hawk 37
If an aircraft is not moving (stopped on a taxiway for example), then its not producing any power.
One definition of Power is that it is the 'rate of doing work'.
Work = Force x Distance
If the aircraft's engines do not apply their force (thrust) through a distance, then no work is being done. Ergo, no power is being produced.
(To be honest, I've never heard this 'myth' being expounded anyway, but then I should get out more...........)