Hi,
Reduce engine wear?!? IF you can find one, please post [a link to] even ONE engineering study that quantifies the reduction in engine wear.
Once you get about 10% below max rated thrust, incremental reduction of engine wear is miniscule. Engine speed and EGT which are the main drivers of wear -- are already significantly below max. In fact, on the 744 and 748 we too often take off with thrust set SIGNIFICANTLY below climb thrust! That is simply a beancounters' exercise to reduce engine lease payments, and has NO operational value.
I agree, the first few degrees of flex save the most on engine-wear. After that it becomes a paper excercise
I don't agree with your opinion. I don't think the engine wear is miniscule if the max rated thrust is decreased about 10%. When you reduce the max rated thrust 25% or 40% (assumed/flex and derate), the engine wear is reduced compared to the max rated thrust and 90% of max thrust (or 10% below max thrust that you mentioned). Please have a look to slides 6,7,8,8,10 of the this link:
Reduced Thrust Operations
It will be very helpful if you can post a link that shows when you get about 10% below max rated thrust, incremental reduction of engine wear is miniscule.
I thought when an airline purchased aircraft, the cost of the engines is included. If the aircraft are leased, the engines are leased. Are you saying that all engines used by airlines are leased?