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-   -   Another A32x engine cowling ? (https://www.pprune.org/rumours-news/521277-another-a32x-engine-cowling.html)

Max Angle 11th Nov 2013 09:35

And flight crews re-educated as to the importance of checking they are locked before going flying.

Cows getting bigger 11th Nov 2013 09:40

... and manufacturers need to be re-educated as to the design of systems and human fallibility. :)

Cough 11th Nov 2013 11:05

Hopefully in time we will see a microswitch retrofitted to cowl latch and a nice ECAM 'ENG 1/2 cowl open' when the engineer helps you out...

jossurf 11th Nov 2013 12:37

Another engine cowling
 
Cough:
Hopefully in time we will see a microswitch retrofitted to cowl latch and a nice ECAM 'ENG 1/2 cowl open' when the engineer helps you out...

I should like to think engine cowlings can be aerodynamically designed in such a way as not to be able to open during flight.
Moreover what is wrong with a REMOVE BEFORE FLIGHT tag on the latches?

Basset hound 11th Nov 2013 14:22

The number of this type of incidents cause me to be embarrased for Maintenance staff world-wide. These cowls are opened ONLY by Maintenance staff; and it is the responsibility of an Engineer to ensure those cowls get closed & latched after said opening.

Volume 11th Nov 2013 14:26

...and there are 4 of them. I can understand if you forget to lock one, or miss to check one during walkaround. But to completely forget to lock any of them or to completely miss to check all of them is just another indicator for where we are heading for, if cost is our highest priority.

Non-Driver 11th Nov 2013 15:25


...and there are 4 of them. I can understand if you forget to lock one, or miss to check one during walkaround. But to completely forget to lock any of them or to completely miss to check all of them is just another indicator for where we are heading for, if cost is our highest priority.
Since the cowls lock together as a pair, it is not possible leave an odd number unlocked. I was also under the impression this was 2 cowls not 4 this time.

Believe me, Maintenance folks don't deliberately fail to follow procedures, it is a repetitive mundane / easily distracted function performed thousands of times per day all over the world and the error is always classic Human Factors. There is nothing to do with cost saving. It is down to the authorities and Airbus's sadly lacking will to correct the design with any great urgency. Airbus's standard response is always "didn't follow procedures".

tdracer 11th Nov 2013 15:39

Are they failing to actually latch the latches? Or are the latches not being latched "properly"?

I was under the impression it was the later....:confused:

DaveReidUK 11th Nov 2013 15:52

They are either latched or not. There is no "latched, but not latched properly" configuration.

Yes, the handles can be pressed flush without the hooks being engaged at all, but that's not the same thing.

Dannyboy39 11th Nov 2013 17:40

Correct me if I'm wrong, but didn't Rohr (or indeed Airbus?) release a VSB, so it was easier to determine whether the latch was insecure? Paint the latch in orange or another high contrast colour?

DaveReidUK 11th Nov 2013 18:13

The latch design, mods, etc (on both CFM and IAE engines) were extensively discussed in this thread following the BA A319 cowl separation:

http://www.pprune.org/rumours-news/5...-heathrow.html

fenland787 11th Nov 2013 18:14


so it was easier to determine whether the latch was insecure? Paint the latch in orange or another high contrast colour?
Not sure that helps, I seem to recall a post on a much earlier thread about this issue that the problem was that when the cowls were open the dangling latch was a nuisance and was sometimes pushed flush to get it out of the way. Then the cowls get closed but unless someone immediately opens the latch, engages and re-latches them it can appear to a quick glance that all is closed and latched whereas they aint.

Have to say it sounds to me like the latch design is the problem here, classic Human Factors issue?

PAXboy 11th Nov 2013 19:32

This Spirit 319, do we know which engines?

west lakes 11th Nov 2013 19:51


do we know which engines?
V2524 according to Av Herald

Wirelock 11th Nov 2013 21:19

training the answer?
 
Maintenance companies need to do more to prevent these events. Saying that this is down to human factors is really only relevant if the company involved analyze where the break down happened and resolve the issue.
In my opinion this is down to poor maintenance standards and a failure of the organisation to prevent a well publicized and preventable event.
I would think that in the majority of similar cases the same would apply.

fenland787 12th Nov 2013 07:49


Saying that this is down to human factors is really only relevant if the company involved analyze where the break down happened and resolve the issue.
Generally, for an isolated incident I would agree. However in this case with this frequency of the issue, across several different organizations, I feel the 'once is happenstance, twice is coincidence but three times is enemy action' rule applies! The 'enemy action' in this case is poor latch design.

Volume 12th Nov 2013 08:47


Since the cowls lock together as a pair, it is not possible leave an odd number unlocked. I was also under the impression this was 2 cowls not 4 this time.
Yes it is 2 cowls locked against each other by 4 locks. Probably locking and latching just one (the forward one) would be enough to fly safely...

The 'enemy action' in this case is poor latch design.
Not too sure about that. If a design is known to be poor, it should normally get special attention by the mechanics. However, it looks more like it gets no attention at all.
Anyway I agree that a latch in a dirty location where you have to knee down to get to it is poor. But it is hard to design it any other way, if you want gravity to close the doors so that the latching can be done by a single person, then this is the only possible design. You may move the handles to the side of the cowling where it can easily be reached and checked and actuate the locks by bowden cable, but that would just create new failure causes. (at the moment these are KISS latches...)

I think the key here is knowledge and attention.

PAX_Britannica 12th Nov 2013 09:25

Whoopsie. Here we go again.

Certain historical aircraft designs have succeeded in both eliminating the risk of loose cowlings damaging control surfaces, stabilisers, and/or engine subsystems, and reducing maintenance workloads. We should learn from the lessons of the past.

A careful comparison of the foreground and background aircraft in the picture linked below perhaps illustrates my point.
http://www.trimotors.awiggins.com/im...nd707atSFO.jpg

In the automotive industry, it has long been recognised that uncommanded opening of engine cowlings can lead to an sudden and disorienting loss of visual references - often abruptly followed by uncontrolled impact with terrain.

To this end, automotive designers have created double cowling locking mechanisms, combined with sprung cowlings, such that if at least one locking mechanism is not engaged, the cowling springs open, and the absence of locking is immediately apparent, except perhaps in conditions of extremely poor visibility.

fenland787 12th Nov 2013 09:27

It would not be difficult to arrange the latch such that it cannot be moved to the 'latched' position unless it was correctly mated with the other half.. That way even a quick glance would show the thing was not latched.

Epsomdog 12th Nov 2013 10:56

It's all about the mindset of the engineer!
 
All of these issues would be of no consequence if the engineer closing the cowls did so correctly! The latches have not been proven to be faulty, ie. open, having been closed correctly.

Cowls should be either open on stays, or fully closed and latched!

It is madness to drop the cowls off the stays and say to yourself ill latch those later!

It requires a discipline and mindset that I'm afraid is not, nowadays, brow beaten into you during the modern abbreviated apprenticeships.

I'm not sure even Human Factors can be used as an excuse. Allowing yourself to be distracted during a critical task borders on negligence! Pilots don't go for a p on finals do they?


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