Incident at Heathrow
Join Date: Apr 2007
Location: uk
Posts: 84
Likes: 0
Received 0 Likes
on
0 Posts
Just as a point of order, no that is not 'fail safe'. It is belt and braces, which is no bad thing.
A 'fail safe' is a situation whereby the failure of the mechanism 'naturally' fails in a safe way. An example would be (if you'll excuse the mention of railways) electro-pneumatic braking system on trains, whereby the natural state of the individual brakes on the wheels is that they are held on using jolly big springs, and the action of the train's braking system is to pull the brakes off using pneumatics. If any part of the train's system fails (for example the train splits, causing the brake-line to separate, releasing the pressure from the braking system) basic laws of physics (Newton & Hooke) cause the brakes to revert to the applied state rather than any backup mechanism* per se.
A fail safe cowl latching mechanism would be one whereby if the latch fails, the cowl nevertheless remains in the safest position while in flight (which is to say, closed.) You can envisage designing the cowls such that while in flight the flow of air passing the cowl naturally tends to push the cowl closed rather than tearing it off. (Simplistically, arranging the cowls such that their hinges were at the front and opened like the petals of a flower, would seem to be a 'fail safe' design in respect to the latches.)
(Note I'm not recommending that design - I'm sure there are plenty of reasons they're not designed like that and plenty of reasons why they are designed as they are, but that would be a design whereby the cowls would seem to fail safe in the event of latches not working.)
* some smartarse (me!) is going to say, 'what happens if the springs don't work'. Well, that's a different failure than the train braking system failing, so doesn't affect whether or not the design of the braking system is fail safe. I suppose one could start to worry about whether or not springs need their own fail safe, but to a certain extent worrying about whether or not springs are going to spontaneously stop being springy is a bit like worrying about whether or not gravity is going to stop working mid-flight. Possibly worth worrying about if you worry about the Bermuda Triangle, but otherwise you have to draw a line somewhere...
Air brakes on a truck work just the same ie if the system fails the brakes are automatically applied....
A 'fail safe' is a situation whereby the failure of the mechanism 'naturally' fails in a safe way. An example would be (if you'll excuse the mention of railways) electro-pneumatic braking system on trains, whereby the natural state of the individual brakes on the wheels is that they are held on using jolly big springs, and the action of the train's braking system is to pull the brakes off using pneumatics. If any part of the train's system fails (for example the train splits, causing the brake-line to separate, releasing the pressure from the braking system) basic laws of physics (Newton & Hooke) cause the brakes to revert to the applied state rather than any backup mechanism* per se.
A fail safe cowl latching mechanism would be one whereby if the latch fails, the cowl nevertheless remains in the safest position while in flight (which is to say, closed.) You can envisage designing the cowls such that while in flight the flow of air passing the cowl naturally tends to push the cowl closed rather than tearing it off. (Simplistically, arranging the cowls such that their hinges were at the front and opened like the petals of a flower, would seem to be a 'fail safe' design in respect to the latches.)
(Note I'm not recommending that design - I'm sure there are plenty of reasons they're not designed like that and plenty of reasons why they are designed as they are, but that would be a design whereby the cowls would seem to fail safe in the event of latches not working.)
* some smartarse (me!) is going to say, 'what happens if the springs don't work'. Well, that's a different failure than the train braking system failing, so doesn't affect whether or not the design of the braking system is fail safe. I suppose one could start to worry about whether or not springs need their own fail safe, but to a certain extent worrying about whether or not springs are going to spontaneously stop being springy is a bit like worrying about whether or not gravity is going to stop working mid-flight. Possibly worth worrying about if you worry about the Bermuda Triangle, but otherwise you have to draw a line somewhere...
Air brakes on a truck work just the same ie if the system fails the brakes are automatically applied....
Join Date: Jul 2008
Location: UK
Age: 69
Posts: 475
Likes: 0
Received 0 Likes
on
0 Posts
what about just employing cost effective "professionalism" endorsed by management and regulators in real terms rather than just hollow words or reports which paint a nice picture but don't relate to the reality.
Join Date: May 2006
Location: London
Age: 69
Posts: 237
Likes: 0
Received 0 Likes
on
0 Posts
I do find the disagreement between AAIB and NTSB rather odd ( see posts from Richard J, lomapaseo and Wiggy above ) rather disturbing.
Surely they should be VERY clear on the facts before publishing ?
( See Guardian story here ;
Air safety officials deny claim that BA jet was close to catastrophe | World news | The Guardian
Surely they should be VERY clear on the facts before publishing ?
( See Guardian story here ;
Air safety officials deny claim that BA jet was close to catastrophe | World news | The Guardian
Join Date: Jan 2001
Location: UK
Posts: 2,044
Likes: 0
Received 0 Likes
on
0 Posts
To be technically correct, the NTSB dod not say "one shutdown, other on fire." They said:
So they quote what (they understand) the pilots reported. There are quite a few links in the chain between the NTSB narrative and what actually happened, especially if you interpret "reported" as what was understood by somone on the other end of the radio, rather than, say an interview.
Pretty academic, wait until this afternoon
The pilots reported that they shut down one engine, there was a fuel leak, and that they were returning. The pilots subsequently reported that one engine was shut down and the other engine was on fire
Pretty academic, wait until this afternoon
Join Date: Jan 2008
Location: london
Posts: 246
Likes: 0
Received 0 Likes
on
0 Posts
Case One:
"A nameless BA mate told me that until this incident he never checked the latches."
If that is really true then I am absolutely flabbergasted. Was he completely unaware that such problems had happened in the past and might just ruin his day if he didn't have a bloody good look?
Breathtaking.
"A nameless BA mate told me that until this incident he never checked the latches."
If that is really true then I am absolutely flabbergasted. Was he completely unaware that such problems had happened in the past and might just ruin his day if he didn't have a bloody good look?
Breathtaking.
IMO there is a world of difference between not checking the cowl latches thoroughly on a quick turnaround, and not doing the same checks on the first flight of the day. Especially on an aircraft that has just come out of maintenance.
Last edited by Sillert,V.I.; 31st May 2013 at 09:45.
Join Date: Jul 2008
Location: UK
Age: 69
Posts: 475
Likes: 0
Received 0 Likes
on
0 Posts
IMO there is a world of difference between not checking the cowl latches thoroughly on a quick turnaround, and not doing the same checks on the first flight of the day. Especially on an aircraft that has just come out of maintenance.
Are we heading for yet another AAIB report focusing on maintenance?
Time will tell.
From the Hobbs report:
‘technical/maintenance failure’ emerged as the leading cause of airline accidents and fatalities, surpassing controlled flight into terrain, which had previously been the predominant cause of airline accidents.
According to former NTSB Board member John Goglia, deficient maintenance has been implicated in 7 of 14 recent airline accidents.
According to former NTSB Board member John Goglia, deficient maintenance has been implicated in 7 of 14 recent airline accidents.
If cutting budget, manpower, spares, tools, inspectors, targetting occurrence reporters qualifies then I suppose yes.
But wouldn't crews prefer to be handed over a plane that is going to work?
Last edited by Safety Concerns; 31st May 2013 at 10:12.
Join Date: Nov 2010
Location: UK
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
Ok, I'm a lurker here (amongst many I guess) and after I post this I will probably return to being a lurker but...
1. the NTSB appears to be a bit of an ass (to use a US phrase)
2. the AAIB needs to kick some ass in its final report
3. Not sure what to say about BA. I don't know if coming back to base was the best option. But, again, I'll see what the AAIB says.
Looking forward to an authoritative update from the AAIB today.
1. the NTSB appears to be a bit of an ass (to use a US phrase)
2. the AAIB needs to kick some ass in its final report
3. Not sure what to say about BA. I don't know if coming back to base was the best option. But, again, I'll see what the AAIB says.
Looking forward to an authoritative update from the AAIB today.
Join Date: Feb 2013
Location: Buckinghamshire
Posts: 34
Likes: 0
Received 0 Likes
on
0 Posts
Join Date: Mar 2002
Location: London, UK
Posts: 437
Likes: 0
Received 0 Likes
on
0 Posts
Join Date: Jan 2008
Location: MAN
Posts: 769
Likes: 0
Received 0 Likes
on
0 Posts
Key finding?
Subsequent investigation revealed that the fan cowl doors on both engines
were left unlatched during maintenance and this was not identified prior to
aircraft departure
Subsequent investigation revealed that the fan cowl doors on both engines
were left unlatched during maintenance and this was not identified prior to
aircraft departure
Folks,
Just listening to Sky News, BA CEO says (I kid you not)
" the cowls are like the bonnet on your car ------ they have no structural strength ------ they should be able to fall off without doing too much damage".
Oh! Well!, that's all right Nigel, back to sleep. And we whinge about the reptiles of the press getting aviation stories wrong!!
And, of course, all car bonnets have a double latch, part of the design standard.
I hope this interview goes viral on the net, so you can all benefit from these pearls of wisdom.
In short, both!!
Just listening to Sky News, BA CEO says (I kid you not)
" the cowls are like the bonnet on your car ------ they have no structural strength ------ they should be able to fall off without doing too much damage".
Oh! Well!, that's all right Nigel, back to sleep. And we whinge about the reptiles of the press getting aviation stories wrong!!
And, of course, all car bonnets have a double latch, part of the design standard.
I hope this interview goes viral on the net, so you can all benefit from these pearls of wisdom.
The last engineer working on the engines or the pilot doing the walk around?
Last edited by LeadSled; 31st May 2013 at 14:50.
Join Date: Feb 2013
Location: Buckinghamshire
Posts: 34
Likes: 0
Received 0 Likes
on
0 Posts
In short, both!!
Join Date: May 1999
Location: Back in the UK from the Sunshine Island for the last 8 years.
Posts: 90
Likes: 0
Received 0 Likes
on
0 Posts
Latches
First fault - the engineer's (s' perhaps)
Ultimate responsibility, particularly after maintenance - flight crew exterior walkround inspection error/omission.
Ultimate responsibility, particularly after maintenance - flight crew exterior walkround inspection error/omission.
Just a thought - according to the AAIB report a photo taken before pushback showed the doors unlatched - who took the piccie - was it someone who might have understood what he/she was looking at?
Join Date: Aug 2002
Location: Europe
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
V2500 engines
The fact remains that the V2500 engines have experienced 32 events of unlatched cowlings falling off of which 80% during take off, this means 32 cases of multiple failures by engineers and pilots, I am therefore not inclined to blame both on this occasion, in my opinion the design must be improved and cockpit warning sensors added to this engine or it will happen again. The pilots could have died too so negligence in my opinion would be an inappropriate excuse to cover Airbus responsibility: misleading, inappropriate design is responsible for these 32 events.