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Author Topic: Ditching into water  (Read 11709 times)

Jeff Victor Hayden

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Ditching into water
« on: June 16, 2012, 01:19:10 PM »

As the "after the landing" thread has drifted towards ditching the plane into the ocean here's somewhere to continue the ditching scenarion.
This is a very comprehensive link on ditching into water...

http://www.pilotfriend.com/safe/safety/ditching.htm
This must be the place
 
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Jeff Victor Hayden

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Re: Ditching into water
« Reply #1 on: June 16, 2012, 01:30:47 PM »

The main concern I have with the Electra ditching is the low wing configuration puts the engine cowlings/nacelles very low in relation to the underside of the fuselage. I suggest that they would contribute to flipping the aircraft on splashdown.
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Greg Daspit

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Re: Ditching into water
« Reply #2 on: June 16, 2012, 03:55:31 PM »

Just a quick calculation
A gallon of water weighs 8.34 lbs (saltwater weighs even more)
The fuel capacity of AE's Electra was 1151 gallons
1151 x 8.34 = 9,599 lbs of displaced water by the fuel tanks alone.
The weight of the plane was about 7,265 lbs
Crew, cargo and other fluid weights are not known exactly but my guess is if the fuel tanks were not ruptured, crushed or had a leak, and were empty, then this "flying gas tank" should float. Likley nose down, more or less, due to the engines, w/ open front cowl not being very buoyant.
3971R
 
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John Ousterhout

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Re: Ditching into water
« Reply #3 on: June 16, 2012, 04:39:31 PM »

Gary and others have discussed the fuel tank design at length, and whether the aircraft would float indefinitely or sink rapidly.  here is a lengthy discussion called "Ditching at sea", which privides good background for continued discussion here.

A point I was anxious to hear discussed was the statistical chance of the search aircrraft spotting a floating Electra in the large area covered, vs. the chance of spotting two people on Gardner island.
Cheers,
JohnO
 
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Jeff Victor Hayden

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Re: Ditching into water
« Reply #4 on: June 16, 2012, 05:22:10 PM »

Gary and others have discussed the fuel tank design at length, and whether the aircraft would float indefinitely or sink rapidly.  here is a lengthy discussion called "Ditching at sea", which privides good background for continued discussion here.

A point I was anxious to hear discussed was the statistical chance of the search aircrraft spotting a floating Electra in the large area covered, vs. the chance of spotting two people on Gardner island.
Thanks for the link Johno. I have read through all of the posts which seem to focus on the Electra on the reef theory plus fuel tank design and possible failure.

If it would be possible to concentrate on the ditch and sink theory for this thread it might shed some light on other aspects of the disappearance.

Good point regarding the floating Electra and SAR. From what I could gather from the other thread mentioned previously the fuel tanks were nigh on waterproof so the Electra had a good chance of remaining afloat for a considerable length of time.
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Jeff Victor Hayden

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Re: Ditching into water
« Reply #5 on: June 16, 2012, 05:35:48 PM »

Gary has kindly done the math for how the Electra would behave on water in a previous thread...
We can do the same computation for the Electra. The empty weight was (in round numbers) 7,000 pounds meaning it consisted of 41.33 cubic feet of aluminum which displaced 41.33 cubic feet of sea water providing 2645 pounds of buoyancy. Add to this the buoyancy provided by 1151 gallon empty fuel tanks, 9783 pounds, makes the total buoyancy of 12,428 pounds. Subtract the empty weight of 7,000 pounds leaves 5,428 pounds of positive buoyancy. Based on this, assuming no damage to the fuel tanks during a ditching or landing, the plane should have floated almost indefinitely. The fuel caps are airtight as are the fuel lines so the only way for water to enter the fuel tanks was through the vent lines which are very small, say 3/8th of an inch, so water could not enter at any great rate through them. In addition, depending on the attitude of the plane and the routing of the vent lines, it is also likely that no water could enter the tanks at all through the vent lines. So if the plane was washed off the reef at Niku, there is no reason to think that it sank anywhere near that island, so your ROV search, just offshore of the reef, is probably a waste of money.

https://tighar.org/smf/index.php/topic,481.msg6010.html#msg6010

With the Electra possibly floating indefiinately the SAR teams would have had a good window of opportunity to find the Electra if they were looking in the right place. The outcome of the SAR operation we all know so, there can be 3 possibles?.

1.Searched in wrong area and plane sank before they got to the right area.
2. Searched in right area but didn't see the Electra.
3. Electra didn't ditch into sea.

Does that sound logical?
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« Last Edit: June 16, 2012, 06:35:16 PM by Jeff Victor Hayden »
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richie conroy

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Re: Ditching into water
« Reply #6 on: June 16, 2012, 06:37:45 PM »

the crew of the Electra, mentioned more than once about the smell of petrol in cabin and fuselage of plane, so i doubt they were as air tight as yous suggest

also i doubt they would have closed roof hatch or the cabin door as there was no point for whatever reason at the time

i.e the plane was a lost cause

Also a part of Tighar's hypothesis is based on the fact the plane landed on reef an was able to send sos

i.e bettys notebook etc

so dont see the point in this to be honest  ???

i found this out the newbie way haha  ;D

 
We are an echo of the past


Member# 416
 
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Gary LaPook

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Re: Ditching into water
« Reply #7 on: June 16, 2012, 10:20:50 PM »

the crew of the Electra, mentioned more than once about the smell of petrol in cabin and fuselage of plane, so i doubt they were as air tight as yous suggest

also i doubt they would have closed roof hatch or the cabin door as there was no point for whatever reason at the time

i.e the plane was a lost cause

Also a part of Tighar's hypothesis is based on the fact the plane landed on reef an was able to send sos

i.e bettys notebook etc

so dont see the point in this to be honest  ???

i found this out the newbie way haha  ;D
Earhart complained that on one occasion the refuelers spilled fuel into the cabin causing the fumes. Regulations require that fuel tanks be vented overboard so that no flammable fumes enter the cabin.

gl
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Gary LaPook

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Re: Ditching into water
« Reply #8 on: June 17, 2012, 12:41:29 AM »

Here is some more information about ditching.

gl
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Leon R White

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Re: Ditching into water
« Reply #9 on: June 17, 2012, 12:19:55 PM »

Thank you Gary.

L
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Jeff Victor Hayden

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Re: Ditching into water
« Reply #10 on: June 17, 2012, 01:17:53 PM »

Trying to find any information on whether AE recieved any instruction/training regarding ditching into water. It would seem logical that she did as a considerable part of the round the world flight was over sea. She did recieve additional flight training...
http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Earhart.html
but it doesn't state whether this included ditching into water.
This must be the place
 
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