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Modification of Canadian Aircraft

What is a design change
The maintenance release for a modification design change
The AC 43.13 as specified data for major modifications
Approved data for major modifications
How do you obtain a design change approval
What is a DAR and a DAO
Why use a DAR or DAO
Standards and Approvals
Mechanics, Engineers and good design
Whose responsibility is the aircraft modification

Responsibility to ensure that the design change “complies” with all the pertinent certification requirements is the person with the delegated authority to sign the Transport Canada form AE-100 Statement of Compliance. The US equivalent of this form is the 8110-3.

The design approval is then issued to a company or an individual who is referred to as the holder of the approval. The holder of a design approval is responsible for:

• Maintaining the design change in accordance with applicable instructions of continuing airworthiness
• Notification of service difficulties (CAR V Subpart 91)
• Transport Canada notification in the event of transfer of the design approval CAR 511.25

Installation of the design change occurs and the individual delegated by the Aircraft Maintenance Organization (AMO) makes a logbook entry recording the work and states that the installation “conforms” to the applicable data. At one time it was the AME performing the maintenance release that was held responsible to ensure that the modification was airworthy. However that has changed now and it is the owner of the aircraft that is ultimately responsible for the airworthiness of the aircraft. Remember that a type design change approval is basically an extension or alteration of the aircraft type design and the definition of airworthiness is:

"airworthy" - in respect of an aeronautical product, means in a fit and safe state for flight and in conformity with its type design

Change Product Rule and the basis of certification