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Tenerife Speculation  
User currently offlineBureaucromancer From Canada, joined Feb 2010, 165 posts, RR: 0
Posted (2 years 9 months 3 weeks 2 days 14 hours ago) and read 12530 times:

I've got a question about the Tenerife collision that has been bothering me lately but that I haven't been able to answer myself... In short, how large of an impact did KLM's tailstrike play in the outcome? Could Van Zanten have cleared Pan Am had he not hit the tail? Could the aircraft have remained controllable with different handling?

[Edited 2011-11-01 21:11:40]

21 replies: All unread, jump to last
 
User currently onlinekaitak From Ireland, joined Aug 1999, 12428 posts, RR: 37
Reply 1, posted (2 years 9 months 3 weeks 2 days 14 hours ago) and read 12461 times:

From time to time, you see incidents where flight crews have miscalculated take off weights and therefore taken off at too low a speed (EK at MEL, SQ at AKL for example); the result is usually serious damage to the tail section.

In the KLM incident at TFN, I don't think van Zanten's 747 had reached rotation speed when the PA 747 was sighted (but I stand to be corrected on this), so a tailscrape would have been inevitable and on top of that, he was obviously pulling back harder than he would normally have done, a natural human reaction when you see another 747 in front of you on a runway. It was a split second decision; perhaps the damage might have been less, but I think a collision was unavoidable.


User currently offlineNWAROOSTER From United States of America, joined Feb 2005, 1081 posts, RR: 3
Reply 2, posted (2 years 9 months 3 weeks 2 days 13 hours ago) and read 12396 times:
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I believe that Captain Van Zanten had an arrogant attitude, as he thought he was a hot shot pilot, played a large part in the collision. He believed he could do no wrong. Both aircraft back tracked on the main runway before they were to taxi onto an adjacent taxiway. It was foggy and Captain Van Zanten failed verify that the PanAm 747 had cleared the main runway and was on the taxiway before he initiated his take off roll. When he was performing his takeoff, the PanAm 747 became visible as it was turning off the main runway onto taxiway. He attempted to pull back on the control column to clear the PanAm 747. He literally pulled the control column into his chest. A 747 then required a long takeoff roll and a tail strike was inevitable. The KLM 747 would not have enough airspeed at the time off when it struck the PanAm 747 and would not be able to remain air born. After the impact, the only result would be the KLM 747 crashing onto runway.
Captain Van Zanten should have waited to begin his take roll until he was positive that the PanAm 747 was not on the main runway in the fog and visible on the taxiway.   


User currently offlineDALCE From Netherlands, joined Feb 2007, 1680 posts, RR: 7
Reply 3, posted (2 years 9 months 3 weeks 2 days 6 hours ago) and read 11885 times:

Quoting NWAROOSTER (Reply 2):
I believe that Captain Van Zanten had an arrogant attitude, as he thought he was a hot shot pilot, played a large part in the collision. He believed he could do no wrong

Did you know him in person? I assume not.....

Furthermore none of your answer is of any importance taking the threadstarters question in consideration.
There is no doubt AFAIK about the fact that the KL captain was wrong. So this is not the discussion here.

The question here is :

Could different handling of the controls ( after starting his take-off roll and wrongly asuming to be cleared for t/o) prevented a collision with the PA 747. We are not looking for an answer like : If he waited for the PA 747 to clear the rwy, then no collision would have taken place.

Did the tailstrike have enough impact on the groundspeed of the KL 747 to prevent a (just) timely take off to avoid the collision.

So please stay to these questions asked by the threadstarter.



flown on : F50,F70,CR1,CR2,CR9,E75,143,AR8,AR1,733,735,736,73G,738,753,744,319,320,321,333,AB6.
User currently offlinePlaneInsomniac From Canada, joined Nov 2007, 678 posts, RR: 0
Reply 4, posted (2 years 9 months 3 weeks 2 days 6 hours ago) and read 11769 times:

Quoting Bureaucromancer (Thread starter):
how large of an impact did KLM's tailstrike play in the outcome?
Quoting NWAROOSTER (Reply 2):
I believe that Captain Van Zanten had an arrogant attitude,

  NWAROOSTER, you cannot possibly be serious.

To get back to the topic at hand, I believe that I have read/heard somewhere that somebody calculated that it would have been possible for the KLM plane to clear the PanAm plane if the rotation had been executed in an ideal manner. This may have been mentioned in one of the TV show episodes discussing the disaster, or somewhere else.



Am I cured? Slept 5 hours on last long-haul flight...
User currently offlineWestJet747 From Canada, joined Aug 2011, 1830 posts, RR: 10
Reply 5, posted (2 years 9 months 3 weeks 2 days 4 hours ago) and read 11442 times:

Quoting DALCE (Reply 3):
Quoting NWAROOSTER (Reply 2):
I believe that Captain Van Zanten had an arrogant attitude, as he thought he was a hot shot pilot, played a large part in the collision. He believed he could do no wrong

Did you know him in person? I assume not.....
Quoting PlaneInsomniac (Reply 4):
NWAROOSTER, you cannot possibly be serious.

I can see where NWAROOSTER makes his point. The CVR recordings suggest that Van Zanten missed a CRM class or two.... But after he began his take-off roll there was little his attitude could have done to change the outcome.

As for the topic at hand: I'm certain under the most ideal of circumstances could the KLM 747 have made it over (or through) the tail of the Pan Am 747 and still be airworthy for at least an emergency landing at the diversion airport. But I have my own questions:

1) Do we know exactly what speeds the two aircraft were at when they made visual contact?
2) Were they both already past V1?



Flying refined.
User currently offlineLHRSpotter From United Kingdom, joined Nov 2006, 182 posts, RR: 0
Reply 6, posted (2 years 9 months 3 weeks 2 days 2 hours ago) and read 10663 times:

A similar incident happened in Chicago some years ago between two 747s. Korean Air 36 was cleared to depart the runway while Air China 9018 got a bit lost just after landing and tried to cross the same active runway. The Korean Air pilot just managed to rotate and also had to dip his left wing a little to avoid hitting the tail of the Air China 747 to his right. NTSB animation with audio can be found in this link

http://www.youtube.com/watch?v=mY2576xOeww


User currently offlinescarebus03 From Ireland, joined Apr 2005, 304 posts, RR: 2
Reply 7, posted (2 years 9 months 3 weeks 2 days 1 hour ago) and read 9539 times:

Given the fact that the KLM Aircraft was heavier than required due to it's fuel uplift at TFN their fate was sealed once the power levers were opened. According to the report the KLM 747 had a tail strike sliding for 65ft prior to rotation which was when it sliced through the fuselage of PA1736. It's widely speculated that IF only the fuel required for TFN-AMS was uplifted then the corresponding reduction in takeoff weight would have allowed the KLM 747 to clear the Pan Am Aircraft and avert the disaster. Unfortunately this crash is one of the best examples of how a chain of apparently random events resulted in the biggest Aircraft accident in history.

On a side note I've been to TFN a number of times and I have always imagined how it would have been when that accident happened. The Airport appears to be rather complex from an approach perspective due to the surrounding mountains and the fog comes down in seconds, even in summer.

Best Regards



No faults found......................
User currently offlinen501us From United States of America, joined May 2005, 220 posts, RR: 0
Reply 8, posted (2 years 9 months 3 weeks 2 days 1 hour ago) and read 9285 times:
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Right or wrong the persona of the KLM Pilot has been portrayed as arrogant though the years. As to the thread, two incidents come to mind:

NWA had a very similar situation occur at MSP years ago with two of it's DC-10s. An error was made and one of the '10s was mistakenly cleared onto the active runway as the second -10 came barreling down the runway. As a result of great airmanship (it was an instructor with much experience) and some luck the DC-10 taking off barely cleared the one on the runway (20 feet I think) and continued onto to it's destination without further incident.

And there was the NWA 727 and DC-9 collision in December of 1990 at DTW. In that case, the taking off 727 clipped the slow moving or standing still DC-9 (causing fatalities). The 727 crew somehow kept control of the a/c.

I am sure there are enough NWA folks that can clarify the two incidents.



Fools and thieves are well disguised in the temple and the marketplace.....
User currently offlineAirlineCritic From Finland, joined Mar 2009, 701 posts, RR: 1
Reply 9, posted (2 years 9 months 3 weeks 2 days 1 hour ago) and read 9255 times:

Quoting WestJet747 (Reply 5):

1) Do we know exactly what speeds the two aircraft were at when they made visual contact?
2) Were they both already past V1?

The Pan Am was not taking off, it was taxing. Wikipedia (http://en.wikipedia.org/wiki/Tenerife_airport_disaster) says that the KLM was travelling at 260 km/h when it collided. The official report (http://www.project-tenerife.com/engels/PDF/Tenerife.pdf) does not seen to tell us the speed. The ALPA report (http://www.project-tenerife.com/engels/rapporten.htm) does say that the KLM plane had reached V1 before they saw the Pan Am plane.


User currently offlineSeptember11 From United States of America, joined May 2004, 3623 posts, RR: 21
Reply 10, posted (2 years 9 months 3 weeks 2 days 1 hour ago) and read 8877 times:

Quoting NWAROOSTER (Reply 2):
Captain Van Zanten should have waited to begin his take roll until he was positive that the PanAm 747 was not on the main runway in the fog and visible on the taxiway.

I understand he was in a hurry..



Airliners.net of the Future
User currently offlineWestJet747 From Canada, joined Aug 2011, 1830 posts, RR: 10
Reply 11, posted (2 years 9 months 3 weeks 2 days 1 hour ago) and read 8849 times:

Quoting AirlineCritic (Reply 9):

Thanks for the links! Interesting reads. My information on the incident thus far had been limited to the Mayday/Air Crash investigation special:

http://www.youtube.com/watch?v=qa4dr...playnext=1&list=PLC46771BA04B000BB



Flying refined.
User currently onlinekaitak From Ireland, joined Aug 1999, 12428 posts, RR: 37
Reply 12, posted (2 years 9 months 3 weeks 2 days ago) and read 8603 times:

Quoting AirlineCritic (Reply 9):
The official report (http://www.project-tenerife.com/engels/PDF/Tenerife.pdf) does not seen to tell us the speed

The PA crew were probably not doing much more than 10-15 knots; they had been asked to turn off on a taxiway which they judged to be too sharp a turn for a 747 and they continued to the next one; they were moving very slowly in the fog, trying to work out where they should turn and were actually turning when they saw the KL aircraft coming.

Quoting September11 (Reply 10):
I understand he was in a hurry..

There have been conflicting reports about this; the cockpit conversation includes a section where they were discussing the new Dutch flight time regulations. However, it's hard to see - given the exceptional circumstances (a bomb at their original destination) - that they would have been too harshly treated.

I read a book some time ago, written by a former KLM pilot who then became president of IFALPA (the International Federation of Airline Pilots Assocations) and who knew both pilots; he does not agree with many of the assertions made, particularly about Capt v. Zanten being an arrogant martinet or FO Meurs being an easily bullied young FO. FO Meurs had been on DC8s before moving to 747s and had actually acted as a DC8 captain for a while, before moving to 747s. Although the perception is that, as a training captain on 747s, he was pretty much at the top of the tree, the reality (this pilot claims) is that he was a relatively junior 747 captain; his seniorty would, it was asserted, be good enough for a DC9 command, but not the 747, which was why he got "secondary" assignments like this trip to Tenerife. How true this is, I don't know, but that was the claim.

There is also the legend that, as the 747 expert at KLM, the team of investigators flying to Tenerife to begin the inquiry were looking for him to join them.


User currently offlineferminbrif From Venezuela, joined Dec 2010, 100 posts, RR: 0
Reply 13, posted (2 years 9 months 3 weeks 2 days ago) and read 8342 times:

Quoting DALCE (Reply 3):
Quoting NWAROOSTER (Reply 2):
I believe that Captain Van Zanten had an arrogant attitude, as he thought he was a hot shot pilot, played a large part in the collision. He believed he could do no wrong

Did you know him in person? I assume not.....

There´s something sure DALCE: Captain Van Zanten started take-off roll wrongly asuming to be cleared for ........ and the fact is: HE WAS NOT......!!!


User currently offlineDALCE From Netherlands, joined Feb 2007, 1680 posts, RR: 7
Reply 14, posted (2 years 9 months 3 weeks 2 days ago) and read 8202 times:

Quoting ferminbrif (Reply 13):
There´s something sure DALCE: Captain Van Zanten started take-off roll wrongly asuming to be cleared for ........ and the fact is: HE WAS NOT......!!!

I fully agree on that. This is a fact.
My point was that the comments of NWAROOSTER had nothing to do with the questions asked in the opening post.



flown on : F50,F70,CR1,CR2,CR9,E75,143,AR8,AR1,733,735,736,73G,738,753,744,319,320,321,333,AB6.
User currently offlineB737900 From United States of America, joined Aug 2010, 174 posts, RR: 0
Reply 15, posted (2 years 9 months 3 weeks 1 day 23 hours ago) and read 7763 times:
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A little side-bar to this very interesting discussion if you will allow me. My father-in-law at the time of the tragedy was a 747 captain for Pan Am. My wife and I were living in a bush village in Alaska where I was teaching school. No cell phones, no emails, none of today's technologies of course. We had no telephone service. We had to use short wave (marine operator). We heard of the accident the next day (28 March 1977) and used the marine operator to call my wife's parents. We were very concerned as her dad was out on a trip. We got thru to her mom and she was very upset as they knew most of the crew. NOVA (PBS in the USA) did a very good program on the tragedy. Regards.


Sounds like a Beaver on floats..........we're saved!!
User currently offlinebueb0g From United Kingdom, joined Jul 2010, 642 posts, RR: 0
Reply 16, posted (2 years 9 months 3 weeks 1 day 22 hours ago) and read 6897 times:

Quoting NWAROOSTER (Reply 2):
He believed he could do no wrong.

Firstly, what does this add to the discussion? Secondly, did you know him? No. He's probably been portrayed unfairly. He was in a hurry, and committed acts of bad airmanship, certainly, nor was he very current with actual line flying. But where you've got this idea that he was an arrogant man in himself and could "do no wrong" I really do not know. He was a human, and he made a mistake.

To answer the question, I believe it was calculated that by the time KLM 4805 sighted Clipper 1736, the collision was inevitable, and indeed, the Pan Am crew's attempt at vacating the runway along with the KLM crew's attempt at leapfrogging the other 747 were both instrumental in sparing the 70 or so survivors from the Pan Am aircraft. Had Van Zanten not attempted to lift, or done so later, all would have died, as would most probably be the case had they hit nose to nose, as in this case as a simulation I once saw demonstrated, the KLM 747 would not have been able to maintain flight and would have crashed right through the Pan Am 747, and both aircraft would pretty much have been obliterated right there. As it was the Pan Am structure survived long enough to spare the handful that made it out.

So no, I don't think so. The final outcome - 70 survivors - was about as good as could have been hoped for after the KLM sighted the Pan Am.



Roger roger, what's our vector, victor?
User currently offlinebrilondon From Canada, joined Aug 2005, 4195 posts, RR: 1
Reply 17, posted (2 years 9 months 3 weeks 1 day 22 hours ago) and read 6567 times:

Quoting WestJet747 (Reply 5):
1) Do we know exactly what speeds the two aircraft were at when they made visual contact?
2) Were they both already past V1?

I believe that the KLM plane had passed V1 but was not at rotation speed when he saw the PA aircraft. The PA aircraft was taxiing off the runway and I believe the captain of the KLM plane thought that the controller had said that the PA plane had cleared the runway so he initiated the take off.



Rush for ever; Yankees all the way!!
User currently offlinecanoecarrier From United States of America, joined Feb 2004, 2839 posts, RR: 12
Reply 18, posted (2 years 9 months 3 weeks 1 day 21 hours ago) and read 5826 times:

Quoting Bureaucromancer (Thread starter):
In short, how large of an impact did KLM's tailstrike play in the outcome? Could Van Zanten have cleared Pan Am had he not hit the tail?

Out of curiosity, I looked at some of the links posted above. It appears the KLM plane struck the Pan Am plane at approximately 140 knots. And, the KLM plane struck it's tail for around 20m (66 feet) before they collided.

140 knots = 236 feet/second or 72 meters/second

If those numbers are even close, then the tailstrike occurred almost immediately (i.e., well under a second) before the two collided. You make your own determination if that effected their ability to get airborne, I'd say it didn't matter at all.



The beatings will continue until morale improves
User currently offlineaviator23 From Pakistan, joined Jan 2010, 24 posts, RR: 0
Reply 19, posted (2 years 9 months 3 weeks 1 day 16 hours ago) and read 3094 times:

Quoting LHRSpotter (Reply 6):

I have been living in the US for over a year and a half now and have possessed good English language skills since childhood. But even I at times struggle to understand things often said by American friends especially when speaking quickly(which Air traffic Controllers do) This is not to defend the Air China pilots or to put blame on the controller but ithink American (and I speak about Americans because that's what I have first hand experience with) controllers especially at airports like JFK,ATL,ORD,LAX,DFW etc that receive traffic from literally the whole world, need to be specially trained for cross cultural language issues. Very often it is not about language but accent especially when transmitted over wireless radios with considerable 'noise'. These incursions are happening with alarming regularity specially at congested American airports. The latest one being the close call at JFK this summer (again between an Arab and a German flight crew). I'm a regular listener of Uniteds Channel 9 whenever on board and often wonder if people who speak English as a Second Language can understand this readily?


User currently offlineburj From United States of America, joined Nov 2007, 901 posts, RR: 4
Reply 20, posted (2 years 9 months 3 weeks 1 day 15 hours ago) and read 2749 times:

Quoting aviator23 (Reply 19):
Very often it is not about language but accent especially when transmitted over wireless radios with considerable 'noise'. These incursions are happening with alarming regularity specially at congested American airports.

You bring up some very interesting points. What is spoken by pilots and ATC is not really English but their own specialized language. Pilots and ATC are required to understand and to speak those certain set of words clearly.

There is definitely room for improvement and I have heard many foreign pilots complain that U.S. controllers are the most guilty of deviating from using standardized ATC language.


User currently offlinebrilondon From Canada, joined Aug 2005, 4195 posts, RR: 1
Reply 21, posted (2 years 9 months 2 weeks 3 days 1 hour ago) and read 1563 times:

Quoting aviator23 (Reply 19):
I have been living in the US for over a year and a half now and have possessed good English language skills since childhood. But even I at times struggle to understand things often said by American friends especially when speaking quickly(which Air traffic Controllers do) This is not to defend the Air China pilots or to put blame on the controller but ithink American (and I speak about Americans because that's what I have first hand experience with) controllers especially at airports like JFK,ATL,ORD,LAX,DFW etc that receive traffic from literally the whole world, need to be specially trained for cross cultural language issues. Very often it is not about language but accent especially when transmitted over wireless radios with considerable 'noise'. These incursions are happening with alarming regularity specially at congested American airports. The latest one being the close call at JFK this summer (again between an Arab and a German flight crew). I'm a regular listener of Uniteds Channel 9 whenever on board and often wonder if people who speak English as a Second Language can understand this readily?



This is the reason I am not interested in Channel 9. What is spoken there is routine communications usually and often I don't really know what is happening and find it just annoying.



Rush for ever; Yankees all the way!!
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