January 14, 2020


Sofema Aviation Services www.sassofia.com considers regulatory requirements concerning Certification of Aircraft Structural Repairs.

Introduction Part 21 Aircraft Repair Considerations

When a repair is carried out, which is essentially outside of the Structural Repair Manual (SRM) criteria or is carried out to a primary structural element, it is necessary to receive airworthiness approval for the repair. It is the responsibility of the CAMO to coordinate with a Part 21 approved organisation and where necessary the Type Certificate Holder – TCH.

FAA and EASA Repair Design Data Approval Process

(a) FAA shall approve design data in support of major repairs in accordance with FAA Order 8110.4 Type Certification; FAA Order 8110.37, Designated Engineering Representative Guidance Handbook; FAA Order 8100.15, Organization Designation Authorization Procedures; and FAA Order 8300.16, Major Repair and Alteration Data Approval”. Minor repairs are made in accordance with “acceptable” data, in accordance with 14 CFR Part 43.

(b) EASA shall approve design data in support of repairs in accordance with EASA Part 21 Subpart M-Repairs and EASA’s procedure Airworthiness of Type Design. A design approval shall be issued for all repair design data.

BOEING Repairs

In the case of Boeing Aircraft, the repair having been designed in accordance with Part 21 Design Standards or designed by Boeing the repair is approved by the issue of FAA 8100-9 FAA form approving the repair.

Boeing may also issue Form FA 8100-9 for any repairs which affects Airworthiness Directives.

AIRBUS Repairs

In the case of Airbus Aircraft, there is a similar process which is called an RDAS (repair design approval sheet). The scope of the Part 21 subpart M (21A.431) is the approval of the repair. This means the elimination of damage and/or restoration to an airworthy condition of in-service aircraft. In Airbus DOA, a RAS is the issuance of the Repair Design Approval as per Part 21A.437.

A Repair design Approval Sheet (RAS) is dedicated to structural damage, mainly ATA structure chapters (52 to 57) and interface with systems like flight controls of ATA 27. The Airbus process for system damages is called a Technical Adaptation (TA).

The difference between Airbus and Boeing is that the FAA form 8100-9 is issued under Organization Designation Authorization (ODA) which is issued to a company (in this case Boeing). The company then decides who to appoint as the individual members. A DER cannot sign the 8100-9 form unless they are also an ODA appointed designee but the DER still uses the 8110-3 form to show compliance to the FARs. Either way, both forms are considered FAA “approved” data whereas the RDAS is issued under DOA privilege.

Design data used in support of repairs must be approved or accepted, as appropriate, by the exporting authority (State of Design). The following describes the process that shall be followed by the FAA and EASA so that repair design data can be approved or accepted. Repair designs requiring the production of new parts that would constitute a design change are not eligible for acceptance under these Implementation Procedures.

However, it is permissible to fabricate parts that will be used in the repair of the individual aircraft, engine, propeller, or appliance.

Notification of Aircraft Lease Management Forthcoming Training Courses Avenue Hotel – Dubai

Aircraft Technical Records Specialist Lessee Management for CAMO & TR Staff – 2 Days (2-3 February 2020)

Managing Aircraft Lease Agreements and Maintenance Reserves – 3 Days (4-6 February 2020)

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Further Guidance

Sofema Aviation Services (SAS) and SofemaOnline (SOL) is pleased to offer a range of EASA compliant regulatory training courses in support of CAMO Continuing Airworthiness Records Management. For details please see www.sassofia.com, www.sofemaonline.com or email: office@sassofia.com or online@sassofia.com.


Airbus Repairs, Aircraft Leasing, Aircraft Structural Repairs, Aircraft Technical Records, Airworthiness, Boeing Repairs, Design Standards, EASA Part 21Subpart M