KELPkid
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Why Was The DC-3 Cockpit So Leaky?

Tue Dec 18, 2007 10:15 pm

Once again, the thread title should say it all  Smile

In my various readings on flying the DC-3, one thing in particular stands out: why did the DC-3's cockpit apparently leak like a sieve?

When it was raining outside, you'd better don the rain gear inside  raincloud 

I wonder if RF burns and minor shocks were the norm since most of these guys also used vacuum-tube radios  scratchchin 
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Starlionblue
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RE: Why Was The DC-3 Cockpit So Leaky?

Wed Dec 19, 2007 12:26 am

Well, for starters the DC-3 wasn't pressurized so a perfect seal wasn't necessary. I would also imagine that the tolerances required for a good rain seal were a bit too expensive to be economically viable.

How does the DC-3 compare to other 1930s designs in this regard?
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HAWK21M
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RE: Why Was The DC-3 Cockpit So Leaky?

Wed Dec 19, 2007 4:24 pm

Where was the Leaking Areas on this Unpressurised Champ.
regds
MEL
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David L
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RE: Why Was The DC-3 Cockpit So Leaky?

Wed Dec 19, 2007 6:59 pm



Quoting Starlionblue (Reply 1):
How does the DC-3 compare to other 1930s designs in this regard?

My thoughts, too. Perhaps the DC-3 only suffers comparison to modern designs because it's one of the very few to last long enough.

I remember an RAF pilot describing the Shackleton as being "semi-pressurised - in other words, it's got more holes in the front that at the back".  Smile
 
411A
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RE: Why Was The DC-3 Cockpit So Leaky?

Wed Dec 19, 2007 7:23 pm

DC-3's leaked in several areas, most notable were the windshield and DV window areas, due to poor sealing.
Just the way it was....
 
metroliner
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RE: Why Was The DC-3 Cockpit So Leaky?

Wed Dec 19, 2007 8:32 pm

I can't imagine the build quality on those Daks, when they were built in the numbers (or should I say 'hordes') they were, would have stretched to ensuring the windows sealed correctly. The most important thing was that it flew, was built like a tank, and just generally ruled the skies for forty-odd years... (no exaggeration there) Big grin

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2H4
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RE: Why Was The DC-3 Cockpit So Leaky?

Wed Dec 19, 2007 8:34 pm

I wonder if the Basler BT-67s are similarly leaky...

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HAWK21M
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RE: Why Was The DC-3 Cockpit So Leaky?

Sun Dec 30, 2007 9:23 pm



Quoting 411A (Reply 4):
DC-3's leaked in several areas, most notable were the windshield and DV window areas, due to poor sealing.
Just the way it was....

Was there Electronics Malfunctions due to these leaks.
regds
MEL
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PGNCS
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RE: Why Was The DC-3 Cockpit So Leaky?

Mon Dec 31, 2007 12:58 am

They leak because they are 60 years old, and because they were built by Douglas.

To let history live on, the DC-9 and MD-80 series still has the same problem. Have paper towels standing by during deicing!

Despite this minor drawback, I still love Douglas products.  yes 
 
KELPkid
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RE: Why Was The DC-3 Cockpit So Leaky?

Mon Dec 31, 2007 1:12 am



Quoting PGNCS (Reply 8):
They leak because they are 60 years old, and because they were built by Douglas.

Ernie Gann was writing about leaky cockpits in the DC-2 and DC-3 from his first officer days at AA in the mid to late 1930's, I doubt it's just age  Wink
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HAWK21M
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RE: Why Was The DC-3 Cockpit So Leaky?

Mon Dec 31, 2007 6:37 am



Quoting PGNCS (Reply 8):
They leak because they are 60 years old

You mean they were built in old times & not airframe is now 60 yrs old & has started leaking  Smile
regds
MEL
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PGNCS
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RE: Why Was The DC-3 Cockpit So Leaky?

Mon Dec 31, 2007 8:50 am



Quoting KELPkid (Reply 9):


Quoting PGNCS (Reply 8):
They leak because they are 60 years old, and because they were built by Douglas.

Ernie Gann was writing about leaky cockpits in the DC-2 and DC-3 from his first officer days at AA in the mid to late 1930's, I doubt it's just age



Quoting HAWK21M (Reply 10):
Quoting PGNCS (Reply 8):
They leak because they are 60 years old

You mean they were built in old times & not airframe is now 60 yrs old & has started leaking
regds
MEL

They're great planes, and they build character!  cheerful 
 
411A
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RE: Why Was The DC-3 Cockpit So Leaky?

Mon Dec 31, 2007 11:24 am



Quoting HAWK21M (Reply 7):
Was there Electronics Malfunctions due to these leaks.

Generally no, not in my experience...just the pilots got...ah, damp.

Although I did have all the radios quit one time, but that was in bright sunshine, with no rain in sight.
Go figure..
 
ThirtyEcho
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RE: Why Was The DC-3 Cockpit So Leaky?

Mon Dec 31, 2007 11:35 am

The DC-3 cockpit is leaky to let the water run out.
 
Buzz
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RE: Why Was The DC-3 Cockpit So Leaky?

Mon Dec 31, 2007 3:23 pm

Hi MEL, and KELPKid, Buzz here. I have a little practice regarding how DC-3's are put together, used to Crew Chief one or two.
The nose has a unique hatch, it opens upward like the hood of a car. Yes, there's a foam tape we put in the gap. I haven't flown one in the rain so I don't know exactly where it leaks.
There's a snap-in curtain on many DC-3's that's just forward of the instrument panel, I don't know if it's to keep the drafts away from the pilot's feet and knees... or to make the rain flow outward to the sidewalls.

MEL, the radios on a DC-3 were often in a rack aft of the cockpit... 1940's radios were large. But modern radios are smaller, lots of people mount them on the instrument panel. And since not many people fly a DC-3 through wet weather for fun, I guess we won't know if that set-up has radio problems in the rain. (Most of the DC-3 flying I know of is for fun on VFR days).

Windshield leaks... I suppose so. When parked, N84KB, and NC18121 didn't leak in the rain here in this damp part of the world. But we didn't plow through rain either.
Oh yes, both the DC-3's I used to play with had 1 piece windshields. Remember there was a 2 section windshield, you could hinge the outboard section open to see for landing... after you had covered it with ice. I haven't dealt with that kind... more areas to leak.

g'day
 
PGNCS
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RE: Why Was The DC-3 Cockpit So Leaky?

Tue Jan 01, 2008 2:21 am



Quoting ThirtyEcho (Reply 13):
The DC-3 cockpit is leaky to let the water run out.

The DC-9 works the same way!  Smile

Happy New Year!
 
MD11Engineer
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RE: Why Was The DC-3 Cockpit So Leaky?

Tue Jan 01, 2008 11:12 am

Are you sure that the Land Rovers were not designed by the same people?
 Wink

Jan
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aviopic
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RE: Why Was The DC-3 Cockpit So Leaky?

Tue Jan 01, 2008 12:22 pm

I guess the biggest difference and reason for leaky DC2's and 3's(and infect all other a/c from that period) is the lack of a pressure cabin which is the best way to keep water out.
Also everything was still riveted rather then glued together.

Problem area's.
http://www.honders.net/tmp/DC2_NC39165_MG_2973.jpg

- "The hood" located right above the lights is not really a problem, there is a watertight seal(like a blanket) underneath and if water comes in it will leave just as quickly via the bottom.
- The square hatch located on top of the cockpit(emergency exit) does leak, a fair amount of DC4(which in this case is not an a/c but a silicon based grease also known as MS4) all around before every flight does miracles though.
- The sliding windows leak depending the wind direction, one crew member is lucky the other one is not  Smile
- Emergency exit's in the cabin are not like today going inwards but outwards which means they are not flush with the fuselage and thus leak.
- Further water can come from anywhere, a cracked beacon light lens hood, a warn out rivet just anything and without pressurized cabin there is nothing to stop it.
All in all it is not that bad either though, water comes in and leaves thru the bottom because it is just as well...... ehh well ventilated  Wink

If you approach weather like this:
http://www.honders.net/tmp/DC2_NC39165_MG_3993v.jpg
You have 2 options
1. Run like hell in the other direction.
2. Get out the old swimming suit and start running around with rolls of tissue paper.
I personally opt for the last just for the fun of it Big grin

Quoting HAWK21M (Reply 7):
Was there Electronics Malfunctions due to these leaks.

It's just a matter of using common sense really.
We removed all 115V systems including the inverters, left with just a 24V bus there is no problem in that area.
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HAWK21M
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RE: Why Was The DC-3 Cockpit So Leaky?

Tue Jan 01, 2008 12:48 pm



Quoting 411A (Reply 12):
Generally no, not in my experience...just the pilots got...ah, damp.

Although I did have all the radios quit one time, but that was in bright sunshine, with no rain in sight.
Go figure..



Quoting Buzz (Reply 14):
MEL, the radios on a DC-3 were often in a rack aft of the cockpit...


Its Important to have a Shield in place to avoid Water contacting those Electronics.

regds
MEL
I may not win often, but I damn well never lose!!! ;)

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