BA engine issue at Heathrow

[airboatr]

He's watching footie at the mo Chris... ... see there ya go , another reason things don't get done right.. somebody's always bothering a person trying to considerate on their job...

[NigelC]

Kittyhawk DC-8-63

Before the accident flight, company maintenance personnel performed work on all four of the aircraft's engine thrust reversers. One mechanic working on the thrust reversers went off-shift before closing the number 2 cowl, and asked another mechanic to close the cowl for him. The second mechanic subsequently lowered the number 1 and 2 cowl doors but was unable to secure and lock them. He reported to mechanics on the next shift that all four engine cowls needed to be secured, and annotated this in the shift turnover log. When mechanics from the next shift arrived to close the cowls, they observed the number 1 and 2 cowls closed but did not review the shift turnover log and did not check to ensure the number 1 and 2 cowls were latched. The flight engineer also failed to detect the unlatched cowls on his preflight inspection, despite detailed procedures in the company flight operations manual for preflight inspection of the cowls (including ensuring they are latched.) The flight crew subsequently initiated a takeoff with the number 1 and 2 engine cowls unsecured. The number 1 and 2 cowls departed the aircraft during, and shortly after, takeoff, substantially damaging the aircraft's left wing and left horizontal stabilizer. The flight subsequently returned to the departure airport and landed without further incident.

If it wasn't for the mention of all four engines and Flight Engineer.......

N

[DaveB]

Yes, I thought that too

ATB
DaveB

[cstorey]

Also, this is the reason I was specifically comparing the 737 and the A32x family. The 737 actually has LESS ground clearance under the engine than the Airbus. So if the Airbus has had 22+ incidences and the 737 family has had less than 10 (which is what I've been able to find) and there's nearly 4 times as many CFM-equipped 737s versus A32x family aircraft,:

I am a bit surprised at the suggestion that CFM on 737 outnumber CFM on A 320 family by 4 to 1 . There are about 4700 CFM equipped Boeings, and about 5500 A 320 family . I did not know that only about 20% of Airbus 320 were CFM equipped ( my figures refer to build numbers rather than those in service today )

[VC10]

http://cdn-www.airliners.net/aviation-p ... 253761.jpg

You will notice the 737 engines don't hang vertically from the wing so if the fan cowls haven't been latched closed the inbd cowl will hang vertically and be obvious to anyone that it isn't latched. I would suggest that is why there have been less incidents on 737's.

Paul

EDIT***

IMG tags removed for copyright reasons GR

[Chris Trott]

Also, this is the reason I was specifically comparing the 737 and the A32x family. The 737 actually has LESS ground clearance under the engine than the Airbus. So if the Airbus has had 22+ incidences and the 737 family has had less than 10 (which is what I've been able to find) and there's nearly 4 times as many CFM-equipped 737s versus A32x family aircraft,:

I am a bit surprised at the suggestion that CFM on 737 outnumber CFM on A 320 family by 4 to 1 . There are about 4700 CFM equipped Boeings, and about 5500 A 320 family . I did not know that only about 20% of Airbus 320 were CFM equipped ( my figures refer to build numbers rather than those in service today )

Sorry, I underestimated what the number was. I was under the impression that the A320 family's CFM numbers were vastly inferior to the IAE numbers. In fact, it's about a 50/50 split, with 3210 produced A32x's having CFM engines of the 5800+ produced or assigned construction numbers. There have been 6420 737's built with CFM-56 engines (-300 thru -900ER including the BBJ's), so the correct number is 2-to-1.

[NigelC]

Why is that these things are always turned into Boeing v Airbus matches?

There is nothing wrong the A320 cowl. There have been 32 fan cowl separations in over 50 million departures. One every 1.5 million departures or 0.0000006 per cent of departures. And in each case, the common factor is the cowls being opened for maintenance prior to the incident flight.

Now, on the basis that 99.9999994% of cycles are completed with cowls still in place, that the design is pretty robust.

My opinion, and I stress opinion, as someone that has sat on airline Flight Safety and Accident Prevention Boards, that the key issue here is procedural/systemic and that the only factor concerning the cowl, is the position and visibility of the latches, in that unless you get down on you knee(s), you cannot adequately check the latching. As the latches cannot be moved from this position, then the answer must lie on making sure the latches are more easily "accessed" for checking, either by some sort of tell-tale or electronic indication (just something else to go wrong in my book) or by giving the flight crew kneepads or cleaning vouchers!!!

N

[Chris Trott]

Nigel, I'm sorry you see this as an "Airbus vs Boeing" thing. I took great pains to make it clear that my points were not such. You are the only one who continues to try and make it such an argument and bring up unrelated models never mentioned in my or anyone else's posts. My only line of comparison is SPECIFICALLY between the A320 family and the CFM-equipped 737's. The only reason for that comparison is because they both have the same engine and cowlings made by the same supplier. As such, it is a very reasonable and correct line of discussion to compare the two aircraft and their installations and why cowling separations are a problem on the A320 family and not on the 737 family. I'm sorry, but 32 inflight separations and an unknown number of near-misses and partial separations is unacceptable. As you pointed out in some of your posts, past cowling departures have lead to significant structural and aerodynamic damage to aircraft. As such, as a pilot, a Safety Officer, and a student of Risk Management, I see a significant RISK that is not being MANAGED by Airbus because they have implemented procedures and modifications to make unsecured cowlings more "evident" yet it continues to happen. If the NTSB, Transport Canada, EASA, and Airbus themselves see the design as enough of a problem to MODIFY THE PART then you claiming that "there is nothing wrong with the A320 cowl" is flat wrong. If it was fine, then Airbus wouldn't be modifying it. If it wasn't a problem, the NTSB wouldn't have spent the time and money researching these incidences and finding that the Airbus A320 family and CL600 families have a vastly higher rate of such incidences than any other flying type and determining that changes were needed. I'm sorry man, but I'm done with this discussion if you're going to ignore that "human factors" includes the guys who designed the thing.

[VC10]

The only reason for that comparison is because they both have the same engine and cowlings made by the same supplier. As such, it is a very reasonable and correct line of discussion to compare the two aircraft and their installations and why cowling separations are a problem on the A320 family and not on the 737 family.

It is not a like-for-like comparison. They may have the same engine and and same cowl supplier but the cowl design is different and the engines hang differently off the wing so on the 737 the inboard cowl will 'protrude' from the faired nacelle design if not latched closed. I would say it was just a lucky combination that causes the 737 to have less events.

Paul

[Dev One]

But....although the cowl is made by the same supplier, do we know if the latches are the same design? Boeing have their own patent for latches, so presumably they would specify those?
Keith