wrote

Greg F. wrote:
Remember, you are not using 100% power for TOGA, and you have FADEC
which will compensate immediately.

Not using 100% power for takeoff? I don't fly jets but that sounds odd
to me. What T/O power setting are you suggesting is used in a 747? Is
it whatever the engine controller will allow when the power levers are
firewalled?

Transport Category Jets normally only use 100% power for takeoff if
the weight/temperature/runway require it. Reduced Thrust Takeoffs
are the norm. Reduced takeoff thrust is calculated to provide the
same safety margins as if the aircraft were weight limited on a short
runway using full thrust.

On the B-727, it was APR (automatic power reserve) that automatically
set the engines to full thrust in the event that any engine lost thrust
during takeoff.

Takeoff thrust is achieved well before the thrust levers reach "firewall".
During 25 years of airline jet flying, I never saw the thrust leverd
"firewalled".

Bob Moore
ATP B-707 B-727
PanAm (retired)