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Dynon Pitot/AOA Mast Locale

rockitdoc

Well Known Member
Sponsor
Hi,

Rooting around the forum I found several posts on the Dynon pitot/AOA for other birds but none for our -14's.

If anyone has installed one I have a couple of questions:

1. Which bay in the wing did you locate it?
2. If you located it aft of the main spar using the Dynon supplied mast, how did you manage to get the tip of the probe to be 2-12" from the leading edge as specified by Dynon.
3. If you did not use the Dynon mast, what did you use or fabricate?

Thanks, in advance, as usual

Scott
 
Locate just past the bell crank bay. Follow the instructions to mount the mast flange to the main spar. The standard Dynon pitot/AOA will work perfectly in this location.

Carl
 
Locate just past the bell crank bay. Follow the instructions to mount the mast flange to the main spar. The standard Dynon pitot/AOA will work perfectly in this location.

Carl

Which direction? Inboard or outboard of the bell crank bay. Outboard seems correct to keep it away from moving pushrods and such and also the prop wash, but I haven't installed the flaps and ailerons so don't know what might be conflicting.

Also, the tip of the pitot will be 16" aft of the leading edge. Dynon indicates that 12" is the limit. I presume you have mounted one as you describe and it works. That's good enough for me, if so.
 
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Which direction? Inboard or outboard of the bell crank bay. Outboard seems correct to keep it away from moving pushrods and such and also the prop wash, but I haven't installed the flaps and ailerons so don't know what might be conflicting.

Also, the tip of the pitot will be 16" aft of the leading edge. Dynon indicates that 12" is the limit. I presume you have mounted one as you describe and it works. That's good enough for me, if so.

Outboard. But just outboard of the bell crank bay rib. You want to be able to reach in to make the electrial and pitot/AOA connections. I put a #6 nutplate on each end of the pitot heat control box and mounted it in the same bay as the pitot, the two mounting screws going from the inside of the bell crank bay through that rib so that the box is on the other side of the rib from the bell crank.

This is how I mounted it on five RVs. All work perfectly.

Carl
 
Outboard. But just outboard of the bell crank bay rib. You want to be able to reach in to make the electrial and pitot/AOA connections. I put a #6 nutplate on each end of the pitot heat control box and mounted it in the same bay as the pitot, the two mounting screws going from the inside of the bell crank bay through that rib so that the box is on the other side of the rib from the bell crank.

This is how I mounted it on five RVs. All work perfectly.

Carl

Thanks Carl. I will sleep better knowing this. Really!
 
Bend the pitot and AOA tubes or Cut?

The aluminum pitot and AOA tubes coming out of the probe are within 1" and 1.5" from the top skin. If I connect the poly to them in this position the poly will kink.

Two options as I see them:

1. Cut the aluminum tubes so a straight fitting from poly to aluminum does not kink the poly.

or,

2. Bend the aluminum tubes to be parallel to the main spar so the poly goes on straight also avoiding a kink.

Problem with No. 2 is that probe can not be removed for maintenance and repair if necessary. I think.

What have others done?

Thanks,

Scott
 
2. Bend the aluminum tubes to be parallel to the main spar so the poly goes on straight also avoiding a kink.

Problem with No. 2 is that probe can not be removed for maintenance and repair if necessary. I think.

Here is a pic of what I did (it's a Garmin, but same idea I would imagine) - you can still thread the aluminum tubes through the Dynon (or Gretz) mast. These aren't the final bend positions, but they are close.

_Alex
 

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Here is a pic of what I did (it's a Garmin, but same idea I would imagine) - you can still thread the aluminum tubes through the Dynon (or Gretz) mast. These aren't the final bend positions, but they are close.

_Alex

If you stagger the pitot and AOA connection fittings it is easier to get it in and out of the mast.

Carl
 
I ran the Pitot Tube in between the 2nd and 3rd inspection panels with a small bend forward and 90 at the top. I did not trim the aluminum tube because the full length is needed on a heated tube per installation instructions. No problems routing through the gretz pitot mast. This keeps the tubes above and clear the pushrod as well. One of the main considerations for this location was making sure tie downs had no chance of damaging the mast. Your tie down ropes will always be out at quite an outward angle when travelling around the country.
 
I mounted my Dynon AND the generic heated tube off a Mooney on the bellcrank inspection panels themselves on both the Rocket and the RV-8. In both cases, the airplanes were first flown in the "as specified" location outboard of the inspection panel. I also shortened the mast up a bit. Airspeed and AoA remains accurate after the relocation.
 
I ran the Pitot Tube in between the 2nd and 3rd inspection panels with a small bend forward and 90 at the top. I did not trim the aluminum tube because the full length is needed on a heated tube per installation instructions. No problems routing through the gretz pitot mast. This keeps the tubes above and clear the pushrod as well. One of the main considerations for this location was making sure tie downs had no chance of damaging the mast. Your tie down ropes will always be out at quite an outward angle when travelling around the country.

Probably the most convincing reason to locate the mast inboard from the tiedown. Thats where Vans has it in the plans for the 14.
 
You can mount the controller to the top of the inspection panel.

This is what I recently did while retrofitting my -6A with one. I put a molex on the wires that connect to the power/ground/signal so the panel/controller could be completely disconnected from the airplane in one piece.
 
Also did not want it near tie downs. I twisted the power lines to help prevent emi. Bracket secures in place so no chance of contacting pushrod.
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Here is a pic of what I did (it's a Garmin, but same idea I would imagine) - you can still thread the aluminum tubes through the Dynon (or Gretz) mast. These aren't the final bend positions, but they are close.

_Alex

do you have a picture with the aileron push rod in place? Wondering how you cleared the push rod with this set up.
 
I've got the Garmin pitot, but that doesn't matter. I spent a while thinking about this and this is what I came up with. The pitot tubes have an AN to push fitting on them followed by a short air line then a 90 degree push fitting. Allows me to remove the pitot with everything in place. The 90 degree AN to push fittings won't fit through the mast (or at least they wouldn't when the AoA and Pitot are the same length) and this allows me to connect the air lines without needing to get everything tightened through the one small access panel.
 

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I've got the Garmin pitot, but that doesn't matter. I spent a while thinking about this and this is what I came up with. The pitot tubes have an AN to push fitting on them followed by a short air line then a 90 degree push fitting. Allows me to remove the pitot with everything in place. The 90 degree AN to push fittings won't fit through the mast (or at least they wouldn't when the AoA and Pitot are the same length) and this allows me to connect the air lines without needing to get everything tightened through the one small access panel.

I have a similar setup except my AN to push fitting is an AN to NPT elbow followed by an NPT to push fitting. As you say this is fiddly through the access panel. its doable but hopefully it’s rare.
One thing I have discussed with a friend locally is an elbow 1/4 to 3/16 push fitting. I know you can get straight 1/4-3/16 but has anyone know of an elbow version?
 
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