Minimum Pitot Tube Distance From Wing Surface?

[Toobuilder]

On the -8, I recently changed my standard Vans pitot tube out for a heated unit that was on my old Mooney (RIP). The inlet of each is the same distance back from the leading edge, but the Mooney mast is about 2 inches closer to the wing than the bent J tube that it replaced. Flight test has proven the shorter Mooney unit to perform exactly like the original. So as I eye my Rocket and its Dynon AOA unit mounted on a exceptionally tall mast, I have to wonder just how short I can go and retain the full functionality. Clearly, the Piper style blade pitot is functional and extremely short, but does not have to deal with AOA measurement.

I'm interested in shortening up the mast on the Rocket both for structural and drag reduction purposes. So... Who has a short (but fully functional) mast and is willing to admit as much. And yes, I'm still talking about the Dynon (or similar), differential AOA unit.

[Ironflight]

I can't speak to the Dynon pitot Mike, but we have the Garmin AoA pitot on a short mast on our RV-6 and it appears to be doing OK.

I don't have the airplane here, so can't give you any measurements - sorry.

[Toobuilder]

Thanks Paul. The Garmin and Dynon use the same concept, right?

If you had to guess, how close is yours?

[rleffler]

Originally Posted by Toobuilder

Thanks Paul. The Garmin and Dynon use the same concept, right?

If you had to guess, how close is yours?

I believe that they all use the Gretz style of mount.

[Toobuilder]

Indeed Bob, but the one on my Rocket is much longer than the one pictured on the Gretz site and my Mooney unit.

Hence the question: How short can I go?

If nobody has experimented with this, that's fine. I'll cut mine down and see what happens. If I go too short, its a simple matter to fabricate a new one.