Rain Drains

NYTOM · #1 08-11-2008, 04:29 PM

Anybody out there have any tips on drilling drain holes for any rain water or other moisture that collects in the plane. I'm finally completing my first wing and realized there's no provisions for any drain holes. My old Ercoupe had drain holes everywhere and it was amazing how much water passed through that thing. I figure it's pretty much common sense where the waters going to collect but what size holes are you guys drilling. I might have to tie-down outside for a while waiting for a hanger rental so it's kind of important .

AlexPeterson · #2 08-11-2008, 04:44 PM

Tom, I don't recall putting any in the wings, it seems like those are ok. The various corner reliefs built into the ribs, etc., make for allowing water to drain. It is the fuselage and the rudder bottom that need drain holes for sure. Once the plane is complete, you can spray water on the belly, and based upon where it collects, you will know where to drill the hole(s). Seems like I had two, somewhere in the vicinity of the aft wing spar. The 7's and 9's would be quite different.

NYTOM · #3 08-11-2008, 08:25 PM

Quote:

Originally Posted by AlexPeterson

Tom, I don't recall putting any in the wings, it seems like those are ok. The various corner reliefs built into the ribs, etc., make for allowing water to drain.

After I read your response I went down and stared at my half skinned wing and imagined I was a splash of water trying to get out. Your absolutely right Alex, it doesn't seem like it's going to be a problem.

Hopefully I'll get to try your idea on my fuselage within the year.
Thanks for your help Alex.
PS Nice web site you have there.

jsharkey · #4 08-12-2008, 05:25 AM

Quote:

Originally Posted by AlexPeterson

Tom, I don't recall putting any in the wings, it seems like those are ok. The various corner reliefs built into the ribs, etc., make for allowing water to drain. It is the fuselage and the rudder bottom that need drain holes for sure. Once the plane is complete, you can spray water on the belly, and based upon where it collects, you will know where to drill the hole(s). Seems like I had two, somewhere in the vicinity of the aft wing spar. The 7's and 9's would be quite different.

Out of interest - how big a diameter were the holes?

Jim Sharkey
RV6 - Details!

Vern · #5 08-12-2008, 05:29 AM

You should consider a 1/8" drain hole in the airbox bottom, rudder bottom,and in front of each fuselage former. I've seen aircraft with 4-6" deep water in the rear fuselage (not RV's).

Most RV's are pampered and live in nice hangars, but being tied down on x-country or a heavy rain during flight could change things.

I saw a famous RV-6 abort takeoff and almost drown out the engine because of no airbox drain after a plane wash.

AlexPeterson · #6 08-12-2008, 06:03 AM

Quote:

Originally Posted by NYTOM

After I read your response I went down and stared at my half skinned wing and imagined I was a splash of water trying to get out. Your absolutely right Alex, it doesn't seem like it's going to be a problem.

Hopefully I'll get to try your idea on my fuselage within the year.
Thanks for your help Alex.
PS Nice web site you have there.

Tom - thanks.

Quote:

Originally Posted by jsharkey

Out of interest - how big a diameter were the holes?

Jim Sharkey
RV6 - Details!

Don't recall exactly - maybe 1/4" since that is the smallest my unibit can make.

noelf · #7 08-12-2008, 06:53 AM

I'm building a -6A and installed drain holes on the aft side of each bulkhead. Taildraggers may want these holes on the front side of the bulkheads. The hole size was smaller than a #40 drill bit...I think.

I positioned the drain holes on the center line (while the a/c was in the jig) so that at some future date, I could relocate the center line with little effort to validate any asymmetric issues/ concerns/screw-ups that I might come up with.