A320 Family Won't Rotate Until 160 knots?

[FL2070]

Exactly as I said. I can rotate at a normal speed (120-140kt) but the plane won't leave the ground until 160+ knots. Any idea why?

[LesterBoffo]

Borked wing area calculation, or bad main airfoil tables? Needs some flap lift/drag adjustments...

Get out your text editor and tinker.

[jwocky]

Is that a JSB or a Yasim? In JSB, I know, there are planes out that took the lift calculation straight from aeromatic and that is often too little lift. Same with their engine thrust tables on altitude.

[FL2070]

The A320-family is YASIM, I think.

[jwocky]

Yasim is not my beer lol. But Lester, Bomber and some others know more about it to run a test with more lift?

[FL2070]

SORRY I'M AN IDIOT

A320 family is JSBSim

[jwocky]

Then go in the JSB file and search for "Lift", there is a channel calculating the lift due to alpha and it contains a little table. Just for a test, set the numbers in this table all over the board higher by 0.1, that should already show you if you have actually a mere lift problem there. If she flies normally, just rotates earlier and is still in balance, then it is just a lack of lift. The table contains basically factors used on the wing area.