M1 vs M2: Which AME Rating Covers Which Aircraft

M1 and M2 are both "mechanical" AME rating categories, and the distinction between them is defined by the type of aircraft, not by experience level or seniority — M2 is not simply "M1 plus more years." Per Transport Canada's licensing standards: M1 covers non-turbojet aircraft built to specific airworthiness standards (Standard 522, 523, 523-VLA, 527, and 549, and equivalent standards) — in practice, piston-engine aircraft. M2 covers all aircraft not included in M1, excluding balloons — in practice, turbine-powered and larger, more complex aircraft. Both M1 and M2 holders are additionally permitted to maintain turbine helicopters and SFAR 41C aeroplanes.

Piston and turbine aircraft maintenance involve meaningfully different systems knowledge — different engine types, different fuel and ignition systems, and often different levels of aircraft complexity overall. Splitting the mechanical category into M1 and M2 lets Transport Canada tailor the examination and experience requirements to the systems actually relevant to each class of aircraft, rather than testing everyone on the full breadth of both.

This also means the two exams cover different (though overlapping, at the level of general mechanical principles) knowledge domains, and study material genuinely specific to piston-aircraft systems will not fully prepare someone for the M2 exam's turbine-specific content, or vice versa.

For most candidates, the practical answer is: whichever category matches the aircraft you are actually gaining hands-on experience on, since Transport Canada's experience requirements for each rating are tied to relevant work on that category of aircraft. Someone apprenticing at a general aviation shop working mainly on piston aircraft will typically build M1-relevant experience; someone at an operation working on turbine or larger aircraft will typically build M2-relevant experience.

It is common for AMEs to eventually hold both M1 and M2 (plus E and/or S) over a career, added one at a time as experience and study allow — there is no rule limiting you to one mechanical rating for life.