Curious: does anyone know just when and what criteria were originally prescribed for what we now know as Type Ratings by the potentates of the Beltway? I have heard of early on there were Horsepower ratings but, no details, or even credibility, of that. Hopefully, there are some wise old owls of the BT Braintrust who can recall (as I can find no one at the Friendly Aviatin’ Association, or any where else that can). Thanks in advance,

MM

Thought it was weight

Weight (12,500#) and engine type (all jets require it). Not sure if there are other benchmarks.

I think the MU-2 and R-22 require type specific training that is very much akin to a TR, but not officially a TR.

Total rabbit hole I went down thanks to the OP!

I dug around a bit and 14CFR20.55 lays out weight classifications in 1940. Could have been in the CFRs before, just chose 1940 as a starting point. Library of Congress website... Looks like a lot was happening between 1936 and 1940. CAA was formed in 1938.

So, weight and engines...

12,500 lbs and/or jet powered are what have been the standard for many years. What I was seeking was prior to these present requirements. Maybe 1930’s or ‘40’s?
Thanks to all who replied.

MM

So…the post about 14CFR20.55 from 1940 wasnt relevant?

So…the post about 14CFR20.55 from 1940 wasnt relevant?

So the Boeing Model 307 Stratoliner/Strato-Clipper went into service in July, 1940 as the first airliner in revenue service with a pressurized cabin. Its gross weight was 45,000 lbs. Compare that to an Airbus A380 with a max takeoff weight of 560 tons (1,120,000 lbs).