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 3rd Feb 2015, 05:21
  #2961 (permalink)  
 
Join Date: Jan 2000
Location: Asia
Posts: 2,372
Likes: 0
Received 1 Like on 1 Post
There are 2 FACs, normally FAC 1 is in use and FAC 2 is in standby. If a failure is detected on any channel of FAC 1, FAC 2 takes over the corresponding channel.

When a FAC is disengaged (push button set to off) but still valid, the flight envelope function of the FAC remains active.

Flight Envelope Function:
1. PFD speed scale management
Min/max speed computation
Manoeuvring speed computation
2. Alpha-floor protection.

FAC 1 must be serviceable for dispatch, FAC 2 may be inoperative with certain conditions.

The FCOM provides for FAC resetting by switching off and back on, there is no procedure involving pulling circuit breakers.

FAC 1 CBs are on the overhead panel and reachable from the seats, FAC 2 CBs are on the rear panel and couldn't be reached from the Captains seat.

Even if both FACs failed the immediate problems would be limited to flying in alternate law with protections lost, max speed 320kts and rudder with care above 160kts. There are further considerations for landing but these would not have been immediate.
Metro man is offline  
Old 3rd Feb 2015, 05:23
  #2962 (permalink)  
 
Join Date: Jul 2009
Location: Not far from a big Lake
Age: 81
Posts: 1,461
Likes: 0
Received 0 Likes on 0 Posts
The A320 family relies on engineers interrogating systems through the mcdu to troubleshoot systems and a lot of the old fashioned engineering practices and knowledge are slowly becoming a lost art,imho.
Having spent a number of years closely associated with Naval Aviation maintenance on what are now ancient aircraft the following observations may be relevant.
The worst troubleshooting problems tend to be in things like connectors, and damaged wire bundles. In cases where the box has to slide in to a rack and mate to a connector on the back side, things like recessed pins and bent pins can do weird things to connections. Even a minor obstruction could keep a box from fully seating on its associated connector with rear mount connections.

Wires can be open, shorted, or cross connected to another wire. Flexing of the airframe and unequal thermal expansion between wires and airframe can impose stresses that eventually damage improperly positioned wire bundles as can adjacent maintenance activity. Access and visibility are typically difficult in aircraft and can mask otherwise simple problems.

Intermittent problems are particularly difficult because they generally do not present themselves for correction on the ground. It frequently can require someone with an electrical engineering background to infer what the problem must be based on the symptoms. In those cases, the more data, the better.
Aviation has relied on easily replaceable boxes to facilitate maintenance for many years, and the advent of computerized troubleshooting improves the odds of fixing a problem accurately but airframe side of the interface problems are another story. Problem is, unsolved technical problems can add to the Swiss Cheese holes that eventually cause an accident.
Machinbird is offline  
Old 3rd Feb 2015, 06:04
  #2963 (permalink)  
 
Join Date: May 2010
Location: PNW
Posts: 76
Likes: 0
Received 0 Likes on 0 Posts
I don't know if this issue has been floated yet, so forgive me if I missed it.

We'll know soon enough from the recording when it's released, but I'm wondering if a contributing factor might have been a native language difference between the Captain trying to deal with the avionics, and the FO flying the plane while everything was starting to go pear shaped.

If the Captain was about to do something in altering the flight computer controls, was he able to communicate that clearly to the pilot who had his hand on the stick? Factor in all the usual difficulties and stress in turbulence, unusual attitude, G-force, etc.

This may not have anything to do with what happened, but with two pilots from dissimilar native language backgrounds, I think it's worth considering.
Photonic is offline  
Old 3rd Feb 2015, 06:39
  #2964 (permalink)  
THUNDERTAILED
 
Join Date: Nov 1999
Location: L200
Posts: 324
Likes: 0
Received 0 Likes on 0 Posts
Summary : two unstallable airbusses stalled and fell into the sea.

There is thus something wrong with the flight control systems.

Bottom line.
AfricanSkies is offline  
Old 3rd Feb 2015, 07:51
  #2965 (permalink)  
 
Join Date: Dec 2013
Location: Weltschmerz-By-The-Sea, Queensland, Australia
Posts: 1,358
Received 74 Likes on 33 Posts
Autoflight...

Not an A320 pilot, but allow me to observe that different organisations have different informal standards of behaviour. And that, from time to time, senior people can be observed doing something that a more conservative person wouldn't. Gradually, the less conservative behaviour becomes the norm.

Earlier in life I was a contract pilot for a few years and got a chance to observe that there were no universally accepted behaviours for things like thunderstorm avoidance, acceptable defect reporting standards, punctuality pressures etc.

We are typically guided by the DDG, but in cases of repeated defects which ground test serviceable the evidence of prior success cannot help but inform your risk picture. Its hard to argue with certain things unless, like me, you are an assh*le.
Australopithecus is offline  
Old 3rd Feb 2015, 07:52
  #2966 (permalink)  
 
Join Date: Mar 2014
Location: N. California
Age: 79
Posts: 184
Likes: 0
Received 0 Likes on 0 Posts
African Skies:

There was an equipment failure on AF447 and it's looking like an equipment failure on QZ8501. So your assertion lacks any foundation.

Not that it ever had any foundation anyway.
Propduffer is offline  
Old 3rd Feb 2015, 08:03
  #2967 (permalink)  
 
Join Date: Dec 2001
Location: what U.S. calls ´old Europe´
Posts: 941
Likes: 0
Received 0 Likes on 0 Posts
In the end no manufacturer can make a “full proof” aircraft and it is up to the pilots to know each aircraft’s “quirks” and systems to fly it properly and safely.
It even is OK for any aircraft to have some "quirks" and it is OK not to redesign if you discover them, as long as the overall accident statistics are fine and the change would even add more confusion to those used to the "quirks". It is quite typical to use some flying techniques which are not exactly textbook style because of design peculiarities, the "Boeing push" comes to mind for example.
The only important point is that you acknowledge that some points of your design might be a bit special or tricky, and include them in detail in the handbooks and in the training syllabus. If pilots are fully aware and trained accordingly, any design feature can be safe. If pilots are poorly informed and trained, even simple and straightforward design features might be a major risk. An airplane alone is never "wrong", only in combination with the pilot training it may be.
Volume is offline  
Old 3rd Feb 2015, 08:26
  #2968 (permalink)  
Pegase Driver
 
Join Date: May 1997
Location: Europe
Age: 73
Posts: 3,661
Likes: 0
Received 0 Likes on 0 Posts
Photonic

I'm wondering if a contributing factor might have been a native language difference between the Captain......., and the FO
I do not believe that one, such pairings are now common place. We have over 25 different nationalities working in my company, and in 40 years of OPS not a single serious incident was reported having native language diffrence as a contributing cause.
Culture maybe , but language, no.
ATC Watcher is online now  
Old 3rd Feb 2015, 08:34
  #2969 (permalink)  
 
Join Date: Aug 2005
Location: fl
Posts: 2,561
Likes: 0
Received 0 Likes on 0 Posts
"An airplane alone is never "wrong", only in combination with the pilot training it may be."

More pilot training costs money so forget that. Pilot hands on skills are deteriorating because of manufacturerers and airlines discouraging non autopilot operation.

Monitoring an autopilot for thousands of hours does not build or maintain basic piloting skills.
bubbers44 is offline  
Old 3rd Feb 2015, 08:47
  #2970 (permalink)  
 
Join Date: Apr 2009
Location: Oakland, CA
Age: 72
Posts: 427
Likes: 0
Received 0 Likes on 0 Posts
OPS not a single serious incident was reported having native language diffrence as a contributing cause.
perhaps not in your company but language barrier in the cockpit was cited as a contributing cause in the Helios flight 522 crash, the precedence was set.
olasek is offline  
Old 3rd Feb 2015, 08:55
  #2971 (permalink)  
 
Join Date: Jul 2005
Location: btw SAMAR and TOSPA
Posts: 566
Likes: 0
Received 0 Likes on 0 Posts
What initiated the zoom climb?

The answer to the key question is answered to the investigators since a long time because they have all the elevator and stick FDR data in front of them:

What initiated the zoom climb?
a) pilot pulling the stick (input recorded by FDR)
b) weather, without stick input (input not recorded by FDR)
c) elevator input by a malfunctioning unit (input recorded by FDR)
d) sort of other mishandling

As there is no AOT out there about tech malfunctions the answer is obvious
threemiles is offline  
Old 3rd Feb 2015, 09:07
  #2972 (permalink)  
 
Join Date: Mar 2014
Location: UK
Age: 74
Posts: 54
Likes: 0
Received 0 Likes on 0 Posts
Summary : two unstallable airbusses stalled and fell into the sea.
There is thus something wrong with the flight control systems.
Bottom line.
Agreed. Sifting for minutiae misses the point. And there are already many things to learn by many parties. The report will try to pin the blame on some chain of causality ... but if we want safer skies then there are already many things to learn, by many parties. Tracking, air traffic control, search and rescue, manufacture, human-computer interface etc...

The business / marketing side of things seems also very important; from what I understand flight control systems were an important factor in Airbus's entry to market, to give it something new to edge into a mostly (at that time) Boeing market.
rideforever is offline  
Old 3rd Feb 2015, 09:29
  #2973 (permalink)  
 
Join Date: Mar 2010
Location: L.A.
Age: 56
Posts: 579
Likes: 0
Received 0 Likes on 0 Posts
Rat 5

All this chat about aerobatic and unusual recovery training is, very sad to say, pie in the sky.
On the contrary, I found the unusual attitude sim session quite illuminating. With practice, I could recover from being totally inverted to normal flight in less than 3,000 ft. Might have spilled a few G&Ts, but it was eminently recoverable.

Likewise the high altitude stalling was interesting too. With the engines at full chat (as commanded by the a/t) it was almost impossible to recover from the stall. And at cruise power, full forward control deflection was required. It was useful to learn that the standard light aircraft nod into a recoverable descent just did not happen, and the aircraft would just pancake down almost tail first - just as AF447 and this one did.
silverstrata is offline  
Old 3rd Feb 2015, 09:41
  #2974 (permalink)  
 
Join Date: Mar 2010
Location: L.A.
Age: 56
Posts: 579
Likes: 0
Received 0 Likes on 0 Posts
African skies:

Summary : two unstallable airbusses stalled and fell into the sea.
There is thus something wrong with the flight control systems.
Disagree. If anything, it proves that the Airbus is too good for its own good.

As I read this, modern FBW aircraft are so symmetric, so stable, and the engines so perfectly synched, that the aircraft will remain stable even when pancaking downwards vertically with a pitch attitude of 20º nose up.

Whereas a 1950s aircraft, like the 'modern' b737, will have so many imperfections in its manufacture and operation that it is bound to drop a wing. And once you have dropped a wing and the nose lowers, you are instantly out of the stall and into the much more easily recoverable dive situation.

But I hardly think that regressing to 1950s manufacture and systems is the way forward. I am sure it is not beyond the wit of Airbus software engineers to program a nice and easy wing-drop (or a thrust reduction), when the aircraft detects a super-stall condition, so that the aircraft exits the nose-high pancake situation.
silverstrata is offline  
Old 3rd Feb 2015, 10:24
  #2975 (permalink)  
 
Join Date: Dec 2013
Location: Weltschmerz-By-The-Sea, Queensland, Australia
Posts: 1,358
Received 74 Likes on 33 Posts
Silversrata....just...no.
Australopithecus is offline  
Old 3rd Feb 2015, 11:45
  #2976 (permalink)  
 
Join Date: Mar 2002
Location: Seat 1A
Posts: 8,511
Received 58 Likes on 37 Posts
b) weather, without stick input (input not recorded by FDR)
Yes it will be recorded. The instant wind velocity will be recorded, the airspeed will be recorded, the pitch attitude and elevator (AP in) (and ATS) and of course the VS will reveal instantly that the aeroplane was hit by a gust/downdraft/updraft whatever.
Capn Bloggs is offline  
Old 3rd Feb 2015, 14:37
  #2977 (permalink)  
THUNDERTAILED
 
Join Date: Nov 1999
Location: L200
Posts: 324
Likes: 0
Received 0 Likes on 0 Posts
Royal Enfield, my dear old stick, here we have 2 cases of Airbusses stalling for whatever reason, when they were marketed as 'unstallable', and in both cases the crew were so confused ..by the aircraft.. that they couldnt recover the aircraft. In the most recent case, an experienced fighter pilot, not some ab initio jock.

Equipment failure should not cause a stall, whichever way you look at it.

And in the event that the aircraft enters a stall, it should be recoverable.

Back to basics. Build aircraft that pilots understand and that respond unconditionally to the pilot's inputs. Then train the pilots to FLY.
AfricanSkies is offline  
Old 3rd Feb 2015, 14:48
  #2978 (permalink)  
 
Join Date: Nov 1999
Location: UK
Posts: 2,450
Received 74 Likes on 41 Posts
For what it's worth. I fly Airbus, and it has NEVER been marketed or 'sold' to me as being un-stallable.

Look at the damn attitude display and the speed !!!!
Uplinker is offline  
Old 3rd Feb 2015, 14:54
  #2979 (permalink)  
 
Join Date: Dec 2014
Location: Schiphol
Posts: 460
Likes: 0
Received 0 Likes on 0 Posts
Understanding this accident in the context of air safety

One of the fundamental pillars of aerospace safety is the way in which people in the industry communicate. Respect, knowledge, experience, and the organization of communication (including Prelim and Final accident reports) are part of that.

Airbus bashing (or Boeing bashing for that matter) has no place in a professional discussion and is in fact detrimental to aerospace safety. And thereby shows a serious lack of understanding.

The present AirAsia QZ8501 discussion, after all these weeks, can still benefit a lot, from knowledge and experience shared by (especially) A320 pilots and designers. So, please show the proper respect to these guys' information and opinions, even if it is contrary to your own views.

Every design is a compromise, each has plus and minus aspects (especially in aerospace). So, if they are willing to take the time and give their views, then plus and minus aspects will be included. So when a pilot gives a balanced view, and shares a minus aspect, please don't jump on it, take it out of context, and use derogatory language. If you do, then discussions will move outside this forum, which in some cases already happens.

One important question after this accident will be - when you would remove the cause, would that improve or degredate safety, based on the present 'state of the art'. It is not about good or bad planes. It is all about even better planes.
A0283 is offline  
Old 3rd Feb 2015, 16:21
  #2980 (permalink)  
 
Join Date: Jan 2005
Location: W of 30W
Posts: 1,939
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Uplinker
For what it's worth. I fly Airbus, and it has NEVER been marketed or 'sold' to me as being un-stallable.
Of course it has, to the point we fully obey the GPWS procedure.
CONF iture is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.