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whiplash
Posts: 136
Joined: Mon Nov 14, 2011 12:47 am

Re: Could TK 981 have been saved like UAL 232

Tue May 12, 2020 7:07 pm

Survivability in a case of total flight control failure would actually depend on a multitude of factors: for example, loading of the aircraft, the type of damage done to it, position of where the flight controls are lost/locked, crew awareness, etc. To simply say that crew of one was more competent than the other is asinine in such cases.

IMHO, the recovery of OO-DLL in Baghdad feels like the most brilliant bit of flying and luck in a case of total flight control failure to date. Not only is it not impossible for the average pilot, but pretty probable if the conditions are perfect. I say this as someone who has practiced this in the simulator on an Airbus A320.

As far as the El Al 747 crash goes, I believe that the plane lost a significant portion of its leading-edge along with the slats on the right side of the airplane. I do not think that plane was recoverable unless the crew knew exactly what went wrong with it, and then too a nail bitter of an attempt.
 
tnair1974
Posts: 324
Joined: Sun Sep 15, 2019 5:37 pm

Re: Could TK 981 have been saved like UAL 232

Wed May 13, 2020 10:19 pm

tnair1974 wrote:
I can't find where TK 981 lost its hydraulics (after the cargo door loss/floor collapse).


Although I had studied TK 981 and other accidents via sources like MacArthur Job's books, this was over a decade ago. But turns out 981 did lose its hydraulics (AA 96 retained at least partial hydraulics). As already mentioned, TK 981 rolled to the left after the cargo door blew off (maybe suggesting the flight control surfaces were "frozen" in a left turn?) and entered a steep dive.

Even if the pilots had applied power on the working two engines earlier, cleared the forest below and started climbing, the odds would have still probably been against TK 981. Perhaps slimmer odds for 981 than even for UA 232 and for the A300 at Baghdad, but still better odds than JAL 123 (due to that 747's loss of hydraulics as well as the severe phugoid cycles and Dutch rolls resulting from the separation of the vertical stabilizer).

BTW, the Eastern L-1011 that experienced the disintegration of its #2 engine still IIRC had its fourth hydraulic line damaged despite it being deliberately located away from the other lines as PSAatSAN4Ever stated earlier. Very fortunately, this fourth line was still able to function, as the other three hydraulic lines lost all pressure. Nevertheless, it's been pointed out about the general lack of redundancy of many aspects of the original DC-10 design vs even the DC-9 and DC-8, let alone the 747 and L-1011. Horrible that the DC-10 shortcuts took so many lives, considering that the DC-10 in many ways was still a great plane.
 
tnair1974
Posts: 324
Joined: Sun Sep 15, 2019 5:37 pm

Re: Could TK 981 have been saved like UAL 232

Wed May 13, 2020 10:43 pm

GalaxyFlyer wrote:
Antarius wrote:
flybynight wrote:

A 747 should be able to fly with 2 engines, even if they are on the same wing only. At least I think so. Should be sufficient power, but I think the El Al crash was due also to wing damage, which of course makes sense if an engine (or two) have separated from wing.
But flying a 747 with engines on only one wing must be extremely difficult.


No more difficult than flying a 77W with one engine. Or any twin really due to asymmetric thrust


How much 4-engine flight time do you have? It’s more complicated than just having power on one side. The twin OEI has more excess power than the quad with two engines INOP due to the certification standards. They took off near 833K, so very heavy.

At least one other case in point I can think of is the 1995 loss of the E-3 (with original P&W JT3D turbofans) in Alaska. Both left-hand engines failed due to ingesting geese seconds after takeoff. Twenty four souls on board, but also a heavy fuel load so sadly the pilots were unable to climb and make an emergency landing back at EDF.
 
CairnterriAIR
Posts: 930
Joined: Sat Jun 28, 2008 1:52 am

Re: Could TK 981 have been saved like UAL 232

Wed May 13, 2020 11:15 pm

tnair1974 wrote:
Anonz263x wrote:
Ive read up about how Turkish Airlines flight 981 crashed because of the cargo door falling and causing hydraulic loss, and that the DC-10 managed to pitch up somewhat in its final moments, but was too low to recover. Had the pilots tried to use the throttles like UAL 232 earlier, could they have had some degree of control to try to land the plane?

At the risk of over repeating what others on this thread have stated, excellent question. The crew of ill-fated Flight 981 seemed to have the right idea in increasing thrust on the two workable engines as revealed by the black boxes. Seems likely 981's crew, along with virtually all DC-10 pilots at the time, would have known what had happened earlier to AA 96. Had 981 sadly not ran out of altitude, they might have had at least a long shot of landing if they had thought of using differential thrust.

I can't find where TK 981 lost its hydraulics after the cargo door blew open. But as mentioned, 981's control cables were highly likely jammed/severed due to the cabin floor's collapse. AA 96 (which barely landed safely back at DTW) still had working hydraulics, but the rudder was jammed to the right (apparently due only to the partial collapse of the cabin floor). BTW, a complicating factor with UA 232 was that when the #2 engine disintegrated, 232 was in a right turn thus the resulting loss of hydraulics left the plane's control surfaces at least partially "frozen" in that right turn.

As a side note, many of us know JAL 123 lost almost all of its vertical stabilizer when the rear pressure dome exploded. JAL 123 losing all hydraulics was bad enough, but that 747 was likely doomed the moment the vertical stabilizer separated even though the pilots somehow kept the plane in the air another 40 or so minutes. The plane was probably too inherently unstable to have done anything better than a slightly more controlled crash even if they had miraculously made it to an airport.


I think it was determined that while AA96 and TK981 had a carbon copy door failure, the AA DC-10 did have some function of control...other than differential thrust from the engines...mainly the ailerons and very slight elevator movement. Turkish Airways had nothing at all other than the engines. The difference being the weight of the passengers on board. AA had a very light passenger and cargo load...almost nobody in the rear most part of the cabin over the failed cargo door...and nothing but a body in a casket loaded in the rear hold itself. The resulting floor collapse was less dramatic due to no weight being pressed upon it and a few control lines still in place.TK was a full flight and the weight of the passengers above, no doubt caused a more complete collapse...cutting all the control lines. The heavier weight of TK no doubt caused the aircraft to nose over more quickly than AA, simply because of the center of gravity being changed more suddenly....6 passengers, the seats, and much of the contents of the full rear cargo hold. The only way, if any...for the crew to have saved that aircraft, was to immediately accelerate and somehow keep the nose up. Then there would have been the whole issue of how to land. With the full load aboard, the landing would have been at best the same result as UA232.
 
aeromoe
Posts: 1914
Joined: Fri Dec 08, 2006 8:34 am

Re: Could TK 981 have been saved like UAL 232

Thu May 14, 2020 12:05 am

GalaxyFlyer wrote:
UA811 was a B747-200, despite earlier design, much better redundancy and separation of cable runs. Douglas really did a poor design.


Semantics, but UA811 was a 747-122 N4713U. Repaired and re-registered and put back in service as N4724U.
 
b4thefall
Posts: 131
Joined: Wed May 04, 2016 7:12 pm

Re: Could TK 981 have been saved like UAL 232

Thu May 14, 2020 12:34 am

GDB wrote:
In 1987, Channel 4's science series, Equinox, aired 'The Air Fix', fronted by a former LHR maintenance engineer, from 1969-77, who later became a actor.
It was a stage like production that centered on his own experience with the DC-10.
He cited UA 232, calling the Capt an American hero, he had caustic comments about the DC-10, more still about the whole FAA process with that cargo door.

I would love to link it, but another recent search, for this thread, has drawn a blank.
It did note how short the training time TK had for this, their first wide-body, compared to other carrier, also noting the management of the airline was based on patronage.

33 years on, it remains a powerful program, with disturbing testimony from emergency services and relatives, read by the host.
Sadly lost, Channel 4's own site only has two of the many Equinox programs it aired, not on any unofficial platforms, I did VHS it at the time, cannot find it either.
Anyone else remember it?


I can't remember the specific episode you refer to, but well remember Equinox! What a fantastic series of documentaries. In the pre internet days, series such as Equinox and Tomorrow's World were invaluable to my quizzical childhood and teenaged brain. What a blast from the past!
 
Max Q
Posts: 10240
Joined: Wed May 09, 2001 12:40 pm

Re: Could TK 981 have been saved like UAL 232

Thu May 14, 2020 4:25 am

B777LRF wrote:
OO-DLL was hit by a SAM climbing through 8.000 ft. It caused the loss of all hydraulics and set the outboard wing on fire. That crew didn't just manage to regain control, bring the aircraft around and perform an approach. Finding themselves drifting away from the runway, they performed a go-around, brought the aircraft around once more and managed to land it on the runway. When the crew exited the burning aircraft, it was still standing on all 3 legs.

And they did all this in a war zone.

Not taking anything away from Al Haynes and his crew, but the gold standard is not him and his crew. It's Captain Eric Genotte, FO Steve Michielsen and FE Mario Rofail and a tank going by the name of A300B4-200F.

Could a more competent crew have saved TK? Yes, it's possible.



They did a superb job I agree


I read that the Captain of this A300 had attended a lecture on UA 232 and the techniques used given by Al Haynes
 
B777LRF
Posts: 3276
Joined: Sun Nov 02, 2008 4:23 am

Re: Could TK 981 have been saved like UAL 232

Thu May 14, 2020 8:52 am

Max Q wrote:
I read that the Captain of this A300 had attended a lecture on UA 232 and the techniques used given by Al Haynes


Not so much a lecture, more a not overtly detailed account of what took place that day. I know, I was there with Eric and Mario, amongst others. Did it help? Not sure, but it certainly impressed upon us the possibility of surviving a total hyd. loss and the all important factor of CRM.

The main main message of the account was indeed the importance of CRM, not so much the nuts and bolts of controlling an aircraft using differential thrust only.

We tried it a few of times in the 757 sim, with results ranging from "yup, we're dead" to "we probably survived, but the aircraft didn't". Nobody, to my knowledge, ever did a landing of the same quality as OO-DLL, that is standing on all three legs. My three attempts didn't go well, with two in the category "dead" and one in the category "me alive, aircraft dead". And we were "only" dealing with loss of hydraulics, not also having to deal with a wing burning away merrily.
 
Max Q
Posts: 10240
Joined: Wed May 09, 2001 12:40 pm

Re: Could TK 981 have been saved like UAL 232

Thu May 14, 2020 9:30 am

B777LRF wrote:
Max Q wrote:
I read that the Captain of this A300 had attended a lecture on UA 232 and the techniques used given by Al Haynes


Not so much a lecture, more a not overtly detailed account of what took place that day. I know, I was there with Eric and Mario, amongst others. Did it help? Not sure, but it certainly impressed upon us the possibility of surviving a total hyd. loss and the all important factor of CRM.

The main main message of the account was indeed the importance of CRM, not so much the nuts and bolts of controlling an aircraft using differential thrust only.

We tried it a few of times in the 757 sim, with results ranging from "yup, we're dead" to "we probably survived, but the aircraft didn't". Nobody, to my knowledge, ever did a landing of the same quality as OO-DLL, that is standing on all three legs. My three attempts didn't go well, with two in the category "dead" and one in the category "me alive, aircraft dead". And we were "only" dealing with loss of hydraulics, not also having to deal with a wing burning away merrily.



Interesting


Well, they did a remarkable job
 
B777LRF
Posts: 3276
Joined: Sun Nov 02, 2008 4:23 am

Re: Could TK 981 have been saved like UAL 232

Thu May 14, 2020 12:38 pm

Max Q wrote:
Interesting.
Well, they did a remarkable job


Indeed. As mentioned in my first post on this thread DHL (European Air Transport, to be precise) and the A300 is the gold standard for this type of incident.
 
Antarius
Posts: 3434
Joined: Thu Apr 13, 2017 1:27 pm

Re: Could TK 981 have been saved like UAL 232

Thu May 14, 2020 6:25 pm

GalaxyFlyer wrote:
Antarius wrote:
flybynight wrote:

A 747 should be able to fly with 2 engines, even if they are on the same wing only. At least I think so. Should be sufficient power, but I think the El Al crash was due also to wing damage, which of course makes sense if an engine (or two) have separated from wing.
But flying a 747 with engines on only one wing must be extremely difficult.


No more difficult than flying a 77W with one engine. Or any twin really due to asymmetric thrust


How much 4-engine flight time do you have? It’s more complicated than just having power on one side. The twin OEI has more excess power than the quad with two engines INOP due to the certification standards. They took off near 833K, so very heavy.

While the right wing slats were damaged and only one set extended while the full left side set extended upon selecting Flaps 1. The “killer” was not clearly identifying the loss of both #3 and #4 hydraulics; that related in only the inboard TE flaps extending. With the outboard flaps retracted, the outboard aierons were locked in; leaving only two spoiler panels and the inboard ailerons for roll control. Upon selecting Flaps 5, the FE told the pilots, FLAP ASYM and loss of both right hydraulic systems. Pilots started using the ELEC ALTN FLAP EXTD, but it was too slow to extend the outboard flaps, unlock the outboard ailerons giving the needed roll control. They had slowed to Flaps 5 speed, no roll control, no outboard flaps, right wing stalled, they crash. As I mentioned above, IF “Loss of #3 and #4 HYD” and ELEC ALTN FLAP EXTD had started the evolution, likely a safe landing. At least, in the sim.


I'm not disputing the loss of hydraulics and lack of timely identification. I was merely replying to the earlier poster about loss of 2 engines on a Quad on the same side.

Factoring in the loss of 2 engines and hydraulic damage makes the situation much more complex.
 
tnair1974
Posts: 324
Joined: Sun Sep 15, 2019 5:37 pm

Re: Could TK 981 have been saved like UAL 232

Tue May 19, 2020 12:13 am

CairnterriAIR wrote:
tnair1974 wrote:
Anonz263x wrote:
Ive read up about how Turkish Airlines flight 981 crashed because of the cargo door falling and causing hydraulic loss, and that the DC-10 managed to pitch up somewhat in its final moments, but was too low to recover. Had the pilots tried to use the throttles like UAL 232 earlier, could they have had some degree of control to try to land the plane?

At the risk of over repeating what others on this thread have stated, excellent question. The crew of ill-fated Flight 981 seemed to have the right idea in increasing thrust on the two workable engines as revealed by the black boxes. Seems likely 981's crew, along with virtually all DC-10 pilots at the time, would have known what had happened earlier to AA 96. Had 981 sadly not ran out of altitude, they might have had at least a long shot of landing if they had thought of using differential thrust.

I can't find where TK 981 lost its hydraulics after the cargo door blew open. But as mentioned, 981's control cables were highly likely jammed/severed due to the cabin floor's collapse. AA 96 (which barely landed safely back at DTW) still had working hydraulics, but the rudder was jammed to the right (apparently due only to the partial collapse of the cabin floor). BTW, a complicating factor with UA 232 was that when the #2 engine disintegrated, 232 was in a right turn thus the resulting loss of hydraulics left the plane's control surfaces at least partially "frozen" in that right turn.

As a side note, many of us know JAL 123 lost almost all of its vertical stabilizer when the rear pressure dome exploded. JAL 123 losing all hydraulics was bad enough, but that 747 was likely doomed the moment the vertical stabilizer separated even though the pilots somehow kept the plane in the air another 40 or so minutes. The plane was probably too inherently unstable to have done anything better than a slightly more controlled crash even if they had miraculously made it to an airport.


I think it was determined that while AA96 and TK981 had a carbon copy door failure, the AA DC-10 did have some function of control...other than differential thrust from the engines...mainly the ailerons and very slight elevator movement. Turkish Airways had nothing at all other than the engines. The difference being the weight of the passengers on board. AA had a very light passenger and cargo load...almost nobody in the rear most part of the cabin over the failed cargo door...and nothing but a body in a casket loaded in the rear hold itself. The resulting floor collapse was less dramatic due to no weight being pressed upon it and a few control lines still in place.TK was a full flight and the weight of the passengers above, no doubt caused a more complete collapse...cutting all the control lines. The heavier weight of TK no doubt caused the aircraft to nose over more quickly than AA, simply because of the center of gravity being changed more suddenly....6 passengers, the seats, and much of the contents of the full rear cargo hold. The only way, if any...for the crew to have saved that aircraft, was to immediately accelerate and somehow keep the nose up. Then there would have been the whole issue of how to land. With the full load aboard, the landing would have been at best the same result as UA232.

Nice additional information I had not considered/heard of. Especially about the more abrupt change in center of gravity for heavily loaded TK 981 vs lightly loaded AA 96 after the two flights lost their cargo doors.

AA 96's schedule that day was LAX-DTW-BUF-LGA. As you touched on, DTW-BUF was light with less than 70 people and almost no one in the back. However, the earlier LAX-DTW segment was heavily booked (most passengers got off at DTW). So if AA 96's cargo door had failed just after departing LAX instead of BUF, the added weight could have more fully disabled the hydraulics/control cables as the cabin floor collapsed thus causing the loss of AA 96. Would this have later spared TK 981 its fate two years later? Perhaps, although this still does not negate that McDonald Douglas knew early in DC-10 development that the cargo door locking mechanism was a potential safety hazard. Yet such concerns were brushed aside.

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