Originally Posted by
Skyjob
You've just answered the OP question to the reason when it exists, in REDUCED thrust settings only, as above 15000' full thrust is always available.
Regarding OP question, selecting CON/CLB merely in this scenario gives you FULL rated thrust, thus is NOT limited to non-normal situations. In fact, when cleared to climb above 15000' it makes sense to expedite the climb using the full available power, taking into account closure rates of course to avoid unnecessary TA/RA's.
Skyjob,
CON and CLB are not the same, although they may match. Note that with U11.0, the limit in cruise reverts to CLB now, not CON.
From Boeing's Jet Transport Performance Methods:
maximum continuous thrust
This is the third of the “certified” thrust levels.
Maximum Continuous Thrust, or MCT, is a special thrust rating that is only usable in the event of some emergency situation. It may not be used in normal operation. *2 MCT is the greatest amount of thrust that can be used in flight, with the exception of takeoff and landing.
*2. For some engines, the maximum continuous thrust rating is the same as the maximum climb thrust rating; in those cases, this statement does not apply