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drinkstrolley
Topic Author
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### 747 Ditching At Sea - How Long Would It Float?

If a fully laden 747 has to ditch at sea, how long would it float?

[Edited 2005-11-08 17:25:36]

ClassicLover
Posts: 5110
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### RE: 747 Ditching At Sea

Boeing would probably have figures on that, as all aircraft need to have their ditching characteristics tested before production using models.

I am presuming you mean a controlled ditching... because the aircraft could conceivably break up into a thousand pieces on impact.

Trent.
I do enjoy a spot of flying, especially when it's not in economy!

drinkstrolley
Topic Author
Posts: 484
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### RE: 747 Ditching At Sea

 Quoting ClassicLover (Reply 1):I am presuming you mean a controlled ditching

Yes, assuming (a long shot!!!) all four engines packed up and he was half way over the Pacific....

F27XXX
Posts: 617
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Drinkstrolley (Thread starter):If a fully laden 747 has to ditch at sea, how long would it float?

My Source: "Airport 77".

(Sorry- couldn't resist)

Tony

[Edited 2005-11-08 17:33:15]
I'M BAAAAAAAACK!

pawsleykat
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting ClassicLover (Reply 1):I am presuming you mean a controlled ditching... because the aircraft could conceivably break up into a thousand pieces on impact.

As ClassicLover says, yes. It probably would break up on impact.

View Large View Medium

Photo © David Unsworth - WorldAirImages

As it says, this plane broke up on impact and I dont think there was any survivors (please correct me if I am wrong). This is only a 767, much lighter that a fully laden 747, so if a 762 breaks up on impact even if it was slightly controlled (as this one was), i don't want to think about a 747!
First Class passengers are my favourites. They can't get any further forward without an ATPL.

klmcedric
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### RE: 747 Ditching At Sea - How Long Would It Float?

If the fuselage is intact and the sea's aren't to rough it might float for more
then 30 minutes

kiwiandrew

### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Pawsleykat (Reply 6):and I dont think there was any survivors

there were some survivors - but having said that it was in shallow water , with people nearby to attempt rescue

http://www.airdisaster.com/special/ethiopian961.shtml

The plane crashed 500 yards from the resort and 16 miles from Moroni Airport; 123 of the 175 passengers and crew died. The majority of the survivors were hanging on to the fuselage section, which was floating; the rear section of the plane was submerged. Many victims were killed as a direct result of the impact, or they drowned because their inflated life jackets prevented them from swimming out of the water-filled fuselage. The pilot and copilot survived but the hijackers did not. Two suspects were initially detained but were not identified by the survivors as the hijackers and were released.

Fokker70NG
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### RE: 747 Ditching At Sea - How Long Would It Float?

If I recall correctly, I once heard in a documentary on plane crashes that there has never been a modern jetliner that managed to ditch in the water without breaking up in a lot of pieces. Even if it's a somewhat controlled ditch, it's almost impossible.
Two things are infinite: the universe and human stupidity; and I'm not sure about the universe. -Albert Einstein

vunz
Posts: 348
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Pawsleykat (Reply 6):As it says, this plane broke up on impact and I dont think there was any survivors (please correct me if I am wrong). This is only a 767, much lighter that a fully laden 747, so if a 762 breaks up on impact even if it was slightly controlled (as this one was), i don't want to think about a 747!

50 out of 175 on board survived the crash. Accident report

halls120
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting ClassicLover (Reply 1):I am presuming you mean a controlled ditching... because the aircraft could conceivably break up into a thousand pieces on impact.

The most likely result.

 Quoting Fokker70NG (Reply 9):If I recall correctly, I once heard in a documentary on plane crashes that there has never been a modern jetliner that managed to ditch in the water without breaking up in a lot of pieces. Even if it's a somewhat controlled ditch, it's almost impossible.

Back in the 50's and early 60's there were several instances of propeller-driven airliners that successfully ditched at sea. The reason? Probably because the engines were integrated into the wing structure, instead of hanging below the wing acting as a huge scoop when hitting the water.
"Suppose you were an idiot. And suppose you were a member of Congress. But I repeat myself." Mark Twain, a Biography

zvezda
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Fokker70NG (Reply 9):If I recall correctly, I once heard in a documentary on plane crashes that there has never been a modern jetliner that managed to ditch in the water without breaking up in a lot of pieces. Even if it's a somewhat controlled ditch, it's almost impossible.

A B787 would have a much, much better chance of remaining intact in a ditching.

 Quoting Halls120 (Reply 11):Back in the 50's and early 60's there were several instances of propeller-driven airliners that successfully ditched at sea. The reason? Probably because the engines were integrated into the wing structure, instead of hanging below the wing acting as a huge scoop when hitting the water.

Another (probably more significant) reason is the ditching speed of a prop plane is much lower than for a jet.

F27XXX
Posts: 617
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Fokker70NG (Reply 9):If I recall correctly, I once heard in a documentary on plane crashes that there has never been a modern jetliner that managed to ditch in the water without breaking up in a lot of pieces. Even if it's a somewhat controlled ditch, it's almost impossible.

Back in the early 70s, an ONA DC-9-33 was enroute from JFK-SXM and suffered fuel exhaustion due to having to route further to avoid storms and ditched somewhere (Ithink) near the Virgin Islands - - it remained intact and all pax got out, i thought. The book went on to say it sunk in extremely deep water.

Sorry i dont have a link to it, but its listed in one of my Aviation Disaster books.

Tony
I'M BAAAAAAAACK!

HiJazzey
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### RE: 747 Ditching At Sea - How Long Would It Float?

Wasn't there a JAL DC-8 which landed in San Francisco bay?

kiwiandrew

### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting HiJazzey (Reply 14):Wasn't there a JAL DC-8 which landed in San Francisco bay?

yes , initially I thought you were mixing it up with the one in Tokyo Bay with the mentally unstable pilot - but then I found this - amazing story - especially that they salvaged it and got it flying again

link for the Tokyo Bay crash as well

http://www.airsafe.com/events/airlines/jal.htm

airbusA346
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### RE: 747 Ditching At Sea - How Long Would It Float?

If recall a China Airlines 744 over shot the runway at Kai Tak and was floating in the Bay for a few days.

They had to blow the tail of the 744.

Tom.
Tom Walker '086' First Officer of a A318/A319 for Air Lambert - Hours Flown: 17 hour 05 minutes (last updated 24/12/05).

kiwiandrew

### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting AirbusA346 (Reply 16): was floating in the Bay for a few days.

sitting in the bay is probably more accurate - it was resting on the bottom of the harbour .

airbusA346
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Kiwiandrew (Reply 17):sitting in the bay is probably more accurate - it was resting on the bottom of the harbour .

So the bay at Kai Tak is sallow enough for 744 to sit on the bottom, but why is the nose floating high than the tail.

And was the tail submerged that much when it over shot. And if so how would the people at the back get out.

Tom.
Tom Walker '086' First Officer of a A318/A319 for Air Lambert - Hours Flown: 17 hour 05 minutes (last updated 24/12/05).

Pope
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### RE: 747 Ditching At Sea - How Long Would It Float?

I saw a video and interview on the 767 crash. It seemed that a lot of the people survived the impact but then drowned after they inflated their life vest while still within the sinking cabin thereby trapping themselves inside the aircraft.
Hypocrisy. It's the new black for liberals.

airbusA346
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Pope (Reply 19):I saw a video and interview on the 767 crash. It seemed that a lot of the people survived the impact but then drowned after they inflated their life vest while still within the sinking cabin thereby trapping themselves inside the aircraft.

Don't people know they are to watch safety demos.

Tom.
Tom Walker '086' First Officer of a A318/A319 for Air Lambert - Hours Flown: 17 hour 05 minutes (last updated 24/12/05).

SATL382G
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Pawsleykat (Reply 6):As it says, this plane broke up on impact and I dont think there was any survivors (please correct me if I am wrong). This is only a 767, much lighter that a fully laden 747, so if a 762 breaks up on impact even if it was slightly controlled (as this one was), i don't want to think about a 747!

 Quoting Kiwiandrew (Reply 8):there were some survivors - but having said that it was in shallow water , with people nearby to attempt rescue

 Quoting Fokker70NG (Reply 9):If I recall correctly, I once heard in a documentary on plane crashes that there has never been a modern jetliner that managed to ditch in the water without breaking up in a lot of pieces. Even if it's a somewhat controlled ditch, it's almost impossible.

 Quoting Halls120 (Reply 11):I am presuming you mean a controlled ditching... because the aircraft could conceivably break up into a thousand pieces on impact. The most likely result

Hey folks you need to point out these accidents where the plane broke up into a thousand pieces. You'll have a hard time because there aren't any. Lets run down the list: JAL DC-8 lands short in San Francisco bay, is raised, repaired and resumed flying. National B727 lands shorts in the Gulf Of Mexico, stays intact with survivors. Aforementioned DC-9 runs out of fuel and ditches. B707 lands short in a lake in Africa with a load of fish, stays intact and has to be towed to shore. And a couple of months ago a ATR ran out of gas in Italy, ditched and the tail broke off, remaining fuselage and wings were towed to shore.

The B767 ditching everybody points to was the result of hijacking with a fight in the cockpit as the pilot tried to ditch, hardly ideal circumstances.
"There’s nothing quite as exhilarating as being shot at and missed" --Winston Churchill

aircanl1011
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Pawsleykat (Reply 6):As it says, this plane broke up on impact

The aircraft had been highjacked and the landing was not controlled. The AC came in steep. I believe one of the highjackers were at the controls after they let it run out of fuel.
CYMRU AM BYTH / WALES FOREVER

kc135topboom
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Pawsleykat (Reply 6):This is only a 767, much lighter that a fully laden 747, so if a 762 breaks up on impact even if it was slightly controlled (as this one was), i don't want to think about a 747!

 Quoting SATL382G (Reply 21):The B767 ditching everybody points to was the result of hijacking with a fight in the cockpit as the pilot tried to ditch, hardly ideal circumstances.

Yes, it was not a controlled ditching. A wingtip went into the water first and the airplane cartwheeled.

The B-747 would float for a long time, in it was a controlled ditching, and it dumped most of the fuel. The pod monted engines on jet aircraft, from the B-367-80 onward are designed to rotate downward and break away from the strut and wing. Both Airbus and Boeing still use this type of system today in designing and building airplanes.

andz
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting ClassicLover (Reply 1):Boeing would probably have figures on that, as all aircraft need to have their ditching characteristics tested before production using models.

Really? I'd be interested to see how a model can represent the characteristics of the real thing. A wind tunnel is one thing but...
After Monday and Tuesday even the calendar says WTF...

ftrguy
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### RE: 747 Ditching At Sea - How Long Would It Float?

There is a video of that 767 ditching. (I have no idea how to find it so don't ask) It touched the water in about a 30 to 40 degree angle of bank turn. The wingtip dragged in the water for a second before the plane started tumbling and breaking up.

I think any aircraft with wing mounted engines would not fair well in a controlled ditch. However, if done right, I think aircraft with rear mounted engines would fair pretty well.

AC787
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Zvezda (Reply 12):A B787 would have a much, much better chance of remaining intact in a ditching.

I know composites are much stronger but will the odds rlly be any good of actually having it get into the water and stay in one piece? Are we talking about a difference of like a 744 having a 0.01% of pulling off a succesful ditching whereas the 787 will have a 0.1% chance of doing the same thing

aloha73g
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting AC787 (Reply 26):I know composites are much stronger but will the odds rlly be any good of actually having it get into the water and stay in one piece? Are we talking about a difference of like a 744 having a 0.01% of pulling off a succesful ditching whereas the 787 will have a 0.1% chance of doing the same thing

Even if thats the correct percentages, that's 1000% better

-Aloha!
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khenleydia
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Ftrguy (Reply 25):There is a video of that 767 ditching. (I have no idea how to find it so don't ask) It touched the water in about a 30 to 40 degree angle of bank turn. The wingtip dragged in the water for a second before the plane started tumbling and breaking up. I think any aircraft with wing mounted engines would not fair well in a controlled ditch. However, if done right, I think aircraft with rear mounted engines would fair pretty well.

Another thing to point out, if I recall correctly, the pilots were fighting with the high-jackers and they had run out of fuel. They were able to dodge a hotel (or some building) before crashing into the ocean.

KhenleyDIA
Why sit at home and do nothing when you can travel the world.

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### RE: 747 Ditching At Sea - How Long Would It Float?

I scratch my head, therefore I am.

MarshalN
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting AirbusA346 (Reply 16):If recall a China Airlines 744 over shot the runway at Kai Tak and was floating in the Bay for a few days. They had to blow the tail of the 744. https://www.airliners.net/discussions...general_aviation/read.main/2283824 Tom.

Well, running off a runway isn't quite nearly the same as ditching. It ran into the water head first, and the tail was sticking out of the water. They painted it white, I suppose to avoid negative advertisement (we just had a plane that landed in water!). IIRC it snapped somewhere, but casualties were light.

prebennorholm
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Drinkstrolley (Thread starter):If a fully laden 747 has to ditch at sea, how long would it float?

In all but the most lucky circumstances, less than 30 seconds. Lucky circumstances includes a totally calm water surface.

Add to that the fact that in all but the warmest waters survivors will freeze to death in 5 to 30 minutes depending on latitude and season of the year.

 Quoting AIRCANL1011 (Reply 22):...a couple of months ago a ATR ran out of gas in Italy, ditched and the tail broke off, remaining fuselage and wings were towed to shore.

And the nose broke off. And the bottom of the center fuselage. The wing stayed in one peace and floated - due to the empty fuel tanks - with parts of some 10 - 15 feet of the center fuselage barrel. Meaning that the plane broke up totally, as it was supposed to do. See pics at http://www.airdisaster.com/photos/ts-lbb/photo.shtml - and it landed much more slowly than a 747 can do. Had it happened today, then all survivors would have frozen to death before they could be rescued.

The safety cards and the safety instruction tells us otherwise, but they don't tell the truth. But they are okay since they tell a much more pleasant story than the truth.

The truth is that if you ditch at sea, then you are 99+% dead.

Even in a clipper liner flying boat of the 30'es - landing at half the speed of a 747 - you wouldn't be much better off. No way could they land on average ocean waves without breaking up. They just used enclosed bays, fjords and wide rivers - and nice weather - instead of ordinary runways.
Always keep your number of landings equal to your number of take-offs

prebennorholm
Posts: 7145
Joined: Tue Mar 21, 2000 6:25 am

### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Zvezda (Reply 12):A B787 would have a much, much better chance of remaining intact in a ditching.

No, not so, the other way around.

The 787 will be built to the same strength standards as other planes. But because carbon fibre reinforced epoxy composites plastic is stronger than aluminum, then the 787 will be lighter than if built of aluminum, and therefore fly longer distances.

Aluminum is a far better material since it can bend a lot before it breaks. Carbon fibre doesn't bend, it breaks. A carbon fibre fuselage plane ditching in ordinary sea waves will explode in a puzzle of thousands of pieces.

But it doesn't matter. You will die in any case. Few people want to have written on their thombstone whether they died in a totally bent aluminum fuselage torn into 3-4 pieces, or in a cloud of puzzle bricks from a carbon fibre composites fuselage.
Always keep your number of landings equal to your number of take-offs

DH106
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting SATL382G (Reply 21):The B767 ditching everybody points to was the result of hijacking with a fight in the cockpit as the pilot tried to ditch, hardly ideal circumstances

 Quoting AIRCANL1011 (Reply 22):The aircraft had been highjacked and the landing was not controlled. The AC came in steep. I believe one of the highjackers were at the controls after they let it run out of fuel.

Yes - it was hardly a controlled, ideal ditching. There was no real attempt to flair the aircraft onto the water, and whoever was flying came in left wing low allowing that wingtip and engine to 'bite' into the water. Hardly supprising it broke up.
...I watched c-beams glitter in the dark by the Tanhauser Gate....

2H4
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Prebennorholm (Reply 32): Carbon fibre doesn't bend, it breaks

 Quoting Prebennorholm (Reply 32):in a cloud of puzzle bricks from a carbon fibre composites fuselage.

With all due respect, Preben, how have you come to the conclusion that A) all carbon fiber materials exhibit the same failure characteristics, and B) that the carbon fiber in quesion is indeed that brittle?

Saying most carbon fiber is brittle is no different than saying most paint is green. It all depends on what's inside. In this example, it depends entirely on what the carbon fiber in question is made up of, as far as type and ratio of resin and specific prepreg specs.

2H4

Intentionally Left Blank

md80fanatic
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### RE: 747 Ditching At Sea - How Long Would It Float?

Once the wings rip away (like the previously mentioned 767) it won't be floating for very long.

SATL382G
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Prebennorholm (Reply 31):The truth is that if you ditch at sea, then you are 99+% dead.

Please site some facts to back up this claim. Even the ATR accident didn't have this level of fatality. Name some incidents please.
"There’s nothing quite as exhilarating as being shot at and missed" --Winston Churchill

BAtriple7
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### RE: 747 Ditching At Sea - How Long Would It Float?

What about that 737 ditching in a river in Indonesia or Philippines (sorry can't remember which country, was on aviation safety network)? Everyone survived excpt a stewardess who drowned, sadly.

SpinalTap
Posts: 392
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### RE: 747 Ditching At Sea - How Long Would It Float?

Would a 747 be bouyant enough to float if undamaged? (It does have a large volume of air in it - and if the fuel was dumped too)

Perhaps this is something better left to the experts like Dave Letterman and his Will it Float? team
"I get what they call a stipend, a stipend is like money but its such as small amount they don't really call it money"

litz
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Kiwiandrew (Reply 15):[quote=HiJazzey,reply=14] Wasn't there a JAL DC-8 which landed in San Francisco bay? yes , initially I thought you were mixing it up with the one in Tokyo Bay with the mentally unstable pilot - but then I found this - amazing story - especially that they salvaged it and got it flying again

Not only flying again, but a long, long healthy career with Airborne Express.

N808AX (the plane in question) was deregistered on 3/12/2004.

According to : http://www.aerotransport.org/php/go.php?q=regn+N808AX

It's at Wilmington Air Park (ILN), parted out and derelict (so presumably scrapped). Talk about a long career ...

- litz

DeC
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### RE: 747 Ditching At Sea - How Long Would It Float?

Also http://aviation-safety.net/database/dblist.php?Event=REED
DEC

sxmna
Posts: 59
Joined: Wed Mar 21, 2001 2:51 am

### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting F27XXX (Reply 11):Back in the early 70s, an ONA DC-9-33 was enroute from JFK-SXM and suffered fuel exhaustion due to having to route further to avoid storms and ditched somewhere (Ithink) near the Virgin Islands - - it remained intact and all pax got out, i thought. The book went on to say it sunk in extremely deep water. Sorry i dont have a link to it, but its listed in one of my Aviation Disaster books.

Not quite correct. It was an ALM DC 9-33 on May 2nd, 1970.
This is what Airdisaster.com has about it in its Dbase: "The flight was scheduled to fly from New York to St. Maarten. Because poor visibility, the aircraft could not land at St. Maarten and was diverted to San Juan, Puerto Rico. Five minutes later the crew was told the weather had improved at St. Maarten and were directed back. After 3 missed landing attempts at St. Maarten, the crew asked to be diverted to St. Thomas. By this time the plane was low on fuel. While flying to St. Thomas, the aircraft ran out of fuel and ditched into the ocean. Improper management of fuel by the crew. Inadequate warning given to passengers before the ditching."

The plane floated quite a while and many passengers survived. I personally know one; alive and well (but old) residing on Sint Maarten as you read this. One of the flight attendants managed to save many passengers. She unfortunately drowned while trying to rescue others. There is (or at least was) a statute for her in front of the old ALM headoffice in Curacao.

prebennorholm
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### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting MD80fanatic (Reply 35):With all due respect, Preben, how have you come to the conclusion that A) all carbon fiber materials exhibit the same failure characteristics, and B) that the carbon fiber in quesion is indeed that brittle?

Because I have built a lot of carbon fibre structures during the last 15 years, large model aeroplanes. And unfortunately also crashed some. So it is not a conclusion I have made, it's long time experience. To some extent personal experience, and to major extent experience shared among hundreds of my model aviation friends all over the world, of whom more than half a dozen are working for companies like Airbus, Boeing, BAe and such. And many more in the aircraft maintenance industry, civil and military.

 Quoting MD80fanatic (Reply 35):Saying most carbon fiber is brittle is no different than saying most paint is green.

Carbon fibre is a pretty well defined material, far less variation than various aluminum alloys for instance. To say that carbon fibre is "brittle" (breaks instead of bends) is much the same as saying that the metal tin is soft.

I wouldn't say that it is "brittle" when it is as strong as steel. But the failure mode is not to bend. Go and test it on your favorite carbon fibre fishing rod.

 Quoting MD80fanatic (Reply 35):It all depends on what's inside. In this example, it depends entirely on what the carbon fiber in question is made up of, as far as type and ratio of resin and specific prepreg specs.

You can produce softer carbon fibre by varying the resin mixture and by using a "fat" resin to fibre ratio. Or by curing it at too low temperature. Unfortunately it also kills the strength, so only the optimal mixtures are relevant in the aviation industry.
Always keep your number of landings equal to your number of take-offs

prebennorholm
Posts: 7145
Joined: Tue Mar 21, 2000 6:25 am

### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting SATL382G (Reply 34):Quoting Prebennorholm (Reply 31): The truth is that if you ditch at sea, then you are 99+% dead. Please site some facts to back up this claim. Even the ATR accident didn't have this level of fatality. Name some incidents please.

This accident was "extremely lucky" for various reasons:
1. The ATR ditching speed was much lower than a 747, or any jet plane.
2. It happened in the warm Mediterranean in the middle of summer - 6th August. You could swim for ever in that water. Like the nicest, heated swimming pool. And no sharks!
3. It happened close to Italian shores, a few minutes helicopter flying time away from a well prepared SAR unit.
25 out of 39 survived.
Transplant that into a wide body ditching in the North Atlantic or such.

Fortunately there are no incidents or accidents to mention because it never happened and hopefully never will happen.

The 767 accident was not a real ditching, it was more a beach landing. Those who didn't get killed or seriously injured during the crash could swim and walk ashore.
Always keep your number of landings equal to your number of take-offs

pdxtriple7
Posts: 641
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### RE: 747 Ditching At Sea - How Long Would It Float?

For my International Baccalourete extended essay, I am researching the shoot down of KAL 007, a 747 that was shot down by the Soviets when it strayed from its intended path. Some believe that the aircraft sustained some damage but was successfully ditched in the sea. There's a lot more information, but I don't feel like typing all that I've come up with, but I find the question about a 747 ditching at sea to be very interesting, since there haven't been any cases of a 747 trying to ditch at sea. Those that believe it is possible cite the Ethiopian 767-200ER and other cases already mentioned, showing that it is possible.

prebennorholm
Posts: 7145
Joined: Tue Mar 21, 2000 6:25 am

### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting PDXtriple7 (Reply 42):...a 747 that was shot down by the Soviets when it strayed from its intended path. Some believe that the aircraft sustained some damage but was successfully ditched in the sea.

Ditching of KAL 007 can be ruled out. A successful ditching takes a fully controlable plane. It is unthinkable that a missile attack should take out all four engines and leave an otherwise controlable plane in the air.

And if that had happened, and it also exactly had taken out all communication means, then Japanese radars would have recorded its half hour long glide from cruising altitude to the ditching.

A 747 with much of the fuel burned will susstain flight at low altitude on even one good engine, at least if it is #2 or #3 engine.

But ditcing or not, only those pax or crew members, who were wearing a cold water diving suit, would have a chance of survival.
Always keep your number of landings equal to your number of take-offs

Citation X
Posts: 46
Joined: Thu Feb 08, 2001 3:01 pm

### RE: 747 Ditching At Sea - How Long Would It Float?

Also, while we're at it, how long can a B747 stay underwater before being completely flooded??
(airport 77)

md80fanatic
Posts: 2365
Joined: Tue Apr 13, 2004 11:29 pm

### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting Prebennorholm (Reply 40):Quoting MD80fanatic (Reply 35): With all due respect, Preben, how have you come to the conclusion that A) all carbon fiber materials exhibit the same failure characteristics, and B) that the carbon fiber in quesion is indeed that brittle? Because I have built a lot of carbon fibre structures during the last 15 years, large model aeroplanes. And unfortunately also crashed some. So it is not a conclusion I have made, it's long time experience. To some extent personal experience, and to major extent experience shared among hundreds of my model aviation friends all over the world, of whom more than half a dozen are working for companies like Airbus, Boeing, BAe and such. And many more in the aircraft maintenance industry, civil and military. Quoting MD80fanatic (Reply 35): Saying most carbon fiber is brittle is no different than saying most paint is green. Carbon fibre is a pretty well defined material, far less variation than various aluminum alloys for instance. To say that carbon fibre is "brittle" (breaks instead of bends) is much the same as saying that the metal tin is soft. I wouldn't say that it is "brittle" when it is as strong as steel. But the failure mode is not to bend. Go and test it on your favorite carbon fibre fishing rod. Quoting MD80fanatic (Reply 35): It all depends on what's inside. In this example, it depends entirely on what the carbon fiber in question is made up of, as far as type and ratio of resin and specific prepreg specs. You can produce softer carbon fibre by varying the resin mixture and by using a "fat" resin to fibre ratio. Or by curing it at too low temperature. Unfortunately it also kills the strength, so only the optimal mixtures are relevant in the aviation industry.

I don't know how you managed this feat.....but I did not say any of those things. I for one know virtually nothing about carbon fibres.

MattMSP767
Posts: 108
Joined: Fri Oct 14, 2005 10:25 pm

### RE: 747 Ditching At Sea - How Long Would It Float?

If a large plane is going down into the water wouldn't you want it to break up? If it didn't break up you'd probably drown in the cabin but if it didn't break up then you could get out to swim away assuming you survived the impact...right?

ChiGB1973
Posts: 1394
Joined: Mon Mar 22, 2004 6:39 am

### RE: 747 Ditching At Sea - How Long Would It Float?

 Quoting AirbusA346 (Reply 18):Don't people know they are to watch safety demos.

I think, in training, they told us this was the crash that changed some FAA regulations about inflating the life vest outside of the aircraft (or at least saying it in the demo). I feel bad for the people, but as with most crashes, something very valuable was learned.

Ethiopian Airlines, Kenya
In 1996, flight 961 took off from Addis Ababa for a flight to Abidjan via Nairobi, Brazzaville and Lagos. Shortly after entering Kenyan airspace, three men seized the aircraft and demanded to be flown to Australia. Approaching the Comores, off East Africa, the aircraft began to run out of fuel. Not allowed to stop and refuel, the pilot was forced to ditch in the shallow waters off Le Galawa Beach. The left engine and wingtip struck the water, causing the aircraft to break up and crash. There were 125 fatalities; 50 passengers survived.
Lessons Learned: Not to inflate life jackets too early. This was a planned emergency and passengers had donned life jackets, but some inflated while still in the aircraft, starting a chain reaction. Most of these died on impact because they couldn't brace, or were unable to escape the aircraft and drowned. Those who inflated after exiting survived. The hijacker in the cabin died, but the captain survived.

http://davesnothereman.blogspot.com/...06_01_davesnothereman_archive.html

It is just from a blog spot, couldn't find any "facts."

M

DeC
Posts: 535
Joined: Mon Aug 15, 2005 5:12 am

### RE: 747 Ditching At Sea - How Long Would It Float?

Date: 23 NOV 1996
Time: 12:15 UTC
Type: Boeing 767-260ER
Operator: Ethiopian Airlines

info : http://aviation-safety.net/database/record.php?id=19961123-0
DEC

jumpseatflyer
Posts: 155
Joined: Fri Sep 23, 2005 12:13 pm

### RE: 747 Ditching At Sea - How Long Would It Float?

Not only did the hijackers of that 767 lack the skill to perform an even "mediocre" water ditching, but I remember reading somewhere that alcohol was involved [please enlighten me if this is wrong, I was a mere person of 9 at the time and it could have been media hype].

I'm guessing [aka don't bother quoting me] that a fully laden 474 would be deplanable for 5-8 minutes.
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