Hi all,
From airbus "safety first" publications "Understanding of take off speeds" there is a part that is a little unclear to me.
The magazine reports:
"“JAR/FAR: AMJ 25-13 / AC 25-13
(4)(b) Derated takeoff thrust, for an aeroplane, is a takeoff thrust less than the
maximum takeoff thrust, for which exists in the AFM a set of separate and independent
takeoff limitations and performance data that complies with all requirements of
Part 25.”
Up to here everything clear but then says:
"The objective of flexible thrust differs from that of derated thrust. Both types of thrust
cannot be used interchangeably.
Flexible Thrust is a thrust reduction, designed to save engine life. This thrust is reduced
to take advantage of the available runway length, when full thrust is not necessary
(from a performance perspective),
but takeoff speeds with full thrust still apply."
What does this last phrase mean? do we take off with a flexible thrust (so actually a reduced one in relation to the full thrust available) but we use the take off speeds of a full thrust take off run?
Any ideas?
Regards,
bio161