China Airlines B747 Crash (Merged)

[I. M. Esperto]

Unc - Why would Al Qaeda do this? They have no quarrel with Taiwan.

[PaperTiger]

Ah yes, cargo doors popping up (or out) again.

For those who have not seen it, this site ( http://www.corazon.com/Page2.html ) proposes that all the previous accidents mentioned in this thread, and some others, were caused by the above.

Not that I subscribe to the theory, nor am I in any way associated with the site, but food for thought ?

[GlueBall]

No record of any 74 having "crashed" due to a cargo door coming unglued. Only known door failure was on a UAL 74-2, but the airplane landed safely at HNL, minus 9 pax.

[UNCTUOUS]

Why would Al Qaeda?

a. When you air-freight something you've no real control over where it goes enroute to its final destination and/or on which carrier/platform - it could have been transhipping from who knows where (with a time-lock on the baro device to make it that much harder to back-track it). It was then, post time-unlock, the baro device that ensured that it went off in the climb. You can set a baro device to go off in the descent (or on landing for that matter). I think they might have learnt something from the Lockerbie crash.

b. Taiwan is a US supported and sponsored ally

c. Al Qaeda want to disrupt international commerce - which impacts greatly, although indirectly, upon the US economy.

d. They had about a 50% chance of getting it onto a US built hull and scoring some US citizens to boot.

e. They cause international concern about airline security (average pax doesn't stop to think about the finer detail - just the fact that an airliner was downed)

f. It's an easy target, utilising minimal resources and defeats post 911 measures. It's eminently repeatable.

g. The new style of terrorism is NOT to claim responsibility (and that continuing unknown just adds to the terror factors). After a while it becomes SOP for all air-crashes to be assumed prima facie to be Al Qaeda accomplishments - nice force multiplier effect.

h. It exploits known deficiencies in the World's airfreight system. That's a known strategy of Al Qaeda's.

The true hallmark of terrorism is in its indifference to the who or what of its victims. They just set out to show that they can exercise their will with impunity and seek to convert more mindless Muslims to the justice of their cause via the kudos of success - and by showing up the hapless nature of authorities forced to take very costly (cripllingly so?) wide-sweeping measures to counter them. At that point they just switch to a new strategy (eg Doubt that we will see another shoe-bomber; next one will be toting his explosives internally with a gastric acid activated fusing).

Even if it was only diversionary, it would have made sense in a terrorist's mind. Not saying that this is what might have happened - but you did ask the question. Smarter people than I could probably come up with many more "reasons why".

[UNCTUOUS]

Euphemist

Despite my post above, still think that it was a TWA800 replay however. Arcing in a fuel tank probe is all that's required to give you a TWA800 - if there's no tank inerting (N2) and the tanks are full of fuel fumes (courtesy of high ambient temperatures and underlying airconditioning packs heat-soaking the Centre Wing Tanks up to the fuel's flash-point).
However the question that's still extant is the role that silver sulfide deposits play in facilitating such arcs. It's one thing to inductively create an unintentional path for a current into a fuel tank, it's quite another for it to create an arc for ignition of those ullage fumes. It has been quietly acknowledged by Smiths Industries (makers of Fuel Tank Quantity Indicating Systems) that silver sulfide is a bad thing to have accumulate on electrical system components within tanks. It is formed from the sulfur that's naturally in the fuel and the silver that's in the silver solder used in wiring and connectors. Trials have indicated that a 9VDC transistor battery will create an arc across any such deposit. Get the idea? The Transient Suppressor units that had to be fitted to Classics under the AD with a completion date of 01 Nov 01 has not been altogether 100% successful (neither the Smiths Industries nor the B.F. Goodrich mod kits). The silver sulfide deposits are a large part of that problem. They have been found in a 757 that was as little as 7 months ex-factory.

So if they don't mandate inerting tanks, then the recurrence of TWA800 and (possibly) CI-611 type accidents is guaranteed. That's freely admitted by the FAA/NTSB in the TWA800 Report - but they didn't expect the next one quite so soon. If they don't want to set up the infrastructure for onboard generation or single-shot (on the ground) Nitrogen inerting, then maybe they should be investigating an immiscible thin layer of distillate that will float overlay the heated fuel in the CWT and either remain in there (via a filtration process) or get pumped out inflight and be assimilated with the engine-supplied fuel. The purpose? It would totally dampen the ullage vapours, much as oil laying on top of water stops evaporation.

That process I've named " EUPHEMIST "

Euphemism: The act of substituting a mild, indirect or vague atmosphere (or proposition or compromise) for one considered harsh, blunt or offensive.

I think the name fits the bill ideally. Maybe we'll hear more about it (under some name or other) - as solutions may well be sought more urgently now. Inerting of fuel tanks is #1 on the NTSB's most wanted Hit Parade. The biggest obstacle to EUPHEMIST is the posturing by the fuel suppliers and the makers of fuel system components regarding testing and purity of aviation fuel. They are 100% against any adulteration of fuel by other than necessary additives (or so I am told). The additives that are presently used are FSII and its variants (for fuel pump lubrication and anti-icing effect on the water held in suspension in the fuel). Some military aircraft have other additives for lubrication of high-speed afterburner pumps etc. But don't let anybody kid you that AVTUR is pure. It is nowhere near pure and an additive such as the one that I have suggested as a solution is technically feasible (and the minimal 50 or 60 gals required in the CWT would contribute its own share of BTU's to the fuel burn). It's just that technical people get as emotive about their fuel quality assurance as you do about the food you give your kids. For that reason it would be as difficult to get it accepted as it will be for the aviation industry to accept the extra infra-structural costs of nitrogen inerting. But bite the bullet time is fast approaching - methinks.

[PaperTiger]

No record of any 74 having "crashed" due to a cargo door coming unglued

I think that's the point of that chap's website - he proposes a 'conspiracy' covering up a supposed design weakness. Like I said I don't believe it, but the breakup pattern does seem similar (maybe superficially). Not that PA and AI would have likely survived anyway.

[AIRBUS ERROR]

Guys,

The whole radar speed/heading/altitude plot doesn't look right. An @ 200kt loss of speed in 2 180 degree turns left and right seems a little too much within 45 seconds... will check it out on the sim tonight but seems improbable. It looks more like the radar was tracking individual pieces rather then the whole aircraft, especially considering the rapid loss of speed. A logical guess would be an Aloha-type incident with cracks running along the stringers resulting in fuse rupture. 4 pieces big enough to each be seen on primary radar suggests both wings, the fuse and the tail assembly, or the wings and the fuse ruptured roughly midpoint. To me it looks like the aircraft structure began to fail at 15:28:08. Let's wait for the FDR data.

But this is VERY worrying... not for the 742 but for aviation in general. As far as I know this is the first non-bomb related fuse failure for the 74. Even the Japanese 74 that crashed only did so becuase of hydraulic failure due to the fatigue blowout.

Let's not get bogged down in blame mode.

AE

[TAT Probe]

Unctuous:- I am sure that Al Qaeda don't need your help in trying to find various weak points in air security. You also said

>>After a while it becomes SOP for all air-crashes to be assumed prima facie to be Al Qaeda accomplishments - nice force multiplier effect. <<

That process depends on people like you giving credence to these wild speculations. It is not a simple matter to put explosive devices into airfreight, and the unpredictability inherent in much freight handling would make it a very unreliable weapon to target. Ask any freight dog...

Your other speculation about ignition of fuel vapour may be a more likely scenario, but that should be revealed by an investigation.

I have 2 worries about the accident and its aftermath:-

1) Taiwan has just completed its first accident investigation, and anyone who knows the status at Taipei airport prior to the SQ accident will realise that the report was a whitewash of their own culpability at the expense of the SQ crew. This does not bode well for objectivity.

2) Taiwan is so dependent on US support that they could get browbeaten into a compliant report that exonerates Boeing if the fuel tank scenario is confirmed.

The big plus this time is the apparently shallow water at the crash site(s), and the likelihood of finding lots of evidence.

[lunkenheimer]

I don't believe everything my government tells me, but I'm not sure where the suspicions arise regarding Boeing, FAA, and US investigators. Judging by some incidents cited in this thread (rear bulkhead failure, center fuel tank explosion) it seems that there isn't much of a conspiracy to exonerate Boeing in the face of facts (unless, of course, it's an incompetent conspiracy )

[UNCTUOUS]

I'm Uncertain about that Unpredictability

Tat Probe
Don't really want to get in a slanging match here, but if there had been some realistic and pragmatic discourse about threats and threat levels prior to 911 (aka wild speculation), we might not have taken a hit. Instead it was preferred that the ATA, FAA and Congress should consistently hold their security hearings behind closed doors and agree to keep their collective fingers crossed (whilst the FBI perfected their archiving and filing systems, the CIA agonised over their locus operandi restrictions and the INS failed in all of its limited aims).

If I'm exposing any soft underbellies to terrorists here (that they've not already exploited in this accident - which I anyways doubt is terrorist-related) - then let them be fixed. The existing deficiencies in checking air-freight consignments have been aired thoroughly in the public (and trade) press, and I suspect that when they're not incantating over the Koran, the bathturds keenly study what is laid out for them (perils of belonging to an open society). If you are implying that it's not possible for an IED, incendiary or caustic to be hidden in a container and eventually fly, then old chap you haven't been reading widely enough. It may not fly on a particular airplane - but I doubt that would matter in the context of what they're trying to achieve. The unpredictability simply doesn't matter.

[SaturnV]

unctuous, a more careful reading of the radar trace and ATC communications (links provided some posts back by peanut butter) would have discounted several of your scenario hypotheses.

on your first scenario (b) depressurization at FL 150 incapacitating the crew. The crew at 15.16.18 reported at FL 187 and climbing. The last communication from the crew was at 15.16,30.

on your scenario (c) a mach overspeed, the max airspeed on the radar trace was 453 knots, at FL 343, which was reached just before a slight drop in airspeed, which may have been coincident with the beginning of the catastrophic event.

on a center fuel tank explosion, it is my understanding that the ambient air temperature and oxygen levels at FL 340 are not conducive to a vapor explosion of the center fuel tank. further, unlike TW 800, there was no fire in the impact area, no reported sign of fire or smoke in the sky, and there have been no reports that I have seen of recovered bodies being burnr or parts of the plane showing fire damage.

on a bomb planted by al-Qaida, I am quite certain that US carriers do not carry 50 percent of the traffic between Taipei and HongKong as you assert. remotely fusing a bomb to explode at a certain time or altitude, particularly if it is sequenced to explode after several flight segments, simply lessens the chance that a terrorist will succeed with respect to target and result. the Sikh bombers who brought down Air India with a bomb off Ireland had another bomb explode on an airport luggage carousel, which led to their being found out. Pan Am 103 had a delayed departure, and crashed on land and not in the middle of the North Atlantic, thus revealing the clues about the bomb and how it got there. An Islamic terrorist placed a small bomb in a seat of a Pan Am 747 out of Manila, timed to go off during the next segment. The terrorist disembarked the plane as ticketed. On the next segment, the bomb exploded, killing one passenger, but the plane survived, and the terrorist was caught.

this is not saying that a bomb did not bring down dynasty 611. but rather than jumping to al-Qaida being the culprits (if indeed it was a bomb) one should probably first look at the on-board passenger list. the long history of aircraft bombings would reveal that a substantial percentage of them were planted by individuals seeking insurance monies.

[Flight Detent]

Yes, Unctuous,
In the Classic, the FE does have exclusive controls and indicators for the pressurization, though some aircraft do have a cabin altimeter mounted in the inbd side of the FOs inst panel.

Your comments regarding the "pilots/FE" stuffing around with these controls whilst not going on oxy and passing out, I find most unlikely and not just a little bit unprofessional!

Those indicators will tell the FE right away if any pressurization problem is due to a system malfunction, ie, outflow valve problem, or is due to a failure of the fuselage to maintain the required pressure, as dialled in by the FE, during climb or not.

The indicators are so positioned so the Capt can see them easily, as are most of the panel, to enable the standard procedure of the Capt & FE to sort the problem whilst the FO flies the aircraft.
This way the Capt can monitor/discuss both the problem solving actions of the FE, and still monitor the flight path of the aircraft.

Normal procedure, practised countless times in the Sim, if the FE announces that he does have a pressurization problem that he cannot immediately control, the oxy masks are immediately donned, and the capt initiates an emergency decent, if required.

This 3crew setup is well tried and works very well, and as such, assuming these crewmembers were competent (?), a pressure problem would not have caused this, as you have implied!
Cheers.

[Flight Detent]

Just curious,
Does anybody still believe that TWA800 just blew up, caused by that centre fuel tank or whatever, I'm firmly with the theory that the navy accidently shot it down.
To many things happened during the NTSB investigation that were not normal, together with the continous FBI input, or should I say output of aircraft parts, undocumented, from the reach of the NTSB, to allow them to come to any defining conclusion.
So the most convenient cause could be announced, with no evidence available to disprove it, nice and tidy!
Cheers.

[Anti Skid On]

Raas767

The reason why it is on p28 of your local newspaper can be seen on the PAX list. No mates of George W on board, all Chinese/Taiwanese names. If it had 50 blue rinsers from the Bronx it would be p1.

[twistedenginestarter]

Flight Detent

There is no doubt TWA800 had an internal explosion centred on the fuel tank. The thing has been virtually re-built. They've done experiments on dead 747s to get the same deformations. I seem to remember it is the biggest reconstruction ever done.

It is always best to wait a few years after a crash. Then the real information starts to emerge.

[UNCTUOUS]

In Reply to Saturn V comments

Saturn V said
<<unctuous, a more careful reading of the radar trace and ATC communications (links provided some posts back by peanut butter) would have discounted several of your scenario hypotheses.>>Don’t yourself misinterpret the radar plot..see Belgique comments at this link. Re the ATC comms and the timing/development of any failure to pressurize, suggest you rethink – some hints below.

<<on your first scenario (b) depressurization at FL 150 incapacitating the crew. The crew at 15.16:18 reported at FL 187 and climbing. The last communication from the crew was at 15.16:30.>> If the cabin was climbing at too high a rate (due perhaps to a hull integrity problem) it is quite conceivable that the first signs of hypoxia will not become apparent until some height in excess of 20K. Hypoxia onset is a function of both time and oxy partial pressures

<<on your scenario (c) a mach overspeed, the max airspeed on the radar trace was 453 knots, at FL 343, which was reached just before a slight drop in airspeed, which may have been coincident with the beginning of the catastrophic event. >> Speed drop may also have been indicative of the commencement of a turn (into the nose-drop spiral) due to the non-asymmetry of lift/drag upon encountering mach buffet – the depressn theory

<<on a center fuel tank explosion, it is my understanding that the ambient air temperature and oxygen levels at FL 340 are not conducive to a vapor explosion of the center fuel tank.>> talk to Dr. Joe Shepherd at CalTech about the possibility of another fuel tank explosion. His govt-funded research shows it can happen up to 40,000 feet. The higher one goes, the greater the necessary ignition energy, but experiments show it can happen. It is in part tied in to the readiness with which silver sulfide deposits within a fuel-tank can provide the conductive path between fuel-probe terminal block terminal posts - for an arcing event. <<further, unlike TW 800, there was no fire in the impact area, no reported sign of fire or smoke in the sky, and there have been no reports that I have seen of recovered bodies being burnt or parts of the plane showing fire damage.>>Day event for CI-611 versus a night-time event for TWA-800. I think that makes a significant difference to the observability. One of the ongoing conundrums with TWA800 has always been that passengers sitting right above the CWT weren’t burnt at all. See this link

<<on a bomb planted by al-Qaida, I am quite certain that US carriers do not carry 50 percent of the traffic between Taipei and HongKong as you assert.>>May have been unclear here, I meant a 50:50 Boeing/Airbus possibility. <<remotely fusing a bomb to explode at a certain time or altitude, particularly if it is sequenced to explode after several flight segments, simply lessens the chance that a terrorist will succeed with respect to target and result.>>Decades have passed since AI182 and IED’s have become much more sophisticated. I assure you that you can now timelock-out the baro part for a specified time so that the incident will occur on a second or third leg of its delivery transit. I believe that you can also step-time such that the baro-trigger doesn’t initiate the fusing until the second or third etc climb cycle. We should try not to live in the past, when the technology does exist. <<Sikh bombers who brought down Air India with a bomb off Ireland had another bomb explode on an airport luggage carousel, which led to their being found out. Pan Am 103 had a delayed departure, and crashed on land and not in the middle of the North Atlantic, thus revealing the clues about the bomb and how it got there.>>ipso facto it was a timed device and quite unsophisticated compared to what is now available. <<An Islamic terrorist placed a small bomb in a seat of a Pan Am 747 out of Manila, timed to go off during the next segment. The terrorist disembarked the plane as ticketed. On the next segment, the bomb exploded, killing one passenger, but the plane survived, and the terrorist was caught.

this is not saying that a bomb did not bring down dynasty 611. but rather than jumping to al-Qaida being the culprits (if indeed it was a bomb) one should probably first look at the on-board passenger list. The long history of aircraft bombings would reveal that a substantial percentage of them were planted by individuals seeking insurance monies.>>….together with a long associated history of them not getting those payouts. Given the present high state of terrorist alert, it would be idiotic to play that game nowadays….not that there aren’t idiots out there – or disgruntled ex-employees.

[RatherBeFlying]

Another Wild Guess

With the mil radar showing flight path deviations for a few minutes before the breakup, possibly a fuel vapor explosion in the CWT was not as strong as TWA800 as to blow apart the a/c immediately, but did enough damage to control runs, electric cables and hydraulic lines to render the weakened a/c unflyable or did enough damage that it progressively came apart. A well placed bomb could do the same damage.

If enough electrics were lost the recorders would get no more data so that no post structural damage information will be present.

As for radio calls, the crew would be too busy aviating to communicate.

Likely the wreakage will yield more information than the recorders.

[UNCTUOUS]

The Caltech Study on Fuel Ignition in Tanks

http://www.galcit.caltech.edu/EDL/pu...cit_fm97-5.pdf

This is the study referred to above.

Regarding fuel vapor ignition at > 30,000 feet

Take a look at Figure 3 on p. 3 (9th page of pdf file) and Figure 4 on p. 5 (11th page of pdf file)

These summarize the previous data on ignition that includes tests at a pressure equivalent to >30kft.

[bblank]

I don't see how to reconcile all data from the radar traces
with any of the theories that have been advanced. The two
items below are FYI only. I have no TWA800-type explosion
theory to push. (Also, I am not posting with the intention
of having Mr. Yeh's comments contradict the post of UNCTUOUS that
just appeared).

The first item is excerpted from the May 27 Taipei Times. It was
prompted by an anonymous tip that is said to be from a veteran
pilot not with CI but based in Taiwan. One might be skeptical of
an anonymous tip but in this case the allegation appears to have
been confirmed by a CI exec. I am surprised that this VP said as
much as he did and, unless it is an imprecise English translation,
I am especially surprised by the use of the term "explosion" so
early in the investigation.

From a Taipei Times article:



China Airlines flight CI611 took off with its center tank
nearly empty -- a procedure that Boeing recommended be
discontinued after the US Federal Aviation Administration (FAA)
in 1998 said fuel pumps on older model 747 planes were a
possible source of faulty wiring that could have ignited the TWA
blast.

China Airlines vice president of flight safety, Samson Yeh
(¸*¤S«C), confirmed that the airline had received notification from
Boeing not to run the center tank dry, but that they made their
own safety modifications to eliminate any potential point of
ignition.

"At the time ... I remember we changed the procedure. In terms
of empty fuel tanks we were not supposed to use the fuel pumps
[when we flew with dry tanks], otherwise you will overheat it. I
believe [the maintenance department] also put some insulation on
the wiring, to isolate [potential sparks]," Yeh said.

Yeh did concede that while an overheated fuel tank was "one of
the possibilities" behind the sudden mid-air break up, "this case is
different from [TWA 800] because that one was caused by the
center fuel tank overheating, whereas this one was a sudden
explosion -- which means it's totally different."




The following is from an AP story about the NTSB reps
that are participating in the investigation. I didn't
record the URL. With regard to SR 111 I don't see what
the ASC's lead investigator can be referring to unless
he is speculating about electrical arc tracking in CI 611.
Once again I am surprised by what was said.



The members of the American team, who assisted in the TWA
and Swissair probes, were chosen because "the cases were very
similar," said David Lee, the lead investigator for Taiwan's
Aviation Safety Council.

Taiwanese investigator Lee said there were similarities
with a 1998 Swissair flight from New York to Geneva that went
down in the Atlantic Ocean near Nova Scotia, Canada, killing 229
people.

[Ranger One]

Re: In Reply to Unctuous comments

<<on your scenario (c) a mach overspeed, the max airspeed on the radar trace was 453 knots, at FL 343, which was reached just before a slight drop in airspeed, which may have been coincident with the beginning of the catastrophic event. >> Speed drop may also have been indicative of the commencement of a turn (into the nose-drop spiral) due to the non-asymmetry of lift/drag upon encountering mach buffet – the depressn theory

I can't look again at the trace to confirm - the Taiwan server seems to be down - but I'm pretty sure the quoted figures were groundspeed, not airspeed....

R1