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Is it possible that a commercial airliner could hit the ocean surface at such an angle that it made a deep dive intact, got filled with water, sank, and got stuck in mud at the floor of the ocean?

voretaq7
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gerrit
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    Intact. No. Planes dont do well on hitting the water. At the velocity with which it would fall coupled with a steep pitch, it wouldn't matter if it was water or ground. – asheeshr Mar 19 '14 at 01:25
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    Answers will be purely speculative, and without any value. "Yes" would be my answer. – DeltaLima Mar 19 '14 at 13:22
  • @DeltaLima I don't think answers will be purely speculative. GregHewgill gave a good answer with explanations. – gerrit Mar 19 '14 at 14:08
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    @gerrit US Airways Flight 1549 landed more or less intact on the water and was "docked" before it sank. In the ocean it would eventually sink, possibly dive nose down and get stuck in the mud. – DeltaLima Mar 19 '14 at 14:14
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    Historical note: this question was motivated by the disappearance of Malaysia Airlines flight 370. – gerrit Mar 19 '14 at 20:50
  • No, it can't be intact. An analysis from CNN explains every possibilities. http://edition.cnn.com/2014/04/10/world/asia/malaysia-missing-plane-wreckage/index.html?hpt=ias_t2 – Cray Kao Apr 11 '14 at 03:29
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    Perhaps slower-moving A/C would have better possibilities of going down in one piece? Thinking of an ATR-42 or ATR-72 turboprop, with the straight wing and engines relatively high above the water surface. – ALAN WARD Jun 16 '15 at 14:30

5 Answers5

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Can a large modern jet airliner plunge intact underwater from flight?

No.

Large airliners are not desgned for this and are not even strong enough to make a landing on water in less than perfect conditions.

enter image description here
E.g. 961

striking the surface at a larger angle would certainly lead to widespread disintegration.

Is it possible for a large modern jet airliner to sink intact?

Yes (as near as makes no difference)

Almost all large aircraft impacting the sea surface in an emergency or uncontrolled will break up immediately and catastrophically.

One notable exception was US1549, an A320, which was landed on water without breaking up. It was described as "still virtually intact though partially submerged and slowly sinking". The left engine detached and sank.

enter image description here

So a controlled landing on water is possible under extremely favourable circumstances. It would then be possible for the aircraft to sink in more-or-less one piece without creating a large amount of floating debris.

RedGrittyBrick
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  • Keep in mind that the belly of US1549 suffered fairly severe damage from the impact, which was the main reason it sank so quickly. – Vikki Jul 01 '18 at 01:57
  • Also, Ethiopian 961 hit the water at a much higher speed than the vast majority of ditchings, and the pilots were fighting with a group of hijackers for control of the aircraft at the time, with somewhat detrimental effects on the aircraft's attitude and direction at impact. – Vikki Nov 11 '18 at 05:00
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Hitting water at speed is a lot like hitting concrete (try experimenting with different positions hitting the water off a high diving board—some will hurt). Aircraft are simply not designed to withstand the sudden forces introduced upon impact with water, no matter the angle. If an aircraft were to hit the water at high speed, the relatively flimsy structures of the aircraft would shatter, disintegrate, and completely lose structural integrity.

Greg Hewgill
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    not to mention intact planes are naturally buoyant so they'll move up to the surface quickly – ratchet freak Mar 19 '14 at 01:58
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    Note: don't try experimenting by jumping off a high dive unless you have really, really, fantastically good health insurance. – egid Mar 19 '14 at 02:03
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    @ratchetfreak Note that my question involved the plane getting stuck at the ocean floor somehow. But I get that many parts would break off on impact. – gerrit Mar 19 '14 at 12:35
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    @gerrit Yeah, assuming the plane did magically stay together (well, magic or aliens) the ocean would have to be awful awful shallow for the plane to actually reach the mud and get stuck in it. – Jae Carr Mar 19 '14 at 13:21
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    @JayCarr Would it still float if it became completely filled with water (I suppose it would)? – gerrit Mar 19 '14 at 14:09
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    Nah, if it completely filled with water, it would sink. But, remember, you are asking about a craft that has retained it's structural integrity. If it was still in one pieces with a few minor cracks here and there, it would take some time for it to fill up with water. Initially the plane would be quite buoyant. So it would have to somehow overcome that buoyancy to get to the mud... A possibly more likely scenario is for the plane to have ditched and, with the transponder dead, for it to have sunk before it was found. – Jae Carr Mar 19 '14 at 16:54
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    @JayCarr: Note that a plane touching bottom before vanishing beneath the waves has in fact happened! – Vikki Jul 01 '18 at 02:14
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My answer is: It depends. As always.

Generally, yes, it is possible to land an aircraft on water intact. But the aircraft has to help you with that. If the engines are not below the wings (turboprop, piston, jet at the rear fuselage), and the pilot flares to minimum speed right above the water, gear up, then most aircraft will stay intact. Many are even tested for ditching qualities during development. I personally know of the ditching tests of the Breguet Atlantique and the Antonov-70, and there are certainly more (see https://www.youtube.com/watch?v=jK8ydLY5QHQ at 2:15 min into the movie).

A Dutch Atlantique once had to go down and landed intact in the North Sea. It was towed into a harbor and lifted out of the water a few days later. The openings (for cooling air etc) have special valves which close automatically when the aircraft is in the water, much like a snorkel on a submarine (sorry, could not find a web source for this).

Peter Kämpf
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It would be judged upon the state of the aircraft once stopped after the collision, taking into account velocity and angle of impact etc.

If the A/C is in-tact and no water is taken on-board it will float for a greater time but I highly doubt it will for a large amount of time because water always finds entry points.

Ben Lavender
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If the plane flew to empty, and the pilot made a manual controlled glide and water landing, he would still strike the water at a speed in excess of 150 mph.

The engines would still be ripped off, baggage hold doors would most likely open on impact. There would have to be some kind of debris field. The plane would sink, but not intact.

Something would come free and float to the surface.

Danny Beckett
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Lew
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  • I doubt the baggage hold doors would open on impact if a normal ditching were performed. Engines breaking off is likely, but I think the cargo doors would likely remain closed. They have some pretty serious locking mechanisms to keep them from blowing out in flight. As far as I know, no cargo doors failed in the U.S. Air flight that ditched in the Hudson, for instance. – reirab Nov 29 '14 at 19:52
  • @reirab: Actually, the US1549 cargo doors did come open. – Vikki Jul 01 '18 at 02:11
  • @Sean Interesting. I stand corrected. – reirab Jul 01 '18 at 04:13