And the FARs still allow 8.00 mains without an STC as this is part of the aircraft specifications listed on the TCDS as shown below. A major alteration is defined in Part 1 as a change affecting certain items and one that is
not listed in the aircraft specifications. This one is so it’s a minor. Alterations on these older aircraft were much more "informal" than today. So this has nothing to do with CAR vs FAR based on what you have posted.
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FYI: if you look at some “TCDS” with a number that starts with an “A” you’ll notice they are actually called Aircraft Specifications vs Type Certificate Data Sheet. Hence the term in the definition. Some like the 140 TCDS got renamed for some reason by the OEM but others remain the same as the example below. But the term still applies even today as those aircraft specification lists were moved to the type design so basically any alteration that is called out by OEM documentation is considered within the aircraft specifications and considered a minor. No STC or 337 required.
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