a320 green & blue failure flap 2 selection
Thread Starter
Join Date: Jun 2008
Location: Mokum
Posts: 43
Likes: 0
Received 0 Likes
on
0 Posts
a320 green & blue failure flap 2 selection
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
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
Join Date: Mar 2000
Location: Sunrise Senior Living
Posts: 1,338
Likes: 0
Received 0 Likes
on
0 Posts
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
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
Join Date: Apr 2004
Location: United States of Europe
Age: 40
Posts: 502
Likes: 0
Received 0 Likes
on
0 Posts
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)
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)
Join Date: Mar 2005
Location: Uh... Where was I?
Posts: 1,338
Likes: 0
Received 0 Likes
on
0 Posts
A Flaps only case.
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.
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.
Join Date: Mar 2005
Location: Uh... Where was I?
Posts: 1,338
Likes: 0
Received 0 Likes
on
0 Posts
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.
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.