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Modification of Canadian Aircraft

What is a design change

Aircraft are manufactured in accordance to a specific type design. A design change is any modification or alteration of the original design. For example, replacement of a part with another part of the same part number is not a design change but replacement of a part with an alternate part is.

So you have made or wish to make a design change to a certified aircraft. The consequence is that a design change, if not done properly, can invalidate the aircraft’s Certificate of Airworthiness “C of A”. Transport Canada defines airworthy as follows:

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

Note that for the C of A to be valid the aircraft must conform to its type design.

Completion of an aircraft maintenance task or design change requires a logbook entry recording the work. This statement also ensures that the work done “conforms” to applicable data or procedures. The question for the individual signing the maintenance release is what is the applicable data?

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
Change Product Rule and the basis of certification