Belgian F-16AM's use the P&W F100 engines (the early blocks until 25 all used a variant of this. Nowadays a 30/40/50 has the GE engine, early blocks till 25 and AM MLU/32/42/52 use the P&W engine). One thing that the P&W engine has, is that the nozzle actuator makes that noise when the nozzle adjusts. It's very common to hear on the birds running the P&W F100 engines, like the 15C and 15E. They even added it to the 15C - Go external view while parked and throttle up and down (its glorious)
It's not something the GE-129 has unfortunately. So not something to expect (sad actuator noises).
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