My 6A is pretty tight up top, even with a tip-up. I posted previously about a 3 piece fiberglass tray which prevents any leakage from the front canopy seal from making its way into the instruments, although the canopy seal rarely lets any water in. Flying some practice IMC approaches the other day in heavy clouds with 700' ceilings resulted in water dripping out of the drain holes in the bottom of the fuselage, specifically the forward most drain hole which is centerline, just aft of the seat back bulkhead. I'd say that approximately a pint of water leaked out after I parked the plane in the hanger, following about 1.5 hours in the clouds (no rain just lots of moist humid clouds).
I found this extremely disturbing and set right away to identifying the source of the leak, while everything was still wet and I could hope to track it. Off came the seat backs, floor panels and the baggage bulkhead panels. I figured it must be coming from the wing area, even though I had sealed the outer floor ribs to the skins at construction which had been recommended. I found that virtually the only evidence of water was along the center of the aircraft, between the two ribs which create the tunnel for the elevator pushrod. The drain hole is in the baggage compartment portion, but there was also water in the portion of the tunnel forward of the compartment in the seat area and even the aft part of the insulation in the center tunnel of the floor area was very wet. No evidence of it coming from outboard and working its way to the center. Aft of the baggage bulkhead was virtually dry, with only a few drops of water visible.
I had previously tape sealed the vertical/horizontal stabilizer fairing thinking it may have leaked there and run forward along the bottom of the fuselage. That tape was still intact and the drain hole aft of the baggage compartment was not leaking. The firewall is well sealed and there is no evidence of it running aft as only the aft portion of the floor insulation was wetted.
My only conclusion is that the source of the water leak is actually the drain hole!!! I'm guessing that the shape of the fuselage and location of the drain hole just aft of the seat back bulkhead must create a low pressure area there and actually force water into the drain hole, which is about 5/32" diameter. My plan is to put a screw with a rubber washer into the drain holes to seal these and next time I fly in the clouds to remove them and then see if any water comes out.
Just wondering if anyone may have had a similar experience or have any other advice. I was really stumped when I couldn't find evidence of water other than in the center channels of the fuselage bottom.
I found this extremely disturbing and set right away to identifying the source of the leak, while everything was still wet and I could hope to track it. Off came the seat backs, floor panels and the baggage bulkhead panels. I figured it must be coming from the wing area, even though I had sealed the outer floor ribs to the skins at construction which had been recommended. I found that virtually the only evidence of water was along the center of the aircraft, between the two ribs which create the tunnel for the elevator pushrod. The drain hole is in the baggage compartment portion, but there was also water in the portion of the tunnel forward of the compartment in the seat area and even the aft part of the insulation in the center tunnel of the floor area was very wet. No evidence of it coming from outboard and working its way to the center. Aft of the baggage bulkhead was virtually dry, with only a few drops of water visible.
I had previously tape sealed the vertical/horizontal stabilizer fairing thinking it may have leaked there and run forward along the bottom of the fuselage. That tape was still intact and the drain hole aft of the baggage compartment was not leaking. The firewall is well sealed and there is no evidence of it running aft as only the aft portion of the floor insulation was wetted.
My only conclusion is that the source of the water leak is actually the drain hole!!! I'm guessing that the shape of the fuselage and location of the drain hole just aft of the seat back bulkhead must create a low pressure area there and actually force water into the drain hole, which is about 5/32" diameter. My plan is to put a screw with a rubber washer into the drain holes to seal these and next time I fly in the clouds to remove them and then see if any water comes out.
Just wondering if anyone may have had a similar experience or have any other advice. I was really stumped when I couldn't find evidence of water other than in the center channels of the fuselage bottom.