China Airlines B747 Crash (Merged)
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Another pdf
http://www.asc.gov.tw/asc/_file/2006...r0625press.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.)
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.)
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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)
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)
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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.
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.
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Very very similar to JAL123 (14 Aug 85)
If you look at the JAL Report 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.
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.
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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?
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?
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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!
Well, it is a rumour BB after all!
Last edited by BlueEagle; 27th Jun 2002 at 06:26.
>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
<
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
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"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.
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.
Peanut Butter,
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.
4) No significant airspeed/Heading/Roll angle changes.
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.
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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.
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An End over End Tumble
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.
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.
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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
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
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- - - - 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.
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.
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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.
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.
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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.
"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.