some numbers
Gentlemen.
Some number crunching (admittedly for an a330)
Taking a 6.6 flight hour average mission, average aircraft weight,
average takeoff derate, cruise derates predicted by AIRBUS performance programmes, and based a 70USD labor cost:
selecting derated climb level 1 brings around 4% DMC saving vs. Max Climb,
selecting derated climb level 2 brings around 5.5% DMC saving vs. Max Climb.
Reference DMC (with Max Climb) for a 6.6 flight hour mission is close to 140 USD per flight hour and per engine.
however when it comes to deciding specific derate policy out of specific airports with known average takeoff weight and temperatures, coupled with known altitude constraints. Then things get interesting.
rgds
O/z