Go Back  PPRuNe Forums > Aircrew Forums > Military Aviation
Reload this Page >

Voyager Plummets (Merged)

Military Aviation A forum for the professionals who fly military hardware. Also for the backroom boys and girls who support the flying and maintain the equipment, and without whom nothing would ever leave the ground. All armies, navies and air forces of the world equally welcome here.

Voyager Plummets (Merged)

Old 17th Dec 2018, 08:59
  #1001 (permalink)  
 
Join Date: Aug 2006
Location: West Sussex
Age: 77
Posts: 4,140
ShotOne, if you have a propriety interest in the design of the side stick mounting (there, is that an acceptable enough term for you?) then I'm sorry to have upset you by calling it a shelf. The point is that the loose object in question (with or without a strap) was somehow placed upon it in order that the subsequent events could occur.

If it can happen once it can happen again, even if this was the only time ever in your squillions of hours of operation that anything at all was placed on the side stick 'mounting' (with or without a strap). There, is that bland enough for you?
Chugalug2 is offline  
Old 17th Dec 2018, 13:13
  #1002 (permalink)  
 
Join Date: Nov 2000
Location: UK
Age: 64
Posts: 966
Chugalug2,
You raise an interesting point about highlighting the risk of a loose object interfering with the control column on Airbus aircraft when the armrest is down and the seat motoring forward. I do believe that it is a difficult, but not impossible set of circumstances, not impossible because it has happened. Once. And that is once too often.

I think perhaps you haven't seen the geometry of the seat, the armrest and the control column, It takes some doing to wedge anything in there, it is difficult to do accidentally, although obviously it can be. Little has been said about what occurs when the control column is forced out of the 'detent' it is in when the autopilot is engaged and what happens when the autopilot is disengaged by moving the control column. If you had seen the geometry and heard the warnings then perhaps you could understand why any extra mitigation of the risk would not be as successful as you think and may possibly not have prevented this particular accident. There are enough very obvious clues as to what had happened and to was going on which this particular pilot didn't interpret correctly. Cognitive dissonance can be exacerbated by unfamiliarity with the environment and a lack of confidence in the system producing the warnings.
beardy is offline  
Old 17th Dec 2018, 14:31
  #1003 (permalink)  
 
Join Date: Aug 2006
Location: West Sussex
Age: 77
Posts: 4,140
So what are you suggesting beardy, that if this particular pilot had taken more notice of the warnings being given then the accident would have merely become an incident and no-one (least of all his co-pilot) need have been injured? Well, no doubt, but he didn't, and they were. A great deal of mitigation is often needed where human factors are involved, or if you like try to make it 'pilot proof'. For goodness sake, no-one is suggesting a mega bucks solution (I did once but I think I got away with it ), just simply mark the top of the side stick mount (!) as a no-go area.

It may be next to impossible to re-enact the accident sequence, but evidently the SI managed to, and that evidence was presumably the clincher for the CM sentence. It happened, it can happen again, let's just try to make sure that it doesn't!

Or is Flight Safety just for wimps now, and we simply prosecute those who mess up, learning nothing from their mistakes?
Chugalug2 is offline  
Old 17th Dec 2018, 18:00
  #1004 (permalink)  
 
Join Date: Nov 2000
Location: UK
Age: 64
Posts: 966
Marking the area between the control column and the edge of the ledge is a cheap simple and elegant thing to do. It may help to prevent one of the holes in the cheese lining up. It would be nice to think so.
It would help you to visualise the situation if you went and had a look at an Airbus cockpit.
beardy is offline  
Old 17th Dec 2018, 19:34
  #1005 (permalink)  
 
Join Date: Aug 2006
Location: West Sussex
Age: 77
Posts: 4,140
beardy:-
It would help you to visualise the situation if you went and had a look at an Airbus cockpit.
According to Google this is the Flight Deck of a Voyager (ZZ338):-



Yes?
Chugalug2 is offline  
Old 17th Dec 2018, 20:15
  #1006 (permalink)  
 
Join Date: Dec 2013
Location: Elsewhere
Posts: 338
Originally Posted by Chugalug2 View Post
beardy:-


According to Google this is the Flight Deck of a Voyager (ZZ338):-


Yes?
Yes, but I donít think youíll gain much of an insight from a photo that doesnít even show the armrest in question.
A look over an actual Airbus flight deck would be much better.
itsnotthatbloodyhard is offline  
Old 17th Dec 2018, 20:17
  #1007 (permalink)  
 
Join Date: Aug 2017
Location: England
Posts: 6
For what it's worth, Chugalug2, I agree with your position.

I managed to do a similar thing with a clipboard, when moving my seat in a a320 fixed based trainer a few years ago. Obviously not a situation physically similar enough to be meaningfully comparable to this accident, but the point is that I was unaware of the position of my clipboard when I adjusted my seat and suddenly the autopilot disengaged and the aircraft started pitching down. I thought there must have been a fault introduced by the instructor until I happened to notice the clipboard dig into the side of my hand while trying to correct the flightpath. It was before this incident and I thought nothing more of it until I heard the detail about it.

This chap didn't go to work intending to be reckless. He put his camera in a stupid place and it's not beyond the realm of possibility that someone else could do the same - Instagram seems to be full of pictures from "the office" (eye roll)... As far as his mental model is concerned, I'm sure it was fairly well screwed up when the aircraft pitched over in response to him moving his seat. I imagine it felt like a totally unconnected event (as it did for me) and when your focus is on trying to recover from the dive, it's not inconceivable that you wouldn't immediately start inspecting the area around the side-stick. I I imagine you might just pull back until the stick stops...

I am happy to leave the judgement and punishment part to the professionals. Without all the facts, who are we to condone/condemn? I believe that if we accept that this chap didn't do this deliberately, then maybe it's worth considering whether anything can be changed to prevent someone else making the same mistake. For me, that's the more important point .
Rhymenocerous is offline  
Old 17th Dec 2018, 21:25
  #1008 (permalink)  
 
Join Date: Aug 2006
Location: West Sussex
Age: 77
Posts: 4,140
Rhymenocerous, much thanks for posting your experience, a far more valuable input than my theoretical postulations. The point is it can happen, and if it can it will.

intbh, it is most unlikely that I will be visiting an Airbus Flight Deck any time soon. No amount of realising how unlikely an event it might be gets us very far, for the point is; it can, and has, and can again. As to the armrest v the side stick, here is a diagram (again courtesy of Google) :-


I'm not sure what position the arm rest is at though. Lowest, middle, highest?
Chugalug2 is offline  
Old 18th Dec 2018, 01:41
  #1009 (permalink)  
 
Join Date: Dec 2013
Location: Elsewhere
Posts: 338
Originally Posted by Chugalug2 View Post

I'm not sure what position the arm rest is at though. Lowest, middle, highest?
FWIW it looks unfeasibly high to me, such that the base of your hand would end up level with the wider portion at the top of the stick. Not how you’d want to try and fly it. The armrest would generally be much lower - the picture looks like a short person’s seat height with a tall person’s armrest setting.
itsnotthatbloodyhard is offline  
Old 18th Dec 2018, 06:05
  #1010 (permalink)  
 
Join Date: Apr 1999
Location: Manchester, UK
Posts: 1,898
Every aircraft with fore/aft adjustable pilot seats and a control column has a pinch point/design flaw/Achilles heel if, say, a flight bag or NVG case was placed immediately forward of the seat. By the same logic being used here, why do all aircraft not have warning hatching (or proximity sensors) there? More so since most types donít have the flight envelope protection which saved the Voyager in this case.
ShotOne is offline  
Old 18th Dec 2018, 06:59
  #1011 (permalink)  
 
Join Date: Aug 2006
Location: West Sussex
Age: 77
Posts: 4,140
SO, I've never flown an aircraft with a motorised seat, and realise that they bring a new issue in themselves. A manually moved seat would immediately feedback any resistance to movement which would tend to be investigated when felt. However, it would be perverse to place an item in front of any seat between it and the control column, knowing that you would be moving the seat forward once sat in it. With the Airbus side-stick arrangement it is less instinctive, for the pinch point is not in front but to the side of the seat. Having looked at the Airbus 330/Voyager layout it would seem to me that there is indeed room to place a small object on the side shelf/mounting/ledge (select a/r). With the armrest lowered below the diagram height, as intbh says, it is then possible that such an object could be driven forward onto the sidestick as posted above, and as per the OP. Ergo, nothing should be placed on the shelf/mounting/ledge which thus needs to be marked as a visual reminder of that.

You are quite right to point out that the built in flight envelope protection saved the aircraft and its occupants.

Last edited by Chugalug2; 18th Dec 2018 at 07:11.
Chugalug2 is offline  
Old 18th Dec 2018, 07:19
  #1012 (permalink)  
 
Join Date: Nov 2000
Location: UK
Age: 64
Posts: 966
Originally Posted by itsnotthatbloodyhard View Post


FWIW it looks unfeasibly high to me, such that the base of your hand would end up level with the wider portion at the top of the stick. Not how youíd want to try and fly it. The armrest would generally be much lower - the picture looks like a short personís seat height with a tall personís armrest setting.
I disagree. The higher up the stick you hold it, the finer control inputs you make for the same hand displacement, think of the geometry of a lever (which it is.) You also get to rest your forearm on the armrest not leaving any muscles in tension. I was always surprised when young pilots held the stick at its base. They in turn were surprised at the finesse they were capable of when they changed their grip.

Chugalug2, your idea of a visual guide in front of the armrest is a cheap and simple one and has much to commend it. Whilst a picture paints a thousand words it is as nothing compared to handling what you are looking at. It would probably be worth going to see the real thing.

I managed to do a similar thing with a clipboard, when moving my seat in a a320 fixed based trainer a few years ago. Obviously not a situation physically similar enough to be meaningfully comparable to this accident, but the point is that I was unaware of the position of my clipboard when I adjusted my seat and suddenly the autopilot disengaged and the aircraft started pitching down. I thought there must have been a fault introduced by the instructor until I happened to notice the clipboard dig into the side of my hand while trying to correct the flightpath. It was before this incident and I thought nothing more of it until I heard the detail about it.
I am surprised that you used a clipboard instead of the clip on the table to hold any paperwork and also surprised that the clipboard wasn't on the table nor in the document stowage on the cockpit wall. Perhaps most surprising is that neither you, nor your instructor submitted an occurrence report of any type.

Last edited by beardy; 18th Dec 2018 at 07:29.
beardy is offline  
Old 18th Dec 2018, 07:34
  #1013 (permalink)  
 
Join Date: Nov 2000
Location: UK
Age: 64
Posts: 966
Originally Posted by ShotOne View Post
Every aircraft with fore/aft adjustable pilot seats and a control column has a pinch point/design flaw/Achilles heel if, say, a flight bag or NVG case was placed immediately forward of the seat. By the same logic being used here, why do all aircraft not have warning hatching (or proximity sensors) there? More so since most types donít have the flight envelope protection which saved the Voyager in this case.
The seat doesn't even have to move. There is a very sobering film of an F4 that over pitches after take off resulting in the crew ejecting. When the pilot tried to pitch forward the control column was blocked by the navigator's....... camera.
beardy is offline  
Old 18th Dec 2018, 07:41
  #1014 (permalink)  
 
Join Date: May 1999
Location: Quite near 'An aerodrome somewhere in England'
Posts: 25,431
ShotOne a C-130 fatal accident occurred for the very reason you state. To assist in loading tall cargo, a pilot initially held the control column aft to improve clearance below the elevators. Then he decided to prop it in that position by jamming an NVG case in front of it - but forgot to remove it before take-off. As a result the aircraft stalled, killing 11 PoB plus 3 troops on the ground.

Surely trainee pilots are taught never to obstruct the controls with anything, nor place loose articles anywhere which could interfere with full and free movement of critical aircraft controls?

Some of the trash-hauling VC10 mob of the lesser squadron developed a habit of sticking their pens / pencils etc. in front of the radio selector box on the centre console. Presumably because when they used to fly in Blues, they had no pen pocket. Some still did when they changed to wearing flying clothing instead - if I found a pen / chinagraph / whatever on the centre console I would confiscate it! When one aircraft was prepared for a full air test, the engineering team told me that they'd found the remains of an RAF chinagraph amongst the TPI sensing microswitches underneath the control column. They also found a first class BOAC teaspoon under the cockpit floor of ZA141 which must have been there for ages as the aircraft had been sold to Gulf Air, flew for years with them, was then bought by the RAF, rebuilt by BAeS and flew as a VC10K2 for many years until the spoon was found!

Cabin crew were also taught never to pass food / drinks to pilots over the centre console, to avoid the risk of spillage - is it the same in the airlines?

I don't know whether civil A330s have the same OITs as fitted to Voyager, or simply sliding trays. If they don't have OITs, the sliding tray is quite a convenient place for loose papers etc. - but sound training, good flight deck discipline and proper SOPs should mitigate jammed control risk in nay aircraft without any need for visual reminders, cheap though some black and yellow hatching would be.

Flying an F-4 once, as I manoeuvred it a large part of the instrument panel surround came loose and fell out of position. I stopped what I was doing and advised that I would RTB. The pilot of the other aircraft queried this (typical of a flt cdr keen to gain hours for the boss's wall graph...), but I made the point that if the panel was loose, what else had been forgotten by whoever had been working on the jet.
BEagle is offline  
Old 18th Dec 2018, 08:31
  #1015 (permalink)  
 
Join Date: Mar 2000
Location: UK
Posts: 1,442
Don’t know what was in the A330 FCOM but other Airbus FBW aircraft had a note explicitly warning against putting objects on or around the sidestick. Also, haven’t read this thread in its entirety but the arm rest was raised or lowered to ensure that the the sidestick could be held comfortably with full and free movement and this was checked on the ground. It was often said that you held the sidestick like your best friend's todger ie rather gingerly and converting pilots were prone to over-controlling. If in doubt, let go often worked!
Megaton is offline  
Old 18th Dec 2018, 08:40
  #1016 (permalink)  
 
Join Date: Mar 2002
Location: near an airplane
Posts: 1,268
Just curious, is the tray-type area immediately in front of the sidesticks on the photo above meant as a storage area? If so, I can see another gotcha, as in one seat position, using that tray will have you put down items beside you on that tray, but with the seat moved back, the same motion will have said items end up further back on the shelf, perhaps behind the sidestick. It is an unlikely event, but (if my interpretation of that tray is correct) could still end up as a hole in the cheese.
Jhieminga is offline  
Old 18th Dec 2018, 08:53
  #1017 (permalink)  
 
Join Date: May 2009
Location: Here
Posts: 1,209
Originally Posted by itsnotthatbloodyhard View Post


Yes, but I donít think youíll gain much of an insight from a photo that doesnít even show the armrest in question.
A look over an actual Airbus flight deck would be much better.
The armrest is visible at the extreme bottom left of the photo - so you get an idea of where it would end up when the seat is moved forward
Davef68 is offline  
Old 18th Dec 2018, 09:28
  #1018 (permalink)  
 
Join Date: Nov 2000
Location: UK
Age: 64
Posts: 966
Originally Posted by Jhieminga View Post
Just curious, is the tray-type area immediately in front of the sidesticks on the photo above meant as a storage area? If so, I can see another gotcha, as in one seat position, using that tray will have you put down items beside you on that tray, but with the seat moved back, the same motion will have said items end up further back on the shelf, perhaps behind the sidestick. It is an unlikely event, but (if my interpretation of that tray is correct) could still end up as a hole in the cheese.
The seat never goes far enough forward for the tray to ever be beside you. It is always on the other side of the control column.
beardy is offline  
Old 18th Dec 2018, 09:32
  #1019 (permalink)  
 
Join Date: Nov 2000
Location: UK
Age: 64
Posts: 966
Originally Posted by Davef68 View Post
The armrest is visible at the extreme bottom left of the photo - so you get an idea of where it would end up when the seat is moved forward
Not unless you can take into account the distortion produced in the photograph, consider it similar to map projections.
beardy is offline  
Old 18th Dec 2018, 09:54
  #1020 (permalink)  
 
Join Date: Oct 2007
Location: Here
Posts: 621
Airbus helpfully have 360 degree images of their cockpits various in quite high resolution - here is an image from a screenshot.

https://static.airbus.com/fileadmin/...ockpit330.html

jimjim1 is offline  

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.