Pitot Tube Screws June 16th, 2010
Before mounting the pitot mast to the wing, we need to drill and tap four holes for screws that hold the pitot tube to the pitot mast. Drilling the holes was a bit tricky, since the pitot mast is a curved surface. I used a leather glove to sort of hold the pitot mast in place, and did my best to drill a hole perpendicular to the pitot mast. Dynon recoments using 6-32 screws, so I drilled the holes with a #36 bit.
I then match-drilled the pitot tube through the mast, and used a 6-32 tap to cut the screw threads on all four holes.
I was not sure which kind of 6-32 screw to use, so I ordered three different kinds from Aircraft Spruce (They are something like $0.05 each, so I figured it was worth the investment…) The one on the right was the ‘safe’ choice, but it kind of looks like crap. I ended up using countersunk screws like the one shown on the left. I was not sure if the mast would be thick enough to countersink, but I decided to try it out anyway. The hole did end up slightly enlarged, but there is plenty of material in the pitot tube for the screw to grab on and hold on to the pitot mast.
