Puzzle me this....
At our company we can elect to derate and/or use reduced thrust take offs. It is my understanding that we are trying to keep EGTs to minimum to assist with prolonged engine life etc. However, is it not more beneficial to then use the lowest assumed temperature, which may then be the higher thrust rating? We have the 20k/18.5k derate fit and a typical scenario is a 20k take off with an assumed temp of say 40 degrees vs. an 18.5k derate with an assumed temp of 34 degrees with the corresponding N1 being higher on the lower thrust rating. Which is the better option?
