Moon11,
Ouch, I didn’t realize that the 6000 lbs extra takeoff thrust offered by the CF6-80C2B5F increased VMCG’s by so much. For comparison.
Full thrust(TO):
OAT 15 C/Airport pressure alt=0
Vmcg=133 KIAS (135 is the –2000 feet PA speed)
Derate One(TO1):
Same OAT/Press. alt.
Vmcg=127 KIAS
Derate two(TO2):
Vmcg=121 KIAS
VMCA data is available in our AFM, for the SL/15°C case, the VMCA is 132 kts.
Boeing don’t give VMCA data to crews, the operations manual has a VRMIN, as this must be equal to or greater than 1.05 VMCA and V1, it protects you for VMCA.
Mutt.