REFLECTOR: Aileron Tube Seal

[Chuck Jensen]

If my Velo is typical, air intrusion around the aileron torque tubes penetrations thru the side of the hull is a primary location of cold air infiltration.  This is apparently a high pressure area.  Ronnie Brown had a fix of building a kind of air-dam ahead to reduce the air pressure in that area.  Better, but not quite what I needed for flying in <32F weather.

After multiple attempts at fixing this problem, I've come up with a near-perfect solution.  I took some 1 1/4" diameter, very thin walled clear rigid plastic tubing (from Aquarium shop) and cut off a chuck 3" long.  I then used a scissor split the side of this short tube, so I'm left with a split tube much like the foam pipe insulation you can put around your water pipes.  

I then snapped this over the 1" aileron torque tube.  You will note, the extra 1/4" overlap come into play--later.  The plastic sleeve is slid outboard so it is situated in the circular notch where the torque tube goes thru the side wall. You will be able to see one end of the sleeve in the cockpit (standing on your head) and the other end outside and under the canard. 

The plastic tube now acts as a sleeve around the torque such that when you move the elevator up/down, the torque tube rotates inside the plastic sleeve which is stationary against the hull.  Then, using silastic or other good caulk/adhesive, fill in all the gaps/clearances between the hull and the plastic sleeve.  You now have a perfect fit with zero in leakage and the torque tube moves without resistance.  If you remove the canard, just pull away the caulk and replace when the canard is reinstalled.  

If you were too fine of a craftsman when you were forming your notch in the side wall for the torque tube, there may not be enough clearance between the hull and the torque tube for the plastic sleeve to slide past, so you may have to open the hole up a little bit to let the plastic tube slide in between the torque tube and the hull.  Now, you'll notice that the oversized plastic tube overlaps on itself on the smaller 1" torque tube so when you caulk it up, the overlap ensures to caulk can not contact the tube.  Total cost:  About $10 for the rigid plastic tube and a little caulk.

Add heated seat pads, and its almost tolerable during a trip thru Iowa in January.

Chuck