Pitot tube

Just to make sure, the pitot bulkhead union exits outward through a hole drilled in the bottom of 806-L-1 main spar?
As far as I see the drawing and my measurements confirm this. Just feels creepy drilling a hole in the spar.

Measure 10 times, drill once! And then order new parts....

Yes, that's the way it is on the -7, but before you commit, give some thought to upgrading to a pitot tube/mast arrangement instead of the stock Van's unit. I drilled that particular hole without thinking it through, later decided I wanted to go with the Dynon pitot that includes an AOA source, and now I have an extra hole in the spar and skin to plug/patch.

maybe try a mod?

SHF said:

Just to make sure, the pitot bulkhead union exits outward through a hole drilled in the bottom of 806-L-1 main spar?
As far as I see the drawing and my measurements confirm this. Just feels creepy drilling a hole in the spar.

Measure 10 times, drill once! And then order new parts....

Click to expand...

Ya know, that fitting will work fine if drilled beside the spar. I also have an aversion of drilling a big hole where I strongly suspect it should not be. So, we drill the hole aft of the spar, and add a doubler for support. Piece o cake! This area is accessible thru the aileron bellcrank cover.

Likewise, we put the tie down fitting on the fwd side of the spar, and drill a hole thru the skin only. You may not have this option with pre-drilled skins?

Carry on!
Mark

yes it is through the spar, according to the dwg's, thats the way i did it

bird

I was indeed considering upgrading to a mast but thought i would drill the hole in the meantime. But I will wait until i know what it is going to look like exactly before i do so.

Thanks everybody.

That makes sense. All the various pitot mast options are mounted through a cut-out in the lower skin, not through a hole in the spar. Wait until you decide to do any drilling.

When I changed to a heated pitot tube I was shocked to find the hole in the spar as well, but apparently it is designed that way. That said, I would not drill the hole if I built the airplane. There are just too many suitable places to mount the tube. For example, I have it mounted on the lower inspection plate on both the -8 and Rocket. Works great