Thinking of a PMC OFF takeoff in a B737 classic, a few doubts came to my mind, and I hope you'll be able to clarify everything.
The PMC keeps engine RPM and thrust constant during takeoff, right?
With the PMC inop, the N1 value will increase during the takeoff roll by as much as 7%.
The initial setting is also higher without PMC.
In fact, the Vmcg also increases by 4-6 knots.
So why on earth there is a weight penalty with PMC OFF
since the engines are pushing harder??