Part 145

Part 145 commonly refers to the aviation regulatory requirements that govern the approval, operation, and oversight of maintenance, repair and overhaul (MRO) organizations. It defines how organizations must be structured, documented, staffed, and controlled in order to be approved to perform maintenance on aircraft and aeronautical products.

Primary meanings in aviation

There are two closely related uses of the term “Part 145” in aerospace and MRO environments:

• EASA Part-145: The European Union Aviation Safety Agency regulation that sets out requirements for maintenance organizations working on aircraft and components under EASA oversight.
• FAA Part 145: The United States Federal Aviation Regulations (FAR) Part 145, which cover certification and operation of repair stations that perform maintenance and alterations on U.S.-registered aircraft and related articles.

In both cases, “Part 145” is shorthand for a specific regulatory part that defines how maintenance organizations must operate to maintain regulatory approval.

Scope and content

Part 145 requirements typically address topics such as:

• Approval and certification of the maintenance organization
• Management structure and accountable roles
• Personnel qualification, training, and authorization
• Facilities, tools, equipment, and calibration management
• Maintenance procedures and work instructions
• Documentation, records, and maintenance releases
• Quality system, internal audits, and corrective actions
• Control of subcontracted and outsourced maintenance
• Control of components, materials, and stores

Operationally, Part 145 influences how MRO shops design their processes, how information systems are configured (for example, for work orders, sign-offs, and traceability), and how records are retained for regulatory oversight.

Use in industrial and digital contexts

In manufacturing and MRO environments, “Part 145” is often referenced when:

• Designing or validating digital MRO systems such as MES, ERP, or MRO software to support required maintenance records and approvals
• Defining electronic signatures, workscopes, and release-to-service workflows
• Setting up audit trails, document control, and training records aligned with regulatory expectations
• Coordinating between OEM production environments and in-service maintenance organizations that must maintain Part 145 compliance

Common confusion

Part 145 vs. AS9100 or ISO 9001: Part 145 is a sector-specific aviation maintenance regulation, while AS9100 and ISO 9001 are quality management system standards. An organization can implement AS9100 or ISO 9001 processes to help support Part 145 expectations, but they are separate frameworks.

Part 145 vs. Part 21 or Part M (or CAMO rules): Part 145 typically governs organizations that perform maintenance work. Part 21 usually relates to design and production approval, and Part M (or equivalent continuing airworthiness parts) deals with continuing airworthiness management. Each covers different parts of the aircraft lifecycle.

Context in aerospace MRO

In aerospace MRO projects, Part 145 is frequently cited when planning digital pilots and implementations that touch live work, traceability, or release-to-service. Validation, change control, and customer or regulatory approvals are often aligned with Part 145 expectations for controlled maintenance environments.