When aircraft engines are evaluated in a test flight, how is the thrust of the engine measured?
You would need accurate thrust numbers to calculate the real-world specific fuel consumption (i.e. not in a controlled environment like an engine on a test bed).
I'd assume it is nearly impossible to measure thrust indirectly with any accuracy since so many factors are involved (wing shape, wind, air density, lift, ...).
So I guess there should be a way to measure thrust directly, probably in the engine pylon.
So how is engine thrust measured in flight?