China Airlines B737 Fire at Okinawa

[FCS Explorer]

-> nitrogen generation system NG

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?) ??

[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...hoto/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.

[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]

Left side also used for evacuation

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/videone...-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]

Nitrogen Generation System NG

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]

Leave it to the Pros

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...urs_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.



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

[UNCTUOUS]

The Airborne Saviour

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.