Originally Posted by
8che
SafetyPee, read the conversation again. More flap BEFORE the take off roll commences great. Changing it in the middle of the roll is not something the FAA or Boeing would ever endorse..
Lets be clear what we are talking about here; you are barrelling down the RW with, for example, a V1 of 130 kts (I'm in an A320). Shortly after the "100 kts" call - say for arguments sake 110kts - the speed trend arrow goes from the top of the speed scale to zero and the CAS stagnates. The wind arrow on the PFD shows a significant and unforecast tailwind.The end of the RW approaches - whats to do? Clearly, your calculated performance is now out of the window and you are in survival mode - the FCTM/FCOM no longer helps.
TOGA - sure.
Rotate at 110kts - maybe.
Sit and wait for Vr - could be noisy and expensive - GS is by now way higher than the CAS
If an increased flap setting is available to aid the ac to fly - maybe.
Stop - no way.
Other positive contributions are of course welcome.
Cheers
mcdhu