View Full Version : Takeoff at heavy weight
Altcrznav
4th Mar 2022, 00:14
Airbus example ahead.
If I have a choice between Flaps 2 and lower V speeds or Flaps 1 and higher V speeds to lift a heavy weight, which one would be the preferred configuration?
Assume a 10000' runway and no obstacles.
No obstacles so consider a NADP2 for a higher climb speed and a quicker transition to clean configuration.
FlightDetent
4th Mar 2022, 08:07
The optimum configuration from FOVE / LPC NG / FlySmart w/Airbus is the one giving the highest P(lim)TOW. That's how it works on the inside.
Normally this is observed by the highest flex temperature, a standard A320 (27.5k) will indeed FLEX at MTOW for the given conditions.
Unable to run the calcs now, but with zero obstacles it is always 1 unless < 2400m or so.
FlyingStone
4th Mar 2022, 09:29
If there are no obstacles, and assuming you are not field limited, the lowest flap setting will be the best. Least amount of drag, and the best performance during initial climbout.
sonicbum
4th Mar 2022, 10:25
Airbus example ahead.
If I have a choice between Flaps 2 and lower V speeds or Flaps 1 and higher V speeds to lift a heavy weight, which one would be the preferred configuration?
Assume a 10000' runway and no obstacles.
If both provide the same RTOW and Flex, go for 2 (higher flaps setting).
Ref. FCOM-PER-TOF Considerations
FlightDetent
4th Mar 2022, 11:47
DU not found?
But this exists: PER-TOF-THR-FLX-40 Takeoff Procedure, saying the same thing.
https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/702x342/snippet_0b0d3ed3d6ad72dd0a90ce72c9b4b135f63b9f44.png
oceancrosser
4th Mar 2022, 15:19
That is a good reference chart for any airplane, just use relevant flap settings and whatever reduced thrust is called on your type.