For those who would like to read the certification basis for the discussion on Detrate / Reduced and why derate has a take off limit see
CS 25 Large Aircraft Amendment 4. AMC Appendices, AMC 25.13 (about page 699).
A few extracts:-
Reduced take-off thrust, is a take-off thrust less than the take-off (or derated take-off) thrust. The aeroplane take-off performance and thrust setting are established by approved simple methods, such as adjustments, or by corrections to the take-off or derated take-off thrust setting and performance. When operating with a reduced take-off thrust, the thrust setting parameter, which establishes thrust for take-off, is not considered a take-off operating limit.
Derated take-off thrust, is a take-off thrust less than the maximum take-off thrust, for which exists in the AFM a set of separate and independent, or clearly distinguishable, take-off limitations and performance data that complies with all the take-off requirements of CS-25. When operating with a derated take-off thrust, the value of the thrust setting parameter, which establishes thrust for take-off, is presented in the AFM and is considered a normal take-off operating limit.
And an interesting snippet re differences between take off and in-flight; which presumably also applies to max thrust or ‘uprates’ used in windshear escape.
The AFM limitations section should indicate that when operating with derated thrust, the thrust setting parameter should be considered a take-off operating limit. However, in-flight take-off thrust (based on the maximum take-off thrust specified in the basic AFM) may be used in showing compliance with the landing and approach climb requirements of, provided that the availability of take-off thrust upon demand is confirmed by using the thrust-verification checks.
Previous/similar discussion here:
http://www.pprune.org/forums/flight-...e-failure.html