> the plane CLEARLY flies differently to a 737[...]
There's no such thing as "a 737". A 737-600 is 31 meters long[1], and a 737-900ER is 42 meters. Both share the same type rating with the MAX[2], and have the same 36 meter wingspan.
That's going from a length:span ratio of 0.86:1 to 1.17:1, you think those sort of airframe changes don't make for a plane that flies differently?
Maybe the whole notion of a "common type rating" is foolish, and pilots should need to re-train from scratch for the smallest of changes. Change the paint job? New type!
There's a lot of "the engines moved!" discussion around the 737 MAX which seems to be ignorant of decades of significant airframe changes not impacting type, to little apparent ill effect until now.
I think it's all about how far off the mean you are.
Consider cars: You can get most full-size sedans with either four or six cyliner engines, manual or automatic transmission, and regular or sporty suspensions. That's potentially eight different sets of handling characteristics. But they're all going to be in a fairly narrow cluster of "this still drives pretty much like a Camry." When you decide "instead of the six-cyliner engine, let's drop in a 700 horsepower turbocharged V8", it's no longer anywhere near that cluster.
The question is whether a Camry with that V8 engine is as different from the less powerful of a Camry variant as it is from a Ford F-150. That's what the type rating is about.
The 737-100 had 62 kN of thrust, the 737 600-900 up to 120 kN[1], that whole line (and beyond) shares the same type rating.
That's going from a length:span ratio of 0.86:1 to 1.17:1, you think those sort of airframe changes don't make for a plane that flies differently?
Maybe the whole notion of a "common type rating" is foolish, and pilots should need to re-train from scratch for the smallest of changes. Change the paint job? New type!
There's a lot of "the engines moved!" discussion around the 737 MAX which seems to be ignorant of decades of significant airframe changes not impacting type, to little apparent ill effect until now.
1. https://en.wikipedia.org/wiki/Boeing_737_Next_Generation#Spe...
2. https://en.wikipedia.org/wiki/Boeing_737_MAX#Specifications