Help researching 1961 Electra crash
The report states,
If you look at the schematic it has an arrow showing the right wing up direction, which also makes it the left wing down.
The piece I think you are referring to,
is only talking about a lack of continuity between the boost unit and the cockpit controls ie left & right control wheels, not the the Captain who was flying.
No.
This failure was caused by a separation of the left wing, down cable from the slack absorber, on the copilot‘s side
The piece I think you are referring to,
a disconnect in the aileron primary control system between the pilot‘s control wheel and the aileron boost
If Co-pilot cable separated, left wing down was available
In your response, you have added a comma.
That is dishonest.
We are done.
The report states,
Quote:
This failure was caused by a separation of the left wing, down cable from the slack absorber, on the copilot‘s side
For thirty four feet, paired cables, running parallel 1.5 inches apart, enter the most robust area on the airframe, the aft wing control locker. They divide, and articulate either side of a bell mounted on the boost quadrant.
One cable, said to have separated in flight, and falling limply into the boost unit’s bay, is adjacent its former join, also hanging limply and attached via slack absorber, the final flexible cable, and a swaged ball end clipped to the quadrant.
The pilot's cable remains continuous, fixed solidly and surviving the impact and slide to be found in pristine condition, such that all its parts are indexed, inspected, and archived.
The separated and limp cable appears to have yanked out the remains of the run to the boost unit, such that everything is obliterated, and never recovered.
Any problem with that? Physics wise?
Last edited by Concours77; 8th Jan 2018 at 22:21.
The report should have read “Pilots’ “ rather than “Pilot’s”. “Pilot’s” is singular possessive, and means it was Captain’s cable that separated. In any case, there was only one pilot on board, the Commander. It was 1961, pre CRM, and the flight deck was NOT a democracy.
The cables are in tension at 70 pounds, as I read it.
I applaud your patience, Captain.
It is my belief that the control cable in discussion did NOT separate in flight from its insertion into the forward junction block of the slack absorber. During your read, remember the cable that survived intact was right where the mechanics left it.
Here’s why.
To remove the boost unit, it is necessary to slacken the cable control loop, which involves “unthreading” both cables from each slack absorber. Now that statement might be misleading, because the cable is not turning, it is stationary; it is the slack absorber that is being rotated. Rotate the slack absorber one way, (sixteen turns), the system slackens. Rotate the other way, the system tightens.
Why is the cable stationary? Because it is fixed at its other (forward) end to the Lockclad run ahead of it via a swaged connector. It is also fixed in place during tensioning by the lead mechanic’s helper. The cable will not rotate sufficient to loosen the one inch the mechanic needs to remove the boost unit. This one inch is only half of the total release, since as the slack absorber turns it “expels” each cable connector; the slack absorber has opposite threaded blocks at either end. So, two inches total.
The cable that remained attached had but one half inch of threads nested in the junction block, and CAB claim that was the position left by the mechanic when the system was loosened. There is no reason to assume the mechanic treated the other slack absorber differently.
This partially enclosed cable connector withstood all impact loads, as I believe its counterpart did. In any case, flight loads were insignificant compared to the enormous stresses of impact(s).
The safety wire is not installed to prevent the flexible cables from “retreating”. Safety wire, in this application, is utilized to keep the slack absorber from rotating. Conceptually, the cables keep the system constant, not the slack absorber.
The Spring in the barrel of the slack absorber? Once the cables are inserted to the prescribed depth, the spring is attached to either end of each flexible cable. It pulls them together, in tension greater than control forces, >70 pounds. Why? So the cable is not loaded to pull out, it is loaded to push in. Ninety nine percent of the time in flight, the cable wants to screw IN not OUT. Seventy pounds is not arbitrary.
I have some comments about the testing method used by Lockheed in its test of the control cabling resistance to failure in tension.
Lockheed mounted an exemplar cabling system and slowly added tension to failure point. The cable snapped. No mechanism for the slow addition of “tension to failure” exists in flight. A more accurate demonstration of failure would be shock loading, something that actually existed in this accident. There was no “slow increase in tension” post impact; none that I can find. In shock, the energy dissipation has a completely different behavior. My thought is that in shock, the brass block would fracture, and release the cable’s connector. This would explain the CAB’s finding re the cable impacting the aft wing spar hole with the connector intact.
My cynical side would claim Lockheed knew beforehand how the exemplar would fail. They were working to a theory, NOT experimentally building a foundation for study.
If this analysis is inaccurate, my bad, please correct. Also, if this is not the design Lockheed used, then it is mine, and it’s for sale.
Best,
Bill
(Your comment about inflight failure re cables is not what I addressed in my post. I was discussing the post impact evidence of failures, including, but not limited to, the control cables.....)
The cables are in tension at 70 pounds, as I read it.
I applaud your patience, Captain.
It is my belief that the control cable in discussion did NOT separate in flight from its insertion into the forward junction block of the slack absorber. During your read, remember the cable that survived intact was right where the mechanics left it.
Here’s why.
To remove the boost unit, it is necessary to slacken the cable control loop, which involves “unthreading” both cables from each slack absorber. Now that statement might be misleading, because the cable is not turning, it is stationary; it is the slack absorber that is being rotated. Rotate the slack absorber one way, (sixteen turns), the system slackens. Rotate the other way, the system tightens.
Why is the cable stationary? Because it is fixed at its other (forward) end to the Lockclad run ahead of it via a swaged connector. It is also fixed in place during tensioning by the lead mechanic’s helper. The cable will not rotate sufficient to loosen the one inch the mechanic needs to remove the boost unit. This one inch is only half of the total release, since as the slack absorber turns it “expels” each cable connector; the slack absorber has opposite threaded blocks at either end. So, two inches total.
The cable that remained attached had but one half inch of threads nested in the junction block, and CAB claim that was the position left by the mechanic when the system was loosened. There is no reason to assume the mechanic treated the other slack absorber differently.
This partially enclosed cable connector withstood all impact loads, as I believe its counterpart did. In any case, flight loads were insignificant compared to the enormous stresses of impact(s).
The safety wire is not installed to prevent the flexible cables from “retreating”. Safety wire, in this application, is utilized to keep the slack absorber from rotating. Conceptually, the cables keep the system constant, not the slack absorber.
The Spring in the barrel of the slack absorber? Once the cables are inserted to the prescribed depth, the spring is attached to either end of each flexible cable. It pulls them together, in tension greater than control forces, >70 pounds. Why? So the cable is not loaded to pull out, it is loaded to push in. Ninety nine percent of the time in flight, the cable wants to screw IN not OUT. Seventy pounds is not arbitrary.
I have some comments about the testing method used by Lockheed in its test of the control cabling resistance to failure in tension.
Lockheed mounted an exemplar cabling system and slowly added tension to failure point. The cable snapped. No mechanism for the slow addition of “tension to failure” exists in flight. A more accurate demonstration of failure would be shock loading, something that actually existed in this accident. There was no “slow increase in tension” post impact; none that I can find. In shock, the energy dissipation has a completely different behavior. My thought is that in shock, the brass block would fracture, and release the cable’s connector. This would explain the CAB’s finding re the cable impacting the aft wing spar hole with the connector intact.
My cynical side would claim Lockheed knew beforehand how the exemplar would fail. They were working to a theory, NOT experimentally building a foundation for study.
If this analysis is inaccurate, my bad, please correct. Also, if this is not the design Lockheed used, then it is mine, and it’s for sale.
Best,
Bill
(Your comment about inflight failure re cables is not what I addressed in my post. I was discussing the post impact evidence of failures, including, but not limited to, the control cables.....)
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This was the only recorded accident involving an Electra that involved loss of aileron control. Whatever mitigating measures were adopted to prevent a recurrance were undoubtably successful, because no similar loss of aileron control resulting in a crash has been reported to this day. That suggests the investigators were correct in their assessment of how the control cable failed.
Good morning megan and G0ULI
I submit loss of aileron Control was the direct cause of the accident.
You’ll get no argument from me.
The flight path and the forensics are conclusive. Without doubt.
N137US entered a right roll from which she did not recover.
This would be a superb foundation for a technical discussion, this concurrence of opinion.
I am doing some research. The CAB report has many flaws.
Should we move to Tech Log?
Bill
I submit loss of aileron Control was the direct cause of the accident.
You’ll get no argument from me.
The flight path and the forensics are conclusive. Without doubt.
N137US entered a right roll from which she did not recover.
This would be a superb foundation for a technical discussion, this concurrence of opinion.
I am doing some research. The CAB report has many flaws.
Should we move to Tech Log?
Bill
This was the only recorded accident involving an Electra that involved loss of aileron control. Whatever mitigating measures were adopted to prevent a recurrance were undoubtably successful, because no similar loss of aileron control resulting in a crash has been reported to this day. That suggests the investigators were correct in their assessment of how the control cable failed.
These squawks point to, among others:
Boost pumps. Boost cylinder and piston. Autopilot as required MEL. Chattering Boost Control valve, fluid filtration, pressure relief and piston balance, improved scavenge of passive side, paperwork requirements, better and more frequent inspections, and many more.
It isn’t cute to leave unsafetied a single, non redundant system. But it might not be the correct answer to 706.
Simply this:
Without any commanded Roll, the Aileron Boost pumps shut down when the Aileron Boost Handle is pulled, and both ailerons are supposed to cycle home. When the co-pilot stated “no Release”, Captain relaxed his LEFT ROLL. With Roll commanded, and both control cables attached, the Boost valve pressure prevents the boost handle from working. This is what happened, it’s why they got no BOOST OFF. Aileron command provided the pressure to the valve, and prevented the co-pilot from de activating BOOST. (“I cannot get release”.) If a cable separated, there would have been no aileron input, BOOST OFF occurs immediately. The conclusion of “separated” cable is not correct.
But it wouldn’t have mattered, something else was terribly wrong, and it made recovery impossible.
Without any commanded Roll, the Aileron Boost pumps shut down when the Aileron Boost Handle is pulled, and both ailerons are supposed to cycle home. When the co-pilot stated “no Release”, Captain relaxed his LEFT ROLL. With Roll commanded, and both control cables attached, the Boost valve pressure prevents the boost handle from working. This is what happened, it’s why they got no BOOST OFF. Aileron command provided the pressure to the valve, and prevented the co-pilot from de activating BOOST. (“I cannot get release”.) If a cable separated, there would have been no aileron input, BOOST OFF occurs immediately. The conclusion of “separated” cable is not correct.
But it wouldn’t have mattered, something else was terribly wrong, and it made recovery impossible.
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Concours 77
A very plausible scenario except that in all the millions of hours these aircraft have flown since, no one has experienced this problem in the way you describe it. I am sure that there have been many occasions where the boost pumps were deactivated due to a fault or intentionally, but none of these events resulted in a crash due to loss of aileron control.
A very good attempt at building a scenario to fit the presumed radio transmission.
A very plausible scenario except that in all the millions of hours these aircraft have flown since, no one has experienced this problem in the way you describe it. I am sure that there have been many occasions where the boost pumps were deactivated due to a fault or intentionally, but none of these events resulted in a crash due to loss of aileron control.
A very good attempt at building a scenario to fit the presumed radio transmission.
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Following used on an investigators course.
“Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence.” ― John Adams, The Portable John Adams
“In our reasonings concerning matter of fact, there are all imaginable degrees of assurance, from the highest certainty to the lowest species of moral evidence. A wise man, therefore, proportions his belief to the evidence.” ― David Hume, An Enquiry Concerning Human Understanding
They conceive a certain theory, and everything has to fit into that theory. If one little fact will not fit it, they throw it aside. But it is always the facts that will not fit in that are significant.” ― Agatha Christie, Death on the Nile
“Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence.” ― John Adams, The Portable John Adams
“In our reasonings concerning matter of fact, there are all imaginable degrees of assurance, from the highest certainty to the lowest species of moral evidence. A wise man, therefore, proportions his belief to the evidence.” ― David Hume, An Enquiry Concerning Human Understanding
They conceive a certain theory, and everything has to fit into that theory. If one little fact will not fit it, they throw it aside. But it is always the facts that will not fit in that are significant.” ― Agatha Christie, Death on the Nile
Last edited by BRDuBois; 11th Jan 2018 at 13:36.
megan
A boost unit has a failure mode called a "hardover", where hydraulic pressure causes the boost to drive to the limit in one direction or the other. The simple remedy is to remove hydraulic pressure, which is the "release" spoken about in the radio transmission. "Release" returns control to pure mechanical, with heavier control forces. The crew thought they had a "hardover", which in one sense they did, but it wasn't caused by the boost unit driving to a limit, but brought about by a separated cable. Flown with boost units for 20,000 hours and never heard of a hardover event, not saying there has never been one.
I do not suggest “hardover”. That is your preconceived opinion based on your calcified experience, and inability to be objective. But you are on the right track and a bit hyperstatic. (Stuck).
I am suggesting that the cables were sound, that the boost unit was receiving a left roll signal. The pressure on the control valve associated with the signal input by the Captain prevented successfully selecting BOOST OFF.
It’s in the manual, have you read it?
There was no hardover. “The aircraft exhibited a gentle and continuous roll to the right.”
A hardover to Roll right would have resulted in the witnesses seeing a beautiful aircraft quickly roll onto her back.
I mentioned Lockheed and the experiment they performed to demonstrate that the only solution for cable separation was in the connector’s imprint on the cable hole in the spar.
And you accuse me of Confirmation Bias? This is a cold case, and wants the appropriate approach to challenge the findings.
The CAB report was conceived and in first draft before the sun set on the day....
I suggest you reread Danny’s command: “play the ball, not the player...”
A boost unit has a failure mode called a "hardover", where hydraulic pressure causes the boost to drive to the limit in one direction or the other. The simple remedy is to remove hydraulic pressure, which is the "release" spoken about in the radio transmission. "Release" returns control to pure mechanical, with heavier control forces. The crew thought they had a "hardover", which in one sense they did, but it wasn't caused by the boost unit driving to a limit, but brought about by a separated cable. Flown with boost units for 20,000 hours and never heard of a hardover event, not saying there has never been one.
I do not suggest “hardover”. That is your preconceived opinion based on your calcified experience, and inability to be objective. But you are on the right track and a bit hyperstatic. (Stuck).
I am suggesting that the cables were sound, that the boost unit was receiving a left roll signal. The pressure on the control valve associated with the signal input by the Captain prevented successfully selecting BOOST OFF.
It’s in the manual, have you read it?
There was no hardover. “The aircraft exhibited a gentle and continuous roll to the right.”
A hardover to Roll right would have resulted in the witnesses seeing a beautiful aircraft quickly roll onto her back.
I mentioned Lockheed and the experiment they performed to demonstrate that the only solution for cable separation was in the connector’s imprint on the cable hole in the spar.
And you accuse me of Confirmation Bias? This is a cold case, and wants the appropriate approach to challenge the findings.
The CAB report was conceived and in first draft before the sun set on the day....
I suggest you reread Danny’s command: “play the ball, not the player...”
Last edited by Concours77; 11th Jan 2018 at 15:22.
For G0ULI
“This was the only recorded accident involving an Electra that involved loss of aileron control....”
Thanks G0ULI.
I think that’s right. However, you don’t mention the many aileron issues (all potentially capable of causing loss of all aileron) that pilots had written in the aircraft’s log’s attached squawks.... and that’s but one airplane in a large fleet.
Common in the Fleet? How were the many squawks addressed? CAB stated “not very well, even casual...”
Question. How many times had this flight crew operated N137US? Were they familiar with the aircraft’s problems?
On the day, the co-pilot told us what was wrong, told us what they were doing to correct, and what was happening to the flight path. Had they ever discussed this individual aircraft, had other pilots? Almost certainly yes. In the flying fraternity, it’s called a “heads up”.
It would not surprise me in the least if other pilots had reached a consensus of sorts:
“Boost issues...” It was the squawks that finally motivated NW to replace the boost unit, the thinking being: “maybe this will help.”? Who does not know a mechanic whose theory of repairs is: “keep replacing parts until the problem goes away”?
It was noted that this boost removal/replacement was the first NW had done. Was the boost unit the cause of all the squawks? It wasn’t the power arm? The Control Valve? The pumps? The check valves? A hung pushrod in the wing? What was the methodology used to chase down these potential and hazardous issues?
As to the “damage” that shows separation of the cable, it was not evidence that led to the opinion about cable separation, it was the opinion that led to the “evidence”, with an experiment designed by Lockheed to prove the opinion, not to challenge it.......
Let’s review the squawks, informally
Aileron Slop. Yoke vibration. Chatter with any input. Sluggish response.
Off the top of my head, this sounds not like the boost unit ouput at all. It suggests a problem with the control valve, and its plumbing.
Thanks G0ULI.
I think that’s right. However, you don’t mention the many aileron issues (all potentially capable of causing loss of all aileron) that pilots had written in the aircraft’s log’s attached squawks.... and that’s but one airplane in a large fleet.
Common in the Fleet? How were the many squawks addressed? CAB stated “not very well, even casual...”
Question. How many times had this flight crew operated N137US? Were they familiar with the aircraft’s problems?
On the day, the co-pilot told us what was wrong, told us what they were doing to correct, and what was happening to the flight path. Had they ever discussed this individual aircraft, had other pilots? Almost certainly yes. In the flying fraternity, it’s called a “heads up”.
It would not surprise me in the least if other pilots had reached a consensus of sorts:
“Boost issues...” It was the squawks that finally motivated NW to replace the boost unit, the thinking being: “maybe this will help.”? Who does not know a mechanic whose theory of repairs is: “keep replacing parts until the problem goes away”?
It was noted that this boost removal/replacement was the first NW had done. Was the boost unit the cause of all the squawks? It wasn’t the power arm? The Control Valve? The pumps? The check valves? A hung pushrod in the wing? What was the methodology used to chase down these potential and hazardous issues?
As to the “damage” that shows separation of the cable, it was not evidence that led to the opinion about cable separation, it was the opinion that led to the “evidence”, with an experiment designed by Lockheed to prove the opinion, not to challenge it.......
Let’s review the squawks, informally
Aileron Slop. Yoke vibration. Chatter with any input. Sluggish response.
Off the top of my head, this sounds not like the boost unit ouput at all. It suggests a problem with the control valve, and its plumbing.
Last edited by Concours77; 11th Jan 2018 at 15:19.
Great news!
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Which comes back to the final wreckage being tail-first and inverted, the discomfiting fact that started me on this project. The CAB investigators decided on the day of the crash that the plane slid tail first and right side up. They never corrected it through the final report. What sort of focus and determination does it take to accomplish that?
It all comes down to whether the final disposition of the tail section had any relevance to the accident and I can't see that it does. Why add additional complication to the report when it isn't necessary? Remember, all of this information was being manually transcribed and typed up. No computers or word processors to do a quick cut and paste edit. Every page had to be typed with carbon paper or a stencil to produce multiple copies for distribution. Speaking from personal experience, you take whatever shortcuts you can and avoid correcting errors that do not affect the final conclusion, when every typing error means going back to the beginning of a page and starting again from scratch.
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There are several ways the main fuselage could have ended in its final position. That's why it's a puzzle. The only thing we can be confident of is that it didn't happen as the CAB report describes.
There was no need at all. The investigators could have said that the main body traveled an additional 820 feet and then burned. There would have been no grounds for criticism, no hint that they misunderstood. But instead they made an explicit statement which is so egregiously wrong that an amateur can see it. That's what makes this strange.
It doesn't come down to whether their error focused on the root cause or not. My subject is not the root cause, it's the impact sequence. Within that subject, the CAB error is a smoking gun that says they did not understand what happened and apparently did not care very much to know. I have to believe that among the CAB team there were at least some who were protesting, shaking their heads over this foolish statement. Why did they not prevail?
Further, they made this erroneous statement on the day of the crash. The Chicago Trib reporter and artist didn't make up that image which so perfectly matches the CAB story. The CAB investigators told them that long before they could have known whether it would have any implication on the root cause.
Once you start evaluating the different modes by which the main body might have ended where it did, you may realize that some of those modes have a huge implication on how the plane was poised and how it hit. If the main body arrived as my latest sim run illustrated, then there can not have been a high bank or cartwheel. If the main body arrived by sliding, then a cartwheel is possible. It's a puzzle.
I know; I have one of the original carbons. I don't think you're suggesting they would knowingly leave an error in their official report in order to save a typist some time. When I had the services of a staff of typists I didn't beat them over the head with extra work, and gave them canned paragraphs to simplify dictation, but I sure wouldn't let any errors pass by.
It doesn't come down to whether their error focused on the root cause or not. My subject is not the root cause, it's the impact sequence. Within that subject, the CAB error is a smoking gun that says they did not understand what happened and apparently did not care very much to know. I have to believe that among the CAB team there were at least some who were protesting, shaking their heads over this foolish statement. Why did they not prevail?
Further, they made this erroneous statement on the day of the crash. The Chicago Trib reporter and artist didn't make up that image which so perfectly matches the CAB story. The CAB investigators told them that long before they could have known whether it would have any implication on the root cause.
Once you start evaluating the different modes by which the main body might have ended where it did, you may realize that some of those modes have a huge implication on how the plane was poised and how it hit. If the main body arrived as my latest sim run illustrated, then there can not have been a high bank or cartwheel. If the main body arrived by sliding, then a cartwheel is possible. It's a puzzle.
Remember, all of this information was being manually transcribed and typed up. No computers or word processors to do a quick cut and paste edit. Every page had to be typed with carbon paper or a stencil to produce multiple copies for distribution.
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The controversy over the report findings in this case are as nothing to other events in the US (and elsewhere) which were filmed and broadcast live as they happened. If people choose not to believe the evidence of their own eyes and the opinions of experts, but seek to put their own interpretation on what happened and the motivation of those involved, then the study becomes less than scientific, fake news for want of another expression.
A far easier explanation of everything that seems wrong is that the newspaper reporters at the time demanded an instant assessment at the site of the crash from anyone they could talk to. The story was published, the purient curiosity of most readers was satisfied and nobody was interested in later correcting the details because there was no longer any public interest and it had no relevance to the cause of the crash.
It is clear from the photographs that some portion of the aircraft slid along the ground after the initial impact. The final position of the tail section with the tail and rudder assembly virtually intact suggests that the sliding must have taken place while the rear fuselage was upright. The only thing that was missed is that while sliding it also rotated as would be expected with one virtually intact wing still attached. It hit the ditch and pitched over inverted. Case solved, probably.
The only requirement for this scenario to work is that the aircraft hit the ground in a vertical bank, which is supported by the available evidence and reports.
What doesn't work is a scenario that has the pilot somehow levelling the wings between striking the railroad embankment and final impact with the ground. All the documents produced to date suggest that this was the least likely sequence of events.
How the aircraft broke up is only important in establishing what components, that may have been contributory to the accident, may have been damaged or gone missing. Giving the same evidential weight to contemporary press reports against the final official report is likely to lead to conflicts in reconstructing events, as appears to have happened in this incident. The investigators were not lying, nor was there a corporate cover up, although the temptation and pressures to do so may have been enormous. Lockheed allegedly ended up losing more than 100 million dollars as a result of this and the whirl mode accidents. Public faith in the aircraft never really recovered and the age of a preferrence for pure jet travel dawned.
A far easier explanation of everything that seems wrong is that the newspaper reporters at the time demanded an instant assessment at the site of the crash from anyone they could talk to. The story was published, the purient curiosity of most readers was satisfied and nobody was interested in later correcting the details because there was no longer any public interest and it had no relevance to the cause of the crash.
It is clear from the photographs that some portion of the aircraft slid along the ground after the initial impact. The final position of the tail section with the tail and rudder assembly virtually intact suggests that the sliding must have taken place while the rear fuselage was upright. The only thing that was missed is that while sliding it also rotated as would be expected with one virtually intact wing still attached. It hit the ditch and pitched over inverted. Case solved, probably.
The only requirement for this scenario to work is that the aircraft hit the ground in a vertical bank, which is supported by the available evidence and reports.
What doesn't work is a scenario that has the pilot somehow levelling the wings between striking the railroad embankment and final impact with the ground. All the documents produced to date suggest that this was the least likely sequence of events.
How the aircraft broke up is only important in establishing what components, that may have been contributory to the accident, may have been damaged or gone missing. Giving the same evidential weight to contemporary press reports against the final official report is likely to lead to conflicts in reconstructing events, as appears to have happened in this incident. The investigators were not lying, nor was there a corporate cover up, although the temptation and pressures to do so may have been enormous. Lockheed allegedly ended up losing more than 100 million dollars as a result of this and the whirl mode accidents. Public faith in the aircraft never really recovered and the age of a preferrence for pure jet travel dawned.
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When it came time to write the final report, the CAB report author filled in the unimportant parts by checking to see what they'd told the newspapers, and just pasted that in? Sorry, I don't buy it.
If it rotated while sliding, then the explicit CAB statement that it slid tail first is wrong. I understand that no one wants to confront that, and perhaps if we ignore it long enough it will go away, but the puzzle remains nonetheless. Why did the CAB include extra incorrect information when they could have just ignored it? The simplest explanation, of course, is that they believed it.
The ditch had nothing to do with the plane flipping over. If the plane had stubbed on the ditch and flipped, the plane would be at least one fuselage diameter past the ditch. Instead the plane is lying across the ditch. I go into that at some length in my report. So if it was sliding forward, what flipped it?
The pilot didn't level the plane between the embankment and the next impact. Those points were 380 feet apart and the plane was moving 270 feet per second. The distance was a little over three plane lengths and under 1.5 seconds. It was all ballistics then.
I never accused the investigators of lying; I accuse them of sloppy work. They gave the clamoring reporters a first approximation that turns out to be bogus. No great surprise there. The surprise is that the investigators either held on to that bogus story, or came back to it in the course of their investigation.
Asking how a bogus scenario ended up in the official report is a legitimate question, old and thin as the evidence may be. Leaving errors in the official report is not justified by the fact that it's an aspect no one cared much about.
If it rotated while sliding, then the explicit CAB statement that it slid tail first is wrong. I understand that no one wants to confront that, and perhaps if we ignore it long enough it will go away, but the puzzle remains nonetheless. Why did the CAB include extra incorrect information when they could have just ignored it? The simplest explanation, of course, is that they believed it.
The ditch had nothing to do with the plane flipping over. If the plane had stubbed on the ditch and flipped, the plane would be at least one fuselage diameter past the ditch. Instead the plane is lying across the ditch. I go into that at some length in my report. So if it was sliding forward, what flipped it?
The pilot didn't level the plane between the embankment and the next impact. Those points were 380 feet apart and the plane was moving 270 feet per second. The distance was a little over three plane lengths and under 1.5 seconds. It was all ballistics then.
I never accused the investigators of lying; I accuse them of sloppy work. They gave the clamoring reporters a first approximation that turns out to be bogus. No great surprise there. The surprise is that the investigators either held on to that bogus story, or came back to it in the course of their investigation.
Asking how a bogus scenario ended up in the official report is a legitimate question, old and thin as the evidence may be. Leaving errors in the official report is not justified by the fact that it's an aspect no one cared much about.
Writing a report
The report states, (paraphrased), that the cabling from the Starboard flight station in the area of the boost quadrant “......was not recovered....”
It also infers that the aft connector “punched through” the hole, leaving shoulder marks. But the brass junction block could not fit through, therefore, the cable was not attached prior to impact.
“Not recovered”. A technical phrase, with a specific meaning. Recovery involves “locating, photography (in situ), isolating and indexing, delicate removal, carefully containing, and a chain of authority whilst in transit to a secure location.”
“Discovery”. A visual happenstance, object(s) protected, left undisturbed, pending assessment.
Was the cable run discovered, found? the language in the report does not state? “Not recovered” is unfortunate use of language exonerating liability? No. It is misleading. If “found” the obligation is to carefully and scientifically research the structure. The aft controls locker is inside the wing box, which survived the impact.
Did the team say “not found”? Need confirmation here. The cable run in question was almost certainly “located”. Did it make the trash truck before anyone granted its critical importance?
BTW. The “aft connector” is intended to pass through the hole in the spar.
It is the only way to thread the cable run into the aft controls locker from forward of the spar, during assembly of the full run.
Why? The flexible cable is permanently swaged to the sixteen foot long Lockclad cable. Lockclad will not pass easily through the hole from the aft aspect.
The “hole”:
1. Drilling through a metallic structure requires care.
2. After through and through penetration, the hole must be “eased” at both faces, to prevent the establishment and propagation of cracks in the spar. It is likely (hopefully) this was accomplished by “rounding” (or at least “chamfering”) each perimeter to forestall later cracks from forming.
This “easing” could easily be mistaken for remnants of a violent pass by the connector.
I maintain: The kit between the Boost quadrant and the slack absorber was stripped away from the quadrant during the first (fuselage) impact. Both Port and Starboard runs. Both terminal installations remained in the control bay.
I am going to further say, subject to further examination, that the cable forward of the slack absorber was connected in flight, and stripped away whilst attached upon impact.
With the number of aileron squawks, and their diversity, I would question whether replacement of the boost unit would have mitigated all of them?
By boost unit, do we mean the cylinder and drive arm only? Do we include the pumps, their power source, and the control valve?
What about the ”taper pin”, and the faulty “indicator light”?
Maybe in FOIA.
It also infers that the aft connector “punched through” the hole, leaving shoulder marks. But the brass junction block could not fit through, therefore, the cable was not attached prior to impact.
“Not recovered”. A technical phrase, with a specific meaning. Recovery involves “locating, photography (in situ), isolating and indexing, delicate removal, carefully containing, and a chain of authority whilst in transit to a secure location.”
“Discovery”. A visual happenstance, object(s) protected, left undisturbed, pending assessment.
Was the cable run discovered, found? the language in the report does not state? “Not recovered” is unfortunate use of language exonerating liability? No. It is misleading. If “found” the obligation is to carefully and scientifically research the structure. The aft controls locker is inside the wing box, which survived the impact.
Did the team say “not found”? Need confirmation here. The cable run in question was almost certainly “located”. Did it make the trash truck before anyone granted its critical importance?
BTW. The “aft connector” is intended to pass through the hole in the spar.
It is the only way to thread the cable run into the aft controls locker from forward of the spar, during assembly of the full run.
Why? The flexible cable is permanently swaged to the sixteen foot long Lockclad cable. Lockclad will not pass easily through the hole from the aft aspect.
The “hole”:
1. Drilling through a metallic structure requires care.
2. After through and through penetration, the hole must be “eased” at both faces, to prevent the establishment and propagation of cracks in the spar. It is likely (hopefully) this was accomplished by “rounding” (or at least “chamfering”) each perimeter to forestall later cracks from forming.
This “easing” could easily be mistaken for remnants of a violent pass by the connector.
I maintain: The kit between the Boost quadrant and the slack absorber was stripped away from the quadrant during the first (fuselage) impact. Both Port and Starboard runs. Both terminal installations remained in the control bay.
I am going to further say, subject to further examination, that the cable forward of the slack absorber was connected in flight, and stripped away whilst attached upon impact.
With the number of aileron squawks, and their diversity, I would question whether replacement of the boost unit would have mitigated all of them?
By boost unit, do we mean the cylinder and drive arm only? Do we include the pumps, their power source, and the control valve?
What about the ”taper pin”, and the faulty “indicator light”?
Maybe in FOIA.
Last edited by Concours77; 12th Jan 2018 at 15:37.
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The CAB made no statement other than it slid rearward for some hundreds of feet, I'm not looking up the figure quoted. It matters not what the aircraft did in its slide because its not pertinent. How the aircraft came to rest inverted is not pertinent, as much as you want to make an issue of it.
This is an untrue statement. It's not a lie, it's an error. It's easy to show the report is wrong, but it's hard to tell what happened. Hence the puzzle.
Current practise in any fatal accident is a toxicology report on the crew, whether they had ingested prescribed medication, over the counter medication, alcohol or illicit drugs, to see if they may have had an effect on the crews performance. Investigation is also made if they had adequate rest, and how much, prior to duty, and if they had any personal issues within their lives - pending divorce, death in the family, extremely sick children etc etc. This report is silent on those issues, should I allege the CAB were slack in not addressing this important issue? Sloppy work?
You have absolutely no idea of what caused the aircraft to invert, and the only part lying over the ditch is the very forward section of the wing box, and only just at that. The aircraft is not lying across the ditch as you are so willing to incorrectly state.
You have absolutely no idea of the aircrafts gyrations from the time it hit the embankment ... to the point at which it came to rest.
At least one fuselage diameter past the ditch? Where in the world do you come up with such ridiculous statements? You have absolutely no idea of what caused the aircraft to invert, nor how the kinetic energy was dissipated in order for the aircraft to end where it did.
For the plane to land on top of the ditch when it flipped, it must have bounced at least one fuselage-height into the air while pitching forward. This is a relatively high-energy arrival, not a sliding stop. I can't quantify it for you, but you're bright enough to envision what I'm saying. So if the ditch played a role, then it didn't hit the ditch and tip forward, it hit the ditch and bounced into the air at least 13 feet.
My postulate is that the tail section and wing, attached and sliding (upright) landing gear forward, dropped into the ditch, snagged, and the assembly “pitch poled” to land as found.
This demands that it was the last of the energy contained in the structure(s) that did the work. From the condition of the tail, any inverted slide would almost assuredly have destroyed the VS, HS, and rudder. This is plausible and demonstrable, hence probable.
G0ULI:
“How the aircraft broke up is only important in establishing what components, that may have been contributory to the accident, may have been damaged or gone missing. Giving the same evidential weight to contemporary press reports against the final official report is likely to lead to conflicts in reconstructing events, as appears to have happened in this incident. The investigators were not lying, nor was there a corporate cover up, although the temptation and pressures to do so may have been enormous. Lockheed allegedly ended up losing more than 100 million dollars as a result of this and the whirl mode accidents. Public faith in the aircraft never really recovered and the age of a preferrence for pure jet travel dawned.”
I have intimated something (post 384, above) that puts the report’s accuracy and integrity in doubt. That is intended. Would you consider a very careful and discerning discussion about what Lockheed and the CAB decided to report in this accident?
This demands that it was the last of the energy contained in the structure(s) that did the work. From the condition of the tail, any inverted slide would almost assuredly have destroyed the VS, HS, and rudder. This is plausible and demonstrable, hence probable.
G0ULI:
“How the aircraft broke up is only important in establishing what components, that may have been contributory to the accident, may have been damaged or gone missing. Giving the same evidential weight to contemporary press reports against the final official report is likely to lead to conflicts in reconstructing events, as appears to have happened in this incident. The investigators were not lying, nor was there a corporate cover up, although the temptation and pressures to do so may have been enormous. Lockheed allegedly ended up losing more than 100 million dollars as a result of this and the whirl mode accidents. Public faith in the aircraft never really recovered and the age of a preferrence for pure jet travel dawned.”
I have intimated something (post 384, above) that puts the report’s accuracy and integrity in doubt. That is intended. Would you consider a very careful and discerning discussion about what Lockheed and the CAB decided to report in this accident?
Last edited by Concours77; 12th Jan 2018 at 15:40.
