Where is water getting in ?

[Enlisted Pilot]

When I am away from my hangar and the plane gets rained on I almost always have water dripping out of the bottom. It doesn't come in the cabin, but the belly of the plane must be getting a good amount of water because it drips for a long time after. I even got the drip the other day after flying in the clouds for about 30 min.

where is the water coming in?? I have heard that the baggage door seal is often one of the ways it gets in and to the belly. My baggage door seal is almost non-existent. I don't notice any leaking around windows or my doors.

I cant imagine that that much water getting in the belly is good for the plane. Thankfully I hangar so it's only a couple times a year that I get the drips.

 

[Challenger1]

Good question, mine drips after flying in the rain also. I am not worried about it since I fed my AP/IA a shop vac hose and a scotchbrite pad a couple years ago when he was in my fuselage. He scuffed loose a bunch of shavings and dirt and sucked it all up with the vac so all my drain holes are open.

I just put new door seals on my plane including the cargo door so I don't think it is getting in through the door seals?

 

[DFMMD]

Wing root areas are a possibility, particularly after flying in rain. The airframe isn't "water-proofed", so the most you can probably do is to ensure the drainage holes are unobstructed, making sure of it after flying in rain or when the plane's been tied down outside in rainy weather. I use a Shish Kebab skewer to open them up. I've seen a steady stream of water flow when opening the drainage holes, after the above conditions are encountered. Grease droppings from the elevator cable pulley can accumulate in the tail cone, occluding that drainage hole.

 

[Joeman434]

One of the great mysteries of airplane ownership. We had an overnight guest about a month ago with an almost new (196 hour) 172. It rained overnight and in the morning when we moved it water was dripping out of two holes....

 

[rkittine]

Two holes inside the cockpit or out of the wing?

Bob

 

[C420sailor]

Condensation, too. Moist air in the voids, airframe cools overnight, vapor condenses, settles in the belly.

 

[Clyde]

 

[Flubber4.0]

One prominent leak is often the upper sealing of the front windshield. It is not sealed by construction and never closed completely to allow movement of the windshield. Rain enters through the capillary effect and is not dripping straight down, but crawls on the seam down to the bottom. I got rid of the annoying dripping by removing one of the screws of the bottom transponder antenna ... Old wisdom from driving Landrovers - if you cannot avoid getting water in, make the hole on the bottom bigger than the holes on top.

 

[Clyde]

 

[Aeromot]

Trapped Rainwater Leads to Crash

Probable Cause: A loss of lateral control during takeoff due to an accumulation of water in the right wing.

generalaviationnews.com

 

[magman]

Drain holes should be part of fabric work and Annuals.

On fabric I prefer to burn holes with a soldering iron.

Location is important.

 

[jwcfbd]

These things are anything but waterproof. None of the access panels are sealed, If it's windy while it's raining, the wing struts are a straight shot in to the fuselage. There are openings around the horizontal stab and wing roots. If the boots around your steering linkage are damaged rain can get in that way while flying. Like Magman said just make sure all the drain holes are kept open and clean.
When I worked of Delta I was out on the ramp and the plane I was working on had a constant drip but it hadn't been raining. When I opened the access I found a blocked drain and a 20 lbs ice block. LOL