Go Back  PPRuNe Forums > Flight Deck Forums > Rumours & News
Reload this Page >

Air Asia Indonesia Lost Contact from Surabaya to Singapore

Rumours & News Reporting Points that may affect our jobs or lives as professional pilots. Also, items that may be of interest to professional pilots.

Air Asia Indonesia Lost Contact from Surabaya to Singapore

Old 1st Jan 2015, 11:52
  #841 (permalink)  
 
Join Date: Jan 2008
Location: Herts, UK
Posts: 748
Likes: 0
Received 0 Likes on 0 Posts
md80fanatic

A good suggestion for an effective (maybe temporary) solution... !
HarryMann is offline  
Old 1st Jan 2015, 12:21
  #842 (permalink)  
 
Join Date: Jan 2008
Location: Cornwall
Age: 68
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
And the point of possible/probable recovery will have been long passed at that stage.
From 35,000ft there's quite a lot of time to try things. In AF447 at the time the Captain returned to the cockpit the stall warning had either already stopped sounding or stopped a few seconds after, so I don't think he suspected a stall at first:

At around 2 h 11 min 42, the Captain re-entered the cockpit. During the following seconds, all of the recorded speeds became invalid and the stall warning stopped...
Roseland is offline  
Old 1st Jan 2015, 12:42
  #843 (permalink)  
 
Join Date: Jul 2006
Location: Australia
Age: 57
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
How does the Airbus hand control stick work? I remember in the Air France AF 447 crash, one pilot had his control stick pushed forward and the other had his full back, who has control in this situation? I also understand that there were major CRM issues in that crash, because no one took control....
727forever is offline  
Old 1st Jan 2015, 12:48
  #844 (permalink)  

Do a Hover - it avoids G
 
Join Date: Oct 1999
Location: Chichester West Sussex UK
Age: 90
Posts: 2,206
Likes: 0
Received 0 Likes on 0 Posts
For the interest of the non pilots here, when I was trained I was taught that should one encounter exteme turbulence in the cruise, you should ignore airspeed and altimeter readings, leave the cuise power as set and just use the controls to maintain the normal cruise aircraft attitude.

I was also taught that if one lost airspeed indication in the cruise you should do the same thing - leave the power as set and maintain attitude.

Of course I do not know what is taught these days.
John Farley is offline  
Old 1st Jan 2015, 13:30
  #845 (permalink)  
 
Join Date: Jul 2013
Location: Maryland USA
Posts: 114
Likes: 0
Received 0 Likes on 0 Posts
The NEXRAD display can be useful, but it NO substitute for onboard radar. If you avoid the "NEXRAD" storms, you are avoiding storms that happened 10-20 minutes ago. Sometimes the "clear" area is where the storm went


@BG47
As for the discussion about radar in cockpits...radars are behind the times not only in the airline industry but also in the corporate world...these aircraft/glass cockpit manufactures should have real time weather overlay like the handheld gps that the civil light aircraft owners use they are excellent at navigating around weather. Itís interesting to see even the Indonesia navy pilots searching for this plane had one on their dash as a back up.
island_airphoto is offline  
Old 1st Jan 2015, 13:34
  #846 (permalink)  
 
Join Date: Jul 2013
Location: Maryland USA
Posts: 114
Likes: 0
Received 0 Likes on 0 Posts
RE 60 knot stall speed:
I can't speak to an Airbus pitot system, but many of the planes I fly can be flown at high enough AOA to have the ASI read 0 knots. Sure the plane is not actually hovering, but the pitot tube is no longer aligned with the relative wind.
island_airphoto is offline  
Old 1st Jan 2015, 13:37
  #847 (permalink)  
 
Join Date: Apr 2013
Location: OK
Posts: 11
Likes: 0
Received 0 Likes on 0 Posts
@ 727forever

If one stick is full aft and one stick is full forward the airplane will take the "total input" and give you an average, which in hat case, would be zero (or stick neutral). You can press and hold a button the joystick that will enable you to take "priority". The A/C will tell you, "priority left, or priority right". the last guy who presses the button "wins" . if you hold it for more than 30s, the other stick is completely useless for the rest of the flight.

This is why in the AF crash if the CA would have jumped in, sat down, yelled, "I have control" and pressed and held his button the outcome may have been different. In all the chaos he may not have heard the airplane screaming "dual input" and probably didnt visually see the inexperienced, clueless F/O holding the stick full aft.

It may be an Airbus but the laws of Physics trump Normal, alternate, direct law etc. The A/C is stalled? Unload the wing and get the nose down for Chr--t sake, BASIC FLYING
JoeyBalls is offline  
Old 1st Jan 2015, 13:38
  #848 (permalink)  
 
Join Date: May 2013
Location: india
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Airbus Weather Radar

Does anyone agree that the current Airbus Weather Radars aren't as good as they used to be ? I've noted the following :

1) Weather picture suddenly changes from yellow to red as you approach closer to the cloud.

2) Auto-tilt is overly conservative (tilt down). Manual tilt needs to be used often.

3) Gaps between clouds disappear as you approach closer.
intellipost is offline  
Old 1st Jan 2015, 13:39
  #849 (permalink)  
 
Join Date: Jan 2008
Location: Cornwall
Age: 68
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
How does the Airbus hand control stick work? I remember in the Air France AF 447 crash, one pilot had his control stick pushed forward and the other had his full back, who has control in this situation? I also understand that there were major CRM issues in that crash, because no one took control....
This is the best description I've seen:

http://www.pprune.org/tech-log/41293...k-command.html
Roseland is offline  
Old 1st Jan 2015, 13:45
  #850 (permalink)  
 
Join Date: Jan 2008
Location: Cornwall
Age: 68
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
Sorry, JoeyBalls, our posts crossed. Your explanation is very clear.
Roseland is offline  
Old 1st Jan 2015, 14:09
  #851 (permalink)  
 
Join Date: Apr 2002
Location: Australia
Age: 68
Posts: 707
Likes: 0
Received 8 Likes on 3 Posts
Joey

Clearest and simplest explanation yet. The Bus allows 2 people to work against each other. Boeing does not allow this to happen. I have flown both, but never in a major upset. I know which type I would prefer to be operating in an upset at coffin corner. I know the bus has a God button but in times of max stress no one remembers it is there.
VR-HFX is offline  
Old 1st Jan 2015, 14:14
  #852 (permalink)  
 
Join Date: Jan 2001
Location: UK
Posts: 2,044
Likes: 0
Received 0 Likes on 0 Posts
We'll have to disagree. I think having stall warning disabled by low IAS (frozen pitots?) is a significant weakness.

What do others think?
It took 3x ADR to "fail" (albeit for the same cause), and it then took the crew to misinterpret/mishandle the situation so badly they stalled the aircraft. NB the crew identified they had lost IAS indications, and they then climbed >7,000'/m.

They then got a (genuine) STALL warning, but maintained nose up control inputs. As a consequence the AoA exceeded 40 degrees (!), and TLs were selected to idle (!!). It was only after this we got the speeds becoming invalid and the Stall warning ceasing.

At some point nose down inputs were made, such speed and Stall became valid again - however, AoA remained >35degrees.

The (very) low IAS caused the stall warning to cease, not the frozen pitots AFAIK. I grant you, 3 simultaneous frozen pitots could have caused the issue, but I do not believe it did here.

So if, by definition, the IAS of the aircraft fell below that considered a "cutoff" for the AoA sensors to work, do you still consider that the systems should still have declared the sensed AoA values as "correct"? And I ask again, down to what IAS (CAS)?

If we now move to the consequence of the Stall Warning on/off, clearly it added some confusion to this crew. However, whether an IAS <60K is considered in the certification process I do not know? Let us presume that the Stall warning had remained - do you really think that crew would have correctly recovered from this stall? This was not what we practice in the sim - a slow declaration to a stall warning, and concentrate on a technically beautiful recovery NB never stalled. This crew had ignored the Stall Warning, and got into an AoA / Stall regime I doubt any Airbus has even been in to including with TPs. The Nose Down attitude to recover (30+nd?) would have been horrendous, and I am not sure I could have been convinced to push that hard for that long (and I'm a current aerobatic pilot, ex-mil fast jet, RAF ex-QFI etc.).

So I am less willing than you to criticise the designers and certifiers of the system. I do not know the Fault Analysis tree, and probabilities assigned, in the design. AFAIK the design has not significantly altered since? (but might be wrong). I am not saying the system is perfect, but the events that occurred that night I do not think would have been considered credible. And the cure for that night is not in systems (re)design, but crew training - which IMO has hardly made a dent in the basic flaws. Relevance to AirAsia? No idea...
NigelOnDraft is offline  
Old 1st Jan 2015, 14:17
  #853 (permalink)  
 
Join Date: Jul 2013
Location: Cohoes, NY
Posts: 23
Likes: 0
Received 0 Likes on 0 Posts
Updraft

@Bloggs re: updraft. I think the scenario being considered is that the updraft was so severe that it stalled them immediately, and also caused enough additional pitch-up (they were already in a climb) that there was not enough time and/or authority to restabilize attitude before the next shock (exiting the updraft or other turbulence/upset). Big holes in rapid succession.
jientho is offline  
Old 1st Jan 2015, 14:19
  #854 (permalink)  
 
Join Date: Jan 2009
Location: Surrey, UK
Posts: 68
Likes: 0
Received 0 Likes on 0 Posts
CEO Mr. Fernandes - tell us about their simualtor training?

Maybe someone will read this and ask him?!
When was the respective crews last sim? One needs to look at the last 3 yrs.
Route checks?
When was the last serious sim session with unreliable instruments/airspeed?
Stall recovery?
OR
What is the syllabus at Air Asia?
What quality of training and standards are used for Grading i.e. do the weak continue to fly the Line?

At least if we knew how proficient they should have been, we cold rule out some of the guessing?
Brookfield Abused is offline  
Old 1st Jan 2015, 15:02
  #855 (permalink)  
 
Join Date: Mar 2002
Location: Seat 1A
Posts: 8,502
Received 54 Likes on 35 Posts
Originally Posted by Mad Villian
I hope that this incident, if found to be caused by poor human machine interface, leads to increased training and awareness of what exactly is happening at the moment of criticality to throw otherwise professional, trained pilots off their game so much to lead to an upset.
How about changing the "poor HMI" to suit the humans? The designers should be designing aeroplanes for the pilots, not the other way round.

Originally Posted by henra
Maybe this is because things are anyway strongly amiss when an airliner troddles along at 60kts? And the point of possible/probable recovery will have been long passed at that stage.
Nothing like full forward stick and full nose-down trim to fix this situation. Oh, I forgot, Airbus pilots hardly ever/never need to trim... So why would it be second nature when needed?

Originally Posted by jientho
I think the scenario being considered is that the updraft was so severe that it stalled them immediately, and also caused enough additional pitch-up (they were already in a climb) that there was not enough time and/or authority to restabilize attitude before the next shock (exiting the updraft or other turbulence/upset).
Fair enough. But I don't think an updraught, in itself, will cause a pitchup; if it does, it will only be because the speed increases, although some Airbii do pitch up automatically if the speed goes super fast, I believe. If the aeroplane stalls immediately, the nose should drop pretty soon after.
Capn Bloggs is offline  
Old 1st Jan 2015, 15:03
  #856 (permalink)  
ZFT
N4790P
 
Join Date: Jun 2002
Location: Asia
Age: 73
Posts: 2,252
Received 4 Likes on 2 Posts
Stall Recovery sim training

You may be asking the impossible. The Airbus data certainly does not support stall recovery in a simulator. (But maybe you knew that?) The only Airbus approved training is Approach to Stall and Initial Stall. Beyond that the data is sorely lacking and there is no guarantee that the simulator response is anything like what would be experienced in an aircraft.

Airbus is strong advocate of not doing stalls in the simulator. They have frequently stated this both in their literature and at conference (although recent proposed FAA requirements will thankfully force them to change).
ZFT is online now  
Old 1st Jan 2015, 15:08
  #857 (permalink)  
 
Join Date: Jun 2009
Location: Bedford, UK
Age: 70
Posts: 1,328
Likes: 0
Received 0 Likes on 0 Posts
Perhaps if the stall warning was latched off following any operation of the inhibition it may prevent some confusion. In this case there is no indication it would have made any difference, however perhaps in the future it might?
Mr Optimistic is offline  
Old 1st Jan 2015, 15:23
  #858 (permalink)  
 
Join Date: Jan 2008
Location: Cornwall
Age: 68
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
NigelOnDraft

Iíve seen many times the claim that the FO held the stick back when the stall warning was sounding.

Looking at Appendix 3 of the final BEA report it doesnít seem as simple as that.
The initial input was nose up, but when the stall warn sounded briefly, FO moved the stick to nose down, and the stall warning stopped.

The only sustained input nose up was between about 2:11:40 and 2:12:30. But even before that started the THS had trimmed full up, and it was game over.

With the benefit up hindsight (and the FDR) we know what the AoA was; they didnít. They only saw pitch.

Of course, this disaster wasnít a single point failure; had they had yokes instead of sidesticks everyone would have seen what was happening. Yes, I believe the stall warning sounding when they gained speed added confusion. And yes, had Air France paid the extra to have AoA indicator that would have helped too. And had the THS made a ďtick tickĒ as it motored inexorably nose up they might have addressed itÖ

You asked at what IAS the AOA sensors should cut off. I maintain if the speed is so low the AoA sensors aren't working then the stall warning should be!

I saw you are less willing to criticise the designers and certifiers. But I am less willing to criticise the pilots. There are, of course, times when itís clearly pilot error. But when a crew of three all fail to understand whatís going on perhaps itís all too complicated.
Roseland is offline  
Old 1st Jan 2015, 15:23
  #859 (permalink)  
 
Join Date: Jun 2001
Location: UK
Posts: 3,981
Likes: 0
Received 1 Like on 1 Post
I've been pondering about the autopilot and auto thrust response to a large and sudden up gust.

The altitude hold would attempt to maintain the selected altitude by selecting a lower attitude and the auto throttle would reduce power to maintain airspeed.

Quiet often after a large gust in one direction there is a reversal of the original gust.

This might lead to a rapid reduction in airspeed with thrust already at at minimum.

Severe turbulence would require pilot intervention to set cruise attitude and power but in the event of a sudden massive gust we have all the potential ingredients for an upset of some sort.

Comments?
fireflybob is offline  
Old 1st Jan 2015, 15:40
  #860 (permalink)  
 
Join Date: Jan 2001
Location: UK
Posts: 2,044
Likes: 0
Received 0 Likes on 0 Posts
You asked at what IAS the AOA sensors should cut off. I maintain if the speed is so low the AoA sensors aren't working then the stall warning should be!
You've got me there - I must confess. I always thought the Stall Warning came from the AoA Sensors So what sensor drives the Stall Warning?

But I am less willing to criticise the pilots
I never criticised the pilots, but put the base issue to training (or lack of). If we are going to blame the technology every time, there is little point in pilots being on board?

NoD
NigelOnDraft is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.