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Iamneon
15th Aug 2011, 12:13
Hi
last time in the simulator I got a green & blue failure and when we selected flaps 2 at 195kts, the stall indication (not vls) when up till 200kts (so the speed tape was totally red)
I can't find anything like his in any manual, not even in instructor manuals.
does anybody have any useful information?
personally I thought it was a sim fault. (but A good and very smart friend told me, that the stall will go up a lot)

thanks

mcdhu
15th Aug 2011, 15:20
You should note that the QRH says 'Passing Vfe next select Flapxxx' not 'Passing Vfe next -5'. This makes quite a difference.

Also, as the PNF selects the 'next' flap, ease forward on the stick to offload as the flap runs and you will avoid 'Stall, Stall'.

Cheers
mcdhu

vilas
15th Aug 2011, 15:43
What was your landing weight?

Iamneon
15th Aug 2011, 18:21
thanks, weight was only 61,5t

rudderrudderrat
15th Aug 2011, 22:12
Hi Iamneon,

I agree with mcdhu. You don't feel anything except 1g in the sim. In real life, you would feel the delta g as Flaps 2 ran out, and naturally lower the nose.

OPEN DES
15th Aug 2011, 23:10
VLS does not change with load-factor.

VSW changes with load factor. The selection of F2 causes a momentary loadfactor increase; unload the a/c by pushing on the sidestick (as suggested by the others)

Microburst2002
16th Aug 2011, 09:53
According to good old FCOM 3.01.20 p9:

Stall speed when clean and 61.5 ton is about 152 kt.
With conf 1+F stall speed is about 118 kt.
With conf 2, stall speed is about 111 kt

Could we say that stall speed for no slats/flaps 1 should lie somewhere between 118kt and 152 kt? Or that stall speed for no slats/flaps 2 should lie somewhere between 152 kt and 111 kt?

Nope! Because this is a flaps only case. Extending flaps only (no slats) means a reduced stall AoA. Remember the curve, with higher CLmax but smaller stall AoA.

For the same attitude, it could happen that you have a "good" AoA flying clean at 190 kt (38 kt margin or approx 20%) but are too close to stall AoA at the same speed when flaps 2 are deployed.

That would explain what happened to you in the sim.

TyroPicard
16th Aug 2011, 14:27
VAPP is 157 kt. - did the Vsw tape stay at 200 kt (sim fault) or go back down to a reasonable figure?

Microburst2002
16th Aug 2011, 17:18
In steady flight at 190 kt, with flaps 2, no slats, there is lot of margin, I'd say. However you can approach stall angle if the deceleration is "very decelerated", with an AoA that is much higher than steady 195 kt flight AoA.

Maybe this is what happened?
Was there a "STALL, STALL" warning?

I had one, during sim, when I pulled up for missed approach with no flaps. Margins can be very narrow in flaps or slats jammed situations... I think they should include, among the many notes of the procedure, approximate pitch attitudes for Go Around.

Iamneon
17th Aug 2011, 20:32
Thanks all,
I tried It yesterday in a better Sim with 2T extra weight the Vsw did get higher than 185kts flying it smooth.

thanks a lot for all your inputs