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billreid
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Math Professor B777 Dive Claim

Wed Jun 10, 2015 9:51 pm

A mathematics professor has claimed that if a B777 nosedived directly into the ocean the wings would be ripped off but the fuselage would stay intact, sink and leave no debris.

If this is indeed possible and the wings were ripped off would it not leave a huge fuel slick.

http://www.news.com.au/travel/travel...ntact/story-fnizu68q-1227392275087

I just do not believe there would be no debris.
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32andBelow
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RE: Math Professor B777 Dive Claim

Wed Jun 10, 2015 9:53 pm

Fuel slick and probably fire?
 
prebennorholm
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RE: Math Professor B777 Dive Claim

Wed Jun 10, 2015 10:14 pm

Thank God he is not my math professor.
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Btblue
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RE: Math Professor B777 Dive Claim

Wed Jun 10, 2015 10:15 pm

Hmm... and what about buffet, winds etc? A perfectly performed dive perhaps - if it's in the middle of the ocean but I'd take this with a pinch of salt.

Still, the mystery goes on.
 
rampbro
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RE: Math Professor B777 Dive Claim

Wed Jun 10, 2015 11:03 pm

Quoting btblue (Reply 3):
A perfectly performed dive perhaps

Could such a dive be programmed into the autopilot? If so, the human element could be removed and the weather element could be dampened by the computer.
 
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pvjin
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 12:14 am

Quoting billreid (Thread starter):
If this is indeed possible and the wings were ripped off would it not leave a huge fuel slick.

I believe there would be no fuel slick either if the aircraft runs out of fuel, which most likely happened if it ended up somewhere around southern Indian Ocean. As the aircraft was searched for a long time from nowhere near its actual final location any debris that there might have been had probably drifted far away already and probably sunk by now.

An ordinary ditching would leave pretty small amount of debris to begin with.
"Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that." - Martin Luther King Jr
 
AngMoh
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 12:32 am

Quoting billreid (Thread starter):

A mathematics professor has claimed that if a B777 nosedived directly into the ocean the wings would be ripped off but the fuselage would stay intact, sink and leave no debris.

If this is indeed possible and the wings were ripped off would it not leave a huge fuel slick.

http://www.news.com.au/travel/travel...ntact/story-fnizu68q-1227392275087

I just do not believe there would be no debris.

The scenario would only be possible in Hollywood movies. The fuselage will disintegrate regardless of angle. Hitting water at high speed is like hitting concrete at high speed.
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JHwk
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 12:52 am

Sure... enough spherical passengers with point mass and an incompressible airframe with no wind resistance, along with an ocean that is perfectly flat and salt water with an infinitesimal viscosity and zero surface tension...

It is basically a tangent cosine debris field at the angle of incidence of the airplane. A "perfect" nosedive would be the smallest debris field, but there would still be one. The smallest possible field would be a very large "crumple zone" running the length of the plane, but once the wings hit it would be game over and the fuselage would rupture.
 
LH707330
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 1:25 am

Quoting JHwk (Reply 7):
Sure... enough spherical passengers with point mass and an incompressible airframe with no wind resistance, along with an ocean that is perfectly flat and salt water with an infinitesimal viscosity and zero surface tension...

Ha ha exactly!

A king goes to his court and asks which horse to bet on a week before the race. On the morning of the race, his statistician tells him that Blue Phoenix is the slight favorite but overrated, and he should bet on the second place horse instead because he'll win big. The witch doctor tells him to bet on the one in the 7th lane because 7 is lucky. His theologian says God favors the third horse. He realizes that the second ranked horse is in lane 3, so he bets that way and wins. After the race, the physicist runs in exclaiming "I've solved the equation for the spherical horse!!!!"

That joke is the first thing that came to mind reading that article. Someone should tell the guy that the average density of a plane is the same as a chunk of balsa.
 
xdlx
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 1:28 am

Remember Airtran? He maybe on to something, cause the glades swallowed the DC9 with a very small footprint!
 
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MrHMSH
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 2:01 am

I don't know how to describe this as a load of b*llocks without being unnecessarily rude. So here goes:

This is a load of b*llocks.

Hitting water fast enough would result in complete disintegration of pretty much everything. Pieces would break off, there would be *some* evidence, something floating in the water.
 
2175301
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 2:13 am

I understand how in a perfect scenario a plane could fly into the ocean and just disappear with very minimal surface indications; which with the right weather would disperse before search and rescue reached the area; but, that would be a rare event.

Read the book "The Perfect Storm" - and imagine a jet flying at a high angle into the base of a cresting perfect wave; where 100 ft of water immediately crashes down on the plane. It would be 100 ft under water with a huge downward water surge pushing further down in addition to its downward impact velocity. While fuel floats, what reaches the surface would be dispersed by the storm.

The chance of that combination happening is extremely small. But, rarer events have happened.

Have a great day,
 
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LAX772LR
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 2:26 am

Quoting AngMoh (Reply 6):
The scenario would only be possible in Hollywood movies. The fuselage will disintegrate regardless of angle. Hitting water at high speed is like hitting concrete at high speed.

Exactly.

Heck, when SR111 impacted the water, the deceleration force was in excess of 350Gs: which is why so many of the victims couldn't even be identified by dental records.... their teeth shattered.  
I myself, suspect a more prosaic motive... ~Thranduil
 
AngMoh
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 2:30 am

Quoting xdlx (Reply 9):

Remember Airtran? He maybe on to something, cause the glades swallowed the DC9 with a very small footprint!


Same with Silkair 185. The reason almost nothing was found back is that the whole plane disintegrated in tiny pieces which disappeared in the mud. Same for the 777: it will disintegrate in tine pieces which will sink immediately. If it will "dive" then there will be large pieces which can possibly float.
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peanuts
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 2:39 am

Quoting billreid (Thread starter):

This professor must love Olympic Diving. Eager to give out that perfect 10.00 ,with no splash.

Reality is never perfect.
 
benjjk
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 2:55 am

Quoting rampbro (Reply 4):
Could such a dive be programmed into the autopilot? If so, the human element could be removed and the weather element could be dampened by the computer.

Not by your traditional aviation autopilot. I doubt even the highest military precision could achieve that with a 777, they have enough difficulty with their usual missiles.

This mathematician needs to stick to the hypothetical world it seems.
 
flightless
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 4:26 am

Wow. Looks like a 9/11 "truther's" convention.

Ok, so the guy is wrong, wrong, wrong. You can prove it - there's tons of MH370 debris floating around.

[OBLIGATORY INDICATION OF SARCASM FOR THOSE WHO CANNOT DETECT IT IN THE LINE ABOVE]

Personally, I'm a little reluctant to buy the possibility of MH370 getting into a near-vertical dive. But if it did, the Indian Ocean would have gulped the plane as per the Professor's simulation.

Also personally, I'm fairly familiar with high-speed water impacts - both subsonic and supersonic. I don't see anything particularly surprising in his findings; it's just good that somebody takes the time to run the numbers. When the math and the pictures say the same thing, then you can start to feel like you're not completely clueless.

Please note that this study is merely (as Occam's Razor suggests) a removal of pluralities. It shows we don't have to add some woo-woo conspiracy - pixies or aliens or phantom Russian submarines - to explain the lack of debris.
 
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zeke
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 9:37 am

Anyone interested in reading the actual paper, rather than the botched information in the press, it's available on the AMS website

http://www.ams.org/notices/201504/rnoti-p330.pdf
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flyingturtle
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 12:22 pm

Quoting prebennorholm (Reply 2):
Thank God he is not my math professor.

  

...never mind the deceleration for the passengers... An aircraft's nose is built to withstand 1 Mach-ish of air speed, but not this speed in water.

Otherwise, ship and submarine builders would love to contact him. 


David
Reading accident reports is what calms me down
 
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cosyr
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 2:09 pm

Does he think the wings are just popped on the fuselage like a snap together model? They are a pretty strong part of the aircraft. Just like when a plumber solders a pipe, the place where the extra metal has been soldered on is often the strongest part of the pipe, and the future leak is likely to happen at some other indiscriminate part of the pipe.
 
AirBoat
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 4:40 pm

The paper does not claim the fuselage stays intact.
It clearly shows points of failure and explains various failure modes for the vertical dive.
Some high level engineering computational fluid dynamics effort went into this.
 
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7BOEING7
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 6:37 pm

First this is Texas A&M University at Qatar so I'm guessing the heat was getting to these people. He also forgot to mention the giant parachute attached to the tail that allowed the airplane to be vertical and enter the water at a speed slow enough that no damage occurred.

Other than the fact that water is like concrete when you hit it at high speed as was mentioned above, to enter the water in a vertical dive would require a pilot -- the airplane couldn't do that on its own and the speed of the dive from altitude would rip the plane apart inflight, also increasing the difficulty of entering the water vertically. The only way to minimize debris is a controlled ditching.
 
LTC8K6
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 6:56 pm

The debris argument is a bit silly, imo.

Well over a week had passed before any effort was made in the SIO, and about 2 weeks passed before a decent effort was being made.

By March 19th, only three planes and three merchant ships were in the area. That's 11 days out and a huge area.

Any debris or oil slick had a lot of time to sink, disperse widely, or move a very long way.
 
PlaneInsomniac
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RE: Math Professor B777 Dive Claim

Thu Jun 11, 2015 9:44 pm

Quoting zeke (Reply 17):
Anyone interested in reading the actual paper, rather than the botched information in the press, it's available on the AMS website

http://www.ams.org/notices/201504/rnoti-p330.pdf

  

It seems the press report linked in the OP has absolutely nothing to do with the content of the article, as is (sadly) the rule rather than the exception when popular media report on scientific results.

The paper in question itself does not even pretend to model the actual damage to the plane, but rather tries to estimate some physical quantities such as deceleration and pressures upon water impact when the plane is treated as a rigid body. It concludes with the remark that the only way to minimize damage upon water impact is to to minimize vertical velocity (i.e., a controlled ditching at a slow rate of descent, a la US1549). The entire idea of the wings shearing off cleanly in the event of a nose-dive impact is presented as a verbatim quote from another source ([syr]) in Box 3, which appears to originate from some Australian professor.

As far as the trustworthiness of the authors is concerned, it is noteworthy that the author in the PI position (last author) is "Director of Impact and Crashworthiness Laboratory at MIT". Other coauthors are from Penn State and Virginia Tech.

Clearly, of course, these scientists have nothing on the experts of a.net, who have concluded beyond any doubt with the sheer power of their genius minds that the plane has landed safely in Ukraine (or wherever), has now been repainted and serves as VIP transport for the CIA (or whatever), because everything else is clearly "not logical", etc. ...

[Edited 2015-06-11 14:46:33]
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