TDK mk2
24th Sep 2008, 22:57
I might be showing myself up here a bit but can anyone shed some light on what the most fuel efficient way of climbing this aircraft is?
My company say that flc is the most fuel efficient climb profile, that's 240kts up to FL100 and then increase to 270kts indicated until it meets mach 0.56 at about FL174 which it maintains from then on up.
I have to admit my understanding of swept wing performance is a bit rudimentary (ex turboprop pilot) but surely accelerating at FL100 when the engines are gobbling nearly 1000kgh each side can't be as efficient as climbing at either best climb speed (220kts) or close to it.
I've found 230kts indicated gives a good rate and the FGS speed mode changes from IAS to MACH mode at FL250 and captures 0.56 perfectly.
I was just wondering if anyone can tell me whether the flc schedule is indeed the most fuel efficient way to climb, and why? I'd like to save my company (and maybe in doing so my job) money wherever possible even if it means flying at the long range cruise speed of 210kts at FL220 as I did the other night which I bet raised a few eyebrows at ATC. I did tell them I would increase on request but they said it was fine, and we were very, very early.
My company say that flc is the most fuel efficient climb profile, that's 240kts up to FL100 and then increase to 270kts indicated until it meets mach 0.56 at about FL174 which it maintains from then on up.
I have to admit my understanding of swept wing performance is a bit rudimentary (ex turboprop pilot) but surely accelerating at FL100 when the engines are gobbling nearly 1000kgh each side can't be as efficient as climbing at either best climb speed (220kts) or close to it.
I've found 230kts indicated gives a good rate and the FGS speed mode changes from IAS to MACH mode at FL250 and captures 0.56 perfectly.
I was just wondering if anyone can tell me whether the flc schedule is indeed the most fuel efficient way to climb, and why? I'd like to save my company (and maybe in doing so my job) money wherever possible even if it means flying at the long range cruise speed of 210kts at FL220 as I did the other night which I bet raised a few eyebrows at ATC. I did tell them I would increase on request but they said it was fine, and we were very, very early.