. A station near your operating base or a major airport hub reduces repositioning expense.