pitot tube

[High Country 69]

just curious where is the best place to mount the pitot tube for best accuracy my very old manual says to mount from rib#4 but I see the newer KF's are a lot further outboard on the wing where should I mount it? also it doesn't say how far from the bottom of the wing it should stick down before it bends. I'm using the speed wing profile with the flat bottom. It would be nice to move it out at least one more rib away from the gas tank so I can add inspection rings to repair if ever it were necessary.

-Robert-

Edited 28 Aug 2012 by High Country

[dholly 718]

Lifted from:

Installing a Pitot-Static System

Sport Aviation - 1/82

By Tony Bingelis -

• The pitot tube should not be located inside the propeller blast area or any place where its pick-up opening might be in air disturbed by the influence of proximate aircraft structure.
  
  
• Almost anywhere under the wing is O.K. for aircraft utilizing the older airfoils (Clark Y, etc.), just so long as the pitot tube opening is about 5" or more below the surface of the wing. An aircraft with a laminar flow airfoil should have its pitot tube located further aft to some point where the maximum camber of the wing occurs.

[High Country 69]

Thanks Doug, I think I will keep its location per the book fore and aft but will move it further out on the wing to give myself room for inspection rings and a way to make any repairs should I ever need to. Also the 5" down from the bottom of the wing I didn't have so that's good to know. I may get started on it this evening. One more question (for now) where is the best location to route the hose from the pitot tube and the wiring from the lights. the book says drill a hole and stick through the spars but I don't want to take a chance of the tubing or wiring being cut over time. also what about the rivets on the inside of the spars couldn't they cause chafing of these parts if they are routed inside the spars. hmmmm. I seem to have too many questions don't I

-Robert-

[EDMO 1078]

Thanks Doug, I think I will keep its location per the book fore and aft but will move it further out on the wing to give myself room for inspection rings and a way to make any repairs should I ever need to. Also the 5" down from the bottom of the wing I didn't have so that's good to know. I may get started on it this evening. One more question (for now) where is the best location to route the hose from the pitot tube and the wiring from the lights. the book says drill a hole and stick through the spars but I don't want to take a chance of the tubing or wiring being cut over time. also what about the rivets on the inside of the spars couldn't they cause chafing of these parts if they are routed inside the spars. hmmmm. I seem to have too many questions don't I

-Robert-

My Kitfoxes pitots dont stick down 5 inches - more like 3 to 4 inches - Believe I drilled thru the 5th or 6th rib - The hole drilled in the forward spar can be slightly bent out by putting a rod into it - then add some silicone there to the "Black, tough, Nylon tube" - that is what Kitfox says.......

The wiring should go thru the rear spar - No holes needed there - Because if they went thru the front spar they would have to be longer and double-back to the rear so wing can fold - as the pitot tube has to - Donno why it goes thru the front, but went by the book there - I elected to enclose my wires in a poly.... tube for chaff protection.

Hope this helps.

ED in MO

Edited 29 Aug 2012 by Ed In Missouri

[Av8r3400 1179]

I may follow my friend's lead on placement: He put his pitot tube on the rib between the jury strut and the attach point for the lift strut. This was done mostly for protection.

It's hard to bump your head on it there and bend it... (Don't ask).

[EDMO 1078]

I may follow my friend's lead on placement: He put his pitot tube on the rib between the jury strut and the attach point for the lift strut. This was done mostly for protection.

It's hard to bump your head on it there and bend it... (Don't ask).

Great thinking (using your head!) Will change my broken one soon.

ED in MO