Classic British Flight Sim

I am in no way qualified to comment on this current discussion but it seems that with 32 previous incidents it is only a matter of time before an even more serious event occurs.Andrew Weir's book 'The Tombstone Imperitive' makes very interesting reading in looking at the aviation industry's attitude to safety vs costs.I can't recall the ISBN but an quick online search will find it.EricT

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.

The BA aircraft and some of the other cowl separation incident aircraft are IAE V2500 powered.

These are the NTSB Safety Recommendations on Fan Cowl Separation. They in no way implicate the design of the A320 fan cowl.

Therefore, the National Transportation Safety Board recommends that the Federal Aviation Administration:

Require all operators of Airbus single-aisle and Bombardier CL-600 airplane models to revise existing aircraft maintenance manual procedures and
maintenance inspection documents to require a dual inspection signoff to confirm that engine fan cowls are latched after completing any engine
maintenance that involves the opening of an engine fan cowl. (A-08-79)

Require all operators of Airbus single-aisle and Bombardier CL-600 airplane models to require maintenance personnel to inform flight crews when engine fan
cowls have been opened before flight. (A-08-80)

Require all operators of Airbus single-aisle and Bombardier CL-600 airplane models to provide guidance to maintenance personnel and flight crews on how to
inspect engine fan cowls to verify that they are latched properly. (A-08-81)

Determine the extent of the problem of engine fan cowl separations on all airplanes and, should a widespread problem exist for any airplanes, require
operators of those airplanes to include a dual inspection signoff in their maintenance procedures to confirm that engine fan cowls are latched after
completing any engine maintenance that involves the opening of an engine fan cowl. (A-08-82)

I have never said that the cowl was perfect, but that it is an inherently robust design proven by a 0.6 per million departure failure rate. As no design is perfect, then all are subject to AD/SB action either by way of continuous improvement or by way of maintenance finding or incident/accident report.

N

Its really easy. If at least one of 3 people had done their job properly, this incident wouldn't have happened.

In any event, although Chris Trott thinks the engines are the same , the CFM on the majority of Airbus 319s is in fact different from that on the Boeing 737-800 - it has fewer compressor stages and therefore the fan cowl probably comes in a different position relative to the pylon ( even assuming that the pylon to engine attachments are the same, which is a very big assumption ). There are many variables, and unless one has conducted a detailed safety study of the reasons for differences in numbers of incidents , all we are doing is speculating . It's interesting, but speculation is all it is

Absolutely Ben.

Doesn't matter what it is...if it's not latched and not checked it will open.

The number of safe flight shows there is no problem if procedures are adhered to.

Even if it proves that some designs are more easily missed then others, that does not excuse the failure to check

Add devices to indicate and they can fail or be faulty and pointless when all you need do is check. In fact there is an over reliance on safety devices with the thought that the light's not on so it must be alright. I recently found the engine oil in the car below limits but the light hadn't come on.

In reality, they'll never remove the human element, just lengthen the odds of things not happening.

But that's it...if it can happen, one day it will, be it Airbus, Boeing or anything else that has opening cowls.

It's not as if the latch can be closed but unlatched...it just needs checking and if closed it's latched...what more can designers add to that??

If a particular type has latches in a harder to spot place then that matters not if you look to check. That only matters if you are happening to notice them unlatched at any time they shouldn't be, but if they have been checked, that won't happen

Maybe an aid could be a tick bocx sheet that is checked as each vital is examined, like a cockpit check list. That wouls be better than some sort of electric warning device.

I bet ATM ground staff are checking them a dozen times.

cstorey wrote:In any event, although Chris Trott thinks the engines are the same , the CFM on the majority of Airbus 319s is in fact different from that on the Boeing 737-800 - it has fewer compressor stages and therefore the fan cowl probably comes in a different position relative to the pylon ( even assuming that the pylon to engine attachments are the same, which is a very big assumption ). There are many variables, and unless one has conducted a detailed safety study of the reasons for differences in numbers of incidents , all we are doing is speculating . It's interesting, but speculation is all it is

CFM-56 installations on the 737 are different in a number of significant ways: the nacelles and cowlings are flattened in section to account for the engines being otherwise closer to the ground. The pylons are of a different configuration for the same reason: the engines are mounted further forward of the wing. Also I'm pretty sure that all 737-mounted engines have sliding reverse cowlings while those mounted to Airbuses are of the "butterfly" type.

Garry Russell wrote:Maybe an aid could be a tick box sheet that is checked as each vital is examined, like a cockpit check list. That wouls be better than some sort of electric warning device.

It doesn't need a tick box Garry, it just needs log book entry to say the cowls have been opened. Especially after the number of repeat incidents that have occurred. That way the engineer signing the flight clearance knows they have been open and so does the pilot or to put it another way good engineering practice.

I could go on about how the aircraft engineering licence exams have been dumbed down since I were a lad and the standards that has produced, but that is another story.

Paul