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Stall warning. In or Out?

jcbarker

Well Known Member
Just started the QB assy instructions. One of the first things is build and install the stall warning system. Hmm. Got me to thinking. Do I really need that? I didn't have one in my -8. Used AOA. I quickly discovered that I never looked at my airspeed indicator once I was below flap speed in the pattern.
Any other thoughts on this?
 
Dont

Don’t install it; it isn’t necessary, especially with aoa. In the first time you walk into that stall vane, you’ll wish you hadn’t installed it!
 
On the other hand I like mine. If I end up a bit high and slow it gently reminds me..... And when doing slow maneuvers at altitude same thing.... I did wire it into the G3X and didn't have a separate board or system for it.
 
On the other hand I like mine. If I end up a bit high and slow it gently reminds me..... And when doing slow maneuvers at altitude same thing.... I did wire it into the G3X and didn't have a separate board or system for it.

Just curious - do you have the AoA on the G3X installed and calibrated (and audio connected)?

I don’t have stall warning vanes on any of my planes because I have AoA (with audio) - which is far better than a discrete “you’re about to stall” because it shows (and tells) you where you are in the AoA regime.

Paul
 
I agree, you don’t need the stall vane once your aoa is working and calibrated. I installed it anyway, just in case I had first flight(s) difficulties before the aoa was calibrated.
But also, I ‘trust but verify’ - I would never deliberately make a landing approach without checking the airspeed indicator as well as the aoa.
 
I don't hear audio from the AOA, but it is calibrated. I hear other G3X alerts. Maybe I'm missing out!
 
AOA

For me AOA with audio is the best VFR avionic tool I have. Being able to hear when you start to encroach on a stall is priceless. Trying to watch AOA I think would be distracting but then again I have never done this. If I don't hear a light beep on touch-down I know I was to fast. I also compare AOA to TAS and can tell exactly what my touchdown airspeed was. I know hours is not an indication of potential wear on our tires but at this point I would bet I will get well over 600 hours on a set of tires. Having the lowest controllable airspeed when landing I think a part of the equation. I have also found that if you smell rubber on touchdown, you were probably going too fast. AOA is also a great teaching aid for optimum landing speeds.

And no I did not install the stall warning vane. (Vans also will not let you delete this, if you've bent yours let me know, I have spares). :)
 

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Decision made

Thank you all for your input. I'm going with AOA only. I'm going to plug those holes with a couple of AN426AD3-3 rivets and move on.
 
We installed it, and the reason was that the early test flights wont have the AoA calibrated. That stall warner tho... she just works.
 
I agree, you don’t need the stall vane once your aoa is working and calibrated. I installed it anyway, just in case I had first flight(s) difficulties before the aoa was calibrated.

My stall warning tab was built per plans, but on first flight it was going on at ~70 knots, way above the -7A stall speed. Was quite an annoyance on the first flight when I was trying to concentrate on final. If I did it over again, I'd have disabled it for the first couple of flights until I was confident in my landings and then turned it on and bent it correctly. I like the stall warning tab because it makes a sound. My eyes are outside when I'm landing.

I don't hear audio from the AOA, but it is calibrated. I hear other G3X alerts. Maybe I'm missing out!

Wait, it's supposed to make a sound? Interesting. Mine doesn't play any sound either. I suppose that would make the AOA much more useful! Time to figure this one out.
 
I have the aoa pitot tube and did not install the vans stall warning. Not going to worry about it.
 
Understanding AOA

My stall warning tab was built per plans, but on first flight it was going on at ~70 knots, way above the -7A stall speed. Was quite an annoyance on the first flight when I was trying to concentrate on final. If I did it over again, I'd have disabled it for the first couple of flights until I was confident in my landings and then turned it on and bent it correctly. I like the stall warning tab because it makes a sound. My eyes are outside when I'm landing.



Wait, it's supposed to make a sound? Interesting. Mine doesn't play any sound either. I suppose that would make the AOA much more useful! Time to figure this one out.

Hopefully someone will help me out but during the calibration process you should hear tones. The faster the tones the greater the AOA. The output seems to be between -0.5 and 1.0 with -0.5 zero chance of a stall and 1.0 you are in a full stall. During landing I get semi rapid sounds and the output is around 0.7. Take-off is a little slower if done with a mild pull. The tones are the key. I have not done a deep dive into the engineering (Read the 987 page manual) but I feel it's important to understand this. There have been times turn to final when I hear very slow beep and after a gentle push goes away. Hopefully I am interpreting this correctly.
 

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I delivered a -7 with a stall warning.. it would blare from short final though roll out into taxi speed.. it was really annoying.
 
flying AOA

Again, thanks for the input/thoughts on the Van's stall warning system. The consensus is clearly "don't install" if your aircraft has an AOA system. RV's are very good at telegraphing imminent stall so I'm not worried about not having it for first flights.
For those wanting to know how to fly AOA and what it is supposed to sound like, watch Paul Dye's YouTube video.
https://www.youtube.com/watch?v=zKSivx7HT98&t=549s
 
Wiring Van's stall warner

I'm currently wiring the stall warner in my RV9A. What do most people connect the signal out to from the PCB board?
I don't have any glass in the cockpit. Should I use an external speaker, or can I connect it into my Garmin GTR 200 auxiliary input? Maybe an indicator light?

Thanks!
 
I'd definitely suggest using a system with an audible alert. One scenario is the traffic pattern is busy, tower is calling out traffic while extending your downwind, the pax is verbally trying to help with useless info, and you end up having little bandwith for flying the plane.

Of course it's a low probability scenario but it can sneak up on you. I always enjoyed saturating my students with data while low and slow.
 
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