airbus perfo question

[kaepa]

anybody flying airbus family , please
airbus recommends in their FCOM to use HIGHER FLAPS slection for takeoff with high altitude airfield to improve comfort .

1. when do you consider the airport to be high altitude ??

2. how technically higher flap selection improve comfort??
ANYTHING TO DO WITH PRESSURIZATION?

regards

[catchup]

1. ? don't know..
2. High elevation with low flaps means you have to run very long on TO


regards

[Pegasus77]

It is offcourse for the comfort of the pilots... ever seen the red end-of-the.runway-lights approach during the takeoffroll? A higher flapsetting would prevent that.

I see no advantage in pax-comfort at all. No I see no pressurisation-advantage. The cabinpressure is completely independent from the flapsetting.

The question whether an airports elevation is high enough for a higher flapsetting is solved when you look in the performancemanual, or if you calculate the TO-performance on your laptop.
There are so many variables going into a TO-performance-calculation, that you cannot say that above 5000' elevation, flaps 25 or higher is mandatory or something like that. It depends on actual weather, elevation, RUNWAYLENGTH!!, obstacles etc. etc.

Cheers,
P77

[square leg]

If you have ever taken off from RWY18 in Frankfurt then you will know why they recommend using a higher flap setting... That runway shakes the plane to bits. Now just imagine Frankfurt having a high(er) elevation (say 6000'), the T/O run would be even longer.

Perhaps high elevation runways get used and abused more than lower elevation ones as aircraft TAS/Ground Speeds are generally quite a bit higher thus more wear and tear and thus generally (perhaps) the condition of these runways is worse.

...get off the ground quicker with more flaps.

as they say... my 2 cents worth.

[CDB.A300]

in some case found that VR is 2 or 3 Kts higher than V2,
Any idea why??