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Stall warning kit in the wing

Bavafa

Well Known Member
Just wondering how many people are installing the stall warning kit that comes with their 14 kit if they are planning on installing AOA? This is one of those redundant part which I am debating to install it or just suffice with the AOA that comes with G3x system
 
When I ordered my qb wings I asked to delete the stall warn parts and Van's told me this is flight critical and cannot be omitted. I'm still going to omit this and use AOA.
 
Since the AOA systems usually need in-flight calibration, you might consider installing the factory stall warning system for the first flight(s); remove it later if you wish.
 
I have AOA (Garmin) but opted to keep the Vans stall warn (it was in the wing kit). My reasoning was that since the hole was already cut in the leading edge skin, filling it in would likely look worse than having the stall vane - connected or not.

I then opted to connect the stall indicator to the Garmin GAD 27 on a discrete input. The GAD 27 is set up to activate the Master Alarm (red light) in the crew alert system (CAS) in the G3X. Originally I also had an audio alert in the G3X but I have since turned that off (simple software setting) and if I want, I can deactivate the red light by just changing a setting in the GAD 27 (or G3X).

I have the AOA calibrated and I find the stall warn (Vans) goes off well before reaching critical AOA.
 
I have AOA (Garmin) but opted to keep the Vans stall warn (it was in the wing kit). My reasoning was that since the hole was already cut in the leading edge skin, filling it in would likely look worse than having the stall vane - connected or not.

I then opted to connect the stall indicator to the Garmin GAD 27 on a discrete input. The GAD 27 is set up to activate the Master Alarm (red light) in the crew alert system (CAS) in the G3X. Originally I also had an audio alert in the G3X but I have since turned that off (simple software setting) and if I want, I can deactivate the red light by just changing a setting in the GAD 27 (or G3X).

I have the AOA calibrated and I find the stall warn (Vans) goes off well before reaching critical AOA.

I think this is a good plan that I might go with. My kit has only two small hole in the leading edge as a template that I need to use to cut the slot for the vane. I just don't like the vane tab sticking out and removing it later is not good option for me since I will have a slot in the leading edge open.

some times having too many options is not a good thing :eek:
 
I will not use it and filled the holes with rivets. You will probably not be able to tell that they are there after scuffing/priming/painting :)

I put a bid of glass on the inside over the holes, the holes themselves had some micro before the glass. After set up sand the mico flush with the skin and paint.

Carl
 
Does anyone know if they can be calibrated for accuracy?

If by they you mean the vane type stall warning?
Yes, they can.

The way they work is that the switch trips when the stagnation point on the leading edge of the wing switches from hitting the leading edge at a point above the vane to hitting a point just below the vane.
Or in simpler terms, when the relative wind transitions through the point where the relative wind switches between hitting the top side of the vane (and holding it in the down position) at a particular angle of attack, to hitting the bottom side of the vane and causing it to lift.
So if you adjust the bend angle of the vane, the switch will occur at a different angle of attack.

If you need the warning to come on at a slower speed (higher angle of attack), you need to bend the vane downward.
If you need the warning to come on at a higher speed, you need to bend the vane upward.

In most airplanes, it should actually be referred to as a pre-stall warning. There is no point in warning you that you are stalled.... you probably would already know at that point.
The typical setting is for it to activate at 5 - 7 kts above stall AOA.
 
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I initially put rivets in the holes but decided to go ahead and install the warning vane. Reasons are redundancy, habit (everything I've flown before has this type stall warning), and option of wiring it to a visual alert that is separate from the audible/visual alert that will be part of my G3X system.

I've never had an issue with the vane either aesthetically or from an ergonomics perspective.

Plus it was one of the "Fun" parts of the build....
 
Why?

Those of you who are omitting the stall warning kit from your build: Why? What benefits are you getting from making that change?

I understand that you may have AOA sensing, but having an independently redundant indicator to warn you of incipient stall would seem to be a benefit.

I am not criticizing but trying to understand the decision-making process.
 
I'm building a -3B instead of a -14, and in my kit, there isn't a stall warning system. So I bought one and installed it.

The reason is pretty simple - I've done most of my flying in Cessnas and am well-trained to the stall warning horn. I wanted to maintain the same cues.

The stall warning vane is, after all, a single-point AOA.

Dave
 
Those of you who are omitting the stall warning kit from your build: Why? What benefits are you getting from making that change?

I understand that you may have AOA sensing, but having an independently redundant indicator to warn you of incipient stall would seem to be a benefit.

I am not criticizing but trying to understand the decision-making process.

Good question. My thoughts:
- The first RV-8A had no stall warning or AOA indication. I found the plane talked to me well to let me know when I was approaching a stall. Shoot fire - the first time a flight instructor asked for a power on stall during a BFR, his eyes popped when he saw the plane pointing to blue sky, hanging on the prop. He never asked again.
- The RV-10 has the Dynon SkyView with AOA pitot. The AOA warning is wired into the audio panel (audio is, for me, far more useful than the visual AOA indication). This is very helpful for achieving repeatable results on various landing scenarios. It is also helpful when I?m flying in the right seat and the new RV pilot gets the audio feedback instead of me prompting him. I did not install the Van?s vain stall warning as it, to me, was more a pants catcher than useful for flight.

So to your question of need for redundant stall warning. There is so much feedback on our RVs that I do not see a need. But as will all such things this is your plane, build it like you want.

Carl
 
Those of you who are omitting the stall warning kit from your build: Why? What benefits are you getting from making that change?

I understand that you may have AOA sensing, but having an independently redundant indicator to warn you of incipient stall would seem to be a benefit.

I am not criticizing but trying to understand the decision-making process.

Great question. I my last plane had the Dynon Skyview and AOA and I really liked flying with that visual queue especially in steeper turns down low. I found that the arrows became yellow well before any audible indication. I guess I would ask..Why would someone not add the AOA if all they have is the traditional stall warning? :)
 
redundancy

I installed mine per the plans, sans the electronics. I connected the switch directly to a sonolert type beeper. I can still hear it while I am wearing my headset. I consider it to be only a backup system to my Garmin AOA though. I think is it nice to have redundancy, but the downside is that you can catch the tab when walking by.
 
I'm building a -7, on the wings right now. So please pardon a -7 guy barging in on y'alls -14 forum :)

I tossed this same question around a few times myself. Van's shipped the warner kit by default, so there was no "monetary" influencing factors. I ended up deciding I would go ahead and install the stall warner, in addition to doing AOA eventually in my panel.

My reason:
Redundancy. The stall warner is a very simple, but very effective little system. It's pretty robust.

Second, think of it like this. AOA is like the gas gauge in your car. It tells you how much "lift" is remaining on your wings (sort-of). Unless you EFIS supports it, it doesn't explicitly WARN you on an impending stall. Its sole purpose is to indicate how much AOA you have.

Now, the stall warner is just like the "low fuel" warning light in your car. Its SOLE purpose is to EXPLICITLY warn you that you are running out of fuel. Same for the stall warner, its sole purpose is to EXPLICITLY indicate to you that you are very very near the point of a stall by a few knots.

It's only gonna cost me a couple hours of labor to install it, so I figured I might as well install it.
 
Those of you who are omitting the stall warning kit from your build: Why? What benefits are you getting from making that change?

I understand that you may have AOA sensing, but having an independently redundant indicator to warn you of incipient stall would seem to be a benefit.

I am not criticizing but trying to understand the decision-making process.

An AoA device is a stall warning indicator. I just don't feel the need for two stall warning indicators.

Every airplane I've ever flown that had a stall warner, had only one. Some of the planes I've flown had none.

One will do...
 
You said the magic word: redundant. It's low cost redundancy for one of the most critical safety features on the plane, and you'll spend less than an hour installing it.
 
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