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RV-12 AOA retrofit

jbario

I'm New Here
I purchased a previously built RV-12 and have decided to install the Van's Angle of Attack kit. On page 3, step 16 of the Notification 16-12-14 (Angle of Attack Installation), the instructions call for routing tubing from the ADAHRS along the same route as the aft pitot tube hose - then through the left side F-1215 seat rib snap bushings. Has anyone accomplished the routing through the F-1215? Any recap of how this was done would be appreciated.
 
AOA Upgrade

I purchased the Van's AOA kit last summer and installed it. I have slept since then so I don't remember all the details. I had the floor panels and the aft bulkhead out. I do remember having to drill some holes and I think Van's provide some 3/4 inch grommets to go in the holes. Van's provides very specific instructions for mounting the connector to the left wing. I ran the tubing from that connector under the pilot's seat, through the center tunnel and back behind the aft bulkhead and then routed it with the tubing for the pitot tube to the AHARS.

In the wing I ran the tubing through the j channel to where it connects to a rivet. I have a fiberglass wire guide (like a fishing pole with out the eyelets for line) that electricans use and I used it to help get the tubing from the wing edge to the location of the rivet.

The hardest part of the process was getting the mandrell out of the rivet. I could not pound it out like the instructions say. After calling Eric at Van's, he told me to cut it off and use a self-centering punch on it. One push and the broke it loose and I got it out then.

I was also installing ADS-B in and out at the time so I already had all the floor panels and aft bulkhead out when I ordered the AOA kit.

The instructions are good and help is a phone call away. Van's gives excellent phone help.
 
To be perfectly honest... I fly my legacy 12 and also a newer 12 with dual HDX and AOA. The chirping from the AOA is enough to drive you crazy. And when coupled with the stall warning on landing - kinda makes you want to get out and walk. If you set stab trim and power for a stabilized approach it is very easy to monitor IAS. Approach should be stabilized for IAS, power, stab trim, and be on runway centerline as you turn from base to final.

Just my opinion - don't shoot me...
 
To be perfectly honest... I fly my legacy 12 and also a newer 12 with dual HDX and AOA. The chirping from the AOA is enough to drive you crazy. And when coupled with the stall warning on landing - kinda makes you want to get out and walk. If you set stab trim and power for a stabilized approach it is very easy to monitor IAS. Approach should be stabilized for IAS, power, stab trim, and be on runway centerline as you turn from base to final.

Just my opinion - don't shoot me...
Hmm. I set up AoA on mine, using methods posted here well before Van's made their retrofit kit available. It's an older RV-12 with a D180 panel. After calibration it's pretty nice. I disconnected the stall warning entirely. The AoA was useless until after I calibrated it, which was fairly simple. Maybe yours isn't well calibrated? You can also adjust the volume. I actually need to bump mine up a little, it's not quite loud enough. I hear it fine, because I'm listening for it, but it's not loud enough to really grab your attention.
 
...And when coupled with the stall warning on landing - kinda makes you want to get out and walk.

Jim, I?m with you, and that is why I?ll be omitting the standard stall warning on mine, AoA is a much better system as is widely acknowledged. Of course adjust the audio volume so that you are aware of it but not overwhelmed or too annoyed by it.

I think the real value of any sort of stall warning is not in standard straight ahead landings, but rather in warning of an impending accelerated stall in non-routine situations where you might not expect it.
 
Both wings?

I just got my AOA Retrofit kit. Instructions say to remove both wings. I have removed both for the condition inspection, but is it necessary to remove both if you remove one - like for balance or something? Naive of me, I know, but...
 
Wing removal

I just got my AOA Retrofit kit. Instructions say to remove both wings. I have removed both for the condition inspection, but is it necessary to remove both if you remove one - like for balance or something? Naive of me, I know, but...

Not with you here. Every time you remove the wings there is always one left on. I?ve had no problems with only one wing on.
 
Not with you here. Every time you remove the wings there is always one left on. I?ve had no problems with only one wing on.

My apologies for a dumb question. After posting it, I discovered that one cannot get access to the area where one needs to do some work for the AOA kit without removing both wings. I did not know that when I asked the question. Instead, I assumed the reason to remove both was for some other reason, like balance.
 
That was the reason I waited to install mine until annual.

As a previous poster mentioned it?s a very good system. You have the visual reference and if you setup according to the manual from Garmin (I?m running G3Xs) I only ever hear a tone when I would expect to (high AOA in the landing flare). The visual bar system is excellent, this is a great tool.
 
AOA Retrofit Kit O-ring

I don't think my Kit from Van's included the O-Ring that slides over the aluminum connector tube. It is said to have 1/4" ID, so that's a start for finding one locally. Anyone know the actual size of the one Van's includes?
 
You can get a box of various sizes pretty cheap at Harbor Freight.

Hmmm... I know that the ID is 1/4", but I do no know what the cross section is, nor the material, both of which I want to get right the first time. If I guess wrong, it involves pulling a wings and try a different one.
 
Found out from Van's, in case anyone else loses their little O-ring :D:D;)

Bunan Nitrile Rubber 3/8 O.D. 1/4 I.D. That means 1/16 cross section width, or thickness.
 
OK, sorry for being so ignorant, but...

Has anyone discovered they have a leak during the leak-down test that requires a syringe and modeling clay and a second person to do?
 
OK, sorry for being so ignorant, but...

Has anyone discovered they have a leak during the leak-down test that requires a syringe and modeling clay and a second person to do?

Leak test can be done solo if you have a hose long enough to reach near the cockpit.
 
OK, sorry for being so ignorant, but...

Has anyone discovered they have a leak during the leak-down test that requires a syringe and modeling clay and a second person to do?

Yes. Just so you know though, I had a **** of a time making the syringe/modeling clay thing work without the setup itself leaking. I opted to using a football inflation needle inserted into the rivet hole, with a small O ring super glued to the needle base. Then I sealed the needle to the wing skin with a small amount of RTV (emphasis on ?small? ) and don?t get any in the rivet hole. I let it cure overnight then conducted the test.

The system leaked down too quickly so went leak checking, starting with the ADHARS box. The first thing I did was remove and reinsert the AoA tube at the box. Luckily that was the source of the leak. The difference was dramatic. It was rock solid after reseating the tube.

One last thing, the syringes I used had a tendency to ?spring back? when applying pressure. I had to carefully hold the plungers steady during the test.

Hope this helps.
 
Yes. Just so you know though, I had a **** of a time making the syringe/modeling clay thing work without the setup itself leaking. I opted to using a football inflation needle inserted into the rivet hole, with a small O ring super glued to the needle base. Then I sealed the needle to the wing skin with a small amount of RTV (emphasis on ?small? ) and don?t get any in the rivet hole. I let it cure overnight then conducted the test.

The system leaked down too quickly so went leak checking, starting with the ADHARS box. The first thing I did was remove and reinsert the AoA tube at the box. Luckily that was the source of the leak. The difference was dramatic. It was rock solid after reseating the tube.

One last thing, the syringes I used had a tendency to ?spring back? when applying pressure. I had to carefully hold the plungers steady during the test.

Hope this helps.

Yes, that helps a lot. Thank you!
 
One last question (I hope)

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As shown in the image with labels, the depth of insertion after installing the wing with both pins engaged shows that the aluminum tube must be too long since the distance from the fuselage end of the tube to the O-ring is too far. As shown by another image, the length of the tube matches that prescribed by the template. The other image shows the depth of insertion when I shove the tube into the wing receiver. It is identical to the depth shown after wing installation. The instructions state that I should remove 1/32 ths of an inch from the length, but it looks to me like I need to remove a lot more than that.

Of note, the leak test is fine, and the wing is fully engaged by the pins in the fuselage.

So, I assume I need to remove enough of the length of the tube to match the gauge. That appears to be more like a 1/4" . Am I missing something?
 
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I ended up cutting off about 1/4" of the aluminum tube. I have not calibrated my AOA yet or checked it for leaks.
 
Once I cut the tube short enough to match the depth gauge, it was too short and it no longer engages the fuselage push-to-connect fitting fully, and leaks. Making a new tube and going to ignore the gauge.
 
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