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Air Asia Indonesia Lost Contact from Surabaya to Singapore

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Air Asia Indonesia Lost Contact from Surabaya to Singapore

Old 6th Feb 2015, 18:46
  #3081 (permalink)  
 
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On the 320/330 aircraft, are the inboard and outboard spoilers able to be deployed independently?

I ask this as "splitting the spoilers" is an excellent solution to pitch problems on some swept wing aircraft I have operated. For example a jammed stabilizer. To lower the nose, outboard spoilers can be inhibited and the required amount of inboard spoiler can be applied for the required results.

This maybe a possible solution to getting the AoA reduced in a stalled condition if all else fails and as a last resort.
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Old 6th Feb 2015, 20:05
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Leightman,

Perhaps you might have misunderstood my post or else (probably the case) I did not write clearly enough. I would most definitely push over into negative g territory if needed to recover the aircraft. What I was alluding to is that RetiredF4 brought forth some food for thought in that even if we have done UAS training in the sim, that it is worthwhile to ponder and fix in our mind that what we have to do is something that we might not have done for years.

Many of us on these threads have been lucky enough to have flown aircraft that will gladly enter this territory and therefore are familiar with the sensations. I count myself among those lucky as do you. I will also admit however, that it has been a number of years (decades now?) since I have done so. Should I be faced with the prospect of a UAS at FL350 with rapidly decreasing airspeed I will do what is necessary to try to recover. I just need to remind myself, as did another poster, that doing so at night, at high altitude, in bad weather/IMC, is going to take very deliberate and conscious effort--including actions that might feel to be a bit outside the comfort zone. F4 was talking about pilots in fighter lead in (probably flying BFM) in what I assume to be day VMC. Even then he notes that they were reluctant to push too much. What does that say about the rest of us?

I would hope that none of us would sit there and watch a bad situation deteriorate even further but recent history is proving me wrong on that count. Training is of course the key but what I was drawing from F4's remarks was that even then it is going to be a lot different than it is in the sim.
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Old 6th Feb 2015, 20:38
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Clarification

Thanks for the clarification UF, but I think I understood what you meant. It may well have been me who was unclear. I have less concern about older pilots who came up through the ranks flying more kinds of AC than with the descriptions posted elsewhere here about the more recent crop of fast tracked new kids who took a different, more 'streamlined', and much less varied route working from small to heavy aircraft. Pilots I've known flew for fun on their time off, often in rag and stick or a wide range of other contraptions, some of which had almost no knobs. I think their curiosity made them better pilots. In any event I'd rather have one of them up front.

Last edited by Leightman 957; 6th Feb 2015 at 22:17. Reason: Clarified
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Old 6th Feb 2015, 21:13
  #3084 (permalink)  
 
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Originally Posted by xcitation
Why not program in an automated stall recovery
Now this is interesting. The consensus in this thread so far is that pilots have become too dependent on automation.

If pilots have become too dependent on automation, the solution is to add more automation? All that does is exacerbate the problem. It's a vicious circle.
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Old 6th Feb 2015, 21:31
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Radix,not all the pilotage is here. Most would like to keep it as simple as possible,-but sure,have the benefits the automation can bring about. Humanly logical automation might be the words we are after.
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Old 6th Feb 2015, 21:46
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Originally Posted by Radix
Now this is interesting. The consensus in this thread so far is that pilots have become too dependent on automation.

If pilots have become too dependent on automation, the solution is to add more automation? All that does is exacerbate the problem. It's a vicious circle.
Perhaps all that is needed is not so much an automated stall recovery so much as automatics sensing approach to stall and stall not making things worse. For example as the aircraft approaches stall the THS could stop trimming nose up, if the pilot wants more nose up then he can manually dial it in. Perhaps _at_ the stall, and you can get there in Normal law if you zoom climb into it at high cruising levels, the THS could motor to neutral; again the pilot could stop it manually if necessary. Had the THS motored to neutral in the AFR447 case the aircraft would probably have pitched nose down and might have been recovered.
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Old 7th Feb 2015, 06:49
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It would be good if pilots could easily download sim scenarios for these newsworthy incidents, and work through them.
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Old 7th Feb 2015, 10:34
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AirAsia flight QZ8501: Bodies of two pilots found in cockpit, one retrieved - South-east Asia News & Top Stories - The Straits Times
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Old 7th Feb 2015, 11:46
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Pushing Over

I know that there are a LOT of posts as far (agreement is probably going too far) to the effect that pushing forward, or anything less than 1.00 positive G is uncomfortable, unfamiliar, non-intuitive, and frowned on by management. But it seems pretty clear that poster opinion agrees that there are circumstances when this action is appropriate and even immediately mandatory.
Aerodynamics 101: The stall speed at 0 'g' is 0 kts. Therefore if you have the elevator authority to push to zero 'g' you will unstall the wing at any airspeed. The nose will drop, the airspeed will increase and when comfortably above Vs1g, gently roll wings level and raise the nose to the horizon. If you don't have elevator authority to push forward enough to unstall the wing, ROLL the aircraft (90+ bank if need be) and convert that pitching 'up' moment away from the horizon into a pitching 'up' moment across (or down from) the horizon to get the nose to drop and airspeed to increase.
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Old 7th Feb 2015, 14:52
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Yes Bleve, the concept of zero stall speed at zero "g" does not seem to be instinctive to pilots that have never worked beyond 30 degrees of bank. If I may add to your post -

"If you do not have elevator authority to push forward enough to unstall the wing - get that authority by trimming forward and reducing thrust if needed".

If the nose does not do as you command it in a 320, the trim is yours!
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Old 7th Feb 2015, 16:36
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Perhaps all that is needed is... automatics sensing approach to stall .... as the aircraft approaches stall the THS could stop trimming nose up
You mean like the A320 does?
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Old 7th Feb 2015, 17:53
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@IanW;
#3109, http://www.pprune.org/rumours-news/5...ml#post8857067, "Had the THS motored to neutral in the AFR447 case the aircraft would probably have pitched nose down and might have been recovered. "
Point-of-information: - the THS would have motored from -13.5 to about -2 had the stick been held fully-forward for a sufficiently long period and very likely the aircraft could have been recovered. Also, manually rotating the trim wheel disengages the autotrim permitting a quicker setting of the THS. When released from manual movement in a few seconds it returns to auto and begins to take into account control inputs, but by that time recovery actions are theoretically taking place and the THS would follow-up with the SS orders.
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Old 7th Feb 2015, 18:00
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Originally Posted by NigelOnDraft
You mean like the A320 does?
Exactly Nigel, but perhaps you should continue with the quote. When it _is_ stalled the A320 just keeps the THS where it got to, if it motored to neutral it could help a lot. Unless you can think of a reason after the stall why the THS should stay nose up at all.
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Old 7th Feb 2015, 18:32
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anything less than 1.00 positive G is uncomfortable, unfamiliar, non-intuitive, and frowned on by management.
I guarantee that meeting the surface of an ocean @10,000fpm is even more uncomfortable...

If the nose does not do as you command it in a 320, the trim is yours!
Every part of an aircraft should ALWAYS do as its commander commands it - else he does not '...have final authority as to the disposition of the aircraft...' as required by the Chicago Convention.

How on earth did we end up designing and accepting aircraft that the pilot cannot COMPLETELY override if necessary, and automation that confuses, confounds, and when the fecal hits the turbine, leaves you to recover from an unusual and precarious situation requiring counter-intuitive actions?
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Old 7th Feb 2015, 18:48
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When it _is_ stalled the A320 just keeps the THS where it got to, if it motored to neutral it could help a lot. Unless you can think of a reason after the stall why the THS should stay nose up at all
How do you definitively define "it is stalled"? To a high enough degree of integrity you can remove pitch control from the pilot?
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Old 7th Feb 2015, 18:48
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Inquisitor

Spot on

The aircraft i've operated, and there has been quite a number, If all else failed I could be pretty sure of having a set of primary controls to manipulate to the desired effect. This now seems to be no longer the case.

Indeed how was it ever certified in it's present state??
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Old 7th Feb 2015, 19:11
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Quote:
Perhaps all that is needed is... automatics sensing approach to stall .... as the aircraft approaches stall the THS could stop trimming nose up
You mean like the A320 does?
NOD-only true for the 99.999% of the time you are in Normal Law. In Alternate law-Not true. During an upset, you are very likely to end up in Alternate law.

One thing that will interfere with achieving the necessary near 0 g in a nose high upset (which must be maintained until the aircraft is actually nose low and flying again) is an excessively trimmed THS.
(There is a good possibility that the THS trim was a factor in the Air Algerie failure to recover from its stall and roll off.)


P.S. I know you know the A320 systems very well.
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Old 7th Feb 2015, 19:20
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Sop Monkey

"The aircraft i've operated, and there has been quite a number ..."

Evidently not an Airbus, seeing your questions about A320 spoilers, which no-one bothered to answer (because G;ggle would have clarified all in 5 min).

How was it ever certified? Because the FAA certified it, that's why. You think jet transports should still be designed with wires pulling the control surfaces?
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Old 7th Feb 2015, 21:26
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When it _is_ stalled the A320 just keeps the THS where it got to, if it motored to neutral it could help a lot. Unless you can think of a reason after the stall why the THS should stay nose up at all
How do you definitively define "it is stalled"? To a high enough degree of integrity you can remove pitch control from the pilot?
When the stall warning sounds?

i.e., if the stall warning goes off, THS must automatically roll forward to at least neutral asap (or go nose-down if you -- controversially -- want to simulate a stick-pusher)

Of course, this should be something not needed to be left to automation
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Old 7th Feb 2015, 21:34
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When the stall warning sounds?

i.e., if the stall warning goes off, THS must automatically roll forward to at least neutral asap (or go nose-down if you -- controversially -- want to simulate a stick-pusher)
So if as I rotate on takeoff, the Stall warner erroneously sounds, the THS drives the aircraft into the ground

PS
...to at least neutral
What is "neutral" in airliner terms?
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