Relationship Between Regulations Part-21, M, 145, 66, 147 and OPS

According to the EASA/CAO.IRI regulations, aircraft and aeronautical products, parts and appliances shall be designed and manufactured according to the initial Airworthiness which has only one annex: Part-21.

After delivery of the above items to the customer, all of them shall be operated and maintained under the relevant regulations. The requirements applicable to the operation of any civil aeroplane for the purpose of commercial air transportation by the operators are determined in OPS regulations whereas the regulations concerning the continuing airworthiness are introduced in 4 annexes:

• Annex i. Part M (Continuing Airworthiness)
• Annex ii. Part 145 (Maintenance Organisation Requirements)
• Annex iii. Part 66 (Certifying Staff)
• Annex iv. Part 147 (Training Organisation Requirements)

The continuing airworthiness of aircraft and components shall be ensured in accordance with the provisions of Part-M. The requirements to be met by an organisation to qualify for the issue or continuation of an approval for the maintenance of aircraft and components are issued in Part-M Subpart F.

Organisations involved in the maintenance of large aircraft or of aircraft used for commercial air transport, and components intended for fitment thereto, shall be approved in accordance with the provisions of Part-145. Maintenance and overhaul of the commercial aircraft must be performed at the approved maintenance organisation per Part 145. This organisation must have certifying staff having approved licence per Part 66. These personnel must have training at an approved maintenance training organisation per Part 147.