Canadian Aviation Regulations — 521.158
521.158 (1) Subject to subsections (2) to (9), an applicant for the approval of a change to the type design of an aeronautical product shall demonstrate that the product meets the standards of airworthiness recorded in the type certificate data sheets and in force on the date of the application for the change. (2) The certification basis for the issuance of a repair design approval or a part design approval is that recorded in the type certificate data sheets, and includes any special conditions referred to in subsection (7). (3) A change to the type design of an aeronautical product may conform to an earlier amendment to a standard referred to in subsection (1) if the Minister determines that the change is not significant in the context of all previous relevant design changes and of all related amendments to the applicable standards recorded in the type certificate data sheets. The change is significant if (a) the general configuration or principles of construction are not retained; or (b) the assumptions used in obtaining the type certificate for the aeronautical product do not remain valid. (4) A change to the type design of an aeronautical product may conform to an earlier amendment to a standard referred to in subsection (1) in respect of an area, system, component, item of equipment or appliance if the Minister determines that the area, system, component, item of equipment or appliance (a) is not affected by the change; or (b) is affected by the change, but conformity with a standard referred to in subsection (1) would not contribute materially to the level of safety or would not be practical. (5) In respect of an area, system, component, item of equipment or appliance that is affected by a change, a standard referred to in subsection (3) or (4) may not predate a standard that is recorded in the type certificate data sheets or (a) in the case of a normal, utility, aerobatic and commuter category aeroplane, the standards set out in section 523.2 of Chapter 523 — Normal, Utility, Aerobatic and Commuter Category Aeroplanes of the Airworthiness Manual ; (b) in the case of a transport category aeroplane, the standards set out in section 525.2 of Chapter 525 — Transport Category Aeroplanes of the Airworthiness Manual ; (c) in the case of a normal category rotorcraft, the standards set out in section 527.2 of Chapter 527 — Normal Category Rotorcraft of the Airworthiness Manual ; and (d) in the case of a transport category rotorcraft, the standards set out in section 529.2 of Chapter 529 — Transport Category Rotorcraft of the Airworthiness Manual . (6) The standards of airworthiness that apply in respect of a change to the type design of an aircraft, other than a rotorcraft, having a MCTOW of 2 720 kg (6,000 pounds) or less, or of a non-turbine rotorcraft having a MCTOW of 1 360 kg (3,000 pounds) or less, are those recorded in the type certificate data sheets, unless the Minister determines that (a) the change is significant and requires compliance with an amendment to the standards that are recorded in the type certificate data sheets and that apply in respect of the change and with any other standards that are directly related to the change; and (b) compliance with the amendment referred to in paragraph (a) would contribute materially to the level of safety and would be practical. (7) An applicant for the approval of a change to the type design of an aeronautical product having a novel or unusual design feature shall comply with any special conditions that are necessary to ensure that the change provides a level of safety equivalent to that provided by the applicable certification basis determined under subsections (1) to (6), (8) and (9). (8) If a change is made to the type design of a restricted category aircraft, or if a change to the type design of an aircraft results in the aircraft being reclassified as a restricted category aircraft, that aircraft must meet (a) the standards of airworthiness referred to in section 521.3