Ocampo,
" Derrated-TO is a max. thrust. Can someone with a bit more of experience in Mr. Boeing's aircrafts confirm this?
Boeing DO indeed state that "Derrated-TO is a max. thrust", for several very good reasons -
(1) Even if you are using Reduced Thrust (Assumed Temperature Method or ATM) with a Derate, Vmcg and Vmca are based upon the full applicable Derated thrust. V1, Vr, and V2 are based upon this set of Vmc speeds. Advancing thrust to the FULL rating following engine failure at Vmc limiting speeds for a Derated Thrust Takeoff would be courting disaster.
(2) The rules specify just how much thrust reduction is possible using Reduced Thrust (ATM) as a percentage of Maximum Thrust. By introducing new sets of Maximum Thrust (e.g. TO-1, TO-2), much larger thrust reductions (as related to FULL Takeoff Thrust) are possible.
Thus, Derated TO IS a maximum thrust.
Other areas where you may find this is in Boeing recommendations such as contaminated runway operation etc., where they state that ATM shall not be used, and Maximum Thrust used, with the immediately following reminder that Derated Thrust/s are Maximum Thrust/s.
Once you are out of the Vmc danger zone (above V2 for FULL TO), you may, if operationally necessary, advance the engine/s to FULL TO with impunity, AEO or OEI. For every Takeoff that I do with Derated Thrust (which is most of them) I always check the V2 speed for FULL TO, "just in case".
John_T, you had to mention the Tennant Bl**dy Creek inversion didn't you! As a young sprog Flying Doctor pilot about 32 years ago, I had a night takeoff there which came to a stop at about 200 ft AGL. The not-so-large aircraft (8,800 Lb) just sat, and sat, and sat at 200 ft, until VERY shallow climb resumed. I've 'enjoyed' the Middle East's inversions on numerous occasions, but none came close to Tennant Bl**dy Creek's mother of all inversions. I recently saw TNK again from 38,000 feet, definately the best way to see it, still get shivers about the night that Young Smokey never made it to Old.
Regards,
Old Smokey