AOA How to fly Dynon’s AOA system on HDX Skyview.

[sglynn55]

Please could an expert explain how I’m suppose to use Dynon’s AOA system with Skyview. I’ve calibrated and I’m thinking it is merely a stall indicator. Is that Right? How can I use it to fly L/D max? I’ve messed around with calibrating it at different speeds. I’ve tried various settings on the sound. But what I think I’m hearing is beeping that increases in speed frequency until it goes solid when I’m about to stall? I have not figured out how to fly a constant speed on final based on AOA indications. I’m using air speed. So can Dynon’s AOA system help me fly “on-speed?”

Thanks

 

[XPRSAV8R]

Stalls occur at the critical angle of attack, and there is a speed associated with every angle of attack in a specific configuration. An AoA system is used for situational awareness and to monitor the onset of a stall. With that in mind, stalls should occur where the yellow chevrons meet the red chevrons. On the approach, this would likely happen during a base to final turn or the landing flare. Your goal is similar except you're trying to stay in the green chevrons (negative angle of attack). Each green chevron should equate to some airspeed number, but won't be exact. You could engage your autopilot and watch the AoA indicator as you pitch for speed. Regardless, it'd be hard to count the chevrons (AoA) vs. monitoring a numeric value (airspeed) on the approach.

 

[sglynn55]

Thanks for the explanation, but it appears to confirm the AOA is for stall warning, not for maintaining on-speed. If anyone knows how to use AOA with audible tone to locate and fly on-speed, please share the secret. thanks

 

[Raymo]

You'll want to contact Michael Vaccaro (aka VAC) on the VansAirforce forum. He and others developed an on-speed for L/D max box that connects to an available Dynon serial port. He also has a couple YouTube videos that show how it works.

I wouldn't call the Dynon AOA a simple stall warning device as those only indicate accurate stall at max gross weight and 1 G. AOA indicators work at any weight and G-load.

 

[sglynn55]

Yes, I've studied VAC's solution but it is to complex for me to implement. I was hoping there are mere settings that could be configured in Dynon Skyview. Maybe Dynon will add "on-speed" to their OAO in a future release.

You'll want to contact Michael Vaccaro (aka VAC) on the VansAirforce forum. He and others developed an on-speed for L/D max box that connects to an available Dynon serial port. He also has a couple YouTube videos that show how it works.

I wouldn't call the Dynon AOA a simple stall warning device as those only indicate accurate stall at max gross weight and 1 G. AOA indicators work at any weight and G-load.

 

[XPRSAV8R]

Yes, I've studied VAC's solution but it is to complex for me to implement. I was hoping there are mere settings that could be configured in Dynon Skyview. Maybe Dynon will add "on-speed" to their OAO in a future release.

I take it your concern is maintaining an airspeed on final which "prevents" stalling.

Something I forgot to mention earlier is that the wing stalls at the same AoA independent of weight, density altitude, loading, bank angle, airplane configuration and more. Aircraft manufacturers offer "approach speed" (or your desire for "on-speed") based on MGW as a proxy for AoA. This works for "winds calm" or "light and variable" days, and this may work where you fly. The dangers to this in most environments are wind shear and wind gusting -- hence the "half wind gust factor on final" rule. AoA systems help with this ... advising you of nearing imminent stalls and reacting by pitching or adding power.

That said... What you've last asked for is available through Dynon's autopilot in advanced mode by commanding a descent based on IAS. Not intended or advised: relying on this leaves pilots complacent and disregarding stall factors previously identified. However, if you know your gross weight doesn't change much on the approach (weight of passengers, cargo, fuel, etc. on final) and you use the same plane, you may be able to approximate the airspeed where you may not reach the critical AoA.

 

[jnmeade]

Stalls occur at the critical angle of attack, and there is a speed associated with every angle of attack in a specific configuration. An AoA system is used for situational awareness and to monitor the onset of a stall. With that in mind, stalls should occur where the yellow chevrons meet the red chevrons. On the approach, this would likely happen during a base to final turn or the landing flare. Your goal is similar except you're trying to stay in the green chevrons (negative angle of attack). Each green chevron should equate to some airspeed number, but won't be exact. You could engage your autopilot and watch the AoA indicator as you pitch for speed. Regardless, it'd be hard to count the chevrons (AoA) vs. monitoring a numeric value (airspeed) on the approach.

I'm not familiar with the AOA on the SkyView system, but used it extensively on the D100. In the D100, the aircraft I used was calibrated per Dynon instructions and the result was to stall at the last remaining red chevron. I take it then that Dynon changed the calibration procedure so the airplane now stalls where the yellow chevron meets the red? I wonder why there is more than one red chevron, if the plane stalls at the first one?