Andy,
They belch black smoke distress signals and the fuel consumption goes into the ****ter, but generally they can keep running to a degree.
Ahh but the mixture knob fixes that
A sweep will find the best of a bad day.
Yr Right, have a think about what it takes to run a compression ignition piston engine at altitude and what happens with a substantial loss of boost from a simple coupling, not a turbo failure even.