AOA Probe Length

[fpullanojr]

I'm trying to find a way to install the AOA prope in the airplane. This is a LongEz type airplane so it parks on its nose.

The AOA probe is far too long to mount it in the nose where the current pitot probe is.

My questions are these. Can I cut the AOA probe down to about half of its length? Does the thing really need to be 18 inches long to function properly?

 

[skysailor]

Frank,

I have been looking at Long EZ's and I think you can easily put the standard L shaped Dynon pitot tube on the plane. You could mount it on the wing easily if removed. Rutan did not put it there since the nose was just sitting there in clear air and it was a convenient place to mount. The length of the straight tube is designed to get it out into undisturbed air and I suspect most are wing mounted. Extending forward from the wing requires more distance to assure undisturbed air than going below the wing the 6" the L shaped probe does to get to the laminar flow around the wing. You may also consider sticking with the straight probe you have and simply not extend it the 18" length of the probe. You could mount it such that much less extends from the nose (say 4") and give it a try. I think you may find that it would work. In the absence of that, the other way you could go is to put the standard L shaped probe on the bottom of the fuselage. You might have enough room forward of the nose gear and still have room when the gear is retracted for parking but you might have to look at slightly increasing the height of the nose bumper.

 

[dynonsupport]

You can cut down the boom AoA carefully if you want to. It doesn't need to be any longer than any other AoA probe, and the nose is a great location for it. I would try and leave an inch or two just to keep it out of the boundary layer.

Don't just chop through it, since the tubes obviously run inside. Cut the circumference carefully and you can slide off the back of the main tube you cut off.

Obviously, once you do this, we can't warranty the part at all, but it should work fine.

 

[stede52]

I assume that if the AOA is not being used, the AOA port on the ADAHRS should be plugged, is this correct? I don't see anything the manual confirming this.

Steve

 

[pbennett]

I've left the red plastic plug in place in the AoA port, on the reasoning that it keeps dirt out but the pinhole in it permits pressure equalisation. I would not seal the port completely.

Peter

 

[stede52]

Crap, now I need to find that plug with the pinhole. I thought I could get away with just plugging it up

Steve

 

[dynonsupport]

Doesn't really matter any way you do it. A lot of people leave the red plug in for debris blockage, which isn't a bad idea.

 

[stede52]

Is it important that you have a plug with a hole in it?

Steve

 

[dynonsupport]

Not really.

 

[stede52]

thanks

Steve