@C100Driver: Thanks. That is one of the best responses I've ever seen and much appreciated.
If I've got it right, when a PBTH operator leases a (hypothetical) 25K engine, plugged at 22K, 1) the pilot cannot go beyond 22k - no matter what and 2) of course, the engine wear will be less than if operated at 24k or maxed at 25k - but such is simply not possible. ANd of course, less-than-max thrust is appropriate for some airframes, all using the same engine, perhaps down-rated (plugged) to fit both the airframe and the buyer's (user's) needs. I can imagine the extensive calculations and flight trials necessary to certificate each available option for a given airframe. (Ouch!)
On point: When an operator buys a new airplane (of a fleet), and rents their thrust from the engine manufacturer under a PBTH program, the cost/benefit calculation must be a complicated one.
Thanks again for the sharp reply!
