Cabin air leak

I have a fairly substantial amount of cold air leaking into the cabin behind the seats. It seems to be coming from around the ends of the spars, most likely from the gap around the gear legs. First noticed it when I reached down between the seats around the spar carry through channel. It seemed to be strongest and most concentrated around the centre of the aircraft but I was able to trace it to each side. As I didn't build the aircraft it's a bit difficult to visualise the path it might be taking. Is there something missing? Or do I just need to work at blocking the gap (wherever it might be) and perhaps installing fairings at the gear leg/fuselage interface?

The heater had been struggling to keep up during our southern hemisphere winter (which is mild compared to most of the US). I could feel the cold drafts coming in where the canopy frame doesn't seal properly but now realise they are minor compared with the blast behind the seats. I now have the canopy seal kit which wasn't available when the aircraft was built but haven't had a chance to install it yet. I'm sure it will help but isn't going to solve the problem.

Jack Moore

The first thing you need to do is to block off the part of the water radiator that is above the heater. Do NOT put duct tape on the aft side of the radiator.THIS POST shows how I installed a baffle. Quick release hinge pins make it easy to install and remove as the seasons change. Pushing down and outward on a pin "handle" releases it.

One helper - -



Clear Vinyl. Can barely see it. Fastened to crossmember with alum rivets. Taped to floor.

Flight testing of the RV-12 prototype showed that the path towards minimizing cold air leakage into the cabin was stop the outflow.
Outflow of air produces a reduced cabin pressure that air via other paths will enter to replace.
There can be significant outflow along the lower sides and across the back of the canopy over the roll bar because of negative pressure at these locations on the outside.
In fact, it was found that once the canopy is well sealed, adding seals at the gear leg exit actually caused flow into the cabin via the lower floor area (out of the control stick and flap control openings, etc.

A seal kit for the RV-12 canopy is available that pretty much stops all of the air leakage on the canopy.

JBPILOT said:

Clear Vinyl. Can barely see it. Fastened to crossmember with alum rivets. Taped to floor.

Click to expand...

Hey John, I like your wheel chogs. What is the rubber looking pieces on the ends that contact the tires. Couldn't tell if that was pieces of hose, or maybe non skip tips for a cane, or step stool.

Wheel chocks - -

A hose that had to be encouraged to go over the PVC. Used them today. Work great. Very light weight.

Thanks John. Think I'll make me a set.........Tom

Thanks for the advice on the canopy seal kit. I will make it a priority to get it installed. It's one of a number of minor upgrades that have been on the list. The negative pressure explanation makes sense - the accelerated airflow over the canopy would certainly create negative pressure around the roll bar, quite apart from anywhere else.

Jack Moore

Recommend the Van's RV-12 canopy seal kit

But remember to install it in heated hanger or when the outside temperature is warm ( I forget the actual temperature the instructions recommend) There are sticky glues, etc... on the various rubber & foam strips that don't set up properly if installed in cold environment. I left it too late in the year to install myself and had to endure some cool breezes until Spring.

Thanks, Brent. Heading into warmer weather down here now - looking at around 30 Celsius (about 85F) in next few days. Should work at that temp. I couldn't get the required 3M product in small tubes. Had to buy a quart. Glue cost as much as the whole seal kit!

Jack Moore