China Airlines B737 Fire at Okinawa

[Airbubba]

CNN has a crawler reporting a China Airlines plane on fire at Okinawa...

Pictures look like a burned out 737 at the airport in Naha, reportedly after landing, no casualties on the first report...

[RiverCity]

CNN now has dramatic video of large flames and heavy smoke. Reports that all 155 (pax and/or pax and crew) off safely.

[shiftkeying]

It's a 737 600 with the letter/number B18616 painted in various locations.

[SIC]

CAL has 737-800 - not 600

[RiverCity]

The CNN video, from Japanese sources, seems to show the flames coming from the rear to the mid-section and not forward of that.

[RiverCity]

CNN report at 0228z: Engine blew after landing; perhaps four people injured and the reporter says there are coflicting reports, but one they are hearing is that these people may still be on the plane.

[shiftkeying]

I stand corrected, It's an 800 not a 600.

[Karaka]

Whatever it was, must have developed late, why would you park it close to the ramp? Looks like fire spread through the airconditioning ducts.

[bomarc]

can you say: how much fuel was in the center tank? ;-)

[Karaka]

Usually none

[Karaka]

Taiwanese jet catches fire at Okinawa airport


Monday, August 20, 2007 - TOKYO (AP)


A China Airlines jet caught fire on the tarmac at an airport in Okinawa after arriving on a flight from Taipei, on Monday, but there were no passengers injured, officials said.

All 155 passengers had disembarked from the Boeing 737 before the fire, Kyodo News reported. National broadcaster NHK said the pilot was also believed to have escaped the plane.


A transport ministry official could not confirm the number of passengers, but said all had left before the fire broke out. He said, however, that the safety of the crew was not immediately known.


NHK showed flames and black smoke billowing from the plane as fire fighters doused the wrecked fuselage with extinguishers.


Flight CI120 left Taipei at 8:15 a.m. and had been scheduled to arrive at Naha, on the southern Japanese island of Okinawa, at 10:45 a.m., NHK reported.

[Karaka]

TOKYO: A China Airlines jet caught fire on the tarmac at an airport in Okinawa after arriving on a flight from Taipei, on Monday, but there were no passengers injured, officials said.

Giant flames and plumes of black smoke erupted from the Boeing 737 after it landed from Taipei at Naha airport on the southern Japanese island of Okinawa.

"I saw passengers getting out of the airplane. And then there were four explosions," a witness was quoted as saying.

All 155 passengers had disembarked from the Boeing 737 before the fire, a local news agency reported. National broadcaster said the pilot was also believed to have escaped the plane.

A transport ministry official could not confirm the number of passengers, but said all had left before the fire broke out. He said, however, that the safety of the crew was not immediately known.

The local media showed flames and black smoke billowing from the plane as fire fighters doused the wrecked fuselage with extinguishers.

Flight CI120 left Taipei at 8:15 a.m. and had been scheduled to arrive at Naha, on the southern Japanese island of Okinawa, at 10:45a.m., the media reported.

In Taiwan, officials from China Airlines were not immediately available for comment.

[Sleep Deprivation Chamber]

NHK is reporting now that the right engine 'caught fire' and that all passengers are thought to be out. They also reported that one FA went back on the plane to ensure all the passengers were out.

[Karaka]

If it was a right engine fire, why did the cabin look more burnt out than the wing?

[Sir Richard]

Remember the BA 737-200 at Manchester, Left engine exploded, ruptured the fuel tank. The cabin was similarly burnt and destroyed. (Flames blown by crosswinds I believe)

[Sleep Deprivation Chamber]

NHK is now reporting (12:40JST) that all passsengers are out and all crew are safe but one of the crew members was slighly injured. They noted that the plane landed, and was approaching (or was at--this was not clear) the gate when four loud thumps were heard, followed heavy smoke, then fire. The fire reached all the way to the top of the vertical stabilizer.

[RobertS975]

Left side is where the problem appeared to be, at least initially:
http://news.ninemsn.com.au/article.aspx?id=287706


Graphic video of the fire:

http://ninemsn.video.msn.com/v/en-au/v.htm?f=39&g=0b86a93a-b0d6-4ec6-ba95-8b0d730c948f&p=aunews_aunationalninenews&t=s29&mediaid=107237

[Karaka]

A China Airlines jet exploded into flames at an airport in Okinawa after arriving on a flight from Taiwan Monday, but all 165 people aboard escaped alive, officials said.
The 157 passengers _ including two small children _ fled the Boeing 737 unhurt on inflated emergency slides just minutes before the plane burst into a fireball, Transport Ministry official Akihiko Tamura told reporters.
China Airlines spokesman Sun Hung-wen told reporters in Taipei the aircraft skidded on the tarmac on its way from the runway to the gate after landing, starting a fire that prompted the emergency exit. The eight-member crew also safely left the plane, Sun said.
"The fire started when the first engine below the main left wing exploded, a minute after the aircraft entered the parking spot," Tamura said.
Accounts of injuries were unclear. Tamura said one crew member had been hurt, but local fire official Hiroki Shimabukuro said two passengers _ a 7-year-old girl and a man in his 50s _ had been hospitalized because they didn't feel well, not because of specific injuries.
National broadcaster NHK showed footage of a squad of firefighters dousing the empty plane with extinguishers as flames and clouds of black smoke billowed from the fuselage.
"After the plane landed, there were flames, and I heard explosions a few times then saw black smoke," airport worker Hideaki Oyadomari told national broadcaster NHK. "We felt the hot air coming our way."
The cause of the fire was unknown. Japan's National Police Agency said terrorism was not suspected.
"The plane landed safely so we are still checking why there was a fire," said Sun.
Taiwan's Civil Aeronautics Administration head Chang Kuo-cheng said authorities have ordered China Airlines and its subsidiary Mandarin Airlines to ground their 13 other Boeing 737-800s pending thorough inspection.
The Okinawa fire is a setback to China Airlines, which in recent years appeared to have improved on a troubled safety record among international carriers.
A China Airlines 747 crashed in 2002 as it flew from Taipei to Hong Kong, leading to 225 deaths, and some 450 people died in China Airlines accidents during the 1990s.

[hetfield]

http://www.spiegel.de/img/0,1020,946092,00.jpg

Doesn't look too good.

[Karaka]

TOKYO, Japan (CNN) -- A Taiwanese jetliner burst into flames Monday morning shortly after landing at the Naha airport on the Japanese island of Okinawa, but 165 passengers and crew got off the plane safely, authorities said.


The China Airlines jetliner caught fire at Naha airport on Monday.

The Japanese Transport Ministry and the Naha Fire Department said the passengers included 155 adults and two toddlers. The crew was made up of 2 pilots and six flight attendants.

According to the ministry, there was "some sort of explosion" on board the China Airlines Boeing 737, but no other details were immediate available. Japanese media reported that a passenger saw a fire in one of the engines before the blast.

The Transport Ministry said the plane arrived in Okinawa from Taipei at 10:31 a.m. local time and stopped on the tarmac three minutes later to evacuate passengers. At 10:35 a.m., the fire department was called to the scene.

[Volume]

Doesn't look too good.
Does look strange, to be exact.

Right engine and left wing on fire!? How can fire in an engine ignite the oposite wing or vice versa? UEF like the AA in LAX recently, with the engine desintegrating punctured the oposite wing tank and sliced the belly fairing? But an UEF at low power setting?

Good news is, all survived.

[Mike773]

All reports I've seen say it was the left engine. This photo confirms it, I'd say.



http://www.asahi.com/photonews/images/OSK200708200077.jpg

From http://www.asahi.com/national/update/0820/SEB200708200017.html (Japanese only)

[HotDog]

Right engine and left wing on fire!? How can fire in an engine ignite the oposite wing or vice versa?

Looks like burning fuel spill from left wing fire spread under fuselage to right wing.

[Mike773]

Looks like it was burning right through to the right-hand side by then. Should help the investigators though, this video. Video says all pax and crew got off OK but 2 went to hospital because they "felt unwell". A JAL maintenance staff member was slightly injured in the explosion as well.

[Standby Scum]

Any 'photos showing any fire appliancies?

[M609]

Video running on TV here in Norway show 3 huge fire engines in attendance , but after the aircraft broke it's back behind the wing.

[B757-200]

Sad to see another 737NG go. But the timing of the last pax getting out of the rear service door and the explosion was incredible. Does anyone know if the crew survived?

[jtr]

http://www.liveleak.com/view?i=6ac_1187580141

[suppie]

http://www.nhk.or.jp/daily/english/index.html
at the right hand sight a link to a video showing evacuation and explosion of nbr 2 engine

[gofer]

Which roughly translated says: (http://www.baz.ch/news/index.cfm?ObjectID=82824AF3-1422-0CEF-70648CE0B4042A88)

8 Mins. after landing at Naha in the Okinawa Province of Japan at 10:35 local time, the fully booked China Airways B737-800 flight 120 from Taipeh from caught fire (165 people on board of which 157 were passengers(incl. 2 baby's)).

On reaching its parking position a ground technician noticed fuel leaking from the aircraft - all on board were immediately evacuated via the emergency slides. A few minutes thereafter the LEFT engine exploded and the 5 year old plane burnt out - the fire took an hour to extinguish.

A 7 year old girl and a 57 year old man who complained of feeling sick were take to hospital. Police reported that a crew member and a member of the ground staff were injured.

Hope that helps. For a change it seemed like a fairly good journo report....:ok:

[Self Loading Freight]

That was close. Kudos to the cabin crew and flightdeck for getting everyone off (although a few of the scattering masses were still clutching their duty-free as they scampered away along the tarmac. I suppose there isn't much time to argue).
A report here (http://www.asahi.com/english/Herald-asahi/TKY200708200207.html) says:
"The explosion was heard some 2 kilometers away by an employee at the Employment Activation Organization, a Naha-based foundation.
Airport runways were closed until 11 a.m., causing delays of outbound flights and forcing incoming aircraft to circle the airport until they were given clearance to land.
Airport traffic controllers did not receive any communication from the aircraft's two pilots about engine trouble or a request to make an emergency landing, ministry officials said.
The fire apparently broke out in the main engine after the plane had landed and stopped at its assigned No. 41 parking spot, said an official of Naha Airport Building, operator of the airport's terminal building.
Japan branch officials of China Airlines said a ground maintenance worker noticed fuel leaking from the back of the engine after the aircraft had landed. "
Wouldn't like to be the guy who last signed off that engine.

[InsuranceGuy]

Aircraft Details

B737-800
S/N 30175
REG B-18616
BUILT 2002
VALUE USD 45M

[larryloader]

Pilots look to be very lucky. After the initial fire the secondary explosion seems to set alight the cabin. As this erupts looks like the pilot and co-pilot jump out of the starboard cabin window.

Hope both are okay and no passengers were hurt.

[kiwibird]

.

The explosion looked as if it was from under the belly and spreading out under the engine - center fuel tank leak? The explosion could be something in the wheel bay envigorating the existing fuel fire. Tyres, hydraulics? (Shouldn't really explode, I know.) Hot center tank, with a few dregs in it?

Fire engines only arrive when evacuation appears complete, so say after 3 or 4 minutes. A bit slow, I would say.

[Bedder believeit]

Looks like the doors were possibly still "armed". How long does it take if the doors have been "dis-armed" whilst approaching the gate (as it looks like this aircraft was), and then to get them back into an "armed" state if an immediate deployment of escape slides is needed? Also, if an instruction is not forthcoming from the cockpit - for whatever reason - and the doors are "dis-armed", then what is needed on the part of FA's (or possibly pax) to get the escape slides to operate? I'm ATC and frequent pax. Anyone care to comment?

KIWIBIRD - The fire services at HK airport (CLK) are required to be able to respond to any part of the aerodrome in 2 minutes. I don't know about NAHA. With all these things, confusion sometimes allows the time to fly by....lives also!

[PAXboy]

It was interesting to see, from one of the news videos, a JAL landing on during the incident. Would it be normal for operations to continue when the fire service are already engaged in a full-on emergency?

This is not meant as a criticism of the fire service at Okinawa as it may well be that they have a suitably large fleet of appliances to enable them to remain fully available, despite such an event as this.

[kiwibird]

Looks like the doors were possibly still "armed". How long does it take if the doors have been "dis-armed" whilst approaching the gate (as it looks like this aircraft was), and then to get them back into an "armed" state if an immediate deployment of escape slides is needed? Also, if an instruction is not forthcoming from the cockpit - for whatever reason - and the doors are "dis-armed", then what is needed on the part of FA's (or possibly pax) to get the escape slides to operate? I'm ATC and frequent pax. Anyone care to comment?

Different airlines have different procedures. Some only disarm when the engines are shut down and a command is given. More recent policy is to disarm when the SCCM thinks they approaching the stand, which I find not entirely satis.

Rearming is simple, a matter of 30 seconds grovelling on the floor - a particular failing of the Boeing, because if there is now a scrum of passengers behind you, you are not going to get back up to open the door.

The FAs are allowed to evacuate on initiative if the a/c is stationary and it is obvious that something catastrophic has happened.

[eagle21]

Is only in these situations that passengers realise why the cabin crew are onboard.

Well done! It reminds me of the Air France in Toronto.

[etops777]

Procedures at CI is slides to remain armed until the engines are shut down and the seat sign is switched off.

[Dogma]

Looks like the "secondard explosion" was a couple of the tyres letting go. Spectacular effect, imagine if they were filled with air.:eek:

[DingerX]

From looking at the nhk video, a bomb or fuel tank explosion (as the root cause) is highly unlikely.
Bomb: bombs are placed in the passenger cabin or cargo, for obvious reasons. If the timing's off, they are still powerful enough to cause a significant disruption in the cabin. Every indication so far is that whatever set this off was from outside the cabin.
Center Fuel Tank explosion: same deal. People would not be evacuating from an intact aircraft. Now, it is likely that the center fuel tank "exploded" at some point. Take an "empty" (=fuel-air mixture) fuel tank, start a fuel fire underneath it, and see what happens.
For that matter, there are all kinds of interesting things that happen in fuel fires, as the vapor is considerably more flammable than the liquid. "explosions" and "fireballs" can occur from an action as simple as increasing the amount of fluid poured on the fire (such as a second fuel leak).

Also, the aircraft appears to have been evacuated on the right side only (with the exception of the Captain being "assisted" out the left window), without the overwing exit. Thus, the evacuation implies a left-side, external incident.

[411A]

SLF may have found a clue here...
Japan branch officials of China Airlines said a ground maintenance worker noticed fuel leaking from the back of the engine after the aircraft had landed. "

Flight data recorder possibly might have the answer as to the fuel HP valve and/or tank valve positions.
If the fire damage to the engine is not too severe, lines/fittings may well be suspect as well.
Sometimes the smallest clue will lead the investigators in the proper direction and if faults in the design are found, it could have rather serios implications, as a lot of these acft are used worldwide.

Full marks for the crew for getting everyone out in time, and...this should put to rest once and for all the idea in some narrow minded CC (mostly based in Europe) that so-called 'foreign' airlines have less than desirable safety procedures and training.
I have personally (many years ago, from a parallel taxiway) watched an evac of a CI B707 at MNL after a heavy landing and subsequent fire, and the CC performed superbly in getting nearly everyone out in record time.

[LindbergB767]

CNN reporting aircraft slide on the runway Media???????
So how about landing on Runway 18 with left crosswind
It is quite bumby on short final on this runway and let say the left engine touch the runway and then a fuel line broke.... and then arriving at the parking ,fire start from the left engine
Just speculating..........
we should know very soon as the black box should be hopefully in good conditions

Anyway very good job from all the crew to evacuate everybody on time

[Dogma]

DingerX - Have not heard so much tripe in a long time! Made me laugh though!

Fire starts.....then tyres blow....plane burns. How the fire started is going to require careful examination of the wreckage.

[ManaAdaSystem]

This one is an eye opener for me. It puts to rest the neverending discussion of "should/should not" evacuate immediatelly if you suffer an engine fire on ground. At least for me it does.

I also consider myself very lucky as I have had three fuel leaks on the ground (NG), but none of them caused a fire.

As for a pod strike on the NG, you really have to place the aircraft in some very unusual attitudes to make that happen.

A big :ok: to the the crew!

[DingerX]

fire starts.....then tyres blow....plane burns. How the fire started is going to require careful examination of the wreckage.
Hey, all I was saying is that it wasn't a bomb or a CFT explosion, contrary to what some were suggesting. Fuel fire (for whatever reason) makes much more sense. Glad I made you laugh though.

I stand corrected about the slides.

[25F]

As SLF I want to say well done to the cabin crew. I hope that this is widely reported and that it will help my fellow occupants in row 25 pay more attention to the safety briefing in future.

[Rossair]

This is a great piece of film to show to passengers to increase their attention to the flight attendants' pre take off safety briefing.

I remember Helen Muir from Cranfield suggesting that the reason that survivability rate at Calgary may have been higher than at Manchester (two very similar engine fire Boeing 737 runway evacuations in 1985) because a greater proportion of the passengers on the Canadian aircraft had payed close attention to safety briefing and had read the safety card.

[lomapaseo]

I'm not sure if there is going to be any recorder data if the engines were shut off at the gate.

There seems to be a continuous amount of fuel, which has to be outside of the engine (pylon). I'm not sure how you can get this fuel external from the lines/tanks though without a rupture.

Does anybody have any experience with similar continuous fuel leaks?

[Bedder believeit]

PAXBOY:

Re your query about continued ops, I would say from a Tower controllers perspective, "most unusual". Our normal response following an accident (though it seems no one died/seriously hurt - I would still call it an "accident") is to close the airfield until everything is well and truly under control. I would think from the video that I saw, where an aircraft is landing(?) in the background, whilst the 737 is well and truly ablaze, by my estimation is unusual.
Also there is the question of RFF resources. If too much of your Rescue Fire Fighting capacity is directed at say a burning 737 on the apron, then what is available for other aircraft operations, not to mention the implied danger of uncontrolled passengers and others running around on the manouevering area.

411A:

I agree entirely with your sentiments re attitudes towards "foreign" CC abilities in an emergency. Maybe the term "Not just a pretty face" springs to mind.

[SIC]

FDR's are not necessarily wiped clean on shutdown as implied in an earlier post. Modern recorders can log many flights over a period of time - so chances are there will be usable data. CAL fleet is generally very new with best equipment available and maintenance is also quite good - a response to their bad safety record in the past is that management don't take any chances with these things.

[Raynet]

I've always worried about "doors to manual" while on taxy as a pax. I'll be even more worried now. What a good evac though! Well done everyone.

[bomarc]

<<One tour guide from Taiwan said there was already smoke when the plane reached the skies over the Naha airport.

Another guide said she did not notice anything unusual until passengers were helped by CAL crews to escape the plane only minutes after landing.

She said explosions took place when she and others had run about 100 meters away from the plane, which was engulfed with heavy smoke. >>

smoke while inflight? oil leak?

this will be a very interesting case to watch...problems with the airline, or the airplane?

[PAXboy]

Bedder believeit Thanks for your reply, I had thought it unusual for operations to continue. I realise, of course, the the JAL would already have been well into it's approach by the time the ground emergency was declared and they may have had limited alternatives with the Okinawa being somewhat isolated. So it may have been the last movement and all others turned away.

With regards to the successful evacuation of pax and crew, I agree that the CC + FC did a fine job but let us also consider that, as the a/c was just pulling onto the stand,all Pax would have been awake, and focusing on getting off anyway. Yes, they then had to get off in a different way but they were already 'mentally' thinking about going to the doors.

Depending upon the exact moment that the emergency was declared, some would already be standing in the aisle. Whereas, if the a/c had been taxying out to the active and then had to pull up short and evacuate - it might have been different. Glad it was a good, fast evac as they had fire on both sides and no time to hesitate.

[fireflybob]

Well done to see that all escaped unscathed.

Goes to show that fire is still one of the aviators biggest hazards.

[ettore]

@25F

Being a SLF too, I'm more frightened by my fellow-pax than by the hazard itself in case of an emergency: in the video, quite a few are carrying a bag while escaping the fire. How can they think their own life, and the life of the crew and other pax, can be as much important as a bag? They just DO NOT THINK. And that's the main danger.:ugh:
Any expert around to explain this type of behaviour and how to prevent it?

[kiwibird]

DingerX - Have not heard so much tripe in a long time! Made me laugh though!
Fire starts.....then tyres blow....plane burns. How the fire started is going to require careful examination of the wreckage.


It is not that fanciful. A fuel leak was apparently reported by an engineer - no doubt engines had been shut down by this time.

Fuel leak + hot brakes = fire. (Autoignition temp of jeta1 is 210 degs)
Fire under belly + fuel puddle + explosive source = big fire-ball.

Explosive source could be tyres or hydraulic reservoirs, but these probably lack the power. A hot center tank with residual fuel is a more likely answer.


This is a lot less fanciful than the comments that an engine exploded!! There is no confined space or atomised fuel in an engine that could cause an explosion. JetA1 does not readily explode, it needs to be coerced.
.

[OneWorld22]

A frightening fireball.....:eek:
http://www.ireland.com/newspaper/breaking/images/2007/0820/image_185895_1.jpg

[Mike773]

Regarding continued ops at ROAH: The runway was closed until 1100L. Everything was under control by then. This incident was also not near the runway, but at the northern international terminal. Ops to the southern domestics were safe.

[PAXboy]

ettore My guess as to why some pax were carrying their hand lugagge was because ... they were planning to disembark in the normal manner. Some would have had their bags in the laps waiting to get off and others would have been standing and had the bags in their hands.

Once again, if the event had happened on departure we might have seen different behaviour.

[ChristiaanJ]

FDR's are not necessarily wiped clean on shutdown as implied in an earlier post. Modern recorders can log many flights over a period of time - so chances are there will be usable data.I don't think anybody implied "FDR's are wiped clean on shutdown". However, they stop recording at that point. Since this event was a few minutes after shutdown, it's unlikely the FDR will tell us much... except maybe excessive fuel consumption earlier on the engine in question, caused by the leak.
In flight it might have been blown out or burned somewhere where it didn't do immediate damage, then once the engine was shut down, it pooled in and under the engine until it reached a spot hot enough to ignite it.
(Just my own attempt at a plausible explanation. I have no intention of out-guessing the inquiry).
CJ

[monkey_wrench]

Maybe all of the required Service Bulletins, including the installation of the Nitrogen Generation Systems being enforced on many aircraft (including the 737NG) following SFAR 88 are justified after all.

[ChristiaanJ]

monkey_wrench,
I won't argue fuel tank inerting here, I think most of us agree on that.
But this was not a fuel vapor explosion, it was ignition of spilled fuel.

[mini]

Anyone else heard that the aircraft was just out of MX?

[ChristiaanJ]

... tires exploding ...I don't think you'd even need that.
A major engine fire after shutdown would have reached the wing tanks within minutes. Once those start dumping fuel on the tarmac (as seen on the video), there's your fireball.

[Philflies]

Just watched above mentioned report on BBC News at 10.

Reporter mentioned it could be due to a leak of oil or petrol.
PETROL???

(or am I being too picky!?)

[wileydog3]

Couple of questions...

I don't think there has been any reported instances of a CFM-56 with an uncontained failure. So what punctured the fuel cells?

The airplane was parked. When did the fuel cell get punctured and how? If the fuel cells were punctured prior to parking, why did not the tower or the ground crew notify the crew of the problem prior to arriving on the ramp?

IF the aircraft was leaking fuel while taxiing in, where was the fire/emerg equipment?

Did the crew make any calls noting an engine failure/problem prior to landing or after landing? If not, what happened enroute to the ramp?

Finally, it presents a very stark image of fires and how little time one has to deal with them. Even if one can locate the source often there is little one can do with the fire. And this evac is remarkably unusual in that no one was reported hurt in the evac. Even in the best of circumstances, an evac usually winds up with someone with a broken leg/arm or bodily injury.

[kiwibird]

I won't argue fuel tank inerting here, I think most of us agree on that.
But this was not a fuel vapor explosion, it was ignition of spilled fuel.

Come on boys, back to school - spilled fuel does not explode. Spilled fuel is what firejocks ignite for fun, and not an explosion in sight.

To get jeta1 to explode you need to atomise it, which is why this was probably a center fuel tank explosion (having got rather too hot and started boiling). Tyres could possibly stir it up and make a fireball, but the plugs should prevent that.

[Ranger 1]

Not sure if the Plugs would prevent much, if the rubber tyre carcases were on fire.
Good to see everyone was off in time, hope that P1 & P2 were ok after their rapid exit, without the use of the cockpit escape rope, it looked like a heavy landing onto the ramp for them.:uhoh:

[ILoadMyself]

Whatever happened, it's farkin scary stuff.

Thank goodness all safe.

Last to hit land were the Capt and FO. From the flight deck window.

Nobody expects the captain to go down with the ship but these guys . . . . . .words fail me.

[ILoadMyself]

Fastest way out?

[aero junkie]

Well looking at the footage, if the pilots had used the slide they would have been right next to the explosion

[Nov71]

Fortunately, lessons from Manchester seem to have been learned, no exits opened or slides deployed on left (fire) side. Maybe they intended to disembark pax from the right-side anyway.
One pax reported a 4min delay in evacuation (prob 40 secs) re-arm time?
The UK televised mobile phone footage of the evacuation suggests an external pooled fuel fire spreading under the central fuselage whilst stationary. Lack of smoke issuing from front & rear doors suggest it had not penetrated the cabin as per MCR. The televised explosion seemed to be a double explosion, 1. ground fire explodes main tyres, 2. debris punctures empty? central tank resulting in fireball.
Query Why were P1 P2 still on flight deck until the last moment? Unaware of severity of incident? Exit via cockpit window without rope suggests panic.
Praise to CC & Pax
As to cause - I leave that to the Inquiry

[bubbers44]

I only had to evacuate one time in my career. I hated it but it was the only thing to do with the slides of the 737. I, the captain, was the last one down the slide and congratulated the FA's on the fine job they did. We had a 100 % full flight and it was one of those positive bomb threats so had to do it. No one got hurt. Wish we wouldn't have had to do it but we did.

[SIC]

Good one: Apparently Aircraft came out of maintenance on FRI the 13th (previous month) - with 13666 :eek:hours on it.
And in China August is "Ghost Month" ie generally bad luck time and people are advised not to travel by the local temples.:\:}:}:}
Glad all ok.

[ZFT]

FRI the 13th


Assume you mean July?

[gengis]

oh for crying out loud... fri 13th, 13666 hrs, ghosts....

can we please at least try to keep it technical?

yes, kudos to the crew for a successful unplanned evacuation

[aero junkie]

Why were P1 P2 still on flight deck until the last moment?
They could have been doing after landing checks? Busy shutting down aircraft systems, electrics, pumps etc? Just a thought

[Volume]

this was probably a center fuel tank explosion
Most probably not!
The center fuel tank is also the center section of the wing, so after an CFT explosion, the right wingtip would have dropped to the ground immediately. Obviously the wing structure is intact after the explosion (I would not even call it that way, it was a minor blast causing a lot of fuel on the ground to be mixed with air and creating a huge fireball).
By the way, the skin thickness of the upper and lower skin of the CFT is much greater than that of the forward or rear spar, so an CFT explosion would not have been visible below the wing, but would have more probably blasted into the forward cargo hold, blowing up the complete forward fuselage (see the TWA 747 explosion...).
Gongratulations to the CC, they have done a perfect job.

[vapilot2004]

Why were P1 P2 still on flight deck until the last moment?
According to early reports, the cabin crew had the evacuation well under control.

Perhaps the flight crew were awaiting the cabin to clear before making their own escape. During the evac, things like emptying fire bottles and killing power would be in order before bugging out of the cockpit.



The chances a tire fire caused that fireball seems remote. It could have been a superheated fuel tank igniting or something in one of the cargo bays going up.

[FCS Explorer]

i've seen one of those on a new delivery, but it was deactivated.
can anyone explain how the system works, i mean, just how does it generate nitrogen (from air?) ??:confused::confused:

[Mike773]

Japanese media are reporting that the Ministry of Transport investigation team have reported that there is a possibility the fire began in the RIGHT engine following a fuel leak in the pylon. A ground engineer reported seeing smoke and a large leak from the right engine and advised the crew to evacuate via the interphone.

Looked like the left engine by the ealier photos/videos.

A good collection of photos is available at http://kyushu.yomiuri.co.jp/news-spe/enjou/photo/index.htm

[SIC]

Hey Genghis if you ve ever worked/lived in Asia you will understand!
Have a sense of humour - China Airlines ( like all others here ) actually hires Feng Shui and Geomancy experts to 'protect' them. So to people here 'bad luck' is a significant thing. And the reality is that this incident looks like bad luck - since the Airline and pilots don't seem to be the ones who caused this.
:p:p:p:p:p:p:p:p:p:p:p:p:p:p:p

[RobertS975]

Sure looks like most of the early action was on the left side of the plane, not the right. Do we know for sure that the evacuation slides on the left were not deployed?

[Mauersegler]

yes, there were emergency slides at the left side, you can see in this video how people is coming from the other (left) side too. Certainly a scary experience!

http://headlines.yahoo.co.jp/videonews/ann/20070820/20070820-00000044-ann-soci.html

[monkey_wrench]

Coincidence? http://www.ntsb.gov/pressrel/2001/010411.htm

See the photographs which show fuel burning underneath the aircraft similar to the China Airlines aircraft.

[monkey_wrench]

FCS Explorer ref your question how does it generate notrogen from the air?

The NGS system separates nitrogen from the air supply from the engine bleed manifold and feeds it into the Centre tank. The it reduces the oxygen content down from 20% ocurring in ambient air to 12%. The military requirement is 9%.

[Rainboe]

armchairpilot94116 there comes a time when people must take responsibility for their idiotic posts and explain, and I think you have reached that stage:
why didnt the pilots just use the escape shute in the front like the passengers did. Maybe the last to get off but ?
How do you know the fire was not burning at the door after they carried out their essential actions?
they couldnt do anything further in the cockpit. I wouldve been out there helping the stews get passengers off and then jumping off myself (well I would have trouble fitting thru the cockpit windows anyway, but thats just me).
They have got duties to perform whilst the evacuation is taking place!
i.e. arranging deckchairs on the Titanic , etc (re: what the flight crew were doing) What an arrogant comment from someone who knows nothing!
Now pray tell me what sort of pilot are you? It's Microsoft Flight Sim, isn't it? Well let me explain. In an evacuation/fire scenario, it is important to try and remove further sources of ignition. It takes the pilots a long time to get the evacuation drills completed before they can evacuate themselves. Look at post#3 here: http://www.pprune.org/forums/showthread.php?t=286354
That solves the mystery- leaving the only mystery why they receive implied criticism from you as 'you would have done it different'. Educate yourself and understand the problem before commenting or implying you know how to do it better! Or better still, stick to the armchair if you don't know what you are talking about!

[merlinxx]

One day you lot of regi spotters will allow an incident, as this was, to be investigated, and a conclusion achieved, published so you prevarications can be put back into the numpty folder. Get a life and join a professional industry or keep the hell out!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Rainboe]

The Manchester 737 accident (and I flew that same fleet of aircraft for 6 years) showed the critical importance of crosswind in respect to ground fires of stationary aircraft. Although the fire damage is seriously worse on the left side, this could easily have been due to crossover of the heat source and it is indeed very possible the cause of the problem was the right engine. When Mt. St. Helens erupted, people right under the volcano on the upwind side in a light to moderate breeze survived and damage was minimal, people up to 30 miles downwind died. With a ground fire, the important thing is to get it blowing away from critical parts, and carbon based life forms.

Out of that Manchester accident developed a rejected take-off procedure in the event of engine fire, and that is to try and turn to ensure the fire is not blowing onto the fuselage. If indeed the initial source of ignition was the right engine, this incident graphically illustrates the importance of when the option is available (it wasn't in this case) of trying to turn the aircraft to get the fire blowing away from the fuselage.

[RobertS975]

Rainboe, that's something I never gave any thought to before... thanks for pointing out the effects of the wind. Now, in this case, it sounds like the ground crew gave the word to the crew to evacuate once the plane had come to a stop. We will no doubt learn more later, but that's the report that I heard. So this crew didn't even realize the gravity of the situation until the ground guys plugged their headset into the nose.

[Rainboe]

You must remember with the locked door procedure, the cabin is very divorced from the flight deck, and the pilots really have no idea what is going on. In the MAN incident, the pilots told me (and this was when flight deck doors were unlocked) that they abandoned takeoff following a loud bang they put down to a tyre bursting (it was the engine disintegrating explosively). They came to a halt just off the runway and started doing their procedures. At that stage they were waiting for a report from the steward and waiting for emergency services. They had no idea that the whole of the rear of the aeroplane was a furnace (engine burst wing fuel tank, cascade of burning fuel falling to ground, and flames burning directly onto rear fuselage), people were dying in dozens and then the doors were being popped open and the evacuation happened under them- those that could. It was all over in 2 minutes.
http://en.wikipedia.org/wiki/British_Airtours_Flight_28M

It's very likely the pilots were not aware of the speed or severity of the situation considering the extremely rapid sequence of events. I would say there was magnificent reaction by the cabin crew. The flight crew were probably frantically shutting down all systems without realising how bad it was behind them.

[forget]

Manchester. Let me throw this one in. The wind on the fire side of the aircraft was a big factor but what I found odd about the enquiry was no mention of the Reverser Buckets on the JT8s. The bucket hinges on the original aircraft were horizontal. Boeing then moved them 45 degrees to stop forward blown FOD; with both the upper buckets directed at the fuselage. Without the ‘new’ buckets, or buckets swung the other way, the aircraft fuselage would, I believe, have taken much longer to burn through. They acted like a runaway blowtorch. Notice the muck from normal reverser use, below. Precisely where Manchester first burnt through.

http://i21.photobucket.com/albums/b270/cumpas/1237326.jpg

Correction. Wrong on the buckets not being mentioned. Point still stays.

http://i21.photobucket.com/albums/b270/cumpas/buckets.jpg

[UNCTUOUS]

Sounds like the airborne safety element is the airflow through the engine - that stops the fuel pump's leak under pressure from pooling and igniting. It's only after landing that the leak can pool and ignite.

This scenario is probably what would have happened to the Air Transat Azores Glider if it had landed with fuel and an operating engine.

[Rainboe]

You are possibly correct. No more than possibly. The reverse exhaust would have been cancelled immediately. What got them was that the engine debris blew out a fuel tank access panel leaving a solid column of fuel about 8 inches wide pouring out onto the ground and into a hot exhaust. the fire was blowing directly onto the fuselage (by the wind) and the burning pool of fuel spread under the aeroplane. With respect, I think the effect of the reverser air was marginal.
The point of it all is: the crosswind effect is extremely critical. One side of the culprit engine itself can be unburnt, and the damage could easily be most severe on the other side of the aeroplane that didn't have the initial problem.
Unctious- very possibly they trailed fuel throughout flight and on taxi in- it may have been the stopping that undid them!

[Rainboe]

The means are there in this forum (Tech Log and Questions) to learn about what goes on- as I pointed you in the direction. When you have appraised yourself of what is happening, then comments would be welcome, but not criticism until we know all the details there are to know.

So presumably, the pilots have parked and set the brake, and the Ground Engineer is jumping about gesticulating. It might take time to get from his hand signals why he is so upset. Shutting engines down, asking each other 'what's with him?', hearing screaming, unlocking door. Jeez- call tower and ask for help. Hydraulics still running because APU on? Fuel pumps still going? Get picture, order copilot to start evacuation drill. Never do it now in the sim-always after abandoned takeoff only. Kill hydraulics, APU, should flaps be extended?- no time, no hydraulics now- make announcement when engines shut off, make sure fuselage is unpressurised or doors won't open, kill electrics, battery power, pull all 3 fire handles, twist to fire extinguishers. Possibly announce again as severity becomes obvious to 'get yer asses orf!', look through door- nobody in sight, smoke everywhere, only way out window- feeling warm- how was it you climb out again? Omigod I hope it wan't my fault- where did that all come from?
Is that enough? You wanted him heroically at the door flinging people off?

[ManaAdaSystem]

Have you ever read an evacuation checklist, Mr Rainboe?

[Rainboe]

I'd like to think they sat down and sensibly read the checklist, but probably like I would actually try and do in real life- reach for switches like a Dutch windmill in a gale, then grab passport and logbook and picture of Mum (and bottle of water) and take a leap!

Doing it proper can be found at http://www.pprune.org/forums/showthread.php?t=286354 post#3

[international hog driver]

Ok I know that this will be a bit long but its here so the non NG drivers out there have an idea of what the paperwork actually says. Cut and paste from my NG QRH & FCTM


B737 NG QRH 8.12

WHEEL WELL FIRE

Condition: A fire is detected in the main wheel well.
Observe extend limit speed (270K/.82M)
LANDING GEAR lever . . . . . . . . . . . . . . . . . . . . . . . . . . .DOWN
Note: Do not use FMC fuel predictions with landing gear
extended.
If the landing gear must be retracted for airplane
performance, leave the landing gear extended for 20
minutes after the WHEEL WELL fire warning light has
extinguished.
LANDING GEAR lever (if needed)
(235 KNOTS maximum) . . . . . . . . . . . . . . . . . . . . UP & OFF
Plan to land at the nearest suitable airport.


No mention of actions on the ground.

EVACUATION (Cockpit crew actions) Back page QRH

Condition: Evacuation is needed.
Parking brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Set
Speedbrake lever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DOWN
FLAP lever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Pressurization mode selector . . . . . . . . . . . . . . . . . . . . . . MAN
Outflow valve switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . OPEN
Hold until the outflow valve is fully open.
If time allows, verify that the flaps are 40 before the engine
start levers are moved to CUTOFF.
Engine start levers (both) . . . . . . . . . . . . . . . . . . . . . . CUTOFF
Advise the cabin to evacuate.
Advise the tower.
Engine and APU fire
switches (all) . . . . . . . . . . . . . . . . . . . . . . . . .Override and pull
If any engine or APU fire warning occurs:
Related fire switch. . . . . . . . . . . . . . . . . . . . Rotate and hold
Rotate to the stop and hold for 1 second.


Yes we can be busy in the front office, especially when coming on stand, paperwork etc (FO checking if he have any numbers of local lass’ in his phone). And not expecting a fire at this stage of the sector would also be confusing (doors have probably been disarmed already).

Dragged this out of the FCTM…… may be of interest/pertinent.

ENGINE TAIL PIPE FIRE

Engine tailpipe fires are typically caused by engine control malfunctions that result in the
ignition of pooled fuel. These fires can be damaging to the engine and have caused
unplanned passenger evacuations. If a tailpipe fire is reported, the crew should accomplish
the NNC without delay.
Flight crews should consider the following when dealing with this situation:
• motoring the engine is the primary means of extinguishing the fire
• to prevent an inappropriate evacuation, flight attendants should be notified without
significant delay by using the phrase “ATTENTION CREW ON STATION”.
• communications with ramp personnel and the tower are important to determine the
status of the tailpipe fire and to request fire extinguishing assistance
• the engine fire checklist is inappropriate because the engine fire extinguishing
agent is not effective against a fire inside the tailpipe.


Discharging Fire Bottles during an Evacuation

The evacuation NNC specifies discharge of the engine or APU fire bottles if an engine or
APU fire warning light is illuminated. However, evacuation situations can present
possibilities regarding the potential for fire that are beyond the scope of the NNC and may
not activate an engine or APU fire warning. The crew should consider the following when
deciding whether to discharge one or more fire bottles into the engines and/or APU:
• if an engine fire warning light is not illuminated, but a fire indication exists or a
fire is reported in or near an engine, discharge both available fire bottles into the
affected engine
• if the APU fire warning light is not illuminated, but a fire indication exists or a fire
is reported in or near the APU, discharge the APU bottle
• the discharged Halon agent is designed to extinguish a fire and has very little or no
fire prevention capability in the engine nacelles. Halon dissipates quickly into the
atmosphere
• there is no reason to discharge the engine or APU fire bottles for evacuations not
involving fire indications existing or reported in or near an engine or APU, e.g.,
cargo fire, security or bomb threat, etc.

[con-pilot]

One possibility is that the pilots could not see the open door because the of the dense smoke.

I realize that the above statement may seems rather preposterous, however, until you have been in an incident such as this one or have gone to training classes that involved a cabin fire scenario you have no idea how dense the smoke will be in just a few minues and in some cases in a matter of seconds.

[armchairpilot94116]

black boxes recovered

http://www.taipeitimes.com/News/front/archives/2007/08/22/2003375265

[madherb]

External cameras would be an advantage in such situations - don't know how expensive they are, probably get the bean counters screaming if retrofits were mandated. But they do work nicely, and depending on where they are mounted most of the exterior can be covered.

Might just save the day somewhere.......

[SIC]

Some Japanese and Taiwan aviation experts ( yes those guys ) are now slagging the pilots on TV for not checking that everybody was out of the cabin before they evacuated themselves. :mad: What the hell were they supposed to do - grab a handheld and go look under every burning seat?

Good one for GENGHIS - Thought I'd brighten up your day a bit : A Taiwanese TV program now reporting that one of the reasons EVA has never had an accident is due to the fact that management requires all cabin crew to be vegetarian. As background many people in Taiwan become vegetarian for a few months as a 'sacrifice' to the gods when they need some good luck for a new business/relationship etc etc. :ok:

[gulliBell]

I am a Rotorhead (pilot) forum watcher and have swung onto this forum out of interest of the China Airlines B737 fire (I am in China at the moment and the incident has been reported widely here in the media, maybe because of the Taiwan factor?). Anyway, I just wanted to say that many of the respondents have been very informative and my interest is stoked on where this thread might lead to - well done!

I would like to throw a "what-if" to the forum. Given that the aircraft was very close to docking at the airbridge when the fire developed, what-if the fire had of started just as the aircraft had docked, how might the outcome have been different? Is there a procedure for the ground support crew to push a burning aircraft away from the terminal? I guess that once the park brake is set, that's where the plane stays. Imagine if a fuel fed fire had of engulfed the terminal, that might have had very dire consequences.

Edit: on CCTV news tonight they showed the Investigators concentrating on the right hand engine cone.

[Mike773]

I'm happy to be corrected, but I think the spot in question doesn't have a boarding bridge; an "open spot". That's what it looks like from the Jepp chart and photos anyway, but I've never been there so can't be sure. :suspect:

[bvcu]

The mention of cameras is a valid one as they have been a standard fit on B777-300/ER and 345/6 for a number of years now basically for ground manouevering but useful for the crew to see whats going on whilst on the ground, generally pretty reliable with very few problems.

[Few Cloudy]

Well whatever could have been done "better", let us be of good cheer, that this accident, unlike so many others has had a pretty good humane outcome.

When you watched those passengers shooting down the slides in threes and fours, it showed just how quickly it can go, when you have obedient passengers leaving their posessions and going for it.

This incident will provide much needed experience of aircraft escape drill and also fire flashover timing.

FC.

[lomapaseo]

FC
When you watched those passengers shooting down the slides in threes and fours, it showed just how quickly it can go, when you have obedient passengers leaving their posessions and going for it.

This incident will provide much needed experience of aircraft escape drill and also fire flashover timing.



Could you cite some related support for your comments above, associated with this incident.

I just don't see it

[Maude Charlee]

Amongst other things, it's a timely reminder why the gobby, half-drunk know-it-alls down the back ought to shut their holes and pay attention whilst the crew run through the pre-departure safety drills. They're not just there to sell you more Stella and Pringles - one day your life will quite literally depend on them.

[polarbearjim]

Did anybody notice the brave soul towards the end of the video link posted by RobertS975 who in pulling an extinguisher trolley over to the right engine, recieves a face full of foam from the fire truck?

[Clarence Oveur]

Im almost afraid to say anything
If that is the best you can come up with you should be.

What an utterly useless post.:ugh:

[Rainboe]

Look armchairpilot94116, You know nothing of this, would you please leave the discussion to people who know what they are talking about? That was a useless, troublemaking post. You are tryiing to start up a Boeing/AB argument. Comments about your girlfriend and your personal cabin evacuation briefing to her are totally uncalled for in a discussion about a fire incident that appears to have been handled impeccably.

[forget]

For God's sake! Mods - it may be time for instant pruning (no pun intended at all) when something as serious as this is being discussed.
What the hell was the point of this from marciovp. :mad:

I would like to throw a "what-if" to the forum. Given that the aircraft was very close to docking at the airbridge when the fire developed, what-if the fire had of started just as the aircraft had docked, how might the outcome have been different? Is there a procedure for the ground support crew to push a burning aircraft away from the terminal? I guess that once the park brake is set, that's where the plane stays. Imagine if a fuel fed fire had of engulfed the terminal, that might have had very dire consequences.

Scares me! :bored:

[Rainboe]

It needs a visit from the Headmaster. Any serious discussion of any incident gets drowned in a morass of troublemaking (attempted AB-Boeing trouble-stirring), daft inane comment from people who know nothing, and desperately rapid attempts to be first to stake a claim to possible causes of accidents (take a look at the ridiculous speculation of the Kenyan incident). Trouble is too many people are sitting there and all it takes is a bit of typing, an 'Enter' key, and you don't even have to be very good at Microsoft FlightSim! If only they would sit there and shut up and try and learn if they are interested instead of giving us the wealth of their (non) experience! There are too many people here saying too many ridiculous things- it drowns out the good stuff totally from people who are experienced in the industry in whatever branch, and who know what they are talking about.

[marciovp]

I did not think that I said something so terrible. But I guess it was by the response I got. I just read what the was said and tried to imagine the scenario. If I did something that went against the goals of this discussion or if I was insensitive or inappropriate I want to apologize and I am deleting my poster.

I respect a lot you all and I like to be here as someone who is adding to the discussion not as someone who should be banned.

Thanks

[PAXboy]

Few CloudyWhen you watched those passengers shooting down the slides in threes and fours, it showed just how quickly it can go, when you have obedient passengers leaving their posessions and going for it.
As has been pointed out, some pax did have their bags with them. Also, my suggestion, the evac was fast and good because the a/c had just arrived and people were awake and THINKING about getting of the a/c, man would have already have stood up and focusing on the doors. Had this have happened on departure, say whilst taxying to the active, then it might have been different.

Wonderful to see 'the system' work.

[forget]

marciovp, Now you've made me feel like a :mad: An awful lot of people here have a great deal of operational experience and they should be given centre stage. Let's just stick with the facts, so far, and 'sensible' opinions. ;)

[interpreter]

Having watchd the excellent and lengthy Japanese video of the incident post evacuation I was surprised to see that although one fire tender stayed at the rear on the starboard side the other truck did not go right round the nose of the aircraft to extinguish the fire clearly emanating from the port side. They had successfully quelled the fire on the starboard side but poured foam over the top of the aicraft on flames the source of which they couldnt see. Trying to stay up-wind? Perhaps I am nitpicking.

[Rainboe]

If the Headmaster visits- he will be very angry and hand out bans and canings (if you are lucky). I suggest some self regulation to show a proper discussion can be carried out! If you are not experienced in the industry or aviation, you think very carefully before posting- by all means I suggest sensible questions are OK, but do not criticise unduly pending the enquiry, or suggest you know a better way of doing things. We do not need the benefit of extensive Flightsim experience!

Let's stick to FACTS and related comments and related incidents and pertinent comment.....and we'll all be happier! Please let's not repeat the idiocy of the Kenyan B737 thread.

[Ben_S]

Im almost afraid to say anything but seems nobody has started to bash Boeing yet.Shame it was almost, having read a lot of the rubbish you came out with in the other thread you refer to, sometimes I wonder why the likes of us are allowed to view, let alone respond to, threads on PPRuNe.

Now to keep my post on topic, glad to see everyone made it out reasonably safely.

[marciovp]

forget and Rainboe: Of course I am paying attention to what you said because if anything, I want to add to this group, not to be a problem.
I did not criticize unduly and for sure I do not suggest that I know a better way to do things. Far from it. I just read a poster from someone about if this fire happened when the plane was at the gate connected to the ramp, wondering how this could have been more difficult to handle. Of course we are glad that this was not the case, and pleased that all went so well. When I read the scenario raised by the poster I just expressed myself and now I know that this did not add to the discussion, and perhaps was kind of silly. I apologize.

I am not a commercial pilot, a pro, like the many I see and respect here. I am involved in another profession but I have experiences flying small planes, Piper Colt Tripaces and Cherokees. Far from having the experiences that I see around. But aviation remains my first love, and I consider myself privileged to participate in these groups.

Of course I like to know when and if my posters are not appropriate, don´t add to the discussion or are plainly silly. Be sure that I will able to listen when anyone feels that my participation was uncalled for.

Regards to all.

[Guava Tree]

Take this only for what you consider it to be worth, after all this is only a rumour network , but I do seem to remember a China Airlines pilot receiving a memo from CAL Chief Pilot Office near the turn of the century : “Maintenance is out of control! Be careful”. As some people say “ The more things change the more they stay the same”
How to “be careful” ?

http://www.yomiuri.co.jp/dy/national/20070823TDY01003.htm

Maintenance error cited in jet blaze
The Yomiuri Shimbun
Joints of a fuel pipe inside the pylon holding the engine under the right wing of the China Airlines airplane that burst into flames Monday at Naha Airport were not properly secured, according to investigators.
Accident investigators believe the joints were knocked out of position when the plane landed, causing a large amount of fuel to leak and trigger an explosion.
The Construction and Transport Ministry's Aircraft and Railway Accidents Investigation Commission suspects a mistake was made during maintenance or other work on the Boeing 737-800, which underwent a regular inspection in July, and is looking into whether appropriate maintenance was carried out.
The investigators believe fuel that leaked from the pylon under the right wing was heated by the second engine causing the fuel to vaporize and ignite.
It is not thought that fuel leaked during flight, but a ground mechanic confirmed that a large volume of fuel had leaked at the aircraft parking apron, leading the investigators to believe the leak started while the airplane was moving between the runway and the taxiway.
The fuel pipes are made of metal and have a diameter of about three centimeters. They are strong enough not to rupture under high pressure and curved sections are connected using joints.
The Boeing 737-800 had such joints in several locations, held in place by metal bolts passed through rubber O-rings to prevent fuel leaking through gaps.
The thickness, material and replacement date of O-rings are clearly determined so that fuel, lubricating oil, water or other fluids does not wear away the components they protect. The component may deteriorate if the wrong type of O-ring is fitted, and it may not be possible to hold it securely in place when a thicker ring is used, since the metal bolt length becomes too short.
Aircraft always undergo a heavy impact during landing. A great deal of force is exerted on the pylons, which shake violently when planes decelerate to land.
These vibrations also affect the fuel pipes.
The accident investigators believe that before the accident, the joints on pipes that pass through the inside of the pylon came loose, making it likely the joints were jerked far out of position when the plane landed at the airport.
A China Airlines spokesman said the airline had carried out a regular inspection on the aircraft's engine in July--including an endoscopy of the inside of the combustion chamber and turbine.
The airline made another inspection--as it does every 500 flight hours--in August, but said it did not find anything wrong with the fuel pipes.
(Aug. 23, 2007)

[gengis]

is it being suggested that a hard landing has caused this? If so I would be interested to know the dfdr readout, and also what vertical acceleration would be required to damage fuel supply lines. all in good time...

[PBL]

A colleague in Japan said that NHK today is reporting statements from the investigators that fuel was seen to be leaking in large quantities from the oil drain ports on the right engine during taxi. Apparently, one port is on the lower edge of the pylon aft of the engine, and the other on the side of the pylon above the engine.

The pylon is being disassembled today. The NTSB, Boeing and CFM is in attendance.

The observation that the aircraft was just out of maintenance is pertinent. There have been incidents caused through misassembly of components such as O-rings and fuel lines. Think of the Eastern Airlines L-1011 incident in 1983, or the Air Transat A330 Azores glider in 2001. Jim Reason has a chapter in one of his books entitled "Maintenance cay Seriously Damage Your System".
He cites a couple of aviation examples, but they are both structural (AA 191 at Chicago in 1979, JL 123 at Mount Osutaka in 1985). So in answer to Gengis's question whether a hard landing can shake something loose, the answer is yes, if it has been misassembled. Just to be clear, I am not speculating on any cause here (we'll have to wait a couple of days to find out what the investigators think of the pylon assembly, I take it) but just reminding people of some history.

BTW, now that everyone has persuaded marciovp to grovel for asking whether there are procedures for dealing with such a fuel fire when the aircraft is docked at a terminal, can anybody answer his very reasonable and pertinent question?

Fire regulations, at least those concerned buildings in the vicinity of structures and vehicles containing highly flammable liquids, should in many countries be covered by rather stringent requirements concerning how to handle fires. Are there any generally-accepted procedures, or is it all just local ordinances? (I know a couple of aviation fire specialists I could ask if no one here can answer.)

PBL

[HotDog]

I'm confused. The video clearly shows the primary fire well alight on the left hand side to be followed by burning fuel spreading under the fuselage to the right hand side with a subsequent explosion under No. 2 engine. Initial reports also stated that fire started in left engine.:confused:

[Volume]

HotDog,

the location of the fuel leak and the ignition source do not neccesesarily have to be on the same side of the aircraft. The crosswind from the right may have had a big influence, too. The slope of the ground might have pushed the fuel to left side also, causing the fire to burn mainly on the left side. It is clearly visible in the picture posted above, that the flames at the right engine burn all along from the ground to the pylon, (due to the wind, it is not just flames reaching up to the pylon, but you can clearly see something burning all the way along) while on the left side no evidence is visible, all fire there might be fuel on the ground.

If the problem was located on the right side, it will be covered up as the firemen did a good job to safe that part of the aircraft for investigation...

[Mike773]

Looking at the initial footage, and especially the charred remains, it really looked like the left-hand side got the worst of it and so I thought the left must have been the start point. Just goes to show you can't tell anything by superficial observations. Not that the investigation is complete (hardly even begun)!

I'm constantly amazed at what they find out in investigations. Such attention to detail. (Some may beg to differ, of course :8) Have to wait and let them do their work.

[Rainboe]

PBL- I made no comment about Marciovp's posting- I was aware he was using someone else's posting.
The question of fire near terminals has been raised. What is wanted here? Aeroplanes are not in the habit of spontaneously igniting, though some do very infrequently. We don't see many 747s fully loaded with fuel go up on jetties. The whole point of having departure gates and jetties is to load people onto aeroplanes- that is what they are there for. So, you build the infrastructure, then do what fireproofing you can. Safety audits are carried out to ensure lack of combustible materials, very adequate fire escape routes and efficient fire services. What is expected now- that we keep all aeroplanes on remote stands/coach access only? On the basis of these concerns, we would not allow fuel tanks behind our children sitting in the back seats of cars, and has anybody thought of the dangers of allowing petrol stations next to major highways where out of control lorries could take them out? And they sell Butane cans as well! And good heavens, some people attach Calor gas cans to their caravans, while they sleep in them!

Where does it end? You have to accept there is an extremely minute risk of having aeroplanes hooked up to terminals. I doubt if this aeroplane had been hooked up to a jetty whether anybody would have been killed. Damage to building probably. This is a whole separae H & S issue that maybe deserves a separate thread to this one if you want to discuss it.

is it being suggested that a hard landing has caused this? If so I would be interested to know the dfdr readout, and also what vertical acceleration would be required to damage fuel supply lines. all in good time...
Any landing that left the undercarriage still attached, the wings still attached to the fuselage at a normal angle, the aeroplane still able to taxy to the apron, and the people aboard still able to walk, should not have damaged the engine in any way! It would seem likely there is a technical cause. In view of the large number of such 737s and the lack of previous problems, it points suspicion towards a unique and individual maintenance issue.

[ZAZOO]

Can someone tell me how long is the flight from Taipei to Okinawa!

And would be nice to hear from any of their crew what quantity of fuel would normaly be carried on this flight.

The whole thing looks like it started in the wheelwell area, I have no experience on the NG but would like to know ere exactly in the wheelwell are the centre tank pumps located on this model. Is it the same as the 300. Pictures would be appreciated a lot.Thanks.

Zaz

[Rainboe]

Why just ask? You can get yoursel all the answers by looking at world airline schedules, the China Airlines schedules, or look at an atlas yourself and work it out, and do your own research. As for fuel, for flights like this, fuel loaded would be about 3000kgs x flight time in hours. Fuel remaining likely to be about 2000kgs+ unless roundtrip was carried. Fuel pumps located within centre fuel tank. Brief yourself here:
http://www.b737.org.uk/fuel.htm
then report back when you have done your homework!

[PAXboy]

I am not in the habit of telling other posters that they are wrong but ZAZOO The whole thing looks like it started in the wheelwell area Have you read this thread? Skip just seven posts back up on this page and read about the likelihood of a fuel line breaking. [#127 but this is not the only] This fire was given large amounts of fuel very quickly and that indicates that a fuel line was broken sooner in the event, rather than later as a result of fire.

When you read this thread, you will see more than one report that ground staff saw the fuel pooling under the a/c and that it was, in all likelihood, ignited in the tailpipe of the #2 engine. It then followed the river of fuel onto the ground, under the fuselage and up to the port wing. The flight crew were advised of the situation by the ground crew. The wheels and all of the u/c just happened to be in the way. Had the wind or other factors been different, the fuel might have run away to starboard and ignited the neighbour a/c or the run forwards to the terminal.

Once the report is out we shall know for sure but there are already examples in this thread (as in other incident threats) where the CCTV and eye witness reports land up as being at odds with the facts when investigated.

[PTH needs tarmac]

A report on the evening NHK News program showed the lastest report made by the Japanese Accident Investigators.

A rupture of 2-3 cm in size in the wing fuel tank was found that had been caused by a bolt lodged in the slat mechanism, which is surrounded by part of the fuel tank. It now appears that as the slat was retracted after landing the bolt was pushed back and pierced the tank allowing fuel to escape.

The orgin of this loose bolt has not yet been determined.

Attention has now switched from the pylon fuel line theory to this newly identified cause.

To answer Zazoo's question, a previous reported stated that the aircraft arrived with 5 tons of fuel remaining.

PTH

[lomapaseo]

A report on the evening NHK News program showed the lastest report made by the Japanese Accident Investigators.

A rupture of 2-3 cm in size in the wing fuel tank was found that had been caused by a bolt lodged in the slat mechanism, which is surrounded by part of the fuel tank. It now appears that as the slat was retracted after landing the bolt was pushed back and pierced the tank allowing fuel to escape.

The orgin of this loose bolt has not yet been determined.

Attention has now switched from the pylon fuel line theory to this newly identified cause.

To answer Zazoo's question, a previous reported stated that the aircraft arrived with 5 tons of fuel remaining.

PTH

I would like confirmation that this indeed came from the investigating team.

I've seen several secondary incidents of fuel tank penetrations of the size of a bolt head and none of them resulted in a ground pool fire. The rate of evaporation vs the rate of flow seems to lower the risk.

Just how large was the bolt suppose to be in this latest rumor?

[marciovp]

PBL- I made no comment about Marciovp's posting- I was aware he was using someone else's posting.
The question of fire near terminals has been raised. What is wanted here? Aeroplanes are not in the habit of spontaneously igniting, though some do very infrequently. We don't see many 747s fully loaded with fuel go up on jetties. The whole point of having departure gates and jetties is to load people onto aeroplanes- that is what they are there for. So, you build the infrastructure, then do what fireproofing you can. Safety audits are carried out to ensure lack of combustible materials, very adequate fire escape routes and efficient fire services. What is expected now- that we keep all aeroplanes on remote stands/coach access only? On the basis of these concerns, we would not allow fuel tanks behind our children sitting in the back seats of cars, and has anybody thought of the dangers of allowing petrol stations next to major highways where out of control lorries could take them out? And they sell Butane cans as well! And good heavens, some people attach Calor gas cans to their caravans, while they sleep in them!

Where does it end? You have to accept there is an extremely minute risk of having aeroplanes hooked up to terminals. I doubt if this aeroplane had been hooked up to a jetty whether anybody would have been killed. Damage to building probably. This is a whole separae H & S issue that maybe deserves a separate thread to this one if you want to discuss it.


Many thanks Rainboe. Very good reasonning, and clear thinking. Settled the imagined issue. Regards.

[PTH needs tarmac]

This all came from a Press conference given buy the Japanese Investigstion team and reported on NHK with photos of the bolt penetrating the tank skin taken from within the tank. The size of the rupture was as stated and it appeared not to be the head of the bolt that penetrated, rather the opposite end.

The photo showed a oval tear-like rupture with space around the bolt that the fuel could have flowed through. I did not catch if they specified the size of the bolt as yet.

It will take a few hours for the translations from Japanese to make their way into English media.

The International Herald Tribune already has a brief report confirming this and here is one paragraph confirming my previous "rumour",


Kazushige Daiki, chief investigator at Japan's Aircraft and Railway Accidents Investigation Commission, told reporters Thursday that officials found a bolt, which is on the right wing slat, piercing through the fuel tank. The hole was about 2-3 centimeters (0.8-1.2 inches) in diameter.

[vapilot2004]

The latest from Seattle News:


By MARI YAMAGUCHI

NEW - 08:35 AM

Taiwanese jet explodes in fireball at Okinawa Airport

Russia stages its largest post-Soviet air show
TOKYO — Investigators today found that a bolt had pierced the fuel tank of a Taiwanese jetliner that caught fire after landing in Japan, forcing all 165 people aboard to evacuate the plane seconds before it exploded, officials said.

A fuel leak through that hole likely caused Monday's fire on the China Airlines Boeing 737-800, said Kazushige Daiki, chief investigator at Japan's Aircraft and Railway Accidents Investigation Commission.

All 157 passengers and eight crew evacuated safely at the airport on the resort island of Okinawa before the explosion. The pilots jumped from the cockpit window just before the jet erupted in a fireball.

Daiki said aviation officials investigating the wreckage found a bolt from a right wing slat piercing the fuel tank. The hole was about 0.8-1.2 inches in diameter. Investigators were still trying to determine how the bolt got into the tank.

"The bolt pierced through the fuel tank, and we believe that caused fuel to leak out," Daiki said.

Following today's findings, Japan's Transport Ministry ordered three Japanese airlines that own Boeing 737-800s to inspect the leading edge slats on the main wings to ensure bolts are in place before their first flight takes off Friday morning, said ministry spokesman Yusuke Asakura.

Slats slide out from the frontal edge of the main wings during takeoff and landing to stabilize the aircraft, along with flaps that come out of the wings' rear edge.

Aircraft maker Boeing Co. has in the past received reports of several similar cases in which the bolt penetrated the fuel tank and instructed airlines in December 2005 to inspect their 737-800s, Kyodo News agency reported, citing Japanese transport officials.

Boeing spokesman Mark Hooper declined to comment on the report because the "investigation has not concluded."

Ground engineers had said they saw fuel leaking from the plane's right engine as it pulled into a parking spot after arriving from Taiwan.

Investigators had earlier suspected damage to the pylon connecting the engine to the right wing. But Harumi Tsurumi, a spokesman for the Accidents Investigation Commission, said the experts took apart the pylon and found no major problems so far.

The explosion was a blow to the Taiwan-based airline, which has been struggling to shake off its reputation for having a poor safety record.

In 2002, a China Airlines 747 crashed during a flight from Taipei to Hong Kong, killing 225 people. Some 450 people died in China Airlines accidents in the 1990s.

[atakacs]

Following today's findings, Japan's Transport Ministry ordered three Japanese airlines that own Boeing 737-800s to inspect the leading edge slats on the main wings to ensure bolts are in place before their first flight takes off Friday morning, said ministry spokesman Yusuke Asakura

could a bolt detaching from the plane itself gain sufficient kinetic energy to actually make a hole in the fuel tank ? Sounds odd...:confused:

[vapilot2004]

I thought the same. Flap drive maybe, but the slats driving a blunt bolt through aluminium with only one cycle ?

Perhaps the damage was cumulative.

[rheum101]

So everyone out safely - only just - and THEN the fire trucks roll up. Is this a little slow?

[atakacs]

So everyone out safely - only just - and THEN the fire trucks roll up. Is this a little slow?

to be honest I don't find the fire service response time, nor overall efficiency, to be breathtaking...

[PBL]

[Asking about inquiries into fire and airplanes when parked at terminal buildings]Where does it end?

I don't know. Looking at that video again and again makes one aware how much uncertainty there is in dealing with fire.

Who noticed the fire first? Who instigated the emergency evacuation? On what basis? On which side? (Answer: the side from which the fire was fed. Turns out in this case to have been appropriate.) When did the cockpit crew (the commander) get to find out about the fire? Were they able to judge it accurately? (Answer: they seemed to be as surprised by the explosion as anyone. I don't think such a multiple-meter jump is planned!)

It seems to me that fires are events with huge amounts of uncertainty for which one can only vaguely plan. Every new event is a mine of information. I incline not to dismiss questions about what would have happened at a terminal so fatalistically as you.

PBL

[llondel]

So everyone out safely - only just - and THEN the fire trucks roll up. Is this a little slow?

That depends on when they were called. I thought the evacuation requirements were to have everyone out in ninety seconds, at least on the certification test. No doubt with a real fire, the pax were incentivised to at least match that time. If the doors were opened about the time the call went out for the emergency response, I'd expect the evacuation to be complete before the trucks arrived unless they were based right next to the terminal. In general, I'd assume the positioning of the emergency vehicles building is more optimised for a fast, clear route to the runways as that's where they're more likely to be needed in a hurry.

[Rainboe]

PBL,
I incline not to dismiss questions about what would have happened at a terminal so fatalistically as you.
Such a fire on an apron is an incredibly unusual and rare event. You can research all you like about what would happen should it occur at a jetty- what are you going to do with the information? There are already terminal fire and evacuation procedures. The jetty might be a problem- airport authorities have seen fit to lock the apron exit gangways with coded security locks. But what exactly is the problem? And your proposed ideas to do something about it? Ban jetties? Park aeroplanes only away from terminals? But you have lounges and gates and jetties in terminals because they are by the aeroplanes.

Last year a thread got seriously hung up over an inane point- the passenger bridge at Gatwick could take 747s under it, but if they had a noseleg collapse when the fin of a 747 was under it, it would smash into the bridge Some people couldn't mysteriously accept this- I never understood why. Likewise, I went to the movies last night (Bourne- brilliant). I accepted the cinema fire procedures were adequate and entrusted myself to their care. Fire, at any time, is a risk in our lives- one has to be fatalistic about it. Can you point me in the history of aviation to any undue dangers caused by aeroplanes parked at terminals spontaneously igniting? It's not exactly a frequent occurence, so wouldn't our attention be better placed elsewhere?

[411A]

And then we have this.....

August 23, 2007
Passengers on a China Airlines plane that caught fire at Okinawa Airport criticized the flight crew on Thursday, saying they gave unclear evacuation instructions that could have caused potentially fatal delays.

China Airlines defended its crew's reactions.

"If the crew hadn't been on the ball and the clients hadn't cooperated, then the result could have been different," said Chen Peng-yu, the Taiwan airline's assistant publicity vice president.

Passengers got at least USD$857 apiece in compensation, and more if their luggage was burned, Chen said.

According to many in a group of about 30 passengers who returned to Taipei on Thursday and spoke to reporters, passengers were crying and screaming for help inside the 737-800 aircraft that caught fire on Monday after landing on the southern Japanese island.

The fire had broken out as the plane neared its gate following its flight from Taipei to Okinawa's Naha Airport.

All 157 passengers and eight crew escaped unhurt minutes before the plane's left engine exploded and ripped the plane apart, sending flames and columns of black smoke billowing into the air.

The crew-members did not see the fire as early as passengers looking through the plane windows did, causing panic among the 157 passengers and attempts to open the doors, the returning passengers said.

They said emergency exits didn't open fast enough and they didn't know where to gather for evacuation.

"Inside it was normal, but outside you could see smoke," said Lin Hsiu-cheng, 52, a returning tourist from southern Taiwan. "Everyone was scared, and why couldn't (the crew) see it?

"Finally all four doors opened," she said, her voice quickening and eyes widening as she spoke. She said the explosion came a minute after she got out.

Another passenger surnamed Liao said: "The crew was not clear on what to do. We witnesses were much more clear."

A Japanese Transport Ministry team investigating the fire said a bolt on the right wing of the plane appeared to have ripped through a fuel tank.

"We found a tear in the fuel tank, so there is a high possibility that fuel from the tank leaked through that opening," Kazushige Daiki, an investigation team official, told a news conference.

(Reuters)

Perhaps the punters expected cooled mai tais once exiting the aeroplane, seeing as how they all got out with no fatalities.

Clearly, you can't please everyone....:ugh::ugh:

[Mauersegler]

Fuel tank hole blamed for Japan jet fire http://seattlepi.nwsource.com/national/1104AP_Japan_Plane_Fire.html

[CallBell]

Of course paseengers will always think it took too long to get out. Yes they probably DID see smoke/ flames before the crew as their windows are bigger and more numerous than crew portholes in the doors. Passengers would have seen the flames and wanted to get out immediately, but bear in mind that cabin crew have to wait until the aircraft has stopped and engines switched off until an evac can be started, otherwise passengers end up evacuating straight into running engines.

Everyone got out ok in this incident. There is little point in saying "it could have been faster"

It really is a great example showing why window blinds should be kept open for all take offs and landings.

[PAXboy]

The item that 411A posts is highly amusing. It reminds of a parent who, inadvertently, allows their child to stray into danger and then - when the child is recovered to safety - gets very angry at the child and scolds them for wandering away. Their own anxiety and self anger, gets turned around.

These pax suddenly realised how very, very, very bad it could have been and get frightened. It's a usual result of stress and fear. At the time of the threat - the person is fairly calm but, when the reaction sets in, they have all sorts of emotions come to the surface.

Naturally, it is almost impossible for them to take a dispassionate look at the situation and realise that they were very lucky and the crew did a first rate job of changing their work stance from "Normal arrival at the gate" to full emergency in a way that they have never imagined. That is to say, an evacuation without more than a few seconds warning.

Also, the pax cannot get the timeline clear because the time they spent in side the cabin - after the fire had been seen - will appear to have been very much longer than it actually was. We are all aware of how time 'telescopes' in our minds during an event. That is how we come to remember it, even though we are told later how few seconds elapsed, it is our perception of elapsed time that we stick with.

Lastly, when someone feels worried, panicked and realises that they might have died, they will lash out both verbally and physically. If money is all that is within their reach, then they might say no amount of money can recompense them. They will, naturally, take whatever is offered but will continue to harbour anger about the event.

For all of their feelings to find a harmonious balance will involve reading a detailed and factual report of the incident (which they might choose not to read!) discussing it with fellow survivors and hearing their memories and personal 'time lines' and, perhaps, the elapse of a good two years. The carrier's PR people have my sympathy, as much as the carriers flight and cabin crew have my acclimation.

A quick word, if I may, about the possibility of the bolt 'puncturing the fuel tank after one rotation' as asked in #142 + #143. Once again, it might be timely to recall the elapsed time from maintenance and how many cycles since then. If this had happened on a departure and the tank punctured as the slats retracted, it would have emptied in flight and resulted in a rapid diversion but, almost certainly, the tank would have been empty upon arrival. It's a funny old world.

[atakacs]

A quick word, if I may, about the possibility of the bolt 'puncturing the fuel tank after one rotation' as asked in #142 + #143. Once again, it might be timely to recall the elapsed time from maintenance and how many cycles since then. If this had happened on a departure and the tank punctured as the slats retracted, it would have emptied in flight and resulted in a rapid diversion but, almost certainly, the tank would have been empty upon arrival. It's a funny old world.
Note quite sure what to make out of this... Yes we can pretty much safely assume that the tank ruptured pretty much at landing or close to it. Still doesn't say much how that bolt managed to get there...

[PaperTiger]

Anybody got a copy of this alleged Service Bulletin ?

[slekic]

Still, it's absolutely amazing that a stray bolt could have been propelled with such force into the fuel tank. I jst can't understand it: it must have gone in like a bullet.
Any explanation for that level of force?

[gengis]

this is reminiscent of concorde in paris in different circumstances

[international hog driver]

The wing tanks are integral to the wing itself, the forward spar, is actually the forward face of the tank, there are no bladders inside the tank.

So if the aircraft just came out of maintenance it is quite possible that a bolt of some nature may have not been tightened sufficiently or had been replace and the old forgotten.

Then after landing and associated flap and slat operation said bolt works it way into a position where the head is against the slat and upon retraction said solid bolt would easily push through the aluminum tank skin. (if you have a look at the picture on the link it is not through the wall of the tank, the slat track channel (thanks IFix!).

Remember that the hydraulic system pressure is 3000psi and the leading edge slats are thicker than other skin surfaces to resist impact damage, so it is quite reasonable that the bolt is the cause of the leak.

Now having said that and seeing the video and amount of wind it is more than likely that the fuel would have run on the under surface of the wing (downhill towards the keel) and pooled. Given the residual thrust from the N1 fan would blow a lot away, only upon shut down does it actually begin to pool.

This would explain why the fire started at the stand and not during taxi in.
As I posted before (#98), any fire not in the turbine or accessory areas of the engine are not within the capabilities of the on board extinguisher, and there are no crew actions to deal with the situation.

Professionally I would say any evacuation of 160 odd people with only two minor injuries and not using the overwing exits is a damm fine effort on the CC part!

All up we will have a lot to learn from the final report which I am sure will be very well documented. It also gives us a new LOFT scenario for the un-expected in the sim,:E

Ie: uneventful landing and taxi, just upon runway exit (while we are going spoilers down, flaps up, paperwork blah blah blah, call to from “lucy” in 2L that she “thinks she sees black smoke coming from near the wingy thingy” (don’t laugh I had that once)!:ugh: No crew indication, outside wx atrocious, pissing rain, wind and blowing snow, at night so the tower can see to confirm……… sounds like fun hey! I’d get the FO to stick his head out the window!:E:}

[IFixPlanes]

You don´t need much force.
The puncture takes place INSIDE the fueltank
http://img292.imageshack.us/img292/9831/slatcanal1.th.jpg (http://img292.imageshack.us/my.php?image=slatcanal1.jpg)
http://seattlepi.nwsource.com/dayart/aponline/29087.38Japan-Plane-Fire.sff.jpg
It can not be compared with the Concorde-Szenario:ugh:

[Few Cloudy]

They were very lucky that the fire didn't happen in flight - or we would never have known what caused it...

On the other hand, perhaps it was leaking already and just needed the hot brakes to drip on, to get it started.

Well this one will be closely observed - from cause to actions - and will provide rich pickings for safety lectures and procedure writers.

FC.

[armchairpilot94116]

Having taken place in Japan, will the Final Report be done by the Japanese authorities then? And if so, hopefully there will be an English version.

[Guava Tree]

Hi Slekic,
I see this is your first post on this network. Welcome aboard. I defer to your age. Do you have technical background?
The leading edge devices on the 737 are powered by hydraulics. Hydraulic pressure is huge . Hydraulics will get the job done. Never get in the way of hydraulics !
You can study more here http://www.b737.org.uk/flightcontrols.htm plus many other sites
Study is good.
This discussion is taking a technical direction now.
I like to study too but I am confused. I see from the photo, that the hole appears to be near the top of the fuel tank, and I believe (perhaps erroneously) that the fuel tanks are not pressurised. So how could so much fuel escape so quickly once the aircraft arrived in the parking position?

[Fareastdriver]

According to the South China Morning Post (Hong Kong) Boeing had issued worldwide alert after two similar cases of the bolts coming off but did not issue a mandatory change of the bolts. It said that China Airlines underwent checks after the alert. There are lot of high speed airflows around control surfaces that would impart a lot of energy to lose bits of metal but the question remains of how do bolts, tightened and then subsequently rechecked, come loose enough to fall off in the first place. Design flaw?

[Guava Tree]

“I see from the photo, that the hole appears to be near the top of the fuel tank, and I believe that the fuel tanks are not pressurised. So how could so much fuel escape so quickly once the aircraft arrived in the parking position?”

“Guanxi” Check in the Wikopedia. It exists in Taiwan , China and Japan.

Just because I am paranoid, does not mean to say that maintenance is not sometimes incompetent and and “when necessary” corrupt.

Check Guanxi in the Wikepedia.

What am I on about ?

The high pressure fuel hoses were correctly reconnected by “friendly” Japanese “investigating” engineers and a diversionary bolt was hammered through the nearest convenient part of the fuel tank.

This is pure speculation designed to elicit a response from those of us especially Flight Engineers. Not a lost breed yet I hope. I know that 737 has no F/E but still many F/E know about it !

Please lets continue the discussion with informed technical knowledge

[PBL]

The high pressure fuel hoses were correctly reconnected by “friendly” Japanese “investigating” engineers and a diversionary bolt was hammered through the nearest convenient part of the fuel tank.


In the presence of those friendly cooperative engineers from the NTSB, Boeing and CFM who agreed not to say a word to anyone about it? If would be especially nice of the Boeing people, since they would be agreeing to take the fall - it becomes a structural issue with their airplane that will lead to an AD, rather than some mechanic just not bolting things together as the manual says.

PBL

[lomapaseo]

Once again, even this thread has progressed predicatably towards manaufacturer bashing regarding "why didn't they mandate a fix" to a known problem.

I say again that you can only mandate against a rule/regulation and that is the repsonsibility of the regulator to interpret, not the manufacturer. And regarding the rules, they are written mostly for operation in the air and not after the aircraft is parked.

The history has numerous incidents of fuel leaks in the air and thankfuly the regulations of the design make it unlikely that they will progress to a catastrophe (leak harmelssly, overboard, no ignition sources, fire detection/suppression etc.)

History has also shown that the greatest problem is fuel pooling with the aircraft parked on the ground (with running engines to stir it up), but as I said before it takes a large leak to pool fuel to this extent.

After seeing the photo, I 'm sure that the regulators will find something to fix other than just maintenance issues.

[monkey_wrench]

Paper Tiger: Can't find any relevant Service Bulletins, AD's or Service Letters.

[Iolar]

Would the fuel in this area be under pressure from the weight of remaining fuel under the influence of the slope of the wing? Is the hole behind the inboard or outboard leading edge slats?

[SeniorDispatcher]

>>>Is the hole behind the inboard or outboard leading edge slats?

Outboard; the devices inboard are not L/E slats but are Krueger flaps...

[A310driver]

It's somewhat hard to tell for certain from the photograph but it appears that the intact bolt head and nut are visible. If so, obviously the bolt did not "fall off" for lack of tightening. unless the mechanic's name was Houdini. Under this scenario, two possibilities present: it was a stray bolt left in a cavity after removal during mainteneance which subsequently got jammed up in the works and was forced through skin duing operation of the flaps/slats, or the members that the bolt was holding together failed under load tearing out the bolt hole(s) and allowing the intact fastener to become free. In the latter case, the bolt could have been propelled by the same forces and penetrated the skin(like a bullet) or simply fell into a spot where subsequent operation of the works forced it through the skin.

[PTH needs tarmac]

The NHK News tonight provided a possible explanation given by the Investigators, but it is a bit hard to put into words.

The bolt in question has several nuts secured along its length, two large outer nuts and a smaller central nut. Next to both of the the large nuts there should be metal washers and these washers fit against the slat mechanism. The current point of investigation is focusing on the large nut nearest the end of the bolt thread. If this came loose then the smaller central nut can pass through the slat mechanism and the bolt falls free. It is this small nut that we can observe in the photo, not the larger outer nut that should secure the bolt in place.

The investigators are now checking to find out if all the washers and nuts can be accounted for in the wreckage.

I hope that makes some sense and it is as closely as I can describe the NHK report, although I admit there does not appear to be much spare thread visible on the photo provided by Ifix.

PTH

[A310driver]

Thanks that is another scenario but like you I doubt there is enough thread showing for that. It would be nice to see the original photo instead of these copies.

[armchairpilot94116]

http://youtube.com/watch?v=qZlVcLCcd4U&mode=related&search=

shows the front slide deploying

[Bedder believeit]

It's interesting, the mind set of humans (and some animals I suppose), there seems to be a slight reluctance on the part of the early exiters at the front right side slide, to get going, but once they have, then people seem to be streaming down. Maybe if we have any psychiatrists (I'm sure we have many of the amateur variety) they might be able to explain this.

[lomapaseo]

It's interesting, the mind set of humans (and some animals I suppose), there seems to be a slight reluctance on the part of the early exiters at the front right side slide, to get going, but once they have, then people seem to be streaming down. Maybe if we have any psychiatrists (I'm sure we have many of the amateur variety) they might be able to explain this.

just an amateur psych but isn't the first guy down a F/A who is there to ensure that the slide is stable and to coax the pax down while at the same time ensuring that they exit the area immediately to allow more to come down quickly.


The reluctance of the first is easily overcome as the pressure builds up from behind,

[Bedder believeit]

Quite a good clip that one, note the brave soul with the hand held extinguisher at about sec :35, and then immediately after an explosion which rocks the starboard wing.
Iomapaseo: I hadn't thought about having a FA down first, but it's obviously the way to go, still a bit of reluctance on the part of the first pax pair to slide. Understandable I guess as it's not the way that most people are expecting to arrive at their destination.

[Mr Seatback 2]

From my experience as a FA, crew are not meant to evacuate themselves first...pax first, crew last (or until it's unsafe to remain on board)...

This is from an Australian perspective, however. Asian airlines may have different perspectives/policies in regards to evacuation procedures for their cabin crew.

Well done to the crew for getting everyone out safe and well. It could all have ended differently.

[armchairpilot94116]

What are they talking about?

http://www.taipeitimes.com/News/taiwan/archives/2007/08/25/2003375737

[BOAC]

Quite confusing! They talk of 'right wing' and then 'No1 left slat' which is outboard on the left wing!

The consensus appears to be the right wing, so I am assuming they should be referring to no5 (inboard) slat. Anyone know for sure? Certainly if 5000kg fuel (2500/2500) is correct this part of the wing would have been 'wet'. Then wing around No 1 slat would probably have been empty.

Of course it could all be a red herring!

[armchairpilot94116]

The jet was well on fire by the time the evac started:

http://youtube.com/watch?v=tHsKltfO-Hg&mode=related&search=

That was why I was wondering if the flight crew had a lot of systems still CONNECTED (if anything really was still working) to shut down or perhaps couldve just gotten out just a bit faster. And I was wondering if the evac shut down procedures could be streamlined somehow. Or systems made easier to shutdown.

As it was they cut it really really fine (not saying they did anything wrong here) . I dont know if evac through the window ought to be SOP or should really be Last Ditch. And thats why I suggested they should perhaps exit right behind the purser from the front slide. The clip showed they couldve in this case, but they may have kept the FD door closed so therefore couldnt see exactly.

Sorry if some of my previous comments seemed unkind, actually I tip my hat off to the entire crew. And I never meant to seem to be mocking them. Keeping super cool and getting things done. The results speak for themselves.

One passenger in the clip said soon as they stopped some people smelled a fire and within another two minutes the stewardesses were announcing that there was an emergency and everyone should listen to instructions and then the evac began.

Another clip made by a passenger after the evac showed a jet taking off and claimed that the airport was still operating and planes were taking off.
This may really have been the ONE jet that may already have been lined up to take off right at the runway. It was clear that the airport was shut down for awhile.

http://youtube.com/watch?v=X-M2_0ZxisY&mode=related&search=

Looks like as well that slides on both sides were deployed (at least you can see that the left front slide was deployed. But I didnt really see people using them.

p.s. The man with the fire extinguisher was very brave but should really have not attempted to put out such a raging engine fire with just that. And he escaped with his life with seconds to spare really.

edit: on review of the clips did see people exiting via front and rear slides on both sides of the aircraft.

[bomarc]

Airline flying might be considered quite safe, and rightly so.

But, we must always be on guard for the unusual and unlikely form of emergencies like this one. Just the other day a hot air balloon caught fire in British Columbia.

We've all been there. Routine flight, either a quick turn or just glad to be done for the day, who is looking for a fire?

Many airlines are using the cheapest poorly trained people around the planes now, instead of well trained mechanics (read engineers for the non USA readers).

I think this was a wake up call, to remind us to always be on guard until we have left the plane in someone else's hands, or secured the plane.



That everyone got out shows that someone did something right. Bravo to the eagle eyed ground person (give him a raise), and the crew that heeded his advice.


I also think that part of the equation will be the cooking off of vapors in the center tank by the external fire. that last explosion seemed big.

Back in the piston days, those big wheeled fire extinguishers were quite handy to have around...that might want to be revisited.

The 737 evacuation checklist is the first item on the cover of our QRH and takes very little time to accomplish. (wondering if I will be banned for this post?)


Bomarc...nuclear tipped.

[PAXboy]

armchairpilot94116And I was wondering if the evac shut down procedures could be streamlined somehow. Or systems made easier to shut down.The report will tell us. All you have to do is wait two years. ;)

Another clip made by a passenger after the evac showed a jet taking off and claimed that the airport was still operating and planes were taking off. It is possible that the severity of the incident might not have been known and so an a/c, perhaps already lined up on the active, was allowed to depart. Equally, in one of the videos that was linked in an earlier post, I noted a JAL landing as the event developed. That, too, may have already been on finals and the severity of the incident not yet known.

[IFixPlanes]

And here is the Emergency Airworthiness Directive:
2007-18-51 (http://rgl.faa.gov/regulatory_and_guidance_library%5Crgad.nsf/0/E8AEEF3D61BB907F862573430015B30A?OpenDocument)

[international hog driver]

Well so much for “Guanxi” and those “friendly” Japanese “investigating” engineers........:hmm:

Thanks IFix, I was wondering if this would end with an AD or an SB. It looks like the insurance companies are going to give Mr Boeing a kicking.:ugh:

:E:ok:

[lomapaseo]

Thank goodness the AD is only an interim action. I don't have a warm feeling about repetitive inspections.

[PAXboy]

For those of us not familiar with AD documents and their procedures, it would seem that this is aimed more at maintenance than at the particular manufacturer? I am not interested in a pro/anti of either of the major manufacturers but am seeking to verify the statement by ihdIt looks like the insurance companies are going to give Mr Boeing a kicking If the component Slat Rack Downstop Assembly has been working fine on numerous airframes for some years. Now, it seems, that one of these components has failed in an airframe recently out of maintenance? Or am I stringing too many things together at too early a stage?

If maintenance was at fault then it is not, immediately, Mr Boeing's fault.

[international hog driver]

You are right PAXBoy in many ways, if a 737 takes of or lands every 30s somewhere in the world that’s 120 slat retractions per hour, 2880 per day, 20160 per week, ……. You get the drift.

If there was a manufacturing fault it would have showed up years ago and Boeing would have had to redesign the system. Think in the terms of what they did to the rudder PCU.

However this does appear to be maintenance related, which of course Boeing may not be directly responsible for the maintenance actions or control on individual aircraft. But they are the design authority and produce the maintenance manuals for the aircraft and systems, hence there is ultimately responsibility.

Someone will sue, for sure, directly it will be China Airlines, who will pass the buck and so on and so forth, Boeing will be called as a co-defendant and well you get the idea.

So at sometime in the last maintenance check, a person installed the bolt and tightened it, whether it was done correctly or not, or if there was metal fatigue in the track assembly….. whatever the Japanese Safety Authorities determine to be the fundamental cause of the accident. The manufacturer will be dragged into someway.

Not to single out Mr Boeing but Mr Airbus has had the same problem. On the 20/1/92 an A320 flew into the top of a hill near Strasbourg. The pilots mistakenly had set “3.3” in the mode control panel of the autopilot, thinking that they had set a 3.3 degree descent path. What they had actually done is set a 3300fpm rate of descent and the promptly crashed. There was nothing mechanically wrong with the airframe before impact.

Airbus as the Design Authority held ultimate responsibility for the accident as I believe it was successfully argued that it was a design error. Just as many people would argue it was the pilots fault, however it was an AD and a redesign of the system by Airbus that was made in the effort that this never happened again.

In essence the insurers will have a $40 million dollar claim for the airframe, the airport will have a claim for someone burning their tarmac, the passengers will attempt to claim post traumatic stress disorder, (when I grew up you would just be happy to be alive) and sue for whatever they can get and Boeings insurers will be awaiting the out fall.

I should have rephrased it that the insurers are going to give Mr Boeings insurance a kicking. Even though the issuance of an Emergency AD is no admission of guilt.

I hope I cleared that up:E

[PAXboy]

Dear ihd,
Thank you for a clear, helpful, complete and interesting explanation to my somewhat peremptory inquiry! :ok:

Rgds,
PAXboy

[PBL]

On the 20/1/92 an A320 flew into the top of a hill near Strasbourg. The pilots mistakenly had set “3.3” in the mode control panel of the autopilot, thinking that they had set a 3.3 degree descent path. What they had actually done is set a 3300fpm rate of descent and the promptly crashed.

Well, not quite. The report did not determine whether that was the case or not. They did rather a careful analysis of all the possible causes consistent with the evidence, of which this is one. The analysis is worth reading.

PBL

[Few Cloudy]

That is definitely not procedure - the crew stays as long as it can to see people out of the cabin.

Indeed it used to be the standard joke, "Follow Meeee...."

FC.

[international hog driver]

PBL has a point.

Two sides to every coin. I know which one I believe.:ok::E

Flight Global
http://www.flightglobal.com/articles/2006/03/21/205526/france-prosecutes-six-over-1992-air-inter-crash.html

Airdisaster.com
http://www.airdisaster.com/cgi-bin/view_details.cgi?date=01201992&reg=F-WWDP&airline=Air+Inter

All in French.. (PBL's homepage)
http://www.rvs.uni-bielefeld.de/publications/Incidents/DOCS/ComAndRep/Strasbourg/Strasbourgrep/strasbourgrep.html

Make up your own conclusion:E

Anyway before we drift too far out into the bandwidth blackhole, the subject I believe is:

China Airlines, B737, Japan, AD's & SB's........ continue;)

[lomapaseo]

I certainly am not interested in any blame game here (operator's maintenance vs Boeings design) but to me the issue is how a minor malfunction (loss of the bolt for whatever reason) could lead to a catastrophe.

At the minumum the regulator needs to relook at their assumptions in the basis for cetification. And even here I'm not to prejudge the adequacy of the regulations. As I opinioned earlier the regulations are not in them selves foolproof in preventing accidents and do accept a level of risk for things that can not be contemplated.

[Sunfish]

Errrrrrr, I think some posters here need to take a deep breath and relax for a while.

I doubt that Boeing's design is fundamentally flawed on the basis of the number of aircraft successfully flying day after day with a similar flap end stop arrangement.

Furthermore, its not really a "bolt" just because it has a head on one end and a nut on the other, it's really a pin in shear.

If it was not attached to what it was supposed to be attached to, then either some component part of it has failed or something wasn't done right in maintenance or overhaul - which could be for all sorts of reasons - and the thing has detached.

It's rather premature to sheet this home to Boeing or anyone else for that matter, let alone predict lawsuits and eventual winners and losers.

Thank goodness no one was seriously injured. Alls well that ends well, it's only money and the plane was no doubt insured. At least the Firey's got a real test of their equipment and procedures out of it:ok:

[Rainboe]

Quite. And I see no relevance whatsoever of an Airbus CFIT accident! Please can we stick to the subject? It involves an apparent maintenance error and evacuation procedures. Any discussion of general design/accident causes should go elsewhere. And let's leave out trying to apportion blame and solving the inevitable court cases.

[lomapaseo]

Rainboe
Quite. And I see no relevance whatsoever of an Airbus CFIT accident! Please can we stick to the subject? It involves an apparent maintenance error and evacuation procedures. Any discussion of general design/accident causes should go elsewhere. And let's leave out trying to apportion blame and solving the inevitable court cases.

Unh, it does also involve the loss of an aircraft that had not completed discharge of its passengers. That in itself goes beyond a pure maintenance issue and certainly there is room for some lessons learned here.

[FlyGooseFly!]

It's interesting, the mind set of humans (and some animals I suppose), there seems to be a slight reluctance on the part of the early exiters at the front right side slide, to get going, but once they have, then people seem to be streaming down. Maybe if we have any psychiatrists (I'm sure we have many of the amateur variety) they might be able to explain this.

I'm sure my old horse would have stayed in her box in a fire - even if the door was open - animals ( including us ) have great trouble resolving dilema.

I dealt with office design in a previous life and took part in some interesting research concerning evac from buildings. In experiment, unknowing members of the public were invited to an office very clearly marked with fire exit signs, while they were filling out forms an alarm sounded, the resulting videos were also quite alarming as the volume had to be increased to the level where no one could ignore it and even then folk only slowly reacted while others continued to complete their forms before attempting to leave - then very few left by following the fire exists - they mostly went out the way they came in.

Just how this would apply to fire in an aircraft I'll leave for others but it would seem that many people have difficulty in leaving their seats even when it's pretty obvious that anywhere else would be better.

[west lakes]

then very few left by following the fire exists - they mostly went out the way they came in.



Looked into this on some training I had at work
Creatures of habit!
it's a well known fact in a fire prople will not use the nearest exit but use what they are used to, alarm volumes have to be so loud as to hurt and encourage the "run away" reaction.
tried a fire drill once where the normal exit was phsically blocked by furniture and a smoke machine- the reaction furniture moved and danger ignored. Habits are bad to break.
I would suggest that the only advantages in the a/c situation is 1/prescence of crew shouting/directing & 2/ normal exit is emergency exit (apart from over wings - not used though) IMO the initial delay is the difference between I expect steps & you really want me to slide down this!

[W Weasel]

Interesting info. Wonder if they had the pumps off or were actually using the old procedures?

http://japan.suite101.com/article.cfm/china_airlines_fire_possible_cause

"...electrical short…in a fuel vapor environment…” is considered the prime culprit."

[ChristiaanJ]

Having read the article quoted above, my question is: "what explosion?".

There is a definite difference between an "explosion" and the ignition of a large amount of spilling fuel in a short time, resulting in a huge fireball. The fire from the initial leak was already well underway before the fireball.

Looking for a fuel vapour explosion in this particular case seems somewhat far-fetched.

[bubbers44]

http://www.yomiuri.co.jp/dy/national/20070827TDY02005.htm

If the nut was still attached to the bolt the mechanics scenario is interesting.

[armchairpilot94116]

I dont think its CAL policy to have CC exit aircraft first and I didnt see any evidence they did in this case. Can anyone confirm this?

[airbourne]

Just seen on MSNBC as Im in NY, the FAA have ordered a check on all 736/7/8/9. This amounts to 2350 aircraft worldwide.

[armchairpilot94116]

http://www.japantoday.com/jp/news/416376

[ORAC]

FAA orders Boeing 737 inspections after fire (http://money.cnn.com/2007/08/27/news/companies/boeing/index.htm?cnn=yes)

WASHINGTON (CNN) -- The Federal Aviation Administration has ordered airlines to inspect wing slats on all newer Boeing 737 aircraft after an initial investigation said a loose part caused a fuel leak and subsequent fire that destroyed a China Airlines 737 last week in Japan.

The FAA issued the directive on Saturday to owners and operators of 783 U.S. planes that have been in service since 1998, but the directive will likely be applied to the nearly 2,300 planes worldwide soon, the agency said. FAA spokesman Les Dorr said other directives would follow. "We consider this an interim action," he said. "Obviously we're looking at it, Boeing is looking at it, and if we come up with something better, there might be some other action, but that is to be determined."

The FAA said the directive was issued after the China Airlines incident and another incident involving the wing slats of a 737.

In the China Airlines incident, investigators found that a bolt from the right wing slat pierced a fuel tank, causing a fuel leak and fire just after landing on Aug. 20. All 165 people aboard escaped moments before flames engulfed the plane. In the other incident, a loose nut pierced the slat housing wall. Maintenance workers found fuel leaking through the hole.

Slats slide out from the forward edge of a plane's wing to stabilize it during landings and take-offs.

The directive gives owners and operators 24 days to complete the detailed inspections. Those inspections are to be repeated every 3,000 flights. It also orders a one-time tightening of the nut and bolt that hold the assembly in place.

Boeing spokesman Jim Proulx said the aircraft maker has received four reports of the nut coming loose from the assembly. It issued a service letter in December 2005 telling operators to check the assembly to be sure the nut was tightened, he said. Two minor updates to the letter have been issued since then, Proulx said, most recently last month.

The directive applies to Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes that have been in service since 1998, the FAA said.

[W Weasel]

Christian J I hate to tell you but your definition is in accurate.
”There is a definite difference between an "explosion" and the ignition of a large amount of spilling fuel in a short time, resulting in a huge fireball.
Definitions found on the Web:
An explosion is a sudden increase in volume and release of energy in a violent manner, usually with the generation of high temperatures and the release of gases. An explosion causes pressure waves in the local medium in which it occurs. Explosions are categorized as deflagrations if these waves are subsonic and detonations if they are supersonic (shock waves).
en.wikipedia.org/wiki/Explosion
The sudden release or creation of pressure and generation of high temperature as a result of a rapid change in chemical state (usually burning), or a mechanical failure.
lnglicensing.conocophillips.com/about/glossary/
A very rapid combustion of a substance using its own oxygen supply. Initiated by ignition.
riv.co.nz/rnza/hist/terms.htm
If you look at all the definitions you have a sudden release or increase in volume of energy in a violent manner that is ignited. Sorry your ignition verses explosion does not hold water. A sudden ignition of spilling fuel in a short time that creates a sudden release and expansion of energy (and temperature) is EXACTLY what you had. That is the definition of an explosion.
Now if you look at what the author said. There was an explosion under the wing… If anyone saw the footage they could not disagree. There was a sudden increase in VOLUME and RELEASE of ENERGY that was caused by an IGNITION source in a SHORT TIME.
What the article said was the cause however, was an “ ..electrical short…in a fuel vapor environment…” nothing about an explosion other than under the wing and minuscule semantics is irrelevant.
http://japan.suite101.com/article.cfm/china_airlines_fire_possible_cause
You can argue about your definition of what is an explosion but it makes no difference. It does not have to be a nuclear bomb to be an explosion. A jet engine has hundreds of explosions a minute. A test: “He theorized the rearward-channeled explosion based on his third law of motion?” Isaac Newton found at NASA http://66.102.9.104/search?q=cache:0hPoNn9BgQkJ:media.nasaexplores.com/lessons/01-085/5-8_2.pdf+does+a+jet+engine+work+by+explosions&hl=en&ct=clnk&cd=1&gl=ae
Burners and Out!

[barit1]

Sorry, W Weasel - you'll not find any agreement in here with "A jet engine has hundreds of explosions a minute." A gas turbine is a CONTINUOUS COMBUSTION process - very much like a gas stove. Once ignited, it burns continuously and smoothly.

[ChristiaanJ]

W Weasel,

Jet-A, even when dumped into an existing fire, doesn't explode. It catches fire in an extremely spectacular manner, but without the destructive pressure wave that is part of the definition of an explosion.
A "true" explosion would have blown part of the aircraft apart, and the photos show that didn't happen.

Explosion : A very rapid combustion of a substance using its own oxygen supply. Initiated by ignition.Not always true, but a good description of what happens in fuel tank explosions: fuel vapor and air (hence oxygen) are premixed.

[redout]

FAA Orders Wing Inspections For New 737s

Taken from CBSNEWS

WASHINGTON, Aug. 28, 2007
--------------------------------------------------------------------------------
A fuel leak through that hole likely caused the fire on the China Airlines Boeing 737-800, said Kazushige Daiki, chief investigator at Japan's Aircraft and Railway Accidents Investigation Commission. (AP Photo/Kyodo News)


Slats slide out the front edge of the main wings during takeoff and landing to stabilize the aircraft, along with flaps that come out of the wings' rear edge

Federal regulators ordered inspections of the wing slats on all newer Boeing 737 jetliners based on findings about the fire that destroyed a China Airlines 737 in Japan last week.

The orders apply to the owners and operators of 783 U.S. airplanes but will likely be imposed by other countries on the entire worldwide fleet of 2,287 newer 737s, Federal Aviation Administration spokesman Les Dorr said Monday.

Dorr said the move was prompted by the fire in Japan and one other incident.

The FAA's emergency airworthiness directive, issued Saturday, applies to all 737-600, -700, -800, -900 and -900ER series planes, the first of which entered service in January 1998 with Southwest Airlines, which flies only 737s. In the United States, the planes also are used by Alaska, American, Continental, Delta and other carriers.

The airlines have 24 days to conduct detailed inspections to confirm
that the movable slat system on the wings, which gives the plane lift, is installed properly, CBS News correspondent Nancy Cordes reported.

Slats slide out the front edge of the main wings during takeoff and landing to stabilize the aircraft, along with flaps that come out of the wings' rear edge.

Last Thursday, investigators in Japan found that a bolt from a right wing slat had pierced the fuel tank of the Taiwanese jetliner that caught fire after landing on the Japanese resort island of Okinawa. All 165 people aboard evacuated safely seconds before the plane exploded.

A fuel leak through that hole likely caused the fire on the China Airlines Boeing 737-800, said Kazushige Daiki, chief investigator at Japan's Aircraft and Railway Accidents Investigation Commission.

The FAA ordered a detailed inspection within 24 days to be sure that the downstop assembly, which limits how far the slats can emerge from the wing, is installed properly and repaired if needed. It also ordered that the nut and bolt that hold the assembly in place be tightened to specifications. And it ordered this process be repeated at least every 3,000 takeoff and landing cycles.

The airlines are going to try to do the inspections during routine maintenance checks, Cordes reported.

The FAA estimated the total cost for the U.S. fleet at $62,640.

The FAA order said that loose parts from one 737-800 downstop assembly had punctured the slat housing, which caused a fuel leak and fire that destroyed the plane - a clear reference to the China Airlines fire, although the company was not mentioned by name.

In the other case, a nut fell off the assembly and was pushed through the housing wall when the slats were retracted, the FAA said. Later, the operator found fuel leaking from the slat housing.

Following Thursday's findings, Japan's Transport Ministry ordered three Japanese airlines that own Boeing 737-800s to inspect the leading edge slats on the main wings to ensure bolts were in place before their first flight took off Friday morning, said ministry spokesman Yusuke Asakura.

Vicki Ray, a spokeswoman for Boeing Co. said the aircraft maker had received four reports of the nut coming loose from the downstop assembly and had issued a service letter to all operators of the newer model 737s in December 2005 telling them to check to be sure the nut was properly tightened. The service letter was updated several times since, most recently in July 2007, Ray said.

[Seloco]

I am of course no expert on what constitutes an "explosion" but it does seem to me on pure visual observation of the videos of this event that the fireball was created when the undercarriage tyres, or at least their fuseable plugs, burst due to the heat. Presumably these very high pressure containers represent a huge amount of compressed air that, when released, inevitably results in significant disruption of a pool of burning kerosene that lies all around them. Is not this in itself enough to produce the observed "explosion"?

[Synthetic]

Are the tyres not filled with nitrogen?

[Ranger 1]

Yes, Nitrogen is used to inflate the tyres.

[bomarc]

nitrogen is the proper gas to be used in airliner tires or tyres.

and as such, the nitrogen shouldn't have contributed to the flames per se...I still think that the center tank vapors, could have been cooked off by the external fire possibly causing an explosion...the largest one visible prior to the major foaming of the plane.

[bsieker]

Are the tyres not filled with nitrogen?

Yes, Nitrogen is used to inflate the tyres.

Which will still, if the tyre bursts, create a blast of gas that will stir up the pooled jet fuel, blow the flames under the wings/engine, increase mixture with air, giving the impression of a deflagration.

[Seloco]

Whether it's nitrogen or air makes no difference to the fact that it is a heck of a lot of compressed gas expanding rather suddenly in a pool of burning kerosene - it's still going to throw a lot of flammable mist around and create the fireball.

[ChristiaanJ]

Seloco,
We're thinking along the same lines, it seems.

But, looking at the video again, just when the fire appliances arrive, I have the impression by that time the fire was fed by far more than the original pool from the original leak. By that time the underwing structure would have burned through, fuel tank access panels would have been blown out, and far more fuel would be pouring into the fire.

[fox niner]

The people at boeing are getting nervous. There might be a design flaw:



http://www.flightglobal.com/articles/2007/08/29/216348/faa-orders-quicker-737-wing-inspections.html

[Blacksheep]

It involves an apparent maintenance error (my bold) and evacuation procedures.The Boeing inspection, subsequently made madatory within 24 days by FAA Emergency AD 2007-18-51 has now been escalated by Emergency AD 2007-18-52 to within 10 days and repeat every 3,000 flight cycles on the basis of initial inspection results. Those initial inspections uncovered several other cases of detached hardware; in some cases on recently deliversd aeroplanes that would not normally have had any maintenance work carried out in this area.

All of which suggests a design deficiency rather than a pure "maintenance error. From the actual content of the two ADs and the relevant Boeing Service Letter, there may also be a 'Human Factors' element, concerning assembly of the parts.

[larssnowpharter]

Re the fire/explosion. Back to basics. There are 3 requirements needed to start a fire:

Fuel
An oxidant
A source of ignition

Jet fuel does NOT burn in its liquid form at normal temps; it is the vapour that burns. Here things get more complex. The vapour will only ignite if it is present in quantities between the LEL (Lower Explosive Limit) and the UEL (Upper Explosive Limit). IE, if the mixture is too lean it won’t burn; if it is too rich it won’t burn.

Looking at the video, what appears to have happened is that a small vapour cloud found a source of ignition at the time it was in a concentration between the LEL and UEL. It may well by that the gas (N2?) from the tyres helped ‘atomize’ the fuel. The N2 then being displaced by air containing O2. The ignition source is open to conjecture.

Same principle is used in FAE (Fuel Air Explosives).

[HotDog]

Why would the tyres burst? By all accounts it was a normal landing.They most probably burst when enveloped by the fire but it was not the ignition point.

[lomapaseo]

All of which suggests a design deficiency rather than a pure "maintenance error.

Let's be careful about the two words together "design deficiency"

Typically those two words imply a deficiency against a specified cause-effect standard. IMO this has not been established in this event. I prefer to look upon it only as a design improvement to make up for a maintenance deficiency

[Seloco]

HotDog wrote: Why would the tyres burst? By all accounts it was a normal landing.They most probably burst when enveloped by the fire but it was not the ignition point.

I don't think that anyone has claimed that bursting tyres were the source of ignition; I would imagine that was the jetpipe from the still running ~2 engine, over which the fuel was presumably leaking as it flowed out of the adjacent slat-track housing. What is being suggested is that when the tyres burst due to the heat build up they did so in the middle of a pool of burning kerosene that was thrown into a mist by the expanding tyre gas and thus formed the dramatic fireball.

[barit1]

This might be deemed a "human error - maintenance" probable cause, aggravated by the hardware design being difficult or impossible to inspect once in place. (Read: "Murphy's Law"...)

Such design characteristics are not at all unusual in aircraft (or any other machinery), and demand a skill and awareness level of technicians to prevent this sort of accident.

It's generally accepted today that such traps should be "designed out" of new aircraft. I'm not sure how much the NG 738 resembles the 732 (or 722, or ...) in this regard, but I doubt the feature is unique to the NG. In that case Boeing has built MANY thousands of aircraft with a similar "trap". It may be quite ironic that the tank rupture occurred on a low-time machine.

[Blacksheep]

I prefer to look upon it only as a design improvement to make up for a maintenance deficiencyApart from terminology, we seem to be on common ground. I prefer to look at it as an error in assembling the parts and it is thus a Human Factors problem.

In this instance we appear to have a significant number of cases of incorrectly assembled parts. In some cases - including the accident aircraft itself - on L.E. Slat systems that had not been disturbed since manufacture. Thus it is not a "maintenance" matter per se, but also includes production assembly - it seems that the correct way to assemble the parts is not clear and unambiguous. My own favourite example is the Air /Ground switch actuator assembly on the B707. It was such a simple mechanism that everyone just 'knew' how to disconnect it to simulate "Air" and put it back to "Ground" afterwards: nevertheless, one seldom found one that was correctly assembled.

The instinctive way is not always the right way and the correction is to design out the human factor.

[Sunfish]

Barit:
This might be deemed a "human error - maintenance" probable cause, aggravated by the hardware design being difficult or impossible to inspect once in place. (Read: "Murphy's Law"...)

Such design characteristics are not at all unusual in aircraft (or any other machinery), and demand a skill and awareness level of technicians to prevent this sort of accident.

It's generally accepted today that such traps should be "designed out" of new aircraft. I'm not sure how much the NG 738 resembles the 732 (or 722, or ...) in this regard, but I doubt the feature is unique to the NG. In that case Boeing has built MANY thousands of aircraft with a similar "trap". It may be quite ironic that the tank rupture occurred on a low-time machine.

I'm glad you said this MIGHT be deemed a human error......aggravated by hardware design, because you are misinformed. There is very considerable science applied to the reliability of aircraft and all their components by people much smarter than I am.

Since at least about 1970, each and every component and assembly in an aircraft undergoes FMEA - Failure Mode Effects Analysis, which is performed by a Committee of Professionals (Engineers, etc.) who use a highly structured decision tree to review the way a part has been designed, its modes of failure and the consequences of failure and how it is to be maintained.
Such traps as you mentioned have existed ( Such as the Dunlop aviation manual for the Viscount cabin supercharger on the accessory pack for the RR Dart - the assembly order of thrust washers was ambiguous, resulting in an in flight fire that killed about 30 people) but these are generally caught and designed out of the aircraft by FMEA since at least 1970. Clearly some design issues will slip through, but its not from lack of trying.

Thats why Boeing and Airbus have service representatives almost everywhere, and anything that starts cropping up is relayed to Seattle or Toulouse(?) where it becomes the subject of discussion and action.

For the record, maintenance protocols for components relate to the severity of failure and the ease of inspection to determine the components condition.
This results in components being classified:

"Hard Time" - set limits on number of hours/cycles/stress history/ etc, which is what you do if there is no way you can gauge the condition of the item by simple inspection - for example disks.

"Condition Monitored" - you inspect the part at set intervals and if its within limits, thats OK. e.g. blades. flap tracks etc. I assume the end stop will be disassembled and inspected in the process of overhauling the LE slat.

"On Condition" - when it breaks, fix it, and not before. e.g seat jacks.

As for a "design defect" causing this fire, I guess its possible, but Boeing would have gone to considerable lengths to ensure that this assembly cannot be put together the wrong way and assumes an average level of skill from the engineers maintaining the aircraft.

Translation: If your car manual says "Torque wheel nuts to forty foot pounds" and you only torque to twenty, and the wheel subsequently falls off your car, that isn't a design defect at all. In fact the design is perfect and is operating exactly as predicted.

(runs for foxhole)

[lomapaseo]

Sunfish
I doubt that Boeing assumed a level of "catastrophe" for this error in their FMEA and under what FAR would they perform this type of analysis for such an error (after all it doesn't prohibit safe light does it?

[Blacksheep]

assumes an average level of skill from the engineers maintaining the aircraft.Or building it on the production line. :rolleyes:

The accident aircraft was too low time to have had any maintenance work done in this area. Which points to it being assembled incorrectly during production. Which in turn implies some ambiguity in how to correctly assemble the components. Which is a Human Factors issue.

I could bore you to death for hours talking about all the poor maintainability that every aircraft I have ever worked on had designed into it. A friend and former colleague of mine works for Airbus "ensuring that what the designers have designed can actually be manufactured" - his words.

[Return to base]

I am afraid that the current method of producing Designers/Engineers for industry means that the "old-fashioned" 5 year UK apprenticeship no longer applies and the current design staff have no idea on how to manufacture or assemble items. This is why people like Airbus have to have a third party to ensure that everything will go together in an orderly fashion. I know of designers who never get onto the shop floor so there is no way they will ever gain experience as to what is happening to their design :(


rtb.

[PBL]

Sunfish gives an excellent intro to FMEA for non-experts. lomapaseo then goes deeper into it

I doubt that Boeing assumed a level of "catastrophe" for this error in their FMEA and under what FAR would they perform this type of analysis for such an error....... ?

Good question. Let me say a little more about FMEA.

An FMEA requires you to identify
* everything that can go wrong (all ways in which things can fail, or "failure modes")
* what the possible causal consequences of such a failure can be (and one failure mode might have many different possible consequences)

but it doesn't stop there. You then

* classify the possible consequences into four or five categories. These categories include one typically called "catastrophic" (the worst: say, leading to loss of the airplane) and one called "minor" (the least bad).

and then

* perform a risk analysis: how often are the failure modes likely to appear; given that a failure mode has manifested, how likely is it that a certain effect (from the many that may follow this failure) is exhibited?

This last is not strictly part of an FMEA, but inevitably follows.

There are then requirements that say how often a particular effect is allowed to appear. For "catastrophic" that would be "not expected within the service life of the fleet". An applicant for an airworthiness certificate must show that the failures in their respective categories satisfy these probability requirements. See LLoyd and Tye, Systematic Safety, CAA Publications 1982, for the most concise explanation of categories, classification and risk classification.

So lomapaseo's suggestion requires some refinement. The bolt separating itself from the assembly would likely be a failure mode in the FMEA. That itself would not be assigned a severity category, I don't think, because it is a failure mode, not an effect. The question is then what effects it might engender. And at least one of them turns out (we now know) to be catastrophic. The question would be whether this effect was foreseen in the FMEA.

PBL

[lomapaseo]

PBL
So lomapaseo's suggestion requires some refinement. The bolt separating itself from the assembly would likely be a failure mode in the FMEA. That itself would not be assigned a severity category, I don't think, because it is a failure mode, not an effect. The question is then what effects it might engender. And at least one of them turns out (we now know) to be catastrophic. The question would be whether this effect was foreseen in the FMEA.


yup, you got it:ok:

So how can you be expected to assess a catastrophe under the FAR/Jars when the flight is over? I doubt that there is adequate guidance on this.

Of course under continued airworthiness, the FEDs can now react,

[PBL]

A colleague in Japan points to the news item
http://www3.nhk.or.jp/news/2007/08/30/d20070830000144.html
in Japanese, which includes the following.

Air Nippon has found one of its fleet of 13 B737s was missing a washer from a slat bolt. (Apparently the english term "washer" is explicitly used.) The aircraft had been acquired directly from Boeing and entered service in January 2007. The area concerned in the recent inspection AD had not yet been either maintained or inspected.

So a manufacturing fault is suspected.

This from the news item. I have no Japanese myself, so have not read it.

PBL

[barit1]

sunfish (runs for foxhole)
Wait! I totally agree!
The problem with the FMEA process is that - for a time at least - FMEA's were written by staff people who had relatively little detailed knowledge of the "workings" of the system and hardware. This came to light in the ASA Embraer Brasilia accident (NTSB DCA91MA033) in which a prop failed to fine pitch, and the drag and turbulent airflow led to an uncontrollable roll. (The ERAU website had a copy of the complete report, but I'm unable to locate it right now.)
In this case, the FMEA predicted a failure to coarse (high) pitch, and the FAA cert. staff accepted this analysis. Neither the manufacturer nor FAA personnel seemed to be aware of several decades of service experience with controllable propellers strongly indicating the opposite.
Sometimes we have to relearn lessons the hard way. :ugh:

Just found this thread; (http://www.pprune.org/forums/showpost.php?p=3503800&postcount=2) In it Cardinal discusses this very Embraer accident.

[FrequentSLF]

Took today the CI from TPE to HAN. Schedule a/c was a 737-800. At a gate found a A330-300. Number of passengers was in accordance to a 737-800.

[Sunfish]

Barit1, thank you for your advice and the link.

[Volume]

For the record, maintenance protocols for components relate to the severity of failure and the ease of inspection to determine the components condition.
This results in components being classified:

"Hard Time" - set limits on number of hours/cycles/stress history/ etc, which is what you do if there is no way you can gauge the condition of the item by simple inspection - for example disks.

"Condition Monitored" - you inspect the part at set intervals and if its within limits, thats OK. e.g. blades. flap tracks etc. I assume the end stop will be disassembled and inspected in the process of overhauling the LE slat.

"On Condition" - when it breaks, fix it, and not before. e.g seat jacks.

This is the "old style" of maintenance program development. Today we work with the so called "reliability based maintenance", based on the MSG-3 document. (you may google for those key words)
Nevertheless it depends on the skill and mindset of the engineers to decide which failures could occur, before the failure effects can be analysed and an according maintenance task can be developed.
Unfortunately today the beancounters make the wrong conclusion : low number of inspection tasks = low costs = good maintenance program. There is huge pressure on the engineers to come out with a low number of inspection tasks when developing the scheduled maintenance program. One key question is always : is the task economical, does the risk of failure and the severity of the failure effect justify the costs of a task.
If you try to inspect every nut and bolt of an aircraft, you will never be economical. So you have to build on past experience, and you will always have a first for every failure to occur, afterwards (depending on failure effect) it will be taken into account.
You can be absolutely sure, that in 10 years every new developed maintenance program will include the slat track downstop.

[PAXboy]

Volume's concern about cost control does not surprise. But, if the new schedules will include the slat track downstop, does that mean that other items will be reduced in the schedule - as they prove themselves to be more reliable?

[Sunfish]

Paxboy:

does that mean that other items will be reduced in the schedule - as they prove themselves to be more reliable?

Sadly, yes, but they shouldn't be.

I refer you to Richard Feynman's Appendix to the report on the Challenger disaster.

http://science.ksc.nasa.gov/shuttle/missions/51-l/docs/rogers-commission/Appendix-F.txt

[PAXboy]

Wow! Thanks Sunfish, that was a fascinating (if somewhat tricky) read. But it was well worth seeing the layers being peeled back. What one then finds is, of course, a system designed, built and operated by human beings and we know that humans are very good at fooling themselves. For the most part we get away with it but, Feynman's closing words in that report are superb:
For a successful technology, reality must take precedence over public relations, for nature cannot be fooled.

[barit1]

sunfish - and others interested in the failure of the FMEA process re prop overspeed: Here (http://www.airdisaster.com/reports/ntsb/AAR92-03.pdf) is the link.

[181.filo]

What happened to those pilots "know all" blamed CAL crew/mtx as soon as the news came on the CNN.? Why dont we hear from them anymore.
I hope that teaches us the old saying "DONT JUMP IN TO CONCLUSION UNTIL...
Whatch for those loose BOLTS.
happy landings to all my mates.!!!

[Guava Tree]

Hi Filo,
So you do despise anyone who might know it all , or at least know more than you do.
Are you a “Company Man” ?
I must admit that I have been surprised about how Boeing can hire assembly workers with such minimum knowledge and intellect but still train them enough (need to know) to get the job done.But history has proved that, for Boeing, this works.
I talked about Guanxi.I still talk about Guanxi A washer is easy to disappear. Are Nippon engineeers checked for isolated washers, gold and diamonds etcetera when they clock off?
I think we need to wait longer to see if worldwide inspections reveal a significant number of such cases.
Meanwhile with some knowledge about both Boeing staff and CAL maintenance staff, but not “know it all”, I would place my money bet for Boeing and against CAL Maintenance.
How come this CAL aircraft operated for quite a long time since leaving Boeing, before this problem occured ?

[Blacksheep]

Unfortunately today the beancounters make the wrong conclusion : low number of inspection tasks = low costs = good maintenance program.One of the banes of our life is Accountants poking their noses into everything. They're not terribly good at financial matters and even less useful when trying to control that of which they know nothing. Which is everything apart from accounting. My own experience is that over enthusiastic attempts to minimise costs generally leads to much larger increases in costs downstream.

Example. We were told we had too much inventory. The auditors declared that we had a lot of stock that had never moved and supplies were not to reorder anything with a shelf-life that had expired. Finance Department runs the show and the BOD know nothing of maintenance anyway. Except that it is a cost rather than an earner. They forget that the aircraft are the production machinery that produces the product we sell and they must be kept in full operating condition to ensure a smooth production run. All profit originates from serviceable aircraft.

An aircraft became unserviceable with a no-go defect at an outstation. We had the component but new "O" ring seals are required when fitting a replacement. Yep! the "O" rings were shelf-lifed, it had expired and under the accountants' instructions they had not been re-ordered. Result? Crew ran out of duty hours. Passengers had to be rebooked on other operators or given free overnight hotels. Add knock on effects causing other delayed services and the total bill came to over $1/2 million. The "O" rings cost $20 for a pack of 5.

When counting beans the first step is ensure you have some beans to count.

Bean counters. Don't we all love 'em! :rolleyes:

[barit1]

Guava Tree puzzles - I must admit that I have been surprised about how Boeing can hire assembly workers with such minimum knowledge and intellect but still train them enough (need to know) to get the job done.But history has proved that, for Boeing, this works.
The difference is that in the Boeing shop, an assembler need only address a few tasks and thus he can master them fairly quickly. A maintenance shop needs versatile folks who can work competently on radomes and trim tabs and all in between.

[PAXboy]

Blacksheep a fine story of our times. Let me guess what happened next: The maintenance department told the middle management what had happened. The middle management did not tell the senior management the same story. Consequently, no lesson was learned.

Unless, of course, the maintenance department decided to start ordering key items of stock as before - despite the order to the contrary. This means that the system continued to operate normally, with the exception that some idiot in so called 'management' thinks they did a good job and received words and/or money to reward them.

Please tell me that I am just too world weary and cynical, that the company learnt the lesson and that the accountants were told to keep their nose out of things?

[lomapaseo]

PAXboy

Please tell me that I am just too world weary and cynical, that the company learnt the lesson and that the accountants were told to keep their nose out of things?

You are too world weary and cynical and you also have a good imagination to support your cynicism

[PAXboy]

lomapaseoYou are too world weary and cynical and you also have a good imagination to support your cynicismUnfortunately, my world weariness is from 29 years of working in commerce and (for a short time) local government, as well as self employment where I got (still get) to watch a very large number of companies at close range. My 'imagination' about what happens (two posts back) is based on bitter experience of 29 years ...

[glad rag]

Sadly, you are on the money with your posts.:D

[VONKLUFFEN]

...should read back to CAL.
It does not matter if someone is company man or not. The facts, if any available yet or when they come out, will talk for itself.
Therefore what ever I say may be completely wrong but hopefully has some common sense.
CAL has work hard to turn around things.
Is there still room to improve? Yes.
Do they take shortcuts? At least not visible ones as they use to.
Crew did a good job based on much better training received in the last few years.
Before Okinawa Boeing issued an AD. It was a regular one. Not an Emergency AD. For the same kind of incidents!!!
The A/C was only five years old.
I have no idea but probably that slat was never removed for a C or D check( time or cycles not due yet) or troubleshooting any problem.
If that is true the washer missing was never installed. ( If this was the probable cause...)
Fact is that after Okinawa several air crafts have been inspected and same part was missing. Latest one ANA aircraft delivered on January 07.
Good news is no one was injured or killed. Bad news is that:
Boeing screw up
Many people, newspaper, pprune writers that know it all will have to eat all the rushed judgements expressed.
Lets wait. If Im the one who should eat my words, I will do it the very next day I read the final report. Don't worry guys I will let you know...
B good!

[rubik101]

Just to make the point that there is nothing new in aviation since Pontius was a pilot, this link provides interesting reading.

http://news.bbc.co.uk/onthisday/hi/dates/stories/march/17/newsid_4276000/4276923.stm

Happy Landings!

[PAXboy]

Thanks rubik101 The BBC list the crash as being 17th March 1957 and Aviation Safety Network list it as 14th March.
http://aviation-safety.net/database/record.php?id=19570314-0

What is interesting is that the post of Sunfish #227 directly applies to this. However, we should not be surprised. Each lesson must be re-learnt by succeeding generations. Sometimes, a hard learnt lesson will last for 50 years, whilst a less severe lesson may last for 25 years. It will usually depend upon how many people died and how much money was involved. However, the less realised, but to my mind greater, factor is: How many people that remember the 'lesson' are still alive and working in the industry.

[off topic]
That is why I am fearful of a severe global financial depression, because the folks currently working in the Stock Market (the ones establishing the 'value' and trading levels) have only heard about the Depression school. Their grandparents can only just remember it and that generation is fast dying out. The 20 and 30 somethings have no concept of what real financial hardship is and have seen some slight rises and falls - but not the big one. Some of them remember the Recession of 1989/1992 but, "Hey - look how much money we've made since then?!"

Running an airline and running a stock market both need a memory that is longer than our own personal memory. Consequently, there are very few new errors of judgement in the world, we just repeat the old ones in a modern and updated way.
[end off topic]

[flyboy2]

August 28, 2007
US aviation authorities have ordered emergency inspections of newer model Boeing 737 airliners in response to last week's explosion and fire that destroyed a China Airlines plane in Japan, officials said on Monday.

A Federal Aviation Administration order sent to airlines over the weekend requires wing slat inspections on all 737-600 and above models within the next three weeks.

There are more than 780 of the affected planes registered to US airlines and another 1,500 flying overseas. Foreign aviation safety authorities usually follow FAA recommendations.

Airlines "were working diligently" to complete the inspections, a Boeing spokesman said.

The FAA, working with Boeing, wants airlines to ensure that a nut inside the movable slat system on each wing does not fall off and possibly damage an adjacent fuel tank.

Slats are panels that extend from the front of the wing to help give an aircraft lift at lower speeds -- during landing and takeoff.

Japanese investigators examining the charred wreckage of the Taiwanese 737-800 on the island of Okinawa found that a loose nut fell into the path of a retracting wing slat after landing and pierced the fuel tank, causing a leak.

The leaking fuel triggered an explosion and fire that engulfed the plane but all aboard escaped safely.

Boeing said it issued a service letter to airlines in 2005 after receiving four reports of loose slat nuts. In one case, a nut fell off a bolt and punctured a fuel tank, but there was no fire. The advisory was updated in 2006 and again last month, Boeing said.

(Reuters)
http://news.airwise.com/story/view/1188287507.html

[armchairpilot94116]

http://www.taipeitimes.com/News/taiwan/archives/2007/09/09/2003377927

[ChristiaanJ]

Steve Yuen (阮祥運), vice president of CAL's engineering and maintenance department, said each Boeing 737-800 has 16 slat track downstop assemblies. In total, CAL has checked 208 nuts on the assemblies and found 100 of them were below the standard torsion value.
The standard torsion value, as indicated in the directive, should be between 50 inches-lb and 80 inches-lb, but the majority of those found below standard had only 40 inches-lb.On average, that's more than 7 out of 16 on 13 aircraft......

The inspection team also found some of the components on the assemblies were not placed in accordance with the Boeing aircraft maintenance manual.
However, Yuen said that the company's maintenance crew rarely tamper with the assemblies.Implying what? That Boeing already had fitted them wrong?

[mohdawang]

Are you also implying that Boeing is infallible?

[ChristiaanJ]

Are you also implying that Boeing is infallible?Quite the contrary. Sorry if I wasn't clear.
Yuen said that the company's maintenance crew rarely tamper with the assemblies.I meant to say that Yuen is implying that somebody else "tampered" with the assemblies. In this case, that Boeing did not fit them correctly.

Without any drawings, I have no idea if the nuts could have become loosened by themselves in normal service.

[BOAC]

CAL has changed five nuts on the assemblies following the issuance of the notice, including one on the aircraft destroyed in the Naha incident. - Hmm!

Presumably they inspected the others on that hull?

[ChristiaanJ]

BOAC,
From your quote: CAL has changed five nuts on the assemblies(My emphasis). They changed them, rather than retorquing them to the correct value? Why?