https://www.youtube.com/watch?v=2tY2HzWCvhw

China Airlines 738 fire in Okinawa. At least the Fire Services seem to have been quicker in Vegas.

And yes, people took their belongings then also.

I have been reading the FAA AD designed to prevent the type of incident which occurred to the BA 777 at Las Vegas. I found the following parts of the document interesting:


Request

Two commenters, General Electric Company and The Boeing Company, requested that we remove the “UnsafeCondition” paragraph from the AD, and reword the Summary section to resemble the Summary section of AD 2002-04-11. The commenters stated that, by their analyses, cracks in the weld joint would not develop into an uncontained failure. The commenters stated that HPCR 8-10 stage spools, P/Ns 1844M90G01 and 1844M90G02, be inspected by an enhanced inspection, similar to those parts covered in AD 2002-04-11.

Answer

We do not agree. AD 2002-04-11 was issued because of additional focused inspection procedures that had been developed by the manufacturer. Because cracks were discovered on one HPCR 8-10 spool between the 9-10 stages in the weld joint, this unsafe condition is likely to exist or develop in other products of the same type design. The unsafe condition could result in failure of the HPCR 8-10 stage spool, uncontained engine failure, and damage to the airplane. We determined that this unsafe condition requires mandatory repetitive inspections for cracks. We did not change the AD.


Well done the FAA for 'sticking to its guns'.


Inspections of the HPCR 8-10 Stage Spool

(f)(1) At the next piece-part exposure of the HPCR 8-10 stage spool after the effective date of this AD, perform a fluorescent penetrant inspection (FPI) and eddy current inspection (ECI) of the weld joint between the 9-10 stages of the HPCR 8-10 stage spool for cracks.

(2) Thereafter, perform repetitive FPIs and ECIs of the weld joint between the 9-10 stages of the HPCR 8-10 stage spool for cracks at every piece-part exposure of the HPCR 8-10 stage spool.


Presumably, this type of inspection can be performed only during major engine overhaul, with the engine removed from the aircraft? If so, will the authorities now need to consider more frequent engine overhauls?


What seems to be missing is any move to find a permanent fix for the problem such as a redesign/manufacture of a HP turbofan which does not have an inherent weakness.

http://www.pprune.org/rumours-news/5...ml#post9114090

Avionista,

Thank you for researching this and summarising key detail. You pose a critical question. I hope it will be answered.

If it is missing it means it was irrelevant, namely design wasn't in question rather perhaps the flaw in manufacturing of random nature. I am not aware of any manufacturing process on this planet that would assure 100% fail free product.

I think that fail-safe might be a more productive route for turbines -- Think how car windscreens have evolved from big lethal broken shards through regularly shaped small bits to the current 'broken but still hanging together' approach

In reply to iomapaseo:

If you watch the video, the first thing the fire appliances do is direct their jets on to the ground beneath the wing.

If you're suggesting that the engine casing should be able to retain any parts from a broken turbine breaking out, that's simply not feasible.

the speed/energy in these parts (especially at take-off power) is simply staggering, you would need something like several inches of Chobham armour backed with heavy armour plate.

If the problem is a manufacturing flaw in a small number of HP turbofans, why does the AD require repetitive inspections, ad infinitum. Surely, the replacement of any components found to be defective would suffice. The FAA, perhaps, believes the problem could develop over time in any of these HP turbofans, hence their requirement for repeated EFI/ECI scans.

I agree that nothing man-made is ever 100% reliable, but vital components should strive for a MTBF well in excess of their expected lifecycle.

I recall video footage of the testing of RR engines where this very feature is demonstrated as a test that the engine has to pass before certification.

Yes, they do strive and there is no data that would indicate this doesn't apply to this part as well. Reliability of these engines is phenomenal by any standards and this includes MTBF.

N1 only....

Failsafe is extremely difficult to imagine without numbers relating to probabilities. Tis true that some parts of a machine such as wing spars are designed with lots of margin to long life with inspections and consideration of storm encounters, damage etc. But most parts can't meet this same requirement and still maintain the total aircraft weight low enough to get off the ground.

Instead mitigation against the consequences of their failing is considered in a probalistic hazard environment.

Things like redundancy/duplication, shielding etc. are considered at the aircraft system level.

If you want to get into this kind of discussion you have to be prepared to work with probabilities and even with that you are still left with some chance of what happened in this event.

We are waiting for the investigation to reveal the causal chain so that one or two of the links can be altered to minimize a future event. Don't for minute believe you can achieve zero engine disk failures, but you can minimize some specific identified cause based on new knowledge.

The message is always the reaction to what we learn and not blame.

For instance re. inspections mandated by this AD - who keeps track of the outcome of such inspections? Boeing and GE only? Assuming there is a trend (with enough statistics), are the reliability models revisited?

flyingchanges and funfly:True it was N1, but the salient fact is that it's a BLADE (airfoil) deliberately released from the fan disk in the referenced video. All new engine models are required to endure this test; The containment for the relatively lightweight blade is established technology. But a DISC failure is several orders of magnitude worse, and containment quite impractical in a flying machine.

Inspection results are reported to the FAA and various models updated as needed. The FAA may update their AD based on any new findings.

At this point I have not seen any linkage between this event and an existing AD but I'm sure they are certainly looking at it quite closely.

This type of failure is extremely rare but the investigators not only need to find the chain of events which likely caused it but also the following chain of events which caused a lot of fuel to leak out from somewhere, probably onto the ground where it then started to vaporise and subsequently ignited.
With all the videos and other evidence they collect from various sources it may be possible to determine where the fuel exited the aircraft and where the first ignition took place. All this is amongst the myriads of things they will have to look at before trying to determine what steps may need to be taken to minimise the chances of it happening again. These processes could take days, weeks or months, or longer. Then of course there will have to be cost and safety evaluations by various parties….
It has already been mentioned by some that the seat of the fire appeared to be below and not in the aircraft and one of my thoughts is that hot brakes could have ignited it or it could have been ignited by another fire already burning in or around the engine. It may of course be difficult to tell after all the damage caused by the fire(s).

Many years ago I was told of an industrial turbine that had a disc failure probably operating in some third world country.
I was told the majority of the disc exited though the casing, out though the unit sound proofing canopy, across the site, though a fence, across a road, then it entered a house though the window 'climbed up' a rear wall, so now going vertically upwards, went through the ceilings, 1st floor and roof structure .......whereupon it finally ran out of energy

When you reject a takeoff and bring the aircraft to a halt the pilots are unable to see anything inboard of the wingtips without opening windows. They may or may not have received a left engine fire warning indication, it depends on whether the fire loop for that engine detected heat. If there was a rapidly expanding puddle of jet fuel on the tarmac that was burning and the flames were going on to the fuselage there would not be a fire indication.


I am sure the controllers were extremely busy coordinating fire services and go-arounds.However if the tower had a clear view of the aircraft would it not have been useful if the controller had told the aircraft that there was smoke and flames billowing from the left engine? Armed with that information the evacuation might have been initiated earlier.


I know that if I were to reject a takeoff, having informed ATC I was stopping I would be very grateful for any immediate feedback from ATC as to whether they could see any smoke, flames, inferno etc. Fortunately in the absence of any ATC info there was an extra flight crew member on hand to go back and see what the passengers and cabin crew could see.


If a passenger had panicked and opened door 2 left off their own bat there might have been a very different outcome. As it was what a great outcome and hats off to all concerned.

Thanks for sharing this. :ok:

Only the even numbers have memory items on the large Boeing where I work. :eek:

This can't be possible right? Surely I have that sim in the basement and am making this up. :confused:

I got the 13 items from Whip's earlier comment:

I heartily congratulate Whip on his retirement and I think our latest reduction in memory items has been since his retirement.

Some of these lists would be called profiles and maneuvers for us, we are indeed expected to know them cold.

However, things that would at one time be considered just common sense troubleshooting, like cycling a transponder, have gradually found their way into a formal non-normal checklist in the AOM (and sometimes, but not always, also in the QRH). And now, Lord help you if you don't write it in the book (or type it on the screen), send a maintenance code and maybe file an ASAP report for CYA whenever anything happens.

Remember when airline manuals only came out every year or two with a few bulletins in between to save printing costs?

Now, with pubs on tablets, revisions seem to be slipstreamed into the manuals almost constantly. At least now you don't have to look at the changes to put the new pages in, right?

Apologies for talking shop so much on a professional pilots forum but these days with events like the BA LAS RTO how you did it is as important to the feds as what you did and how it turned out.

I hope I never see a high speed RTO in the plane (but I'm sure it will be on next year's sim training ;)) however if I do, hope my coworkers watch me and make sure that we all do it right.

Ka-2b pilot, kerosene's vapour is not flammable like petrol's is. ;)

dsc810, many years ago we had a reheated Spey let go of it's HP disc and it exited at 7-0-clock, chopped through the test cell's main fuel inlet pipe, hit the floor, ran up the test cell wall like a Catherine wheel, along the ceiling, down the opposite wall and buried itself into the substantial steel test cradle. The resulting fire was spectacular and the cell out of commission for weeks. And that's with a small engine. A modern large bypass engine's disc failure is a sight to behold! :eek:

DevX there is a good set of pictures of an HPT disc failure outcome at:

http://www.dauntless-soft.com/produc...bies/aaengine/.

Or a similar set of pictures is at http://criticaluncertainties.com/201...3-rotor-burst/

Great pics, thanks. :ok:

Porterhouse - see post 248, took a while to find it in all the c**p about baggage.

At DevX, Kerosene most definitely does vaporise and ignite, just at a much higher temperature (about 110 deg F) than petrol (-40F). If it didn't it wouldn't be used for fuel.

Keeping a Door Closed!
 

Quote: "If a passenger had panicked and opened door 2 left off their own bat there might have been a very different outcome."

I agree with you, but... Let's keep in mind that the cabin crew are well trained here! On such an aircraft, ALL regular doors are monitored/guarded by a crew member. Regardless of evacuation orders, they are trained to look out the window to assess any potential threat and Before popping their assigned door. If fire/smoke or other problems are noted, their job becomes one of keeping that door closed and directing SLC to another route.
The pix of this event suggest that opening L2 likely would have caused far more serious problems. That much I'm sure about.
What I do not know is how cabin crew monitors the Over-Wing exits in a similar event. In this case, popping the first Left Over-Wing hatch would have been almost as bad as opening L2. They do not have sufficient staff to monitor the Over-Wing pop (in or out) hatches and I do not know how they control their use. Does anyone out there know?
I think it is already obvious that this event demonstrates both extremely professional action by the BA crews, ATC, Fire Staff and others, as well as a significant measure of ordinary luck. Had the flight crew not noticed 'a problem' for an additional 20 seconds, this event would probably not be enjoying a happy ending. :D
The single item that continues to trouble me is the firm evidence the the IDIOT Passengers continue to haul their carry-on bags out with themselves. It is a stupid practice, very common and yes, I kow that I'm preaching to the choir.:{:ugh:

"What I do not know is how cabin crew monitors the Over-Wing exits in a similar event"


The 777-200 does not have over wing exits. Door 2 left is in front of the wing and door 3 L is behind the wing.

The photos I've seen of the engine are severely underexposed in the damaged area. Using Photoshop to bring up those areas, it's apparent that the cowling is shredded front-to-back (moreso at the back) at around the 7 o'clock position (viewed from the front), with torn metal sticking down, and that the rear edge of the cowling is missing from the inside of the pylon to roughly the 7 o'clock position (viewed from the rear). Whether this qualifies as 'shrapnel damage' I don't know, but it certainly looks chewed up.

As PAX sitting in the over wing exit seat over 100`s of flights - the only time i have ever been briefed to look for fire before opening the door was on Eastern Airways from LCY to IOM.

This should be a mandatory brief item.

https://www.flightglobal.com/news/articles/ntsb-detects-signs-of-uncontained-engine-failure-fro-416634/

Ka-2b pilot, you said, and I quote: ".....which caused a lot of fuel to leak out from somewhere, probably onto the ground where it then started to vaporise and subsequently ignited".
I was simply remarking that unlike petrol in that particular situation, kero would not ignite. ;)

The photo I've seen (not published elsewhere and I wont post as its not mine) was taken on the aft inbd side and shows all the px relief doors open and C duct material blown outwards consistent with an explosion/high velocity exit of high energy matter for the non daily mail readers... Very reminiscent of that AA 767 that lost hpt1 on eng runs.
Outstanding job by all concerned.

Regarding having important items about your person, a typical piece of non-joined-up aviation procedure is that if you present yourself at security with the relevant items (passport, wallet with CCs, etc) in your pockets, at a number of stations, although not all (so it's not legislation) they will insist you take these off your person, and put them in your laptop bag, which is of course going up in the rack. We know about keys and phones but some places want all this off you as well. Dublin is particularly zealous in requiring this, there are many others. Now often I transfer them all back afterwards, but also can find the first time I need them that they have done the journey up in the rack.

Given the media reports of the subsequent treatment of the passengers from the accident flight at the hotel they were taken to in Las Vegas, which was, simplistically, no credit card = no service, no refreshments, no phone calls, nothing (a typical USA reaction to someone without a credit card, and probably also a standard Las Vegas reaction to anyone who has the temerity to check in without tipping the desk clerk US$20), let alone how you might anticipate be treated at immigration the next day on arrival with no passport, and given the eternity it takes bureaucracy nowadays to reissue passports, you can understand more why people would want these items with them.

DevX, midday in the Nevada desert you suggest the surface temperature would not be 110ºF in the sun, which it would have been seconds before the aircraft cast its shadow. I think it is very possible. Surface temperature of runways in those conditions are often a lot higher than air temperature, often 50-60ºC, roughly 120-140ºF. At the time of the accident the air temperature was 39ºC, that is already 102ºF in the shade. The actual flash point of Jet-A fuel is 100ºF/38ºC.

Story of a past crash - and guess what - the expensive laptop in the hand baggage left on the aircraft goes 'missing'
Well...now what a surprise... who'd have guessed it.
The Crash Landing of Southwest 345 | Nick Bradbury

Mzguilty. Thank you for your reply. I am not arguing with anything you say, nor decrying the good job evidently done in this case. I am listening to what people say but I think others are not listening to me! Point I was trying to make is that it is all very well for us all to agree that the passengers acted selfishly in carrying their luggage, and acted clearly in contravention of instructions, nevertheless a hero went down the slide with a wheelie. Point is, should his action cause harm to another passenger, wouldn't that passenger have a complaint against the operator? Being incapacitated at the bottom of the slide could be a serious issue during a full evacuation.

If the instructions are clear but the staff member at the exit allowed contravention, then I reckon there is the risk of a claim.

So, yes, letting the guy go may well be for the greater good but you now have to argue in law against a passenger who was hurt in consequence of your actions.

Ultimate answer in my view is to shrink the overheads and restrict carry on but guess what, the safety is paramount mantra seems to stumble here against the convenience of passengers.

I hope they find the guy with the wheelie and make him eat it.

No_Fly_Zone wrote.

The pix of this event suggest that opening L2 likely would have caused far more serious problems. That much I'm sure about.
What I do not know is how cabin crew monitors the Over-Wing exits in a similar event. In this case, popping the first Left Over-Wing hatch would have been almost as bad as opening L2. They do not have sufficient staff to monitor the Over-Wing pop (in or out) hatches and I do not know how they control their use. Does anyone out there know?

I know at our Airline, the flight attendants come back and give the overwing exit row passengers a quick briefing on how to open this exit, and (sometimes ) advise them to check for fire first. Often it seems these passengers are just happy to find themselves with the extra leg room, and don't even listen to the briefing. Many seem to me to be incapable of opening/lifting the exit window, but F/As are reluctant to pull someone from one of these exit rows and find them another seat. .Some airlines even offer these rows to passengers for an upgrade price for more legroom.
In my opinion these rows should be offered to deadheading/retired crew first, who have trained in a smoke filled sim to pull the handle down, and throw the overwing exit out of the way. As I have, in mixed crew training with Flight Attendants. These are plug type doors, so you must pull the window exit in, which is counter intuitive.

Another safety issue that bothers me. I often find myself sitting far from the overwing exit rows, while untrained passengers sit there, possibly unable to open the over-wing exit in an emergency..

HP Disk failures at power
 

Just an observation from this thread, as all the cited disk failures have been in GE manufactured engines. Do the other manufacturers have a similar failure rate? or is this a peculiarity of GE's design and manufacturing processes that make their engines vulnerable to these types of failures?

Nothing statistically unique per hour flown when you include all fleets

Hopefully the problems are unique so all don't make the same mistakes.

I suspect the actual causal chain in this one relative to the fire will be unique.

Whilst I do not dispute what you state, if this really is an issue, then it's a regulatory matter, not an operational matter.

I'm well aware of the flash point of kero Ka-2b, but that's not to say that it's guaranteed to combust every time at that point. In my personal experience of engine failures conditions have to be ideal otherwise it's it's more likely that a flash over won't take place, therefore I still don't hold with your original theory.

You joke but I have had it happen on a flight where I was operating as the First Officer.