China Airlines B747 Crash (Merged)

[Noctivaga]

Chinese Media is reporting that China Airlines B747 CI 611 has gone missing near ELATO en route to HKG from TPE. As I write this, it is over 90 minutes. Any other info from other sources???:(

[Man-on-the-fence]

From the Beeb

A Taiwanese airliner carrying more than 200 people is reported to have gone missing during a flight to Hong Kong.
China Airlines flight C1611 disappeared from radar screens near the Taiwanese island of Penghu at 0713 GMT, shortly after leaving the capital Taipei, television reports said.

Taiwan's air force and coast guard were looking for the aircraft, a government spokesman said.

[lambchopboy]

A 747-200 by all accounts, however OAG states a 744

:(

[Aeronavigant]

Here is an article from Skynews:

Taiwan Plane Crash: 219 Feared Dead





A China Airlines passenger aircraft has crashed into the sea on a flight from Taiwan to Hong Kong.

The Boeing 747-200 was carrying more than 200 passengers and 19 crew on the 90-minute flight.


The jumbo jet took off from Taiwan's Taipei airport at 3.11 pm local time and disappeared off radar screens 19 minutes later.

Military planes and vessels have been deployed in the area.

China Airlines is the national carrier of Taiwan and the Taipei-Hong Kong route is one of the busiest in Asia.

"The cabinet has formed an emergency team to deal with the situation," said Taiwan government spokesman Chuang Suo-han.

More to follow....

[MrBig]

When oh when are the Chinese authorities from both sides of the 'straights' going to stop killing people. Surely, even they now recognise enormous shortfalls in thier aviation industry?

[Psittacine]

So? 'twas a time when the prune always had the post before the media. But then again navels have always been so captivating.

[JR_wilco]

19th hull loss for CI incl. 3 747´s now.
Type was confirmed as 747-200 (B-18255)
254 plus 19 crew on board.
What a terrible year and a disastrous safety record for CI.
I thought CI had emerged out of their safety troubles and was on the way of rebuilding customer confidence...
Wondering what could have gone wrong. No hint of any emergency call yet.

more @: www.jacdec.de

My condolences and sympathies to all the victims relatives and friends.

[stickyb]

This route is known locally as the Golden Route because of the amount of traffiic it carries. As direct air links betwen Taiwan and mainland China are still banned, a lot of travellers route via Hong Kong.
According to IATA, the route carried 4.7miilion passengers in 200, double the second busiest route between SG and KL.

Cathay Pacific and China Ailines between them do over 80% of the flights. CX does around 15 flights a day.

Local news media is now reporting that at least one body has been recovered from the water.

Condolences too all involved.

[HotDog]

Here we go again! Armchair experts with statistics at hand. You could at least wait until the wreckage is located, not to mention the FDR.:mad:

[HotDog]

This post has been inserted in the wrong place.HD

[stickyb]

Hotdog, my apologies if I offended you. I do not claim to be an expert and I am certainly making no comments on the cause of the crash, just reporting information that others may not have.
I do have the advantage at the moment of having access to local media and the ability to get rt translation from Cantonese and Mandarin to English.

[HotDog]

It's not you stickyb, you are quoting facts not connected to this accident.

[twistedenginestarter]

HotDog
Here we go again!

Just a reminder this is a Rumour Network. That is a network that is concerned with rumours. Maybe you pressed the wrong keys? Maybe you were looking for PPCrCi (The Pussy Preeners Crochet Circle)??

[Alpha Leader]

Hot Dog:

Too much chilli on your dog today?

All posts prior to your outburst are fair comment. Commercial airline operations on either side of the Taiwan Strait over the last 20 years are statistically proven to be of greater risk than in Europe or the US.

No one has ventured any guess as to the cause of the crash, so what's the point of your criticism of previous posters?

[AEROVISION]

New record.

Within 90 minutes of original posting of this tragic accident the slagging has started.
45 years in aviation and 20000hrs in the logbook, sit back and relax Hot Dog.

Best regards
AV

[flch10000]

>I thought CI had emerged out of their safety troubles and was >on the way of rebuilding customer confidence...

Ermmm we don't know the cause yet - it may have been nothing to do with (your implied) Pilot error

>Wondering what could have gone wrong.

Exactly.

[Kalium Chloride]

This better not turn into another TW800 bullsh*t-fest.

[Grandad Flyer]

Another terrible accident.

I cannot confirm or dispute whether China Airlines safety record was improving. But wasn't it China Airlines that took off on a taxi way at Alaska, which was 90 degrees off the direction of the runway (as well as being very narrow and almost too short for the aircraft to get airborne), leaving tyre tracks in the snow bank at the end of it?

[Peanut Butter]

Just a little note:

The plane (747-200D, B18255) is 22.8 years old and logged about 65000 (Edited: 64810) flight hours and 21000 (Edited: 21398) landings. It was to be flown to HK as it's last passenger flight for CI and back to Taipei at night, refurnished and sold to Orient Thai Airlines in June.

So The plane's last passenger flight for CI proved to be the last flight for the plane itself.

More: A check was done May 3rd, B check done April 4th, C check done November 25th 2001. Captain and Co-pilot both have about 10000 hrs and flight engineer have roughly 18000.

Edited again for spelling mistakes. :)

[Whalerider]

Peanut Butter beat me to the same info' - Orient Thai will have to look elsewhere for a replacement.
By the 320 Driver - completely agree with you !!!

[J-Class]

Peanut Butter, that's very interesting...

It seems almost too awesome a coincidence that this plane crashed on its last revenue flight (having said that - Peanut Butter, what's your source for this piece of info?)

I've often wondered about the economic temptation that airlines must have to under service airframes that are about to be sold on. I wonder how many 'known but acceptable' faults this particular B747-200 was flying with...

Does anyone have any first hand experience of CI's record in this particular area? Has anyone, for example, acquired an ex-CI aircraft?

Sorry to be feeding speculation - but that's life and this *is* a rumour network!

[Peanut Butter]

J-Class:

I just happened to be like Stickyb which I know both Cantonese and Mandarin and also having access to local media. (Thank god for Satallite TV!)

[lomapaseo]

I wonder if there's any chance that the forum members could cite a few facts or rumours of facts regarding this accident before insuating defects in safety.

I don't mind commenting about facts and what if's but slagging matches aint my game.

Early on I heard that the aircraft was at 35000 ft, if true, then any fuel in the tanks is surely way above ignition temps.

I also heard that local farmers had found a piece with a logo on it in their field. This could be sgnificant. Anybody with more info?

I can't recall any previous history with B747 that lead to any suspicion of cause for a flight just after reaching 35,000 ft either as a mechanical or crew error

[lomapaseo]

What we really need is the ability to edit the thread titles so that the readers can understand what the cntinuing thread is about.

For instance I've seen thread titles in the past where the title screams that XXX Crashed today !! yet the thread is days old and its really all about an old crash. (figuring that planes crash once a week )

Then we have the multiple threads about this latest China Crash saying the plane is missing, when in fact wreckage has been found.

These thread titles are too time specific and therefor short lived.

If I was a moderator, I would merge them into a more general thread early on.

[christep]

As far as I can tell from HK TV with the aid of some local translation, there is debris spread over a very wide area (on land and sea) which is being taken to show a substantial midair breakup. It is also reported that two nearby CX pilots report hearing a distress call from the CI plane, but there are no further details.

[Thomas Doubting]

On the TV news here they are showing much light weight scattered wind blown debris being picked up on the island. Paper, light weight insulation material etc.

[Peanut Butter]

Christep:

I'm pretty sure the distress calls are from the ELT, There were no radio transmission that I know of which indicates a distress call. I'm also seeing pictures of baggage tags, cash, traveller's cheque and other debris lying around.

There's all sorts of rumors about the cause of the crash like CAT, being struck by a meteor, or even a terrorist bomb plot....perhaps another conspiracy after TWA800? :D

[stickyb]

The airline has posted a complete crew and passenger list, plus other bits of information, here:

http://www.china-airlines.com/us/index.htm

[steamchicken]

Initial media reports said missing. Later confirmed as a loss.

[Analyser]

My condolences and sympathy to the families and friends of those who perished in the crash.
Another sad day for the aviation community.

[El Grifo]

Thats really going to help Analyser.
Talk about well worn cliches !!!
I thought we were going to give up all that crap.
It means ABSOLUTLY NOTHING !!

It is simply Mealy Mouthed Garbage

[steamchicken]

Within seconds, the Boeing vs Airbus neanderthals swarmed in like weird piranhas...

[doggonetired]

Just following on from the "last commercial flight...." point. I have no idea as to the ownership/lease state of the aircraft but if it was subject to some kind of leasing deal they usually require the aircraft to be returned in the state in which it was first obtained. So as such, would have to be kept up to date with maintenance etc. In my limited experience of obtaining previously owned/leased aircraft there are always "minor" tech problems but usually associated with the leasing requirements not airworthiness requirements. For what it's worth...

[Psittacine]

Thanks stickyb.
Can anyone translate and post the Tech Crew names?

[SaturnV]

Excerpts from the New York Times:

"The Aviation Safety Council, Taiwan's air safety regulator, said rescuers began finding bodies and wreckage in the water less than three hours later about 12 miles north of Makung, the county seat of the Penghu Islands near the southern end of the Taiwan Strait. That would put the crash site within Taiwan waters....

"Papers and even foam scraps from the aircraft's seats began floating into rice paddies up to 60 miles east of the crash site on the main island of Taiwan, local television here reported, prompting discussion of whether the plane came apart at high altitude......

"Civilian and military rescuers plan to begin an underwater search on Sunday morning; the plane crashed in about 80 feet of water."

If 80 feet is accurate, that should help in recovery of the recorders. And IF the 'foam scraps from seats' is also accurate, that may indicate an explosive decompression at 35000 feet.

[casual observer]

There are many ways to Romanize Chinese names, especially in Taiwan. I will try to use a simplified variation of Wade-Giles that is commonly used in Taiwan (and China's Hanyu Pinyin in parenthesis)

Captain: Yi Ching-Fung (Yi Qing-Feng)
Co-pilot: Hsieh Ya-Hsiung (Xie Ya-Xiong)
Flight Engineer: Chao Sheng-Kuo (Zhao Sheng-Guo)

[stickyb]

Psittacine, if you follow the link I gave earlier, look at the 1900 hours release, and you will seee the names there, along with such things as flying hours.
Alternatively, here:
http://www.china-airlines.com/us/e_news/2002/20020525b.htm

[Knave]

Terribly sad for all concerned. Media started reporting the story where I live by showing footage of the families as usual being swarmed at the airport by camera crews itching to get that heartbreaking facial expression or first tear. Am I the only one whos getting thoroughly sick of having the media treat the worst moment in these peoples lives as an opportunity to score rating points? If someone did that to me at the airport theyd have a whole new story on their withered little hands.

[Lanastar]

From the Ananova site.


--------------------------------------------------------------
China Airlines jet broke up in the sky.

A Hong Kong-bound China Airlines jet broke up in the sky before crashing into the Taiwan Strait with 225 people on board, says the chief Taiwanese crash investigator.

Military radar provided a clear picture of the Boeing 747- 200 splitting up into four pieces, said Kay Yong, managing director of Taiwan's Aviation Safety Council.

"There was an in-flight break-up above the altitude of 30 thousand feet. We are very positive about this," he said.
---------------------------------------------------------------

[HotDog]

You can hardly blame that on the crew or China Airlines, it would seem.

[Kaptin M]

"There was an in-flight break-up above the altitude of 30 thousand feet. We are very positive about this"............................caused by WHAT??

I wonder if the public will ever be told, during our lives, the real cause of this disaster?
The Pan-Am "tragedy" (during military exercises off the coast) might prove a handy alibi here as well.

What Government ANYWHERE is ever going to admit that its defence forces shot down an airline civilian passenger aircraft.

Only in recent days has the TRUE story of the chopper that was shot down in the Afghanistan war, been released. At the time, it was stringently DENIED that the helicopter was downed by enemy fire, but rather that due to "foggy conditions, extremely bad weather, and heavy snow falls" the 'copter crashed.

If the story line to be pushed is one that this B747-200 "broke up" in flight, then as responsible professionals, we should call for the IMMEDIATE GROUNDING of ALL -200 and -300 747's.

[RatherBeFlying]

Factual New York Times article (http://www.nytimes.com/aponline/international/AP-Taiwan-Plane-Crash.html)

(Free registration may be required to view this article)

[stickyb]

There are now rumours startiing to be carried by some of the local media that there was a live fire military exercise going on somewhere in the area. At this point in time I have no idea if the report is accurate.

[sottens]

Could there be any similarity between TWA Flight 800 and China AL accident?
If I am right, TWA was also a B747-200 and also exploded in the middle of the air.
this was just a thought...

[Frangible]

Just so long as we're speculating wildly, what about PRC fighters that sometimes bump into US spyplanes. Did that military radar that saw the CI 747 break up spot any other a/c in vicinity?

[Wino]

TWA 800 was a 747-100. One of the first ones built and one of the very highest time/cycle aircraft in existance.

Cheers
Wino

[Huck]

I knew an ALPA accident investigator who spent a year full-time on the TWA 800 investigation. He said absolutely no evidence of a missile. No shrapnel marks or punctures that could be lined up through multiple surfaces.

Also, the China Air flight was way too high for a surface to air missile.

I'll say this, though, whether it was a bomb or structural failure, this accident will impact all of us.

[RiverCity]

They also found a China Airlines seat cover that appeared to be stained with blood. Does this seem odd to anyone? If the plane broke up that fast, would there be time for a person to bleed on a seat? I'd think a break-up that fast would preclude any body fluids going anywhere quickly enough to cause a stain.

[Kalium Chloride]

Glance at the Taipei weather shows that temperatures have been in the 80s-90s there. Departure at 14:50 would be at the high point of the day's temperature cycle.

[lomapaseo]

> If the story line to be pushed is one that this B747-200 "broke up" in flight, then as responsible professionals, we should call for the IMMEDIATE GROUNDING of ALL -200 and -300 747's.
<

As long as your a responsible professional could you enlighten us on why your proposed grounding stops at the -200 and -300 models and does not extend to all aircraft and types.

Me thinks that there is more ignorance than understanding to such a proposal.

[El Grifo]

Yeah Huck, I know of a National Government, that said they had absolute evidence that the Libiyans were responsible for downing of Pan Am 103 :eek:

[NigelOnDraft]

Huck...

<<Also, the China Air flight was way too high for a surface to air missile>>

Oh well, my 10 years in the RAF on fast jets obviously taught me all the wrong stuff, and I was wasting my time worrying about SAMs at altitudes above 30,000'...

You presumably are a military expert making statements like this?

NoD

PS And what height do you think Gary Powers was in his U2 when shot down by a SAM-2 in the 1960s...??

[Kaptin M]

Were there any CB's in the area?

[Huck]

Sorry Capt. Nigel in my mind I was thinking of shoulder launched SAM's of the terrorist variety. Admittedly a ground based system with intercept radar could do it, as could a missile "gone ballistic" as happened near Turkey recently.

All I can say to El Grifo is that ALPA pilots wouldn't cover up for Clinton's government, if said government had killed over 50 fellow crew and non-revving employees, as in the TWA accident. The pilot I spoke with lost several good friends on 800.

By the way, my prayers and (mealy mouthed) condolences to those who died yesterday, as well.

[crusin level]

Isn't it amazing how all these "experts" suddenly appear.
why don't we wait for the FDR tapes are read.

remember - lots of "jumbos" flying around the world all the time without mishap.

[El Grifo]

Sorry Huck, I am a little confused. are we talking ALPA Investigators or ALPA Pilots here. Surely totally different breeds of animal.

On the ALPA pilot issue I surely agree with you.

As far as the prayers and Eh, "condolences" are concerned, I suppose we all have our different beliefs and "limitations"

Since a condolence is something which is normally offered, or delivered in person to the families of the deceased. I just find it a little sick making, to see it rattled out in text, on a site which few of the victims, if any, will ever read.

Main reason being of course is that they are eh, no longer with us.

It is truly meaningless and a little silly.

[SaturnV]

The four previous 747 hull losses that began while the aircraft was apparently at FL 300 or higher were: KAL007 (shot down); AI 182 (bomb); PA103 (bomb); SAA 295 (Combi) (fire in a freight container being carried on main deck). UA 811 was at FL 230 when the cargo door ripped away, taking a large section of fuselage skin with it.

The Ukranian surface to air missile that brought down Air Sibir 1812 was supposedly fired from a position 250 km. distant.

[Huck]

All right all right I promise never to post again after more than 2 MGD's. When I said "ALPA Accident Investigator" I meant a TWA line pilot who was an ALPA volunteer accident investigator. TWA's insurers actually paid to have a few of those guys taken offline and put on the investigation for a long time. They participated in the NTSB side of the investigation, which of course was at the mercy of the FBI team. But they did eventually get full access to the recovered pieces that were hung on chicken wire and steel jigs to "reassemble" the fuselage (this monstrosity, I hear, is going to be placed at an NTSB facility for training purposes).

As to condolences, point taken. I think we're all just expressing our own feelings, for our own sakes. This one could be particulary bad because, unlike most, pilots can't see where the crew could have avoided it. Explosion/structural failure accidents are pretty nasty.

[411A]

Wonder if section 41 termination work had been carried out on this aeroplane.....or repairs to the aft pressure bulkhead. Breaking into 4 large pieces seems quite .... unusual.

[Peanut Butter]

Frangible:

According to Taiwanese media the military said that there's no exercises, planes, missiles or ufos. There's nothing.

one more note:

The 747 broke into 4 pieces. The 747 was originally heading south-west (to HK) but 1 of the 4 pieces of the plane ended up going north-east. :eek:

[GlueBall]

30 January 1979 a VARIG 707-323C, PP-VLU (s/n 19235) en route NRT-LAX crashed in cruise, about one hour after takeoff at Narita.
At the time it was believed that the airplane may have been hit by a missle, but the true cause of the crash/disappearance has not been published. The cargo consisted of an art gallery. Ironically, the captain of that flight was the captain of the B707-345C PP-VJZ that had crashed short of Orly in 1973 after an uncontrollable cabin fire.

[Peanut Butter]

This will make some interesting reading....

Flight path and radar data:

http://www.asc.gov.tw/asc/_file/2006/upload/news/CI611-RADAR.pdf

Radio Transmissions:

http://www.asc.gov.tw/asc/_file/2006/upload/news/CI611-ATCtran.pdf

[Shore Guy]

Very interesting are the course reversals and speed degradations indicated from the previous link. Could be stall/spin, breakup ….. could be other scenarios. I hate to add to the pre CVR/FDR analysis, investigations, and conclusions and emphasize this is conjecture. Long-term investigations will, I am relatively sure, will reveal the ultimate culprit.

But…..if there were an explosion of some sort my guess would be that the trajectory would be forward, unless one wing or part of one wing was the first to separate (i.e. relative constant heading/course), I welcome to be contradicted in what should be a straightforward and intellectual discussion…..please don’t let this post degenerate into another PPRUNE bashing of previous posts…. It seems to be heading in that direction. There is immense talent in the members of this forum. It is my fear that some are scared away when a thread rapidly degenerates from a truly informed, intellectual discussion to a traditional PPRUNE bashing ceremony….

[Shore Guy]

As a follow up to my previous post, please look at the number of "posts" vs. the nunber of "views" on this thread. There is certainly immense talent in the "viewers" who have chosen not to post.

[Kaptin M]

Wow, there are some pretty crazy altitude and heading deviations commencing around 15:28.43 - 2,200 feet UP in a 12 second period to 1,800 feet DOWN in the next 12 seconds, accompanied by heading changes of up to 180 degrees.

The altitude, airspeed and heading deviations are indicative of an encounter with severe weather and a possible engine(s) flame out.

Were there any reports of Cb activity at that time yesterday? Is Taipei's radar weather-suppressed?

[SaturnV]

From the May 27 New York Times (Reuters):

"TAIPEI (Reuters) - Taiwan investigators sifted through wreckage of a China Airlines jet Monday to try to find out why it fell apart at over 30,000 feet, but the military dismissed speculation it may have been hit by a Chinese missile.

"Frogmen were expected to recover the black-box flight recorders which could yield information on what caused the Boeing 747-200, belonging to Taiwan's largest carrier, to crack up and plunge into the sea Saturday, killing all 225 people on board in Asia's third major air disaster in six weeks.

"Now that we know the location of the black boxes, we should be able to retrieve them today,'' said an official at the government's emergency response center.

"Fishing boats and naval vessels have so far plucked about 80 bodies and several pieces of wreckage from the rough waters off the west coast of Taiwan.

"The Taiwan military spokesman dismissed speculation that a Chinese missile may have hit the aircraft.

"Communist China has denied it. We think its denial is highly credible,'' the spokesman said by telephone, responding to a report on cable news network Formosa TV which quoted an unidentified military analyst as saying a Chinese missile may be to blame.

"Based on our own judgement, we can also say it's absolutely impossible,'' the spokesman said, adding that Taiwan's military was not conducting any exercises or missile-testing in the area at the time of the crash.

"The emergency response center said signals from the flight recorders showed they were about 20 nautical miles north of the island of Penghu, off western Taiwan.

"They're about 50 to 60 meters (130 to 165 feet) below the surface. They're not difficult to retrieve,'' Kay Yong, managing director of the cabinet's Aviation Safety Council, told reporters."

[lomapaseo]

> But?..if there were an explosion of some sort my guess would be that the trajectory would be forward, unless one wing or part of one wing was the first to separate (i.e. relative constant heading/course), <

I think the issue today is to time the initiation of the event, whatever it was, to the radar trace. It is entirely possible that any possible asymetrical wing effect was later in the sequence (ala TWA800, PA103, AA587)

[unwiseowl]

height + speed changes appear consistant with three stalls and two recoveries????

[N380UA]

In early summer of 1991 LaudaAir lost a 767 due to a reverser deployment in flight. Seeing the variation in altitude as well as in heading, a similar situation could have occurred. Obviously just a guess, based on the info of this board.

p.s. good point Shore Guy.

[lomapaseo]

>In early summer of 1991 LaudaAir lost a 767 due to a reverser deployment in flight. Seeing the variation in altitude as well as in heading, a similar situation could have occurred. Obviously just a guess, based on the info of this board.
<
There have also been other uncommanded deployments in flight documented on DFDR, none of which match the reported traces of CI611.

Also the reported flight envelop for CI611 should have plenty of control margin for an unexpected reverser deployment (unlike the early climb envelop)

[Wino]

Don't leave out the possibility of a struggle in the cockpit either. That BA aircraft made some pretty impressive maneuvers over africa as was very lucky it didn't come apart.

Cheers
Wino

[Jump Complete]

What about fatique? I understand that high density, short range routes are common in that part of the world, which must have an adverse affect on an aircraft that age. The Aloha Airlines 737 that lost half its upper fuselage was got down with just one loss of life. Perhaps this was simular, but more catashropic, or maybe they were simply not so lucky.
What ever the cause, whoever the 'guilty' party( if any) my condolences to the relatives, friends and collegues of the pasengers and crew.

[Ruslan]

Thanks Peanut Butter for links

It looks like plane flown inverted for some time, and it is not clear for me whenever data is based on echo trail or transponder returns for some graph, if transponder has been stop at 15:28:40 it might be debriefs showing echo both on military and primary radar explaining such strange oscillation..

[Clear Air Turbulence]

On the flight path and radar data reports that Peanut Butter obtained. Why would there be a gap in the traces at 15:16? The military data plot shows it dropping 1,000 ft at the same time.

[ijp]

Could very well be pilot error, have lost pieces off of 2 airplanes in the recent past due exceeding airframe restrictions. I also wonder how they get insurance!

[Volume]

Very interresting radar data.

The military plot shows one signal point with about 1000 ft less altitude but maintaines climb afterwards on the same line as before, this looks like a momantary malfunction of the altitude encoder (caused by whatever).
About 10 seconds later the civil radar plot ends for about 100 seconds and then starts again. Altitude is still in coincidence with data before the gap, but heading and altitude shows some deviations from the normal values indicating some trouble. Military data does not look unusual at that time.
At shortly after 7:28 the civil plot ends and the military shows a plane in great trouble with heading reversals.
A altitude gain of about 2500 ft and a ground speed reduction by half together with a heading reversal looks like a half loop upwards. This is followed by total loss of ground speed (which means very steep dive) but only about 5000 ft drop, before military data plot also end (about 3 1/2 minutes later).

Time between first indications of trouble and loss of signal (at the same altitude !) is more than 8 1/2 minutes, and there was no time for an emergency call for any of the 3 crew members ? Verry unusual.

Aviation week online reports, none of the 80 bodies recovered so far show burn marks. Otherweise some sort of fire could explain the temporary signal loss due to loss of electric energy for the transponder, this could also explain the missing emergency call simply because the radio was not avaiable. Very strange alltogether.

Let´s wait for the FDR/CVR and hope data aquisation does not stop at the time the civil signal was lost ...

[SaturnV]

The radar values for heading, airspeed, and groundtrack position are so bizarre and change so abruptly that one has to wonder whether these are all of the same target, or whether this reflects a capture of that part of the plane that presented the greatest cross-section at any moment. There were reports in the press of one part of the plane going 'backwards', while three parts went forward.

[lomapaseo]

>Sorry to sound like a moron chaps, but could someone, in a couple of lines, summarise what happened to this machine? Have tried reading back through these pages but it's all too confusing for someone with a brain the size of a single bacterium.

And yes, I know it broke up in flight but what was the profile and what's the latest theory? Am currently stuck in the back-of-beyond (Portland, USA) and can't find any other info.
<

Good summary Flat Spin, that about sums up where the overall investigation is. Now if only we all can be a little more patient maybe we can work on this, one fact at a time, and slowly break away from this confusion.

[Anti Skid On]

To add to glue ball (and others I think) comments re structural failure, this from airsafe.com

28 April 1988; Aloha 737-200; near Maui, HI: The aircraft had an explosive decompression due to metal fatigue in upper cabin area. The crew was able to execute a successful emergency landing with a significant portion of the upper fuselage missing. One of the five crew members was killed.
Note: Even though no passengers were killed and therefore not a fatal airline event, this mishap is included in this list because of the effect it had on air safety practices. As a result of this accident, there were a number of regulatory changes involving inspection requirements for older aircraft such as the one involved in this event.

Link (http://www.airsafe.com/events/models/b737.htm)

[I. M. Esperto]

Nobody seems to be making the right connections. It is the
August, 1985 B747 crash (JAL 123 Haneda-Osaka, 527 people
killed) that this mostly recalls. It too ocurred after a cabin
event as theyr eached altitude. The aft pressure bulkhead
failed, inflating and blowing off part of the vertical fin. The
plane went into a dutch roll oscillation cycle, flew an erratic
course and began to spiral in, the crew recovered from that and
figured out how to control it but they hit a mountain in Gunma
before they could gain back altitude.
The failure was blamed on a Boeing field repair. It was a high
time plane with lots of operational cycles, a candidate for slow
cycle fatigue if there ever was one.

[Volume]

Big difference between CI 611 and JAL 123 is the loss of radio contact. JAL crew was in contact with the tower all the time between pressure bulkhead rupture and impact. CI 611 first lost transponder contact, regained again but had no more radio contact, although time in trouble lasted several minutes.

[Raas767]

I don't know about overseas, but this accident has received very little press in the U.S. I'm always very suspicious about that. It was buried on page 28 in the Dallas paper.
Someone probably shot the damned thing down by mistake.

[katana.flyer]

Yeah the UK press seem to have let it go too. Plenty in the Taipei Times and other regionals as you would expect. Don't think it's anything sinister, just happened along way away for the average American reader.

Taipei Times is reporting that the recorders haven't been found yet. The signals that were detected may 'have been from ships in the vicinity'.

[PAXboy]

Yeah the UK press seem to have let it go too. Plenty in the Taipei Times and other regionals as you would expect. Don't think it's anything sinister, just happened along way away for the average American reader.
I agree. Perhaps if we were a lot closer to the 2008 Olympic Games in Beijing, people would be taking more notice! When the games arrive, how many nations will allow 'The official Airline of the Games' to carry their competitors?

It will be interesting to see what CI does in the next few years to recover this loss of face before the Olympics.

[TAT Probe]

PAXboy, you said:-
>>I agree. Perhaps if we were a lot closer to the 2008 Olympic Games in Beijing, people would be taking more notice! When the games arrive, how many nations will allow 'The official Airline of the Games' to carry their competitors?

It will be interesting to see what CI does in the next few years to recover this loss of face before the Olympics.<<

Unless you know something that the rest of us don't, I think it unlikely that a Taiwan based airline would be the chosen carrier for a Chines mainland event like the Olympics.

I wish the badmouthing of airlines would cease until facts are known. I have many friends in China Airlines, and it is far from the gash outfit portrayed in many (racist?) posts:(

[J-Class]

Let's get this right, shall we? We've got the same problem going on the thread about the recent B747 crash:

CA = Air China, the international carrier of the People's Republic of China (i.e. mainland China)

CI = China Airlines, the flag carrier of Taiwan, Republic of China.

They are different airlines, from different countries (at least as far as we in the West are concerned), and it's really not that hard!

[TAT Probe]

The "Scraping, banging noise" is more likely the attempts by you and others to scrape the barrel to find minor events like this to batter airlines like China Airlines.

I don't work for them, and hold no particular brief for them, but I do wish that accidents and minor incidents like this tailstrike were not used by the ignorant to defame airline reputations.

If an inquiry finds fault, then OK, lets go for the jugular, but until then we should try to keep a sense of perspective. :(

[Simon W]

Ok, I got another silly question. Roughly how long would a broken up B747 take to fall 30,000 feet to the sea?

[375ml]

Simon, I'd take a stab at approximately 2 to 2.5 minutes for a broken fuselage, although aerodynamic surfaces may take significantly longer due to lift forces and lower terminal velocity.

[jafa]

jeez you guys go on. Being serious for a minute, if anyone actually knows the 41 section mod. status, kindly say.

Thank you.

[GlueBall]

Hey, J-Class: True. But the fact that Taiwan has B registry
blurs the distinction...so do the HKG carriers, as of course do the Mainland carriers, eh? :p

[HotDog]

In answer to the general direction of this thread:DK taught me a useful lesson in the reason behind air accident investigation a few years ago in a meeting at Farnborough. We were discussing the causes behind a particular fatal accident in some depth, when he paused the meeting without warning, saying "sorry guys, we're getting too close to blaming somebody here, let's take a break".

[Rockdoctor]

For what it's worth, Taiwan News and the only English language radio station in Taiwan is reporting that CI have so far refused to respond to a supposed statement by Orient Thai that they did not purchase the aircraft involved.

http://www.etaiwannews.com/Taiwan/2002/05/29/1022635569.htm

Yesterday, the same radio station was quoting Orient Thai as saying that they had inspected the aircraft, but passed on its purchase due to "structural problems".

Obviously significant, if it's true.

[druckmefunk]

The JAL incident was due to a faulty repair that had been carried out (by the manufacturer i think). I can't remember exactly but the aircraft was originally damaged by a tailstrike or something similar and a repair was carried out. Unfortunately, the repair method was not completed correctly (something along the lines of it needed double rivetting, but only a single row of rivets were put in a critical area). Eventually the repair failed with the previously mentioned results.

[Peanut Butter]

Rockdoctor:

In another report CI responded by saying that the deal had already being signed and some of the money already paid. The 747 will be turned over at June 20th to Orient Thai for about US$1.45 million but CI did not reveal any documents. :rolleyes:

[Alpha Leader]

Rockdoctor:

Very intriguing indeed..... If memory serves me well, it was within hours of CI611 crashing that HK TV stations were reporting the fact that the ill-fated a/c had been on its last commercial voyage for CI and had already been sold to Orient Thai.

It is thus surprising that Orient Thai are only now voicing their displeasure at being (wrongly, they say) identified as the buyer of the stricken a/c; you would think they would have tried to put the record straight (if that is indeed what is required) right away. For that matter, I haven't seen anything in the BKK Post or The Nation on this mysterious purchase/no-deal, either.

[Volume]

JAL 123 was a repair of the aft pressure bulkhead after a tailstrike, designed by boeing and performed by JAL mechanics. Unfortunately these guys confused a doubler with a shim on the drawings, resulting in the installation of a gap.filling piece of metal instead of a load carrying structural member.
The high local bending stresses resulting from this led to a very short fatigue life of the repair and to a complete failure of the pressurized fuselage.



something different :

TAIPEI (Reuters) - U.S. crash experts who took part in an investigation into a mid-air explosion of a Trans World Airlines plane in 1996 arrived in Taiwan on Tuesday to help find the cause of a China Airlines crash that killed 225 people.
[...]
Experts from the U.S. National Transportation Safety Board and the Federal Aviation Administration will work with local officials to determine the cause of the disaster.
[...]
"They are familiar with deep sea and salvage operations and are experienced in analyzing wreckage," Kay Yong, Taiwan's top aviation safety official, told reporters.

once again, U.S. specialists investigate whether there might be a problem with an U.S. bestseller ....
gues what they will probably NOT find out ....

Probable accident cause will be pilots error of an untrained third world (= non U.S.) pilot from some unknown country somewhere in the far east or a shotdown by some communist red navy or an explosive device from irak (A nice opportunity to bomb these guys again)

[Vortex what...ouch!]

From Reuters, www.reuters.com

TAIPEI (Reuters) - Taiwan search teams have located the two "black box" recorders of a China Airlines Boeing 747-200 plane that crashed into the sea and killed 225 people, Transport Minister Lin Lin-san has said.

"We have located the position of the black boxes," Lin told a news conference on Wednesday. He did not say when they would begin operations to retrieve them.

On Sunday, officials said search teams had found signals from flight CI 611's cockpit voice and flight data recorders, but said later they turned out to be false.

The Taiwan carrier's Boeing 747-200 broke apart in mid-air on Saturday and plunged into the sea off western Taiwan shortly after taking off from Taipei for Hong Kong -- a scenario similar to the mid-air explosion of a Trans World Airlines 747-100 in 1996.

[wes_wall]

Is there a possibility this could be another TW800 situation. I thought that at a high altitude the fuel would not explode. Is this not correct?

[UNCTUOUS]

Most probably a TWA800 replay however,
There have been a few other theories put forward hereabouts

In a Classic, how easy would it be for this climb scenario

a. a depressurisation problem to go unnoticed in the climb?

alternately (and much more likely)

b. circa 15,000ft in climb, Pilots/FE stuff around trying to rectify a pressurisation -problem and forgetting to go on oxygen/descend, pass out (with cockpit door locked) due to a T.U.C. in the climb of about 2.5 minutes (only)

or

c. FE accidentally opens outflow valve(s) at height in climb whilst trouble-shooting (possibly trouble-shooting systematically a failure to pressurize that's actually due to a hull rupture). Pilots/FE pass out and aircraft enters powered spiral and breaks up. Does the Classic FE have exclusive access to pressurisation controls, cabin altimeter and outflow valve?

If the aircraft had not pressurised, crew passed out - and the aircraft continued climb on autopilot, what would happen at top of climb? Would the aircraft accelerate into a Mach comp encounter (FL330 to FL350, about M0.89 I'd guess) and then lose it laterally (Classic autopilot unable to cope with the non-symmetric lift, enters spiral and breaks up at about 30,000ft).
Just interested in this as a poss scenario because airline crews receive very little hypoxia or altitude chamber training (if any).
**************

It's equally possible that it was an altitude-triggered bomb in the cargo area (or a cargo-hold fire that could rage there undetected in an old 747). For Al Qaeda to get a bomb into some air-freighted shipment - too easy by far. If they wanted to throw international commerce into total disarray, what better way? How many pax would then be happy to travel on an airplane with unchecked airfreight containers? We know that no more than a few percent of all air-freight is ever checked and then go on to be held in secure areas. So what happens when airlines cannot make up for the lack of passengers by jamming holds full of opportunity air-freight? They go broke that much quicker. If I was advising Al Qaeda, that's what I'd be telling them to go for. They can get away with it about four or five times before public outrage would force a change in air-freighting security procedure. Imagine by how much air-freight costs would zoom if all air-freight had to be secured and guaranteed world-wide?
***************

Cargo door blow-out

[I. M. Esperto]

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

:confused:

[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]

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]

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 :D )

[UNCTUOUS]

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]

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]

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 (http://www.pprune.org/forums/showthread.php?s=&threadid=54563). 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 (http://www.geocities.com/Eureka/Concourse/7349/twa801.html)

<<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]

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]

http://www.galcit.caltech.edu/EDL/publications/reprints/galcit_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 (http://www.taipeitimes.com/news/2002/05/27/story/0000137770):



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]

<<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

[Shore Guy]

Underwater cameras give first glimpse of submerged China Airlines wreckage

By WILLIAM FOREMAN
The Associated Press
5/31/02 4:34 AM


TAIPEI, Taiwan (AP) -- Murky underwater video footage provided the first glimpse on Friday of the submerged wreckage of a China Airlines jet in the Taiwan Strait: a battered luggage container, a dining cart and a wing ripped from the plane's body.

Investigators are trying to determine why the Taipei-Hong Kong flight suddenly broke apart 20 minutes after takeoff on Saturday and plunged into the sea before the pilots could send a distress signal. The crash killed all 225 aboard the Boeing 747-200.

Hundreds of relatives attended a Buddhist memorial service for the victims of the crash on Friday. They bowed before strips of symbolic yellow paper that filled the walls of an auditorium in the capital, Taipei.

The underwater images shown to reporters were filmed by naval underwater video cameras 200 feet underwater about 25 miles north of the Penghu island chain, off Taiwan's west coast.

The cameras showed a wing that appeared to have been ripped from the plane's fuselage. Nearby was a section of an overhead luggage compartment and a dining cart.

Investigators still declined to speculate on the accident's cause.

Raising the wreckage could take time, investigator David Lee said. Strong currents and high waves were making diving conditions unsafe, he said.

"The divers haven't been able to go into the water very much," Lee said.

At another spot nearby, divers were closing in on the plane's "black boxes," or the voice and flight data recorders, Lee said. The devices might be key to explaining why the plane went down.

So far, no bodies have been seen in the underwater footage, Lee said. Less than half of the victims have been found, and relatives mourned those killed Friday at Buddhist funerals traditionally held seven days after a deadly accident.

At the large ceremony in Taipei, a chorus of monks and nuns chanted Buddhist scriptures to put the dead souls to rest. About 400 relatives joined airline executives in dark suits and pilots in their white uniforms.

Yu Chia-yi and her two siblings lost their mother, who was on a group tour to China. A picture attached to a symbolic yellow paper strip showed the woman in her 50s smiling in her newly permed hair.

"We had encouraged mom to travel and enjoy herself now that we have all grown up and can take care of ourselves," said a sobbing Yu.

Nearby, a woman mourning another victim put two bags of sweets on a table of dishes being offered to the dead.

"These are the candies mom loved most," she said.

Meanwhile, Taiwanese investigators briefed a newly arrived team from American Underwater Search and Survey Ltd., which specializes in deep-sea recovery, Lee said. The company, which searched for a TWA flight that crashed in 1996 near the coast of Long Island, N.Y., had been hired to help with the recovery.

It is customary for Taiwanese airline leaders to resign after a crash, and the 10 board members of the quasi-governmental foundation that owns a controlling stake in China Airlines have stepped down. It was not certain how many, if any, would be asked to keep their jobs.

Those who resigned included China Airlines Chairman Y.L. Lee and President Philip Wei. Traditionally, the airline's chairman and president are board members of the foundation, called the China Aviation Development Foundation. If they are not rehired, they might also lose their top jobs at the airline.

[Shore Guy]

From ATW's news...no further source listed....

Recorders recovered from China Airlines crash
Dateline: Monday June 03, 2002

Searchers recovered the FDR and CVR of the China Airlines 747-200 that crashed on May 25.

Investigators said it will be several months before all the wreckage is recovered. So far, less than 1% has been found, the largest piece being the vertical stabilizer. Sea floor depth in the search area is 165-265 ft. A majority of the bodies recovered so far have broken bones and dislocated jaws but no evidence of burns. Most bodies are from the rear of the aircraft.

[christep]

I just have to ask this... "broken bones" I understand, but why, in particular "dislocated jaws"? Can anyone explain this?

(Just out of idle, ghoulish curiosity)

[Kaptin M]

My money is on an encounter with Severe Weather - but then again airline inflight catering DOES have a reputation!

[bblank]

Based on the radar data Taiwan's Aviation Safety Council (ASC)
originally said that CI 611 broke into four large pieces.
The ASC apparently has hinted that the original interpretation
of the radar, whether right or wrong, was hasty. According to the
Taipei Times of May 31:



"The council later said it needed to double-check radar data
to verify whether the aircraft had indeed disintegrated into four
pieces."



China has now made their radar data available. The excerpt below
refers to "the last eight seconds." That is exactly what was
reported (but it was filtered first through a television
journalist and then through a print journalist).



Officials from the Civil Aviation General Administration of China
will deliver the desired radar data at Beijing airport.

The television reported that Liu Yajun, a Chinese aviation official,
told reporters in Beijing the radar data contained the ill-fated
plane's altitude and the direction of the flight at the last moments.

"The reading from the radar screen indicated the plane flying up
twice and down once ... in the last eight seconds," Liu said.



Finally, there was another article in which Hsieh Ching-hui,
who, if I correctly understand the article, is the leader
of a government task force, raised some questions about the
condition of the a/c based on its sale price.



As to the matter of the aircraft's age, Hsieh said that the plane
had operated for over 22 years and that China Airlines intended
to sell the plane to a domestic airline firm in Thailand for
US$1.45 million, which is considered a relatively low price.

"Is such an old plane appropriate for use as a passenger jet? The
age of the plane and its low sales price seem to imply that the
plane was in bad condition," Hsieh wondered aloud.



Kaptin M: I have tried to fit the radar data to four trajectories.
I cannot do so without the presence of severe weather. But the
ASC has said that there wasn't any.

[atakacs]

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....

Anyone with a source for these charts ? Seems they have vanished from the net... :confused:

Regards

[Ranger One]

Anyone with a source for these charts ? Seems they have vanished from the net...

atakacs:

From PB's original post:

Flight path and radar data:

http://www.asc.gov.tw/asc/_file/200...CI611-RADAR.pdf

Radio Transmissions:

http://www.asc.gov.tw/asc/_file/200...611-ATCtran.pdf

They are now available again, the speeds quoted are indeed groundspeeds.

R1

[atakacs]

They are now available again, the speeds quoted are indeed groundspeeds.

:confused:

Doesn't work for me... Can anyone confirm that those files are indeed at the mentioned URL ?

[Ranger One]

Doesn't work for me... Can anyone confirm that those files are indeed at the mentioned URL ?

grrrrrrrrrrrrrr

That site must be up and down more often than.... errr something that's up and down a hell of a lot! It was fine for me half an hour ago, now it's dead. Keep trying.... I've saved a copy of the radar data, if the site is totally fubared I'll post in in the pprune files area... errrr do we have a files area?

R1

[atakacs]

If you feel so inclined could you forward me the file by e-mail:

[email protected]

Thanks & regards

--alex

[Ranger One]

If you feel so inclined could you forward me the file by e-mail:

Done.

R1

[Anti Skid On]

Another 747-200 of China Airlines is listed by Ansett (http://www.ansettworldwide.com/capacity_exchange/view_capacity.asp) as for sale (S/N 21843) - and also a 742 freighter. Would be interesting to know the hours/cycles of those, and whether they will be looked at as part of the investigation.

[Shore Guy]

^^^^^^^^^^^^^^^^^
Server won't take entire article in single post (too large) - sending in two posts
^^^^^^^^^^^^^^^^^^

By Michael A. Dornheim/Aviation Week & Space Technology

03-Jun-2002 11:40 AM U.S. EDT



LOS ANGELES -- Investigators of last week's top-of-climb disintegration of a China Airlines Boeing 747-209B are engaged in a month-long effort to retrieve 80% of the wreckage.


Major pieces of the airplane and the black boxes were located last week in the Taiwan Strait but not immediately recovered because of strong currents and high seas. At least 92 bodies had been found in the water by late last week, and the 209 passengers and 16 crew are all presumed dead.


The unusual accident with no obvious cause raises anxiety in a region that's home to many 747s and has an accident rate that varies greatly among carriers. Memories of the TWA Flight 800 inflight fuel tank explosion in July 1996 linger, especially since the ignition source was not definitively found.


China Airlines Flight 611 took off from Taipei's Chiang Kai-Shek International Airport at 3:08 p.m. local time on May 25, heading southwest on a 1.6-hr. flight to Hong Kong. Twenty minutes later, the final radar transponder signal indicated 33,500 ft. altitude, then died at 3:28 p.m. The skin echo broke into four separate track groups on a military radar. There were no distress calls; the crew talked to air traffic control at 3:16 p.m. to confirm they were cleared to 35,000 ft., and that was the last message heard from them.


The recorders were found at 23 deg. 35 min. N. Lat., 119 deg. 24 min. E. Long., where the ocean is 40-80 meters (130-260 ft.) deep. Near that location searchers using sonar also found a large piece of wreckage about 130 X 30 ft. in size.


The Aviation Safety Council (ASC) of Taiwan is conducting the investigation. The U.S. NTSB sent a five-man team headed by Greg Phillips as the accredited representative, and the FAA sent three people. Boeing and Pratt & Whitney personnel are also at the search headquarters at the Makung region on the Penghu Islands several miles east of the accident area. Information is being posted on the ASC Web site at www.asc.gov.tw.


The air traffic controller following Flight 611 noticed the data line indicating actual altitude disappear at 3:28:03 p.m., and the entire signal disappeared on the next radar sweep, said Kay Yong, managing director of the ASC. The controller called Flight 611 repeatedly but was unable to raise them, and other controllers were not able to find the aircraft. The civil radar does not have the power to detect primary skin echoes, Yong said.


The Taiwanese military provided the ASC with primary radar data. They show the aircraft moving at about 430 kt. on a 226-deg. ground track, then breaking into four track groups. Curiously, one of these groups moves in the opposite direction of 50 deg. at a speed of several hundred knots, Yong said. It is not yet clear whether this is a radar anomaly or the actual motion of the objects. The military data are not individual skin echoes but fused tracks based upon several radars, and so far the military has been reluctant to discuss radar algorithms that could cause strange results, e.g., from the many echoes of a cloud of debris. The viewing geometry may also give some speed ambiguity on short-duration tracks.


"We can't assess the possibility of a midair collision right now," Yong said. "We need more radar data." Through the NTSB, the ASC has asked the U.S. Defense Dept. if it has any radar data covering the accident. It is asking the same of China, and would like helpful satellite pictures as well.


The sound beacons from the flight data and cockpit voice recorders were located on May 29, but ocean currents were too strong to retrieve them with divers or a remote-control submersible. The currents vary daily. A boat was keeping a round-the-clock vigil on the recorders in case the current moved them. Fishermen say there are small local ocean floor trenches in the area. The batteries for the sound beacons should last 20-30 days.


The wreckage found nearby is believed to be a piece of the fuselage. A boat used its anchor to scratch the metal and found green zinc chromate primer paint, indicating it is an aircraft part and not other debris. High currents prevented recovery late last week. Pieces already recovered include a trailing-edge flap and the leading edge of the vertical stabilizer.


"Personally, I think the wreckage is more important than black boxes," Yong said. He aims to retrieve 80% of the wreckage in 30 days and reconstruct it on the Penghu Islands, but as of late last week he estimated that less than 1% of the wreckage had been recovered. The ASC has engaged Massachusetts-based American Underwater Search and Survey Ltd. to help with recovery. The company worked on the TWA Flight 800 recovery. The search area on May 28 was 16,129 sq. km. (6,230 sq. mi.), according to Transportation and Communications Minister Lin-shan Lin. Fortunately, northwest ocean currents tend to push wreckage away from a 150-200-meter-deep oceanic trench.


The recovered bodies are mostly intact but with broken bones. There has been no sign of a fire in the bodies or the debris so far, Yong said. At 33,500 ft., Jet A fuel would be flammable from 135F down to 60F or lower, and it is plausible that the fuel would still be in this temperature range just 20 min. after takeoff (AW&ST July 7, 1997, p. 61). It is not known yet what type of fuel was in Flight 661.

[Shore Guy]

Part Two......


INVESTIGATORS HAVE RULED out weather and air traffic control as causal factors. The weather in the area was clear with winds at 35,000 ft. about 40 kt. and no turbulence or icing.


Government officials did not think it was an on-board bomb or a missile attack from China. "We haven't found any evidence suggesting the possibility of a missile launch," said Lai Huang, deputy director of Taiwan's National Security Bureau. He also ruled out a terrorist attack. Officials said Taiwan was not conducting any live ammunition drills that day. Nonetheless, the one radar track in reverse direction is puzzling--if it is a valid track. Police have brought explosive detection equipment to the crash site, and investigators are reviewing videotapes from the baggage and immigration counters, as well as records of luggage X-rays.


The aircraft, tail No. B18255 and Boeing serial No. 21843, was delivered to China Airlines in July 1979 and had accumulated about 64,800 hr. and 21,398 cycles. "It's not high cycle compared to other 747s--there are others above 30,000 cycles," a Boeing official said. The aircraft was previously registered as B1866 and was re-registered in the late 1990s. An A check was performed on May 3 and a B check on Apr. 4. It finished a major C check on Nov. 25, 2001, and the next C check would be due Nov. 25 this year. It was powered by Pratt & Whitney JT9D-7AW engines.


China Airlines had five 747-200s but the other four flew cargo; B18255 had been the only one carrying passengers for several years. The Transport and Communications Ministry ordered the four remaining aircraft grounded, affecting a dozen cargo flights per week.


The captain of the flight, Ching-Fong Yi, joined China Airlines on Mar. 1, 1991, and had a total of 10,148 flight hours, including air force service. The copilot was Yea Shyong Shieh, who joined China Airlines on Feb. 1, 1990, with 10,173 hr. The flight engineer was Sen Kuo Chao, who joined the company on Mar. 1, 1977, with 19,117 hr.


Flight 611 was to be the final passenger trip for the aircraft under China Airlines ownership. Orient Thai Airlines was negotiating to buy B18255 and had made a good-faith deposit, but the deal had not been completed. The private Thai carrier is based in Cambodia.


The crash is China Airlines' fourth major accident since 1994 and the 18th since 1960. On Mar. 26, 1994, an Airbus A300-600R crashed at the Nagoya Airport, killing all 264 people on board. On Feb. 16, 1998, an A300B4 on a flight from Bali plowed into a row of houses on approach into Chiang Kai-Shek International, killing all 202 passengers and crew. On Aug. 22, 1999, an MD-11 with 315 passengers flipped over on landing at the Hong Kong International Airport. Fortunately, only three passengers succumbed to their injuries.


The accident has affected the carrier's plans. A code-sharing agreement with Delta Air Lines was to be announced on May 31, but this has been delayed "so CAL can focus on more important things," such as dealing with the accident, a Delta official said. However, "the code-sharing will begin; it's just delayed," the official said.


On May 28, Taiwan's premier, Shyi-kun Yu, said the airline would be privatized within two years, but the China Aviation Development Foundation (CADF), which holds 71% of China Airlines stock, said now isn't the time to privatize because of the weak price. The majority of CADF's board members are appointed by the Transport and Communications Ministry, giving the government effective control. CADF Chairman Jaw-Yang Tsay was the transportation minister until he resigned in 1994 following the Nagoya crash.


Some Taiwanese legislators berated the carrier and criticized the appearance that the ministry both oversees airline safety and also in some manner owns the airline. "We will look at that relationship if necessary," Yong said.


A SEPARATE BRANCH of government unique to Taiwan called the Control Yuan is also taking a role. The Control Yuan is similar to an Inspector General's office, but with more power than in most countries. It has formed a task force to examine issues raised by the accident, such as airplane preflight inspection, whether the May 3 A check was adequate, pilot training, company management of personnel and government supervision.


Task force chief Ching-hui Hsieh said the 23-year-old airplane was being sold to Orient Thai for a low $1.45-million price. "Is such an old plane appropriate for use as a passenger jet?" he asked. "The age of the plane and its low sales price seem to imply that it was in bad condition."


Stephen Rehrmann, vice president of the Morten Beyer & Agnew aircraft valuation firm, said a Stage 3 747-200 of that vintage would be worth about $7.5 million if it were halfway to an airframe D check and engine overhaul, and terminating fixes to major service bulletins had been accomplished. But the noisy JT9D-7AW engines are not Stage 3-compliant, and if the aircraft was near major overhaul (which could cost $8 million) and expensive service bulletins had not been accomplished, the value could be near scrap.


The Control Yuan's power to reprimand frightens civil servants, and some fear their reaction may be to protect themselves rather than to cooperate to find the cause of the crash.


William Dennis contributed to this report from Kuala Lumpur.

[Shore Guy]

Hope I'm not considered a thread hog ...but here is some interesting news from todays (6-4) Taipei Times.

China's data reveal details of CAL crash

DISASTER INVESTIGATION: Radar information provided by Chinese aviation experts shows that unusual changes in air speed may be responsible for the 747's break up

By Chang Yu-jung
STAFF REPORTER

Radar data provided by China to assist in the investigation of the crash of China Airlines' flight CI611 shows that the Boeing 747-200 experienced unusual changes in speed during its last 11 minutes before breaking up in mid-air and plunging into the Taiwan Strait, KMT Legislator Mu Min-chu (¿p»Ô¯]) said yesterday.

Mu, who received the optical disk containing the data from Chinese officials on Sunday, released at a press conference the views of the Chinese officials who viewed the data. The press conference was held just before she was to hand the disc to the Cabinet's Aviation Safety Council (ASC, *¸¦w·|).China's radar data
* Information provided by China shows the plane experienced unusual changes in speed prior to crashing.
* Chinese officials support the Aviation Safety Council's view that the plane broke into four pieces at an elevation of more than 9,100m.

Mu traveled to China on behalf of the private Cross Strait Trade Association (¥xÆW®ü®l¨â©¤Áp¦X¸gÀÙ¶T©ö¨ó·|) and returned to Taipei early yesterday.

Mu said that Chinese aviation experts told her that they had ascertained from the data that the fluctuations in air speed were "unusual and believed by the Chinese officials to be the key to the accident."

The data showed, she said, that in the 11 minutes before the aircraft disappeared from radar, it had continued to gain altitude but its speed had decreased from more than 800kph to 752kph. Its speed then increased again to more than 850kph.

"It is unusual for a plane that is climbing to slow down suddenly and then accelerate again," Mu said.

The Chinese officials concurred with the ASC's view that the plane broke up into four pieces at an elevation of more than 9,100m.

The ASC said that it would examine the data and integrate it with information from local aviation authorities for further analysis.

Asked whether the ASC agreed with the Chinese aviation experts, ASC investigator Tracy Jen (¥ôÀR©É) told the Taipei Times that while investigators appreciated China's help, "It is too early to draw any conclusions before we have the data analysis from the laboratory because we presume that the information provided is very general."

The ASC said that a preliminary description of the new information would be released within 48 hours.

Taiwanese naval vessels and fishing boats have been scouring the sea for bodies and wreckage since the CAL flight crashed 11 days ago.

Only 102 bodies have been recovered and the crucial "black boxes" -- the flight data recorder and the cockpit voice recorder -- have yet to be found. The jet crashed with 255 people aboard on May 25.

Taiwan's Straits Exchange Foundation (®ü°ò·|) requested China's assistance on Friday, but China responded to the Cross Strait Trade Association, which was founded by KMT Legislator Ho Jyh-huei (¦ó´¼½÷) and is dominated by KMT legislators known to have good relations with China.

According to Jen, Taiwan has also asked the US to provide satellite data for the investigation and is awaiting a response.

A second tape showing submerged wreckage filmed by an undersea camera attached to a navy minesweeper was screened in Penghu yesterday for the benefit of relatives of the victims. An earlier video was shown Friday.

According to China Airlines, the tape showed some first-class seats and the front cargo cabin but a large part of the wreckage filmed was covered by sand.

[UNCTUOUS]

<<ascertained from the data that the fluctuations in air speed were "unusual and believed by the Chinese officials to be the key to the accident."

The data showed, she said, that in the 11 minutes before the aircraft disappeared from radar, it had continued to gain altitude but its speed had decreased from more than 800kph to 752kph. Its speed then increased again to more than 850kph.

"It is unusual for a plane that is climbing to slow down suddenly and then accelerate again," Mu said.>>

Starting to look like an insidious (rather than explosive) decompression i.e. HYPOXIA (further explained and supported by the failure of the pilots to signify to ATC that anything at all was wrong- in that last 11 to 12 minutes during the large speed excursions).

And so that would make the rapidly subsequent loss of control/breakup due to no-one in the office being awake. (as described earlier on in my page 7 post on this thread). A cockpit invasion/ fight in the cockpit might explain the speed excursions (as might a large C of G change due to pax rushing or being herded from one end to the other) - but hypoxia brought on by switchology or hull rupture seems more likely.

<<Nonetheless, the one radar track in reverse direction is puzzling--if it is a valid track.>> (possibly an operating engine and a section of wing and still briefly under thrust - it would take off fairly quickly on its own, for a very brief period).

[bblank]

<<Nonetheless, the one radar track in reverse direction is puzzling--if
it is a valid track.>> (possibly an operating engine and a section of
wing and still briefly under thrust - it would take off fairly quickly
on its own, for a very brief period).


If it is a valid track then this piece initially ascended over
2000 ft and then, on the way down, nearly two minutes after
break-up, reversed its vertical direction, substantially increasing
groundspeed, and ascended at least around 400 feet. How do you account
for that under your theory?

[jafa]

If someone replied I missed it - does anyone have the mod status of the 41 section and the fuse pins. Thanks.

[Sick]

The ground speed deviations are hardly huge (+-25-30 kts)- easily due to eg climbing through layers of different winds.

[UNCTUOUS]

bblank
The range and bearing accuracy of a military radar depends upon the type (PRF,PW,Scan Rate, band etc) - but the greatest factor would be the distance of the radar head from the scene of the incident and whether it was on all-round scan (at the time) and how long until/whether it was switched to sector across the area of interest (thereby increasing the paint-rate). With no skin paints from the civil ATC radar, it was suddenly a matter for the investigators of trying to marry up a myriad of radar plots (secondary giving way to a number of primary returns deduced from radar tapes from an unknown number of military sites). The inaccuracies that creep in are related to time-locking the radar sweeps (remember the Valujet debate over that). In addition of course, you have the loss of echo persistence when the primary target dissolves into a number of tumbling pieces. Some primary radars use Doppler or MTI circuits to guess ahead and can easily pick up another (different) piece of nearby wreckage that happens to be presenting a good cross-section at that instant. The resulting deduced track-plot of "debris" might be totally skewed by invalid data. And so the end result of any multi-radar correlated plot might be so much wishful thinking (or at best, the best guess, and possibly useless for any meaningful deductions).

The speed variation might be the best indication of what eventually happened. One explanation of the airspeed discrepancies 750-850kph may be that as they climbed, a door or hatch may have part-opened / lost its seal and started a vibration. Varying the speed within a reasonable band can give a crew the clue as to whether it's aerodynamic or not (or maybe engine-related). Let's say that they concluded that a door or hatch was part-open (seal blown or something lodged in the seal) and that seal finally gave way and caused alarming noise/vibration. If the engineer then went aft and maybe did something a bit adventurous or foolhardy?.... Or maybe it was just the noise-investigation varying-of-speed prelude to a door/cargo-door letting go (of its own accord) as they climbed higher. It may have been (post-maint) some thermal/acoustic blanket stuck in an outflow valve (that's happened in the not too far distant past). Probably a good idea NOT to climb higher in such a situation (i.e. keep the pressure differential down, descend at low IAS).

Inflight trouble-shooting rarely works out happily.....best done on air-tests without pax.

[bblank]

"The resulting deduced track-plot of "debris" might be totally skewed
by invalid data. And so the end result of any multi-radar correlated
plot might be so much wishful thinking (or at best, the best guess,
and possibly useless for any meaningful deductions)."

UNCTUOUS, that was my point. The ASC called the reverse direction
track "puzzling" for good reason. Until it is understood it can't
really be used to support any particular theory. A long time ago
I worked on radar problems that involved deliberately introduced
"debris." Balancing the two possible errors of a statistical
decision algorithm (false positives and false negatives) is an
especially tricky problem in this setting.

[Anti Skid On]

Apologies re. the Ansett link; didn't realise the same aircraft was/is still being advertised there (thanks Shore Guy - I mistook the reg as the Boeing serial no.)

[bblank]

Excerpted from the June 6 Taipei Times (http://www.taipeitimes.com/news/2002/06/06/story/0000139142)



Data show flight CI611 broke up during ascent

With the assistance of data provided by China, authorities have also
concluded that the plane's speed and heading were highly erratic before
the accident.

Chinese radar data given to Taiwan has helped confirm that the
ill-fated China Airlines flight CI611 broke into four pieces during
its ascent, an official from the Aviation Safety Council said yesterday.

Council Managing Director Yong Kay (¦¥³Í) yesterday confirmed
that the plane broke apart at an altitude of between 10,360m and
11,250m and that the aircraft's speed and heading were highly
erratic in the moments before the disaster.

"The data are very consistent. It shows the plane had not
reached cruising altitude when the accident occurred,'' said
Yong.

"Before today, we thought that the plane had actually reached its
cruising altitude -- which is at about 10,668m."

Meanwhile, radar information provided by Beijing's Chinese Civil
Aeronautics Administration shows that the aircraft flew at varying
speeds and in the wrong direction two minutes before it hit the
water. Taiwan's radar systems failed to register this data, officials
said.

"To sum up the information that we have, we can confirm that the
aircraft broke into four pieces. According to the radar data, one
piece of the debris reached a height of 11,250m after the plane
broke up" Yong said.

"In addition, Chinese radar information shows that the plane
briefly flew at the wrong speed and in the wrong direction before
it crashed. Unfortunately, we do need the `black boxes' -- the
flight data recorder and the cockpit voice recorder -- to confirm
our observations."

Yong said radar data shows that it took approximately 1 minute
and 40 seconds for the biggest and heaviest debris to fall into the
sea and 1 hour and 30 minutes for the lightest piece to "float"
down and finally land.

After the crash, Tainan radar recorded unidentified material
"floating" in the air and finally disappearing above Changhua
County.

Aircraft passengers' belongings, found by investigators in the
Changhua area, confirm the radar information.

[SaturnV]

>"In addition, Chinese radar information shows that the plane
briefly flew at the wrong speed and in the wrong direction before
it crashed."<

I fear something is being lost in the translation, and clarity may have to await release of the radar track values for all four parts of the plane. It is hard to envision how an intact plane could achieve the values already published, such as for the 36 seconds below:

time/heading/speed/altitude
15:28.31 224/452/347
15:28.43 070/413/347
15:28.55 057/417/369
15:29.07 186/241/351

For what its worth, a similar number of TW 800 bodies were recovered floating on the seasurface as were recovered from CI611. Approximately 10 percent of the TW800 floating bodies showed evidence of thermal burns, generally first and second degree. Apparently, there is no indication of burns on the CI 611 bodies recovered from the seasurface.

[UNCTUOUS]

Possibly Relevant

1.17.01 Previous Cargo Door Incident

On March 10, 1987, a Pan American Airways B-747-122, N740PA,
operating as flight 125 from London to New York, experienced an incident involving the forward cargo door. According to Pan Am and Boeing officials who investigated this incident, the flightcrew experienced pressurization problems as the airplane was climbing through about 20,000 feet. The crew began a descent and the pressurization problem ceased about 15,000 feet. The crew began to climb again, but about 20,000 feet, the cabin altitude began to rise rapidly again. The flight returned to London. When the airplane was examined on the ground, the forward cargo door was found open about 1 1/2 inches along the bottom with the latch cams unlatched and the master latch lock handle closed. The cockpit cargo door warning light was off.

According to the persons who examined the airplane, the cargo door had been closed manually and the manual master latch lock handle was stowed, in turn closing the pressure relief doors and extinguishing the cockpit cargo door warning light. Subsequent investigation on N740PA revealed that the latch lock sectors had been damaged and would not restrain the latch cams from being driven open electrically or manually. It was concluded by Boeing and Pan Am that the ground service person who closed the cargo door apparently had back-driven (opened) the latches manually after the door had been closed and locked. The damage to the sectors, and the absence of other mechanical or electrical failures supported this conclusion. Further testing of the door components from N740PA and attempts to recreate the events that led to the door opening in flight revealed that the lock sectors, even in their damaged condition, prevented the master latch lock handle from being stowed, until the latch cams had been rotated to within 20 turns (using the manual 1/2 inch socket drive) of being fully closed. A full cycle, from closed to open, is about 95 turns with the manual drive system.

[yellow dust]

Is anybody else suspicious that the recorders have not been found? Surely by now they would be. I wonder if they have been recovered and the data is not such that the authorities want known? Conspiracy, anyone?

[atakacs]

Is anybody else suspicious that the recorders have not been found? Surely by now they would be

I agree that it's surprising knowing that the beacons have been located... Anyone with local sources ?

[Kaptin M]

I hate to admit it, yellow dust, but I expressed EXACTLY those words to the F/O I was with today.

TWO WEEKS, and the "black boxes" have STILL not been recovered??!!

[Dr Dave]

I believe that the reason for the lack of recovery of the Black Boxes has at least in part been the presence of a typhoon in the area. This is Typhoon Naguri, which is currently situated off the NE coast of Taiwan, having routed from the South China Sea to the south of Hang Kong, initially eastwards then northwards parallel to the Taiwan coast.

Although the typhoon has been some distance from the crash site, it is enough to cause signifcant swells that make underwater operations in the shallow water of the Taiwan Straights very difficult. It is likely that the debris is also being redistributed by these processes.

Unfortunately we are now at the start of the typhoon season, so recovery of the debris is urgent.

Incidentally, the typhoon may also be an interesting factor in Wednesday's World Cup match, being forecast to route along the east coast of Japan over the next two days.

Dr Dave

[bblank]

Good grief! It's never too early for conspiracy theories, is it?

American Underwater Search and Survey, the outfit used by the NTSB, is
on hand mapping the seabed. They may be hampered by weather as Dr. Dave
has suggested, but, according to the ASC, nothing is being recovered
because Taiwan lacks the specialized equipment needed for the salvage.
They have hired Global Industries (http://www.globalind.com) for that.
The divers and equipment are not scheduled to arrive until June 14.

[warp factor]

Heard rumour from Taiwan maint rep that structural failure
is possible cause

[Shore Guy]

Time Running Out for Taiwan to Find Crash Black Boxes
TAIPEI (Reuters) - Nearly three weeks after a China Airlines jet crashed mysteriously killing 225 people, Taiwan is running out of time to retrieve the "black boxes" from the ocean floor with signals from them weakening and possibly stopping in days.

Though the location of the cockpit voice and flight data recorders have been known for more than two weeks, officials said on Tuesday choppy seas and strong underwater currents have made it difficult for divers to retrieve them from waters nearly 70 meters (230 feet) deep.

A 23-year-old Hong Kong-bound Boeing 747-200, belonging to Taiwan's largest carrier, broke into four pieces at a height of 30,000 feet (9,000 meters) and fell into the Taiwan Strait near Penghu island some 20 minutes after takeoff on May 25.

The cause of the crash remains a mystery and investigators are hoping the black boxes will help explain what caused it.

Officials said signals from one of the black boxes, which normally last for up to 30 days, had begun to weaken.

Navy divers went underwater again on Tuesday, but strong undercurrents prevented efforts to recover the cockpit voice and flight data recorders.

"Undercurrent is delaying recovery," said Kay Yong, managing director of the Taiwan cabinet's Aviation Safety Council.

"Sometimes, the wind is pretty bad. Wave height is around two to four meters (6.5 to 13 feet)," Yong told Reuters.

"The weather will get worse in the next couple of days."

Salvage teams have instead focused on the retrieval of bodies and wreckage in the choppy seas, but only a fraction of the aircraft has been recovered.

Search teams recovered five more bodies on Monday, bringing to 110 the total number found so far, a spokesman for the government's disaster response center said.

The ill-fated jet's cabin chief was still strapped to his seat when his body was found, puzzling investigators.

Normally, food is served to passengers on Taipei-Hong Kong flights at around 12,000 feet (2,700 meters) because such flights are short and take only 90 minutes, but the cabin chief was still buckled to his seat when the plane broke apart at 30,000 feet, the spokesman said.

Grieving relatives have vented their anger at the government and the airline not only for the carrier's poor safety record and delays in retrieving bodies but also for giving no explanation for what caused the crash.

U.S. crash experts who investigated the mid-air explosion of a Trans World Airlines 747-100 in 1996 are in Taiwan to help determine the cause of China Airlines' fourth fatal accident since 1994 which in total have claimed more than 650 lives.

Aviation experts have floated several theories for the crash, including metal fatigue, an internal explosion, sudden loss of cabin pressure, a mid-air collision or a military accident.

[Kaptin M]

"Aviation experts have floated several theories for the crash, including metal fatigue, an internal explosion, sudden loss of cabin pressure, a mid-air collision or a military accident."................................but still NOT an encounter with severe weather??

Which might help explain why, "The ill-fated jet's cabin chief was still strapped to his seat when his body was found, puzzling investigators.

[SaturnV]

Excerpted From Aviation Week

Crash Spurs Revamp Of China Airlines

MICHAEL A. DORNHEIM/LOS ANGELES

The search for victims' bodies is occupying the imited recovery resources at the China Airlines Flight 611 crash site, and slowing the retrieval of wreckage and the "black boxes." The flight data
and cockpit voice recorders were located on May 29, but had still not been recovered as of late last week.

Military radar shows debris falling in several different directions, grouped by color, over a 4-min. period (3:27:56 to 3:31:55 p.m.) following loss of the beacon signal (except the dot marked *, which was observed 7 sec. before loss of signal). [Chart omitted]

Investigators are anxious to retrieve them as their beacon batteries may get weak around June 14. Ocean currents and weather also have been hampering recovery from 130-260-ft. depths.

Shortly after the accident, the ASC obtained primary radar data of the falling debris from the military, but it was in a processed form that did not show individual pieces, and it stopped below about 31,000-ft. altitude. The last transponder return indicates the 747 came apart at 33,500 ft. Since then, raw skin returns going down to almost the ocean have been obtained from two civil radars, one
nearby and the other about 150 naut. mi. away.

The new civil data generally confirm the military tracks, which show the debris initially falling in about four different heading groups, including some that are opposite to the airplane's direction, Yong said. But he cautioned that the calculated speed is
questionable because the radar could be hopping between pieces.

China has provided a transponder track to the ASC. It is overall similar to the Taiwanese transponder track with some minor shifts in reported altitude and speed, possibly caused by timing differences. "It shows an altitude dip of 100 meters (330 ft.) 5
sec. before the transponder signal disappears, which we didn't see," Yong said. But neither track shows any rapid maneuvers.

The new skin returns give a more precise location of where pieces hit the ocean. An initial imaging sonar survey shows the major wreckage is in a rectangle about 4 naut. mi. north-south by 5 naut. mi. east-west, surrounding the data recorders, which are at 23 deg. 35 min. N. Lat., 119 deg. 24 min. E. Long. The resolution of the broad search was too low to identify anything, and a higher resolution survey is now being made.

A remote control submersible took pictures of what was suspected to be a large fuselage piece, but it turned out to be a 40 X 10-meter field of smaller debris, including either first- or business-class seats. Most of the recovered wreckage, 454 pieces
as of late last week, has been parts of control surfaces floating on the ocean. These include the vertical stabilizer leading edge and parts of flaps, slats and ailerons.

The year-round ocean current of 2-4 kt. makes underwater operations difficult, and the recovery crew will try to take advantage of roughly half-hour periods when the current stagnates, Yong said. The Taiwan Straits are also windy and choppy.

Maintenance records show that the aircraft, tail No. B18255, had its last full heavy maintenance in December 1993. The D check takes place every 25,000 flight hours and was subsequently split into two staggered "mid-period" half D checks, Yong said. The last mid-period D check took place in January 1999 and included corrosion work, though it is not clear whether that meant prevention or repair. The check was done by CAL during a
40-day period. The 1979-vintage aircraft had about 64,800 hr.

The last C check was done in November 2001. "We can't say yet what was done in the C check, but we're looking at it very carefully," Yong said. The Taiwanese Civil Aeronautics Administration principal maintenance inspector for CAL has been
interviewed, and "we are seeing how they comply with all the airworthiness directives, service bulletins, and so on," he said.

A major maintenance item on 747-200s is ensuring that the "section 41" fuselage nose is not weakened by cracks. This can be accomplished by repetitive inspect-and-repair, or by extensive reinforcement that can cost $5 million. "It seems it
was done from a first look at the records," Yong said, but it was not clear yet whether it was by inspection or reinforcement. "We haven't gotten further because we are short on people." The ASC
will also look at how CAL's other four 747-200s were maintained.

[atakacs]

but still NOT an encounter with severe weather??

My understanding is that the weather was reported as fine, with low winds at all altitudes...

:confused:

[CR2]

"Black boxes" :rolleyes: :rolleyes: :rolleyes:

[atakacs]

"Black boxes"
Mind to expand ?

--alex

[Rice Whine]

Haven't read every post in this thread but had a quick look thru and have found no reference to CAT. Is it not possible that an a/c of this age and condition could break up quite rapidly if it hit a patch of severe CAT?

[Rice Whine]

Well??

[HotDog]

Well, it seems there was no CAT. Synoptic data didn't show any and there were no reports of CAT on that very busy airway.

[Kaptin M]

5 posts above, AND a couple of pages back, Rice Whine, this was one of the possibilities floated by :) when "an encounter with severe weather" was mentioned.

Regardless of age, severe turbulence can have catastrophic effects on airframes and occupants, as controllability of the aircraft, in any of it axes, is almost certainly impossible.

[lomapaseo]

>posted by Rice Whine

Well??<

Expect to be reimbursed for WAGs after you have provided suffcient supporting facts and confirmed by real investigators.

We no longer reimburse for simple passing references, wet dreams and inuendos not supported by analysis or facts.

[wes_wall]

Firehorse

I don’t think I agree with you. Seems to me that there is a lot of capability not requested by the Chinese. Several countries who have both the expertise and equipment could have been on the
scene the week of the accident, and using robotics, underwater submersibles, and personnel, the flight recorders could already be at the labs. Given the extend time of the abnormality shown by the radar, the recorders should shed considerable information on what happened, making their recovery a number one priority. Like the ocean, it is beginning to smell fishie.

[Shore Guy]

Rumor....Rumor....anyone heard that the ROCAF (Republic of China Air Force) is missing an F-5 since the day of the accident? There is a rumor floating about a head on with a ROCAF F-5 (which would explain some debris moving opposite direction of radar track). I know, we should just wait and see, but...........

[747FOCAL]

I have heard they have fished a few pieces of it out of the water which is why they must be talking about it. Can't hide it now.

[lambchopboy]

that theory doesn't fit the fact that an air-steward was found strapped into his seat!:o

[bblank]

CVR recovered. (http://story.news.yahoo.com/news?tmpl=story&u=/ap/20020618/ap_wo_en_po/taiwan_plane_crash_black_boxes_3)

[747FOCAL]

Thats not what I am hearing.

[wes_wall]

Firehorse


Thank you for the reply. With respect, the recovery phase of this should have been straight forward. There is unfortunately history to fall back on, and proven procedural methods to aid in
recovery. Two of recent come to mind immediately. If the recovery process is driven out of concerned for (granted, very important) public relations, then the approach is erred to begin with. Body and personal effects recovery should be and remain totally divorced from those activities associated with the investigation. I admit that is a cold way to look at it, but life goes on. Lets be thankful that they have at least recovered one of the recorders, and hope that they will be sucessful with the other.

747FOCAL

Care to enlighten us on what you “are hearing,” and from what source?

[maus-warra]

2nd "Black Box" found...reported on CNBC

[Shore Guy]

Reuters Company News
Taiwan recovers second black box of crashed jet

By Angus Chuang

TAIPEI, June 19 (Reuters) - Taiwan navy divers recovered on Wednesday the second "black box" from the China Airlines ews) jet that broke up in mid-air and crashed into the sea last month, killing 225 people, the Aviation Safety Council said.

Retrieval of the Boeing 747-200's watertight flight data recorder, which logs flight information, could help investigators determine why the Hong Kong-bound plane broke into four pieces at 30,000 feet (9,000 metres) and crashed into the Taiwan Strait.

The box was found on the sea floor about 300 metres (1,000 feet) from the cockpit voice recorder recovered on Tuesday, said safety council spokeswoman Tracy Jen.

"The two black boxes appeared largely intact, but it remains to be seen if the data is complete," Jen said.

"We hope to find out tiny bits of detail about what happened to the plane minutes before it broke up. It's the recorders' turn to speak."

Investigators have said, even with the recovery of the black boxes, it might take a year to determine the cause of the disaster -- the carrier's fourth fatal accident since 1994. Together, the accidents have claimed more than 650 lives.

Aviation experts have floated several theories for the crash, including metal fatigue, an internal explosion, a mid-air collision or a military accident.

U.S. experts who investigated the mid-air explosion of a Trans World Airlines Boeing 747 off New York in 1996 are in Taiwan to help investigate the crash.

The two recorders would be brought back to Taiwan from Penghu island, near the crash site, later on Wednesday for analysis, Jen said, adding that it would take about a week to find out the contents.

ANGRY RELATIVES

The data recorder from the older-generation Boeing 747-200 may not have gathered as much flight information as newer models, but its recovery was still crucial to the investigation, she said.

Grieving relatives have vented their anger at the government and the airline for both the carrier's poor safety record and for delays in recovering bodies from the May 25 crash.

Taiwan and foreign salvage teams have so far recovered 123 bodies and some 10 percent of the 23-year-old aircraft, which crashed about 20 minutes after takeoff from Taipei.

The chairman and eight other board members of the state-controlled China Aviation Development Foundation, which owns 71 percent of China Airlines, resigned last month in the wake of the accident.

The awkward ownership structure of the carrier -- the government appoints a majority of the board members of the foundation -- has been widely blamed for paralysing management and making safety reforms almost impossible.

The airline's shares have slid around one fifth since the crash. On Wednesday, China Airlines shares were down 0.77 percent at T$12.85 by 0223 GMT, in line with a 1.93 percent fall in Taiwan's main TAIEX (Taiwan:^TWII - News) index.

[747FOCAL]

I understand your skepticism. Can you tell me that you are actually out there floating around helping look for wreckage? Although I will admit when I was first told, I thought to myself how would you ever find any part of a small fighter after smashing into a 747 and then going in the ocean? :confused:

[HotDog]

747 man, I hope you will have the integrity to say "sorry, I was wrong", when the facts are finally revealed. There is no evidence whatsoever of a midair collision with a military fighter. However, if that is proven, I'll beat you to it with an apology. I have been in aviation too long to jump to conclusions without adequate proof of opinion. Cheers, HD.

[747FOCAL]

I can see admitting I was wrong, but why the need for an apology? It's not like I ranted and stepped all over everybody's dignity with unprofessional comments aimed at embarassing a single person or group. But, if it is real important to you Yes I am big enough to admit fault and apologize. :)

[atakacs]

Out of curiosity: now that the black boxes have been recovered are they already pouring out the wreckage ?

--alex

[stickyb]

There were reports earlier that a member of the cabin crew had been found still strapped in.
Does anyone know if that also applies to the passengers?

[HotDog]

I wouldn't read too much into the ISM being found strapped to his seat. It's a very short sector from Taipei to Hong Kong, he could well have been doing his necessary paperwork strapped into his seat or could have been adjacent to his seat when the upset commenced and had the opportunity to sit down and strap himself in. Best wait for the FDR results.

[firehorse]

A voice of reason, here here Hotdog well said.

[widgeon]

errrrrr....... guess not

[Shore Guy]

Any word on the status/condition of the FDR-CVR? Has it reached the lab yet? If the FDR is the same vintage as the aircraft, I guessing there are just a few parameters recorded....does anyone know what type of FDR?..........It's been very quiet.....

[lomapaseo]

From Firehouse

> The hard work is the breaking down of the last few milliseconds of the CVR to identify structural "noises".<

Quite a significant statement. Coming from a "reliable" source as you have already established in this thread.

The implications are comparative to Ua811, PA103 and TWA800 where nothing of substance was heard on the CVR conversations and only the last miliseconds of electrical ringing of the severed circuits could be heard. Also evident but not easily distinguishable were the comparative frequencies of structural borne noise vs overpressure or underpressure shcck effects from the pressure vessel events.

If indeed the only scraps of such evidence are available in the last miliseconds then it is an event far beyond KAL007 and UA811.

I'll be hanging around waiting for another tidbit from you and I promise I won't try and depose you <grin>

[Peanut Butter]

The Taiwan Aviation Safety Council will announce the findings from the CVR and the FDR at 3:00pm Local time on Tuesday 25th. (0700UTC)

A photo of the cockpit after being raised from the seabed can be found Here (http://udnnews.com/NEWS/MEDIA/877397-358130.JPG)

[bblank]

The ASC reported today some initial impressions from the CVR. An
undetermined sound described to be like "a human heart beat" a few
minutes before the accident. Unexplained noises shortly before the
accident. A "sharp thud" just before power was lost. Crew conversation
did not indicate awareness of a problem. In other words, no easy
answers from the preliminary hearing.

In addition to the ASC, reps from Boeing, the NTSB, the FAA, and
several 747 pilots have listened to the tape. News report here. (http://story.news.yahoo.com/news?tmpl=story&u=/ap/20020623/ap_on_re_as/taiwan_plane_crash_1)

[atakacs]

The ASC reported today some initial impressions from the CVR

What is not reported is when does the recording end... From the radar returns it seems that the plane experienced problems for quite some time before breakup (8-9 minutes if I remember correctly), so the questions is obviously to coralate the CVR timing with that.

As for the other noises, I am at loss...

Anyone ?

[lomapaseo]

What you hear on a CVR is not necessarily what it really sounded like in real life. And in the case of electrical annomalies, they might not have been heard at all.

Clipping, saturation.......

Methinks that what is about to be released/confirmed on Tuesday will be all we'll get until they release some tidbits from the FDR. Synching all this up with the longer lasting radar will probably take more time than this forum will devote to waiting.

[Volume]

China Airlines 747 crash tape records mysterious noises.
Reuters

TAIPEI (Reuters) - Taiwan investigators said on Sunday they heard a series of unidentified sounds in the cockpit recordings of a China Airlines jet that mysteriously broke up in mid-air and crashed into the sea last month, killing 225 people.
"Our initial judgement is that it is not a sound from normal operation of the plane," Kay Yong, managing director of Taiwan's Aviation Safety Council, who is also lead investigator for the air disaster, told reporters. "I do not know what the sound is," he said.
The recording raises more questions on an already mysterious accident. Aviation experts have floated several theories for the crash, including metal fatigue, an internal explosion, a mid-air collision or a military accident. A team of experts including U.S. investigators from the Boeing Co, the U.S. National Transportation Safety Board and the Federal Aviation Administration had listened to the recordings dozens of times, Yong said. He said the investigation was still in the fact-finding stage and declined to comment on possible causes for the sounds.
The recording was taken from one of two "black boxes" recovered earlier this week from the submerged wreck of the Boeing 747-200 which crashed off the Taiwan-held islands of Penghu, or the Pescadores, en route to Hong Kong. By Sunday, some 161 bodies, including that of the co-pilot, had been recovered from the crash site and 153 identified.
Investigators have said it might take more than a year to determine the cause of the disaster -- China Airlines' fourth fatal accident since 1994. Together, the accidents have claimed more than 650 lives.

Does anyone know more abaout the timing ? Was the ´unusual sound´ the last thing recorded or was it at an much earlier stage of the crash, at the time the transponder stopped ? Is the end of the recording at the same time the military radar shows breakup or at the time the civil stops recording ? Is there a transscript aviable anywhere in the web ?

[wes_wall]

Firehorse

From what you report, it appears that the cockpit area may have been fairly well intact. This would seem to follow a similar pattern to PA104, in that the forward fuselage (forward of the L
and R1 doors) impacted the surface in a flat attitude with very little forward velocity. The impact speed after calculating the drag coefficients was low, 120 ks. In the PA104 case, this section was
approximately 2 miles from the wing and engine craters at Lockerbie. Any idea, or reported, relationships of the debris being recovered or recorded. Would be interesting to see the
relationship (if any) of the debris footprint between the two accidents. With PA, the path followed a line parallel to the air craft track, but lighter pieces were carried by the winds aloft
some distances, almost to the north sea. The cockpit separated at the beginning of the event, and the descent was almost immediately vertical.

[atakacs]

Hello !

Just wondering about the chain of events vs. the CVR recording…

Am I correct that as far as we know, the events were

1. Normal, uneventful flight
2. While approaching the end of the climb (approx 30000 ft), some wild altitude and heading variations for approx 9 min.
3. Break-up in four different pieces

Further facts

1. No radio transmission / mayday call
2. No sign of explosion
3. No sign of mid-air

Now where does the CVR recording fit into this ? As far as we know there is no sign of the pilots reporting anything unusual. So my guess would be that whatever happened was between phase 1 and 2 and did stop the CVR recording. If so, I guess that the FDR will also be mostly useless…

Any comments ?

[lomapaseo]

Posted by Atakacs

1 No radio transmission / mayday call
2 No sign of explosion
3 No sign of mid-air<

I doubt that we should accept items 2 & 3 above as fact at this time, since much of the wreckage remains to be examined by experts.

[bblank]

"2. While approaching the end of the climb (approx 30000 ft), some
wild altitude and heading variations for approx 9 min."

According to the Taiwanese military radar track the heading was
constant for the eight minutes prior to the accident. The civilian data
shows fluctuations of a few degrees in the last three minutes. Both
show a steady climb for most of the last three minutes. In Yong's
press conference today he said "In the flight's final seconds, the
plane climbed at three times its previous rate — from 3,960 meters
(1,200 feet) per minute to 11,220 meters (3,400 feet) per minute"
but "that such a steep ascent shouldn't have caused problems for the
plane."

Other statements from Yong today according to this AP story (http://story.news.yahoo.com/news?tmpl=story&u=/ap/20020625/ap_wo_en_po/taiwan_plane_crash_2):

- The disaster apparently wasn't caused by a fuel tank explosion, bomb,
missile or meteor.

- "From the bodies and wreckage that have been recovered so far, we haven't
seen any signs of burning or an explosion."

- "No evidence of flight operation errors, such as pilot mistakes or
communication problems."

- "One engine seemed to be running slightly abnormally. But it was unknown
if this was related to the crash."

- "No evidence that any of them [PAX] were carrying hazardous materials."

- "No evidence that any passenger purchased large amounts of insurance"

[747FOCAL]

If he held that rate of climb for long he would have stalled the aircraft at that altitude. 747s won't even maintain that rate of climb and maintain speed at sea level.

I wonder if all the bleeping and clicking came from either a bomb wired into the aircraft systems or a bomb that was in close prox to a wire junction box and the aircraft was picking up static or electrical interference. the fact that the noises had patterns and were not random leads me to believe that they were mechanical.

:confused:

[Shore Guy]

"The flight data recorder from Flight 611 shows that the plane began gaining altitude at a significantly faster rate in the 27 seconds before the plane broke apart" NYTimes

Does anyone have any information showing a cooresponding speed deterioration during these (approximately) 30 seconds.
Or even better, is someone going into a 747 sim that could see what kind of speed deterioration occurs under these circumstances? Would the aircraft come close to stall?

The aircraft appears to have been on autopilot until the end of the recording. I seem to remember some years ago, a DC10 that stalled at altitude while on autopilot in the vertical speed mode.

Firehorse, you out there?

[lomapaseo]

>"One engine seemed to be running slightly abnormally. But it was unknown if this was related to the crash"<

Anybody know what parameter looked abnormal?

N1, N2, EGT, EPR, FF?

Most interesting if only a single parameter like N1 looked abnormal.

Of course in TWA800 it was red herring like FF

[gas path]

Could possibly the stab. have failed mechanically?????

[SaturnV]

From the June 25 New York Times:
Taiwan Investigators Rule Out Blast or Pilot Error in 747
Crash

By KEITH BRADSHER

TAIPEI, Taiwan, June 25 — Investigators analyzing the crash last month of a China Airlines flight said today that the flight data and cockpit voice recorders, together with autopsies on the victims
and an examination of the wreckage, showed no evidence of an explosion or pilot error.

The findings indicate that something probably went wrong inside the aircraft, a Boeing 747-200, said Kay Yong, the managing director of the Aviation Safety Council, the government agency here that is conducting the investigation.

Investigators are paying special attention to whether structural failure or engine problems might have caused the plane to break into four pieces in mid-flight. The crash of the Hong Kong-bound flight into the Taiwan Strait on May 25 killed all 225 people aboard.

Searchers have recovered 162 bodies and 15 percent of the wreckage, including part of the cockpit, and have found no signs of burns or of any explosives or gunshots, Mr. Yong said.

But China Airlines, which is struggling to preserve its commercial viability after nine fatal crashes since 1970, said that it was too soon to rule out "external forces," as opposed to mechanical failure, as a cause of the crash.

Roger Ham, a company spokesman, said that only a small part of Pan Am Flight 103, which was destroyed by a bomb over Lockerbie, Scotland, had been burned. "You have to recover all the wreckage to see what part is attacked or exploded," he said, while declining to comment on what China Airlines thinks caused the crash.

Because it occurred in a heavily militarized area between China and Taiwan, 20 miles north of Taiwan's huge naval base in the Penghu Islands, there was speculation immediately after the crash that a missile could have been involved. But Mr. Yong and other Taiwanese officials have repeatedly dismissed that idea, pointing out that there is no radar evidence of a missile. Taiwan also has no history of terrorism.

There was also early speculation that the aircraft's fuel tank might have exploded. A fuel tank explosion was implicated in the crash of Trans World Airlines Flight 800, a Boeing 747-131, into the Atlantic Ocean off Long Island shortly after takeoff on July 17, 1996. But Mr. Yong said today that there was no evidence this happened to the China Airlines flight.

On Monday the airline offered to pay $372,000 to each of the families of the people who died. But the offer, made by airline officials to a gathering of more than 300 relatives of crash victims, drew a rancorous reception from some, who said the company should pay $588,000 per victim, or twice what it paid after a fatal crash in 1998, and called for punitive damages.

Some families of crash victims have accused to airline, and to a lesser extent Boeing, of ducking responsibility for the crash. Lee Ham, a crash victim's son, said that China Airlines was to blame for having kept a 23-year-old plane in service too long. The aircraft crashed on its last flight before it was to be sold to a small carrier in Thailand.

Boeing declined to comment on today's statements by investigators. But Ivy Takahashi, a company spokeswoman, said that the plane that crashed had been on 21,398 flights, below the average of 23,000 flights for all Boeing 747-200s in service.

The breakup of China Airlines Flight 611 has drawn international attention because it comes at a time of increasing concern over how long older jets can remain airworthy. Some research has suggested that metal fatigue may be a particular problem in planes that are used regularly in very warm, humid places
like Taipei and Hong Kong. But Boeing maintains that with proper maintenance, aircraft aging should not be a problem.

The flight data recorder from Flight 611 shows that the plane began gaining altitude at a significantly faster rate in the 27 seconds before the plane broke apart, although the extra gain in altitude was well within the plane's design limits, Mr. Yong said at a news conference here today. The plane was supposed to be leveling off then as it approached its cruising altitude of 35,000 feet.

No one in the three-member flight crew said anything to indicate an awareness of the extra lift, Mr. Yong said. The autopilot had been engaged earlier in the flight, and there is no evidence that it was turned off before the plane came apart, he added.

Shortly before the breakup, one of the aircraft's four engines began providing slightly less thrust. By coincidence, the same engine is the only one that has been recovered so far from the sea floor.

Phil Tai, the investigator overseeing the recovery of wreckage, said that the engine was intact except for a tiny piece that was missing from the nose cone. Many parts of the engine had been split along the side, apparently when they hit the water after falling more than five miles.

On Sunday, Mr. Yong had separately announced that the cockpit voice recorder had picked up a dozen faint, mysterious sounds in the 13 minutes before the plane came apart. A computer disk with the sounds has been sent to the United States for further analysis, which will take at least a week, Mr. Yong said today.
_______________________________________

From Taipei Times on the anamolous sounds detected on the CVR (the New York Times indicates that these were recorded over a span of 13 minutes, but the duration of and interval between sounds was not given).

"The cockpit voice recorder (CVR) picked up three "unusual sounds" before the ill-fated China Airlines CI611 passenger jet
crashed into sea with 225 people on board, Kay Yong, director of the Cabinet's Aviation Safety Council, said.

"According to Yong, shortly before the crash, the CVR recorded unusual noises that sounded like "ta-ta, ka-ta, ta-ta" and noises that sounded like a heartbeat. Then, after a loud thud at 3:28pm, the time when the airliner disappeared on the radar, the CVR lost power."

[lomapaseo]

From Gas Path

>Could possibly the stab. have failed mechanically?????<

Well Gas Path, your typical posts have been very enlightning, but this one is quite terse, so I will pay you in kind.

There was a BA 747-200 incident on approach to Boston about 15 or so years ago where part of the wing fell off onto a driveway and it was subsequently learned that it involved an engine.

I'll be interested to see how well you do on that one.

[UNCTUOUS]

Looking more like a section 41 failure than a cargo-door, however that one engine running abnormally, if it was #3, may be significant to a possible cargo door event. Ka ta ka ta could be door unlatch motor trying to unlatch. And heart beat may be on all CVR of all the affected A/C, only Taiwanese raised it up 10 times, as they say.

But not necessarily just the Section 41 problem for structural failure; it might have been an aft pressure bulkhead failure [see the AD below] (which, when it compromised elevator control, would explain the rapid height gain i.e. pitchup into a stall and ensuing loss of control (due to no subsequent elevator or rudder control). Similar to the JAL event.

2000-12-19 BOEING: Amendment 39-11797. Docket 99-NM-330-AD.

Applicability: Model 747 series airplanes, as listed in Boeing Alert Service Bulletin 747-53A2425,

dated October 29, 1998;
Detect and correct cracking in the aft pressure bulkhead, which could result in rapid decompression of the fuselage or overpressurization of the tail section.
Repeat the HFEC inspection thereafter at intervals not to exceed 3,000 flight cycles.

[aviator_38]

Came across this website: www.ntsb.org which has an interesting speculation that the failure of the latches of the forward cargo door, from either a wiring or electrical fault, may probably be the reason why CI 611 went down.

Cheers

[lomapaseo]

Other than the Smith table containing numerous false facts. I have never seen the terminology "may probably be the reason why CI 611 went down."

used in accident summaries.

['%MAC']

I imagine most astute readers will realize this is not the National Transportation Safety Board web site, but a conspiracy theory site benefiting from a similar address. The NTSB web address is of course a dot gov. http://www.ntsb.gov

[Peanut Butter]

http://www.asc.gov.tw/asc/_file/2006/upload/news/fdr0625press.pdf

There are only several noticeable things in the FDR:

1) EPR on Engine 4 dropped from 1.52 to 1.49.
2) Vertical Gs remained stable until the last second of the flight, with a change of 0.25g and a slight change (1-2 degrees) of pitch.
3) Rate of Climb also increased from 1200fpm to 3400fpm.
4) No significant airspeed/Heading/Roll angle changes.
5) Final Altitude reading is ~34600ft.
6) FDR tape ends earlier (0.06 seconds) than CVR.


(Note: you might need the Chinese Font Pack to see the PDF.)

[Peanut Butter]

Firehorse:

What I said was The photo is showing the cockpit after it had being raised. (the cockpit went into the water with the nose section of the a/c and the divers seperated the cockpit from the nose section because the whole thing is too heavy to lift up to the surface.)

An extra note: The cockpit A/P MCP (or FCU) shows the autopilot was disengaged but the FDR and the CVR (no aural warning) failed to show that. (and please note that there is only a 0.26 sec interval between CVR stoppage and the breakup of the a/c)

[SaturnV]

The last fdr record of the plane reaching an altitude of 346 is consistent with the radar trace:

time/heading/speed/altitude
15:28.31 224/452/347
15:28.43 070/413/347
15:28.55 057/417/369
15:29.07 186/241/351

Given the report that the plane broke into four major pieces, with one section going backwards, the wreckage pattern may hold the clue as to which part of the aircraft failed first. The "thud" noise just prior to loss of power to the two recorders, and the radar indicating some (most?) of the plane ascended to 369 after CVR and FDR cutoff might be more suggestive of an aft bulkhead failure. If the tail/rear fuselage is the part that was seen as going backwards, that might be consistent with a profile of the rest of the plane briefly continuing in powered flight before final breakup.

[UNCTUOUS]

If you look at the JAL Report (http://aviation-safety.net/database/1985/850812-1.htm) it becomes apparent that we are probably looking at the same thing here, the only difference being the significantly greater differential at 35,000ft icw the 23,900ft of the JAL onset.

Prior heavy landing or tail-strike may have set up latent undetected damage that had been "working" for quite some time. Once damage or fatigue cracks start really "working", the final manifestation of structural failure is likely to be sudden, particularly if the final "bridge too far" is to be the pressurisation differential.

The ka-ta-ka-ta noise may have been similar to the "unusual vibration" of the JAL report, the effect upon the hydraulics as the empennage sundered over a period of mere seconds (feedback to the rudder pedals/autopilot?). The rate of climb increase recorded seems to be unsupported by any zoom-climb increase in pitch attitude or decrease in IAS. It may have been an anomaly generated in the CADC by the pitot-static system being compromised early in the breakup.

[747FOCAL]

Firehosed,

Did anybody ask for anything other than crash facts? This is a discussion forum, not a place for you to bash what other people say. Talk like that to people in person is a good way to get your eye dotted.

An explosion does not have to be big to bring down an airliner. A very small explosion in certain areas could cause rapid structural failure without a big burning bang. Especially with an old bird that was prolly as fatigued as this one was.

Are they really believing the 3400 fpm climb rate at the end?

[firehorse]

747FOCAL:
Bit OTT don't you think?

[BlueEagle]

The difference here, I think, is that Firehorse obviously knows what he is talking about and does have the facts available, consequently he is able to keep wild specualtion in check and debunk silly rumours, whilst others, seem to prefer speculation, rumour and wild guesswork.

Well, it is a rumour BB after all!;)

[lomapaseo]

>The difference here, I think, is that Firehorse obviously knows what he is talking about and does have the facts available, consequently he is able to keep wild specualtion in check and debunk silly rumours, whilst others, (particularly 747FO), seem to prefer speculation, rumour and wild guesswork.
<

I for one respect both posters and sincerely hope that this cools down before folks take sides.

I also agree with 747FO regarding the noises not being random and likely mechanical borne.

If anybody has got a beat frequency in mind like 7-12 cps I would be very interested

[bblank]

"Are they really believing the 3400 fpm climb rate at the end?"

747Focal, That's what it was for a brief interval. There were two
statements about the climb rate that have been quoted in this thread.
Kay Yong's was accurate but I think the statement of the NY Times
was misleading. According to Yong, "In the flight's final seconds,
the plane climbed at three times its previous rate — from 3,960 meters
(1,200 feet) per minute to 11,220 meters (3,400 feet) per minute."
That's a true representation of the FDR data. It appears to me that the
climb rate was about 3375 ft/min for the last four seconds. The NY Times
reported "The flight data recorder from Flight 611 shows that the plane
began gaining altitude at a significantly faster rate in the 27 seconds
before the plane broke apart." That I find misleading. During the last
21 seconds of the FDR (including the 4 second interval just mentioned)
the climb rate was 1785 ft/min. In the 17 seconds before the last 4
seconds the climb rate was only a little over 1400 ft/min.

PB, or anyone who can answer: There are two events that are described
only in Chinese on the plots that appear on page 14 of the FDR pdf. I
guess from what you said about the 26 interval between CVR stop and
breakup that 7:28:29 was the time of breakup. What is the event at
7:28:17?

I wonder if there is anyone from the Taiwan military trying to make
sense of their radar reading of 36911 ft at 7:28:27 (7:28:55 without -28s)?

The openness with which the ASC has made the radar tracks and FDR data
available has been impressive.

[atakacs]

Peanut Butter,
4) No significant airspeed/Heading/Roll angle changes.
According to another post: The last fdr record of the plane reaching an altitude of 346 is consistent with the radar trace:

time/heading/speed/altitude
15:28.31 224/452/347
15:28.43 070/413/347
15:28.55 057/417/369
15:29.07 186/241/351

No significant heading changes? We go from southwest, then to ast-northeast, then to northeast, then south, all in less than 45 econds !

Let's see, a 747 turns from a heading of 224 degrees with a speed of 452 knots to a heading of 70 degrees while slowing to a velocity of 413 knots in a period of 12 seconds at an essentially constant altitude of 34,700 feet. That is a change of heading of either 154 degrees or 206 dergees depending on which way it turned. Then it allegedly gains a little speed (to 417 knots as it turns to a heading of 57 degrees and climbs to 36,900 feet in another 12 seconds.

Hummmm... that is a change of altitude of about 2,200 feet in just 12 seconds or an average rate of climb of 11,000 feet per minute.

There just isn't anyway that a 747 could climb that rapidly coming out of a turn in which it was slowing down. They would have had to have a big rocket booster attached to pull that climb off IMHO.

I have to question this data on the grounds that it appears to violate the laws of physics. And if that isn't enough, how did it lose about 1,800 feet of altitude while slowing to a mere 241 knots while turning at least 129 degrees to get to the final heading speed and altitude in just another 12 seconds.

Something just doesn't look right here.

[SaturnV]

atakacs, the heading, altitude, and speed changes after 15:28.31 were a radar trace, and almost certainly occurred after power was lost on the FDR. The FDR, prior to the "thud" noise, seems to have recorded heading, altitude, and speed consistent with the radar trace. Many posts back, the point was made that the abrupt changes in heading, altitude, and speed recorded after 28.31 (and there were several, distinct sequences of such changes) may have resulted from the radar picking up that portion of a disintegrating plance that showed the biggest cross section to it.

[atakacs]

I see.

We could really use some timing information regarding the CVR, FDR and radar datas...

;)

[sclub99]

Can anyone tell me how the radar data is derived. That is, is it "real" or just imputed from a/c position relative to the 12 second previous trace?

[UNCTUOUS]

bblank

In my last post on the previous page I said:

"The rate of climb increase (and climb?) recorded seems to be unsupported by any zoom-climb increase in pitch attitude or decrease in IAS. It may have been an anomaly generated in the CADC by the pitot-static system being compromised early in the breakup."

However there are other explanations for a "zoom climb" being recorded on both the FDR (and

radar plot). Consider the likely aftermath of a differential-induced aft pressure bulkhead failure being followed by empennage separation:

You would naturally think that if the tail was to wholly separate, because of

losing the downforce on the horizontal stabilizer, the nose would rapidly pitch down. Not

really all that simple now because the lift-drag / thrust-weight couple is now totally

re-arranged (out of kilter) and the primal force has become the still-thrusting underwing engines. I would

expect that the aircraft would pitch up into a looping manoeuvre - but one that would quickly

end up in an end-swapping tumble. The effect would be similar to an overinflated balloon

being released i.e. with no coherency in the flight path at all, but rapidly leading to breakup

as the non-aerodynamic shape, still under thrust, was presented to the airflow. This would

also explain the dislocated jaws.... and lack of any fuel-fed explosion.

[norodnik]

Looking at the data from the FDR and reading the posts, it may be interesting to look at the data from the TWA incident.

Those who support the missile theory, and I am agnostic on the entire incident, have shown conclusively what happens to the data recordings as a result of over-pressure and shock readings on the measuring devices.

I seem to recall (but would have to check again) that the last few seconds of recording on the TWA flight also had wild fluctuations that were outside the realms of normal (and abnormal) flight.

The fluctuations were tested in the lab and almost the exact same readings could be reproduced

The lab results were created using an explosive device, and I have no idea if a blow out (ie sudden hole in airframe) in a similar region would have the same results

happy to look up the actuals if their is any interest

[wes_wall]

- - - - also explain the dislocated jaws - - -


One might think that if the front of the airplane separate from the fuselage, the sudden 400 K plus wind encountered by the pax would be enough to dislocate a yaw, not to mention all the other trauma events taking place.

[747FOCAL]

FireHose,

Sorry was a bit cranky yesterday morning. I just get tired of the bashing some people choose to give the laymen around here.

I spoke with(and I can't reveal who I am or who I am about to talk about) a person that most probably knows 747 flight performance better than anyone. He said that an old 747 on initial climb will have zero rate of climb at 30,000 ft at 830k. I would assume this airplane was much lighter than that.

He did say that even an empty 747 at 30,000 ft will not climb like that and maintain speed. Did they bleed speed to get this rate. :confused:

[wes_wall]

747FOCAL

"I spoke with(and I can't reveal who I am or who I am about to talk about) a person that most probably knows 747 flight performance better than anyone. He said that an old 747 on initial
climb will have zero rate of climb at 30,000 ft at 830k. I would assume this airplane was much lighter than that. "

Can you clarify the above? I have not seen a 747-2 carry that much air speed, or do you mean 830K for the weight? Again, a bit heavy don’t you think. They were only going to HKG. Better go back to your 747 contact and
get him to explain.

Awaiting.

[747FOCAL]

wes_wall,

Yes 830k is the BRGW. I will check their fleet, specifically that airplane and find out what weight they normally operate at.

Basically nothing but a fighter jet and the Concorde climbs well at that altitude.

[SIDMANJED]

I think he was talking about 830.000 LBS. Depending on the engines that could be the MTOW. But it is probaly a 800.000Lb
A/C.

[patrickal]

This incident reminds me of a 737 crash that occurred many years ago in either Columbia or Panama. It was documented in a NOVA episode on public television here in the US. The plane broke up in the air during a night flight over mountans. The first reaction was that a bomb had detonated, which seemed to make some sense because of the scattering of the debris and drug cartel incidents that had happened in the past. Once the FDR was recovered, it showed roll rates in both directions that made no sense. In fact, Boeing engineers said that they were inpossible rates. What the investigators finally determined was that there was failure in the gyro for one of the artificial horizon indicators. Once a bank angle was reached in a turn, the AI would lock in that position. Reverse input from the crew would indicate no change, so they would bank opposite even harder. With no visual reference, they assumed that the indicator was correct. This was compounded by the fact that in a 737, normaly, both the pilot and copilot AI's run on seperate gyros, but in this case, a selector switch was set to have them both operate off of one. Hence, they were both seeing the same thing failure. When the gyro would unlock, it would snap over to the actual bank angle of the plane, which at this point was a steep angle in the other direction. The crew would then correct back to the opposite direction again and the same thing would happen. The result was they rolled the plane over and entered a dive which exceeded the limits of the airframe.

The reason I bring this up is that it sounds like the FDR in this recent case recorded information that, on it's own, makes no sense. What kind of instrument failure could fool pilots into making incorrect inputs into either yoke and throttles, and at the same time give indications on the FDR that are also incorrect? I would not jump to the conclusion that the strange FDR outputs are the result of an explosion or breakup. They could also be an indication of instrumentation failures.

[UNCTUOUS]

"I would not jump to the conclusion that the strange FDR outputs are the result of an explosion or breakup. They could also be an indication of instrumentation failures."

Patrickal

Pneumatic inputs of erroneous pitot/static pressures to the CADC (Central Air Data Computer) could have this effect... if the failure compromised the pitot-static system prior to the FDR losing power.

However, thinking outside the box a little here, both the non-transponder secondary (raw paint) radar data and FDR info would be consistent with the gyrations of an aircraft that had lost its tail and had then pitched up violently under climb power. I have said in a prior post on this thread that I consider that the aircraft gyrations following loss of the empennage would be a drastic pitch-up into violent end-over-end tumbling - because the engines would be still under high power.

The radar plots roughly tie in with the tail departing and then, some finite time later, the breakup of the remainder of the wings engine and fuselage. If you look at my prior posts you might see the picture more clearly. The Airworthiness Directive that I quoted is quite clear about this being a possible outcome. Unreported/misassessed/improperly repaired heavy landings or tail-strikes can initiate damage (cracking) in the aft pressure bulkhead area that can "work" over time and eventually give way under the greater pressure differential at height.

[Volume]

UNCTUOUS,

I disagree with the idea that a plane would pitch UP after loosing its stab or its tail. It is much more likely that it pitches down.
The horizontal stab normally produces downforce, although on modern planes part of this is produced by fuel weight in the stab, which is more drag efficient.
Taking into account the lost mass at the tail, the DOWN pitching moment is even larger.
So loosing the tail would explane the reverse heading (half loop forward) and the breakup, but not the altitude gain. If something broke apart and caused an pitching UP, it must have been the nose section.

There had been the idea, the crew might have allready been passed out during breakup due to pressurization malfunction and hypoxia.
Did the FDR tell us something about that ? Had there been normal conversation in the cockpit ? Have not read anything about words spoken by the crew, are there indications they were noticing problems and try to analyse and react ? Or are there just ´abnormal sounds´ and no signs of human life on the tape ?

[UNCTUOUS]

"I disagree with the idea that a plane would pitch UP after loosing its stab or its tail. It is much more likely that it pitches down.

Volume
Fully expected someone to take me up on that aspect. It's wholly dependent upon whether:

a. empennage detached cleanly and instantly, or

b. it tore off from the bottom, hinging at the top, or

c. vice versa, but

d. momentary random (or hardover) inputs to elevator and/or rudder before detachment are also possibilities - as is prior loss of a single primary control surface and FCS or crew intervention with power and trim changes causing a pitch-up (and detachment occurring sometime thereafter). It is perhaps more likely that control would be lost some few finite seconds before empennage detachment - and then (logically) that the gyrations resulting from control loss would assist (or ensure?) complete detachment.

Who's to know? And with an ancient 18 parameter FDR, it may never be known for sure. My first guess was that after the loss of the minimal tail downforce (there likely being little tail-tank trim fuel in there on a short hop), the initial commanding couple would be Thrust/Drag and that four climb-thrusting underwing-podded jets would rotate it into a climb.


It's not feasible to upgrade old jets to modern DFDR's but it is quite practical to throw in some recording cameras in crash-proof boxes. They would just need to be mounted rationally and plumbed into power. IMHO cameras internally and externally are now necessary post 911. Investigations can drag on for five years or more and in the interim passenger confidence is eroded as they suspect:

1. maybe it was a terrorist act (they don't really seem to be sure and need all this time to tell for sure - and
would they tell us if they then knew (or do they know now - and it's all a time-gaining pantomime)?)

2. maybe old airplanes just aren't being maintained properly because they wouldn't then be so profitable to continue operating them; maybe they just keep their fingers crossed and hope that things like this DON'T happen.


So if you simply fin-mount a non-CCTV wide vista recording camera as a post-crash disclosure device, you need do no more than provide a one hour endless loop tape (or a hard disk), mount it in a transponder-fitted crash-proof housing and then functionally check it on a regular basis. It need not necessarily be cockpit monitorable. Improvements upon that external system would be that it was to be a CCTV which could be displayed in real-time on cockpit monitors as an aid to crew trouble-shooting and surveillance. Dollar cost of the basic system? US$150K per airframe maybe. Swissair was planning to be first to have such an in-fuselage system internally in their finalized post SR-111 MD-11 upgrade, but I would guess that Swiss Lines would've canned that project as they too are now struggling to remain afloat. You have to review for yourself what cameras might have disclosed immediately post-crash in Silkair, Valujet, TWA800, SR-111, AI182, the Helderberg, Panam103, KAL007, KAL 801, GF072, AA587, Egyptair Flt 990, China Northern MD-82 fire off Dalian and the CrossAir RJ-100 Zurich etc. Then you have to wonder what use to the crew fin-mounted cameras may have been (Concorde, the Air Transat A330 Glider, Alaskan 261, British Midland 737 at Kegworth etc).

But primarily weigh up that the significant percentage minority of the now post 911 non-flying public might be more likely to engage if answers were more readily available. It would also do much to dampen the cult of conspiracy theorists that now thrive upon airline accidents and foment public anxiety. That fearful ex-passenger minority are perhaps the difference between operating in the red or black.

Food for thought.

[HotDog]

Unctuous, there is no fuel tank in the tail section of the B747 Classic airframe (i.e. -100,-200,-300). However, I think the camera is a very good idea.

[bblank]

I am skeptical of theories that either don't explain all observations
or which, if true, would have led to consequences that were not observed.

Unctuous, there was an increase in pitch, not much except
percentagewise, for the final seven seconds of FDR, which is the time
interval during which the climb rate appears from the FDR to have
increased. The final FDR climb rate and the final FDR altitude (at
7:27:58) would lead to an altitude 29 seconds later that would
be in the ballpark of the Taiwanese military radar reading
of 36911 at 7:28:27 (which is about the time of the breakup, if I
understand PB correctly). I am very skeptical of that radar reading
- it is not consistent with the preceding sweep - but unless and until
it is repudiated there it is.

If I correctly understand the superposition that the ASC made on one
of the FDR plots then there was a cockpit communication 93 seconds
before the end of the FDR recording, 80 seconds before the start
of the vertical and lateral acceleration anomalies, and perhaps
less than a minute before the decrease in EPR4. I am not knowledgable
about the onset of hypoxia: would that communication be consistent
with a hypoxia theory?

It would help to have a more precise understanding of the
chronology. Can anyone shed light on the three question marks below?

7:26:25 Cockpit crew communication - Was this the last recorded?

The next four instants of time are identified with vertical lines on
the ASC's time synchronization plot. But the last two are labeled only
in Chinese.

7:27:58 FDR Stop
7:28:03 CVR Stop and last beacon return
7:28:17 ?
7:28:29 Breakup?

[wes_wall]

bblank

IMHO, it would be difficult to build a case involving Hypoxia with the info we know. However, from memory, the key, USEFUL consciousness depends largely on the individual, but the general rule of thumb is that above FL300, you don’t have a lot of time. It varies, at FL300 perhaps better than a minute, but as you climb, the envelope becomes much smaller. FL340 less than 45 secs, and above 350, less than 30 secs. At FL400, perhaps 15 secs. These numbers may be further reduced if the loss of pressure is sudden because of the corresponding sudden escape of gas from the lungs. That why you have quick-donning O2 masks, remember.

[UNCTUOUS]

bblank
Not sure what you're exactly being sceptical about. I assume, since you named me, that I am the offender. There are some suppositions in what I've said - but nothing that seems to diverge from your time-line.

7:26:25 - last cockpit communication
1min26 secs later at
7:27:51 - beginnings of a pitch increase
7 secs later at
7:27:58 - no further FDR data
5 secs later at
7:28:03 - CVR stop and final transponder return
14 secs later at
7:28:17 - unknown recorded event
10 secs later at
7:28:27 - peak altitude recorded on skin paint of 36,911ft
7:28:29 - breakup?

I'd agree with Wes_Wall on the hypoxia question. If hypoxia was involved I suspect it was more as an incident outcome than a contributor. The breakup occurring very noticeably just 2 secs after the observed max altitude is not normally a logical sequitur, the greater probability being always that a loss of control breakup will occur (per say, Egyptair MS990 and the Lauda 767) after it's wound up a little in a g-increasing spiral dive. However in this case (as my theory goes) the structural failure had already happened and so, minus its structural integrity (and tail), CI-611 was free to begin its breakup well short of gaining any additional downward knots or g's.

So, as far as "explaining all observations or which, if true, would have led to consequences that were not observed.", I think I've filled in the first box, but not sure where I ended up on the deficient unobserved consequences. The "unobserved" bit is actually the pretext upon which I introduced my fin-mounted (and cockpit) camera suggestion as a necessary solution to these type enigmas.

[lomapaseo]

UNCTUOUS

After running short of further facts (the quiet time) I tend to concentrate on aligning the facts against possible scenarios under columns of Pro and Con.

The Pros and Cons can be analysis related (a better form of opinion) and then with the help of others with competeing theories/scenarios one can chip away at the pro & Cons trying to convert them to fact. Eventually one can pare the list down to only a couple of theories and pursue from there. The difficulty of doing this on a forum is the abscence of fact and the plethura of theory.

I see you already have some cons against hypoxia, even though its pro is that you can imagine all sorts of outcomes with it. Also some of the passengers were sure to excperience acute distress long before all of the flight crew. Surely this would have been evident on intercom calls on the CVR from the cabin crew.

Might I also suggest that some other scenarios might consider the lack of radio communication and intercom calls as a con.

[bblank]

Sorry Unctuous for the lack of clarity. I was only addressing you
in the one paragraph in which I responded to your previous
post in which you said "The rate of climb increase (and climb?)
recorded seems to be unsupported by any zoom-climb increase in
pitch attitude." I just wanted to point out that pitch did increase
during the last seven seconds of the FDR.

There is a lot we don't know (that is, those of us who only have access
to the data that has been made public). We don't know about the CVR sounds,
we don't have a map of the debris field, recovery of a large percentage
of the a/c, a model for the flight path after things started to go wrong,
models for the trajectories of the major pieces after the breakup, an
understanding of what was going on with engine 4 and whether it had anything
to do with anything, an explanation why the flight crew did not utter
anything in the last 12 seconds of the CVR (if that is indeed the case),
a history of this particular a/c, information about what experts in
the Taiwan military say about their radar data, ...

I'd like to have a better understanding of what happened before
considering any theory. You can only judge a theory after you
know everything that it must explain.

[wes_wall]

bblank

Firehorse in several messages back said the following:

Quote
The tail wreckage group was closest to the last radar return with the cockpit group being .way south and to the west, almost the furtherest group from the tail. The tail incidentally
is rigged and ready to lift any time now. Unquote

Can we read into this that the order of debris is the tail area first, then other parts, then the cockpit?

I wonder if Firehorse can shed any additional information on the location of key peices? Has anyone see a map?

[lurkio]

I don't know if it has been done before as this is a long thread, but I would like to thank firehorse for his contributions so far. A bit of good, real time info sure cuts out the cr@p that sometimes surfaces on these threads.

[Kaptin M]

Agreed, firehorse has been VERY generous to PPRuNer's who have been following this thread, in allowing us a FACTUAL tracing - step-by-step - into this (as yet) unresolved accident.

My initial "gut feeling" on this one, was an encounter with severe weather. However the issue of crew "interference" (ala the Silk Air B737 "accident") might now appear to be something that may have to be factored into this scenario, because of that which appears to be UNSAID (and unheard) immediately prior to the final sequence of events.

[wes_wall]

Firehorse

Thanks for the update on the debris field. Interesting, and I guess we can be thankful about ruling out the CWT scenario.

Kaptin M

Lets wait until we have more information before we begin to point fingers at the crew. That will be done in due time, you can bet, so why not let it rest until then.

[HotDog]

Kaptin M, would you care to elaborate on the meaning of your second paragraph on your last post? I have a feeling you are leaving yourself wide open for a sh!t load of flak, legal and otherwise.:(

[OVERTALK]

1. Request status of two midspan latches of forward cargo door: May be missing.

2. Request status of two pressure relief doors in forward cargo door: May be jammed open or missing.

3. Request number of pieces of forward cargo door retrieved so far: Door may be shattered and broken longitudinally.

4. Any paint transfers above hinge of forward cargo door?

5. Any inflight damage to right wing leading edge wing fillet?

6. Any FOD to engine number three?

7. Request status of aft cargo door: May have opened in flight.

[HotDog]

fwd cargo door intact and locks in place so there goes that theory.

[wes_wall]

Firehorse

Are there any updates you can share regarding the recovery process and early physical findings? Also, has any additional info on the FDR tapes been forthcoming?

Thanks.

[ORAC]

AWST 1st July:

'Relative Abnormality'
Near End of Flight 611
MICHAEL A. DORNHEIM/LOS ANGELES

China Airlines Flight 611 appears to have experienced no major problems before it came apart, but the flight data recorder shows small anomalies in the last 20 sec.

The cockpit voice recorder (CVR) reveals a few noises that experienced observers found unusual for a Boeing 747-200 and were unable to identify. One type started 7 min. before the breakup, and in the last second of the recording there is a "not very loud 'chahhh' sound," said Kay Yong, managing director of Taiwan's Aviation Safety Council (ASC), which is leading the investigation of the May 25 accident ( AW&ST June 24, p. 41).

There is no obvious correlation between the noises and anything on the flight data recorder (FDR), Yong said. The ASC is now studying the CVR with a spectrum analyzer.

Yong said the ASC has ruled out flight crew operational error as a cause. Also, there is no sign of impact with another object because the wreckage so far shows no marks of fire or explosion, he said.

The Flight 611 FDR recording started at 2:56:28 local time and stopped at 3:27:58.9. The CVR stopped 4 sec. later, at 3:28:03 when referred to radar site timing. The final radar beacon transmission observed by Taiwanese radar was also at 3:28:03, though mainland Chinese radar picked up three more beacon signals ending at 3:28:12. The FDR was powered by the essential instrument bus while the CVR and No. 1 transponder beacon were on the essential radio bus. The No. 2 transponder was on the secondary radio bus.

THE TWO BEACON TRACKS plus a Taiwanese military primary skin track indicate the airplane came apart at about 34,700-34,900 ft. It was climbing to 35,000 ft. and had taken off 20 min. earlier. The final altitude on the FDR is 34,573 ft. The FDR is a Lockheed 209F digital tape device with about 44 parameters. Some of the tape was crumpled around the reel, but the Flight 611 section was unaffected.

The FDR shows that once the airplane accelerated to 300 kt. at 12,000 ft., the vertical acceleration stayed well within a ±0.04g range until the last seconds. The lateral acceleration was within ±0.008g, except there is a curious +0.04g spike to the left at about 3:23:58 p.m. local time, or 4 min. before the FDR stopped, and at about 30,400 ft. It is not clear if this is just a glitch, but other parameters are smooth at that point.

Starting at 3:27:37, 21 sec. before the end of the FDR, the indicated thrust of outboard right engine No. 4 drops from 1.51 engine pressure ratio (EPR) to 1.49 EPR over about 6 sec. The EPRs of engines Nos. 1 and 3 rose about 0.05 in apparent response. However, this may not be unusual--4.7 min. earlier there was a greater drop by the No. 3 engine. In fact, if the airplane was flying a 300 KCAS/Mach 0.84 climb speed schedule, this is the altitude at which it would switch from holding knots to holding Mach. The FDR shows the airspeed decreasing and rate of climb increasing, which is consistent with this switch.

VERTICAL ACCELERATION was indicating a constant 0.95g approaching the top of climb, but increased to 1.00g at 3:27:48 without any change in body attitude or airspeed. (These are preliminary readings, uncorrected for instrument error.) Then the body pitched up about 0.8 deg., increasing vertical acceleration to 1.09g. As the nose came back down to its original 2.1-deg. attitude the gs dropped to 0.87, then returned to 0.94 a split second before the FDR ended. It is not clear where the accelerometer is located and how it is affected by body pitch rate. The positive load factor increased the climb rate to 2,800 fpm. from 1,500 fpm. at 34,500 ft.

Yong said these measurements are within normal tolerances and are only being looked at because of the accident. "They are only relatively abnormal. The flight was very smooth and well-behaved, then something changed. If it had landed in Hong Kong, these changes would be totally acceptable."

THE CVR WAS REVIEWED by two China Airlines pilots, a Boeing official, an FAA official, and two ASC investigators. They found seven heartbeat-like noises that occurred from 3:20:53-3:21:14 to be unusual. Also, the final 'chahhh' sound was unusual. The tape has a number of unidentified clicking and squelch break sounds, but they may be switches or other normal noises. The CVR stopped recording for 0.3 sec at about 3:12, but this was likely a problem with the CVR itself, Yong said.

Wreckage recovered from the Taiwan Strait includes the cockpit, a 72-ft.-long section of the forward right wing, the upper deck skin between fuselage station 620-780, and the No. 4 engine. The copilot's body was in the cockpit. The No. 4 engine, which showed the last-minute slight EPR drop, was found 0.8 mi. southwest of the main wreckage area that included the cockpit and right wing. Other parts of the right wing are still attached to the fuselage there and had not been recovered as of late last week.

There is a shape on this right wing that might be the No. 3 engine, but divers were not able to tell for sure. The left wing appears to have broken up more in flight--most of the floating wreckage consisted of control surfaces from that wing. The structural part of the left wing has not been identified. "We're pretty sure the left wing is not by the right wing, but the main wreckage area has lots of debris," Yong said. The No. 1 and 2 engines have also not been found yet.

[JohnBarrySmith]

From AW Week:
There is a shape on this right wing that might be the No. 3 engine, but divers were not able to tell for sure.
Also, the final 'chahhh' sound was unusual.

Well, yes I know that Firehorse reported fcd 'intact and locks in place'...

But..when the nose comes off when forward cargo door ruptures in flight, the nose turns to right and hits number three engine usually tearing it off early. (3 is also fodded from cargo compartment of passengers and on fire.)

Also, aft cargo door is identical to forward and possibility of mixup always there.

And, 'chahhh' is not 'thud' and closer to the sound of door unlatch motor trying to unlatch the ten latches...which only have eight locking sectors on bottom eight latches leaving the midspan unprotected from uncommanded opening. So...when one says 'locks' he may be referring to the bottom eight locking sectors which would be in place after AD 88 12 04 that strengthened them after PA 125 door was found open after landing and implementation accelerated after United Airlines Flight 811 door opened in flight

But...the nose should be first in sequence of debris from last radar contact, and sound should have been loud. If tail first and sound soft, then it may have been aft cargo door rupture or aft pressure bulkhead failure.

If shape on right wing is engine number three that may mean nose did not come off and hit it.

The evidence will clearly show where the hull rupture occurred. If forward area there will be inflight damage to wing and right stabilizer and engines 3 and maybe 4. If tail came off there should be no inflight damage forward of tail.

Question remains, hull rupture in flight, where and when and how?

[I. M. Esperto]

John - Excellent analysis. Thanks.

[firehorse]

How can I attach pics to this post???

[PickyPerkins]

wes_wall Has anyone seen a map?

Well, I dont have a map, but out of curiosity I did try plotting the Mainland Chinese data in the pdf data originally pointed to by Peanut Butter on 27 May, 2002, and the position of the data recorders given in Aviation Week, 1 July, 2002, p. 43. The plot and some more words are on the following web-site:

http://home.infionline.net/~blueblue

[JohnBarrySmith]

Firehorse>Good work there John and I agree with your closing question.

Flattery will get you everywhere. And thank you very very much for your inputs.

Hull rupture in flight: Where, when, and how?

Each location has specific evidence revealed in the wreckage.
For China Airlines Flight 611:
Midspan latch areas of the two cargo doors (four latches) need to be examined for outward ruptures in a petal shape. Bottom eight latches may be attached to lower sill. If midspan latches are attached to latching cams then it is unlikely the cargo door ruptured open in flight. If outward twisted door skin is evident and midspan latches missing, it is likely that door may have ruptured open in flight.

Other helpful observations:

1. Request status of two midspan latches of forward cargo door: May be missing.
2. Request status of two pressure relief doors in forward cargo door: May be jammed open or missing.
3. Request number of pieces of forward cargo door retrieved so far: Door may be shattered and broken longitudinally.
4. Any paint transfers above hinge of forward cargo door?
5. Any inflight damage to right wing leading edge wing fillet?
6. Any FOD to engine number three?
7. Request status of aft cargo door: May have opened in flight.

Let us look at likely places for the balloon to pop from within:

Aft pressure bulkhead.
Forward cargo door.
Aft cargo door.
Side cargo door if present.
Passenger doors.
Windows.
Aft bulk cargo door

Permit me to lay out some history.;

1. Aft pressure bulkhead. (One failure in flight)
12 August 1985; Japan Air Lines 747SR-46 JA8119 JAL flight 123 en route from Tokyo-Haneda to Osaka experienced a rapid decompression which damaged the rear bulkhead, destroyed most of the fin and disabled the flight controls. After some 30 minutes of uncontrolled flight, the 747 crashed into Mt Ogura 100 kms west of Tokyo. Only four of 524 people onboard survived the disaster, which was due to a faulty bulkhead repair in 1979

From CASB report for Air India Flight 182: (Explosion in forward cargo compartment)
2.11.6.3 Target 35 - Portion of Rear Pressure Bulkhead
Looking forward from behind the aircraft, this segment of pressure bulkhead occupied the 9 to 1 o'clock position. The piece from 12 to 1 o'clock had the flange from the outer ring attached. The web below the outer ring flange had areas of buckling. From the 11 to 12 o'clock position, the outer edge showed sinusoidal buckling, and the edge sector at 9 o'clock was partially collapsed and its edge was turned under. Samples taken for optical stereomicroscope and SEM examination revealed that the fracture characteristics were consistent with an overload mode of failure. The examination suggested a general direction of failure from the aft to the forward edge of the rear pressure bulkhead panel.
3.4.2 Aft Pressure Bulkhead
The localized impact mark found on the leading edge of the right horizontal root leading edge is indicative of an object striking the stabilizer in flight before water impact. This suggests that the loss of the tail plane was not the first event. The horizontal and vertical stabilizers were found separated and each was intact and in good condition. Items from the aft cargo compartment were found further to the west of the tail plane. The absence of the type of damage to the tail plane as was found in the Japan Airlines (JAL) Boeing 747 accident where the aft pressure bulkhead failed and which took place shortly after this occurrence, and the rupture of the aft cargo compartment before the loss of the tail indicate that there was not an in-flight failure of the aft pressure bulkhead. In addition, examination of the recovered portions of the bulkhead shows evidence of overload failures from the rear to front only and no evidence of any pre-existing defect, premature cracking or pre-impact corrosion damage. The aircraft structure had a random scatter pattern. That is, items such as the aft pressure bulkhead were broken into several pieces, and these pieces were located throughout the pattern.

3.2.9.10 The aft cargo and bulk cargo doors were found in place and intact, and 5L, 5R and 4R entry doors were identified. Four segments of the aft pressure bulkhead were positively identified (targets 35, 37, 73 and 296). Much of the fuselage which was forward of the number five door and above the passenger floor area was not located, or if located was not recognisable as having come from a specific area of the aircraft.

3.4.2.1 Kanishka was equipped with a Fairchild A-100 Cockpit Voice Recorder Serial No. 5809 and a Lockheed 209E Digital Flight Data Recorder Serial No. 1282. These were each equipped with Dukane Underwater Acoustic Beacons and were installed adjacent to each other in the cabin on the left side near the rear pressure bulkhead.

The conversations in the cockpit were normal, and there was no indication of an emergency situation prior to the loud noise heard on the CVR a fraction of a second before it stopped recording. The DFDR showed no abnormal variations in parameters recorded before it stopped functioning. The only unusual observation was the irregular signals recorded over the last 0.27 inches of the DFDR tape. Laboratory tests indicated the possibility that these signals resulted from the recorder being subjected to a sharp disturbance at the time it stopped recording. The other possibility for the irregular signals on the DFDR is that they were caused by a disturbance to the Flight Data Acquisition Unit in the main electronics bay. Since there was an almost simultaneous loss of the transponder signal, this indicates the possibility of an abrupt aircraft electrical failure. The millisecond noise on a CVR as observed in this case is usually, as described in the available literature, the result of the shock wave from detonation of an explosive device. However, in this case, certain characteristics of the noise indicate the possibility that the noise was the result of an explosive decompression.

2. Forward cargo door. (Two officially opened in flight)
On February 24, 1989, United Airlines flight 811, a Boeing 747-122, experienced an explosive decompression as it was climbing between 22,000 and 23,000 feet after taking off from Honolulu, Hawaii, en route to Sydney, Australia with 3 flightcrew, 15 flight attendants, and 337 passengers aboard.
The National Transportation Safety Board determines that the probable cause of this accident was the sudden opening of the forward lower lobe cargo door in flight and the subsequent explosive decompression.
1.17.1 Previous Cargo Door Incident
On March 10, 1987, a Pan American Airways B-747-122, N740PA, operating as flight 125 from London to New York, experienced an incident involving the forward cargo door.

Difficulty Date : 10/11/00
Operator Type : Air Carrier
ATA Code : 5210
Part Name : Controller
Aircraft Manufacturer : Boeing
Aircraft Group : 747
Aircraft Model : 747422

[JohnBarrySmith]

Difficulty Date : 10/11/00
Operator Type : Air Carrier
ATA Code : 5210
Part Name : Controller
Aircraft Manufacturer : Boeing
Aircraft Group : 747
Aircraft Model : 747422

[lunkenheimer]

Where are the voice and data recorders installed on this A/C? I assume rear fuselage, but does anyone know more specifically?

[JohnBarrySmith]

To continue possible locations for hull rupture China Airlines Flight 611: (Unknown location in China Airlines Flight 611 for FDR and CVR but probably the same as AI 182, another 747-200 series.)


What happens when nose comes off, from NTSB AAR 0003 for Trans World Airlines Flight 800:
Effect Of Nose Separation
The separation of the forward fuselage will result in large changes to the
aerodynamic and mass property characteristics of the aircraft. The center of gravity
will shift aft, the weight will go down, and the aircraft moments of inertia will be
reduced. The mass properties as estimated by Boeing are summarized in the
following table.
Parameter Before Nose Separation After Nose Separation
Gross Weight (lbs.) 574000 494606
C.G. %MAC 21.1 57.8
Iyy slug-ft2 27790000.0 15780000.0
Ixx slug-ft2 19110000.0 18970000.0
One aerodynamic effect of the loss of the forward fuselage is the loss of the
aerodynamic loads on the forward fuselage itself. A second aerodynamic effect will
be due to the replacement of the smooth forward fuselage with a blunt open front.
This will result in a direct increase in drag but will also effect the flow around the
inboard wing. The changes in the longitudinal aerodynamic coefficients (lift, drag
and pitching moment) due to the separation of the forward fuselage were estimated
by Boeing and are presented in figures 1, 2, and 3. Flight control positions are
assumed to remain at their pre nose-off positions.

3. Aft cargo door. (None opened in flight, yet)
1.17.6 Uncommanded Cargo Door Opening--UAL B-747, JFK Airport
On June 13, 1991, UAL maintenance personnel were unable to electrically open the aft cargo door on a Boeing 747-222B, N152UA, at JFK Airport, Jamaica, New York.

[JohnBarrySmith]

To summarize possible locations of known rupture points in 747 hulls.

1. Aft pressure bulkhead. One officially, JAL 123, bad repair
2. Forward cargo door. Two officially, PA 125 and United Airlines Flight 811, wiring.
3. Aft cargo door. 3. (None opened in flight, yet)
Uncommanded Cargo Door Opening--UAL B-747, JFK Airport
On June 13, 1991, UAL maintenance personnel were unable to electrically open the aft cargo door on a Boeing 747-222B, N152UA, at JFK Airport, Jamaica, New York. It opened when CB pushed in.
4. Side cargo door if present. (One almost opened inflight, 11 of 12 latches had unlatched) Not present in China Airlines Flight 611apparently.
5. Passenger doors. Boeing 747 could withstand a hole the size of a passenger door in flight according to design.
6. Windows.Comet ADF window metal fatigue
7. Aft bulk cargo door DC 10 (Three confirmed events, two in flight) Improperly latched

[Kubota]

CVR and FDR are located on the stbd side of the fusilage aft of door R5 outside the pressure bulkhead.

An approximate location is in this schematic:

http://www.dgac.fr/img/allabout/progres2.gif

[tinyrice]

On older 747 Classics, the CVR and FDR are generally mounted on the P83 panel aft of the L5 door above the left hand side ceiling - and inside the pressure vessel, i.e.forward of the aft bulkhead.