747 EEC in Alternate Mode

[tdracer]

Cosmo

While "Overboost" may not be a technically accurate term for exceeding the max rated thrust, I've been working turbofan propulsion systems for over 37 years, and it's the commonly accepted term for exceeding the max thrust rating (EPR or N1) for the conditions. It's used by Pratt, GE and RR, Boeing propulsion engineers, the FAA specialists, and every pilot I've ever talked to about the phenomena. As barit1 notes, a large 'overboost' may require an inspection. And 'overboost' isn't all that inaccurate since, at least at sea level, a large overboost will exceed the design pressures in the compressor.

It is not the same as 'overspeed' which generally means a redline exceedance.