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Strongresolve
11th Mar 2008, 00:13
I have heard that Iberia has implemented a new VLS+5 landing performance charts for landing weight calculation in high airports in their A340 fleet, and it reduces around 10.000 - 20.000 the landing weight of the previous charts.
I´m an airbus sticker in another spanish airline and I´m anoyed. I have always believed that the charts that we normaly use are VLS+5 not VLS. Anyone with knowlege in Airbus performance know something about this?
The normal charts that we use in the A320/330/340 are VLS+5 or VLS?
That means that Iberia is going to use VLS+10 without knowing it?

Thanks.

Mäx Reverse
11th Mar 2008, 07:20
Airbus has always been giving landing distances under the assumption, that you are touching down with Vls, at least for the A319/A320/A321 which I'm flying. Operating this way wouldn't be the wisest choice under most conditions, so my airline has defined Vapp = Vls + 5.

As long as we are not operating into lilmiting fields we even add an increment to Vapp if th FAC calculates a heavier aircraft than on the loadsheet in order to restore the 5 Kt between the FAC-calculated Vls and the FMGC-calculated (based on Loadsheetdata) Vapp.

Unfortunately there are no performance chart available for Vls +5, hoever 10% will do the trick, as is noted below 'per 5kt speed increment (and no failure) add 10%).

That the landing distance tables don't state the assumptions under which they are are calculated is a shame. Even the 'Performance' section in our OM-B only states 'Landings Distances are calculated using a speed 1.23 times the stall speed'. Under Speeds and Definitions you can look up, that this is Vls.

Safe Flying, MAX

Mephistopheles
11th Mar 2008, 09:26
330/340 have 'Autoland landing distance' charts in the QRH which would take care of the extra 5kts. Also it is a limitation that unless the landing is to be carried without A/thrust then the min speed is VLS+5. So I guess that Iberia will be doing all their landings now with manual thrust!

Jonty
11th Mar 2008, 09:42
Airbus landing distance charts are based on touching down at VLS. In the Corrections section at the bottom of the page it says to add 8% for a 5kt speed increment, so VLS+5.

I imagine the percentage increase changes with MSN.