AMC No 1 to 21.A.263(c)(1) Procedure for the classification of changes to a type certificate (TC) or to a supplemental type certificate (STC) and of repair designs as ‘minor’ or ‘major’
CAA ORS9 Decision No. 1
1. INTENT
This AMC provides the means to develop a procedure for the classification of changes to a TC, APU UKTSO or to that part of the product covered by an STC, and repair designs.
Each design organisation approval (DOA) applicant should develop its own internal classification procedure following this AMC in order to obtain the associated privilege under 21.A.263(c)(1).
2. PROCEDURE FOR THE CLASSIFICATION OF CHANGES TO A TC, APU UKTSO, OR TO THAT PART OF THE PRODUCT COVERED BY AN STC, AND REPAIR DESIGNS
2.1 Content
The procedure should address the following points:
— the identification of changes to a TC, APU UKTSO or to that part of the product covered by an STC, and repair designs,
— classification,
— justification of the classification,
— authorised signatories, and
— supervision of changes to a TC, APU UKTSO or to that part of the product covered by an STC, and repair designs initiated by subcontractors.
For changes to a TC, APU UKTSO or to that part of the product covered by an STC, the criteria used for the classification should be in compliance with point 21.A.91 as further explained in GM 21.A.91.
For repairs, the criteria used for the classification should be in compliance with point
21.A.435 as further explained in GM 21.A.435.
2.2 Identification of changes to a TC, APU UKTSO or to that part of the product covered by an STC, and repair designs
The procedure should indicate how the following are identified:
— major changes to a TC, APU UKTSO or to that part of the product covered by an STC or major repairs;
— those minor changes to a TC, APU UKTSO or to that part of the product covered by an STC or minor repairs where additional work is necessary to demonstrate compliance with the applicable CSs and environmental protection requirements; and
— other minor changes to a TC, APU UKTSO or to that part of the product covered by an STC or minor repairs that require no further demonstration of compliance.
2.3 Classification
The procedure should show how the effects on airworthiness as well as on operational suitability and environmental protection are analysed, from the very beginning, by reference to the applicable requirements.
If no specific CS or environmental protection requirements are applicable to the change or repairs, the above review should be carried out at the level of the part or system where the change or repair is integrated and where specific CS or environmental protection requirements are applicable.
2.4 Justification of the classification
All decisions on the classification of changes to a TC, APU UKTSO or to that part of the product covered by an STC, and repair designs as ‘major’ or ‘minor’ should be recorded and, for those which are not straightforward, also documented. These records should be easily accessible to the CAA for sample checking.
2.5 Authorised signatories
All classifications of changes to a TC, APU UKTSO or to that part of the product covered by an STC, and repair designs should be accepted by an appropriately authorised signatory, belonging to or tasked by the Office of Airworthiness, as explained in GM No 1 to 21.A.239(a)(3.1.4)(r).
The procedure should indicate the authorised signatories for the various products listed in the terms of approval.
For those changes or repairs that are handled by subcontractors, as described under paragraph 2.6, it must be described how the DOA holder manages its classification responsibility.
2.6 Supervision of changes to a TC, APU UKTSO or to that part of the product covered by an STC, and repair designs initiated by subcontractors
The procedure should indicate, directly or by cross reference to written procedures, how changes to a TC or to that part of the product covered by an STC, and repair designs may be initiated and classified by subcontractors and are controlled and supervised by the DOA holder.