From Part 43 Shop to FAA Part 145 Repair Station: What Really Changes

A practical, inside look at the regulatory, operational, and cultural shift from a traditional Part 43 maintenance shop to a certificated FAA Part 145 Repair Station, what it takes, what it costs, and why it matters.

For years, many general-aviation maintenance facilities operated solely under 14 CFR Part 43, which governs how maintenance, preventive maintenance, rebuilding, and alterations are performed on U.S.-registered aircraft. As scope, specialization, and customer expectations increase, some shops choose to evolve into an FAA Part 145 Repair Station — a company-level certificate with formal quality systems, manuals, training, and FAA oversight.

Stew’s Aero officially became a Part 145 Repair Station in 2025, formalizing processes that support consistent outcomes, transparent records, and controlled data access across airframe, powerplant, avionics, and component work.

Part 43 vs Part 145 — The Difference in Plain Language

• Part 43: Rules for how maintenance is performed. Applies to all maintenance personnel (A&P, IA) and shops.
• Part 145: Rules for who may operate as a repair station and under what system. Requires approved manuals, facilities, personnel qualifications, tool control, training, data management, and quality assurance.

Think of Part 145 as systematized compliance: the FAA certifies the organization’s ability to consistently perform Part 43 work under documented processes.

Why a Shop Chooses to Become a Part 145 Repair Station

• Capability and scope growth: Complex avionics, instrument/radio work, specialized inspections, and major alterations benefit from repair-station structure.
• Fleet and contract maintenance: Many operators prefer or require 145 providers for traceability and oversight.
• Formal quality system: Required inspections, calibration programs, and internal audits reduce risk and rework.
• Ratings and capabilities: Airframe, powerplant, propeller, radio, instrument, accessories — defined in a controlled Capabilities List.
• Customer confidence: FAA surveillance and documentation standards support defensible maintenance records.

What the FAA Requires to Issue a Part 145 Certificate

1. Application: FAA Form 8310-3, requested ratings, facility data.
2. Pre-application & formal meetings: With the local FSDO/MIDO; scope, management, training, and facilities are reviewed.
3. Manuals:
   • Repair Station Manual (RSM) — organization, roles, procedures.
   • Quality Control Manual (QCM) — inspection system, calibration, records, corrective action, internal audits.
   • Training Program — initial/recurrent training, qualification tracking.
   • Capabilities List (CL) — the makes/models/components the station is authorized to maintain.
4. Facilities, tools, and housing: Adequate work areas, lighting, environmental protection, secure parts storage; calibrated tooling with scheduled control.
5. Management & key personnel: Accountable Manager, Chief Inspector, Director of Maintenance (or equivalent), and training designee with defined experience and duties.
6. Data control: Current technical data (ADs, manuals, ICAs, service information) for all items on the Capabilities List.
7. Demonstrations & inspections: The FAA evaluates procedures, records, parts control, and conformity before issuing the certificate and Operations Specifications (OpSpecs).

The Cultural Shift: From Individual Mechanics to a Managed System

• Controlled work orders: Every job flows through a documented order with parts traceability and sign-offs.
• Authorization under the station: Mechanics work under the repair station’s privileges; qualifications are tracked.
• Parts & materials control: Incoming inspection, tagging, vendor qualification, and shelf-life management.
• Tool control & calibration: Scheduled calibration, labeling, and audit trails.
• Internal audits: The quality system verifies that the process works — not just the aircraft.

Timeline, Cost, and Ongoing Commitment

• Typical timeline: 8–18 months, depending on readiness and FAA workload.
• Up-front investment: Manuals development, training, calibration equipment, facility updates, subscriptions, specialized tooling.
• Ongoing cost: Recurrent training, audits, manual revisions, calibration cycles, FAA surveillance, and recordkeeping.

What It Means for Aircraft Owners

• Standardized quality assurance: Required inspections and independent QC sign-offs.
• Traceability: Documented parts, processes, and approvals (e.g., STC/ICA/337) are controlled and archived.
• Defined capabilities: Ratings and Capabilities List make scope clear from the start.
• Consistent returns to service: Documented testing and conformity checks before sign-off.

The Paperwork Backbone (Beyond the Manuals)

• Revision control for manuals and procedures.
• Employee qualification and training records.
• Tool calibration logs and labels.
• Vendor qualification files and receiving inspection records.
• Work orders, parts traceability, and return-to-service documents.
• Internal audit reports and FAA correspondence.

Lessons Learned Making the Jump

1. Documentation equals capability. If it is not written, trained, and auditable, it is not part of the system.
2. Quality must be independent. The Chief Inspector’s authority and resources are non-negotiable.
3. Data access matters. Up-to-date technical data (ADs, manuals, ICAs) is essential for scope control and conformity.
4. Culture is the differentiator. A disciplined process turns good mechanics into a great organization.

Bottom Line

Transitioning from a Part 43 shop to a Part 145 Repair Station is a transformation in accountability and structure. It formalizes what competent shops strive to do: consistent work, controlled data and tools, and fully traceable records. Stew’s Aero completed this transformation in 2025, aligning our operations with the standards that owners and operators increasingly expect.

Notes

• This overview is for general information. Always consult current FAA regulations, guidance, and your local FSDO/MIDO for certification specifics.
• Timelines and costs vary by facility readiness, requested ratings, and FAA workload.