AOA boom add on

barntt1

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Jun 17, 2011
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I have a flying plane and want to add AOA. Since I already have a working Pitot can I just add the boom and only plumb the AOA side? Or does both tubes need to be plumbed to get accurate AOA? Seems some are using two pitots plumbed together but is this necessary? I was just going to use adell clamps and offset clamping the boom to the strut bracing and run one hose! Thanks Bruce
 

skysailor

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Dynon Support will be along shortly to confirm but I believe the units compare the pressures between the AOA and pitot ports and as such both are necessary.
 

Dynon

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The AOA/pitot has two tubes - one is normal pitot, and the other is on a bottom beveled edge of the AOA/pitot and is tuned to be reponsive to AOA. Essentially, you do need to have both ports, and the AOA port design is very different from the pitot port design.
 

barntt1

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So I will need to remove the original pitot hose from the stock pitot and run both hoses from the Dynon boom mount. I was hoping to only run the one hose from the AOA tube and just use the original pitot hose. Ok Then AOA needs both hoses from the boom to get a accurate AOA
 

Dynon

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Oh, sorry. If you have a pitot line coming from somewhere else, and you use just the AOA side of the AOA/Pitot, that can work. It just depends on the existing pitot being in a well-suited location and not being too sensitive to AOA. Our Pitot port is designed with this goal in mind, but other people have used just the AOA side of our AOA/Pitot when the pitot is coming from another source with success.
 

dynonsupport

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Also, the closer they are to one another the more accurate you will be. If you put the pitot on one wing an AOA on the other, then you will have inaccuracy anytime you are not well coordinated.
 

barntt1

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That was what I was hoping. The Plan was to mount the AOA boom on the outside of the strut brace that goes between the front and rear strut which puts it within a few feet of the stock pitot and just run the third hose so this should work great. If it looks easy to do once I get the wing tip off just switch the pitot hose off the original pitot to the AOA but till I get to that point its up in the air so Thanks Bruce
 

jnmeade

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Any special considerations if I add an additional pitot AOA boom on the left wing of a Flight Design? I will run two independent 10" SkyView systems. Obviously, the two AOA systems will be about 20' apart. It would seem obvious that the two should read as close as possible. I assume each will drive the AOA on it's on EFIS and the one that hits the alarm threshhold first will sound the aural alarm. I assume that in a slip or skid, the wing that may be closer to stalling will reflect that in the difference in the readout and aural alarm.
If I decide to use an underwing AOA as opposed to the in-wing boom, does that introduce a different reading?
 

Dynon

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So the normal configuration on a Flight Design is to have two pitots, one on each wing. If this is an S-LSA, you really need to start with Flight Design before you make any modifications to the airplane.

Generally, in this configuration, you can have two ADAHRS, each with their own AOA/Pitot (or sharing one AOA/Pitot with the lines t'd off), and then you need to do the AOA calibration once you have everything installed and both ADARHS networked. The AOA indications should be virtually identical no matter which ADAHRS is active.
 

jnmeade

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Mine is an E-LSA so I don't need to talk to Flight Design at all. My plane came with one pitot/aoa boom on the right wing. I will have to either drill a hole into the leading edge of the left wing and mount the normal boom or use the under wing pitot/AOA boom. As I understand what you said, either source should give similar readings.
 

Dynon

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Most folks get http://www.aircraftspruce.com/catalog/inpages/gretzbrackets.php?clickkey=157605.

AN5812 is the name of the shape of the mast.
 

jnmeade

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This looks like the bent type that mounts under the wing. I was asking about the boom pitot tube that projects straightforward, as with the Flight Design planes.
 

Dynon

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Ah. There is no specifically designed socket for it, but the outer diameter of the aluminium pitot itself is 3/4".
 
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