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Dynon AoA Settings

AOA Audio Setup

Go to SETUP MENU > SYSTEM SETUP > AUDIO SETUP to configure audio output settings. Most of the items in this menu control whether the audio output for a particular alert or alert category is played or not. The settings that can be adjusted here that are not voice alert toggles are:

o In this menu only, audio is only outputted from the actual display that is in the setup menu.

? ANGLE OF ATTACK ? This sets a pulsing, progressive tone that increases in frequency, similar in nature to a conventional reed type aircraft stall warning sound to a reed-type stall warning sound, although it is much more predictable in its progression. It can be set to start its pulsing tones at either the border of the yellow/green marks on the AOA bars, the middle of the yellow, or the yellow/red border. The pulsing tones start at the level selected and get progressively quicker and closer together until a solid tone is played at critical AOA (in the red.)

o INHIBIT AOA BELOW AIRSPEED ? Allows you to set an airspeed below which no AOA tones are played. This helps prevent nuisance alarms while on the ground and taxiing, especially in tail draggers.
 
Got it, thanks. I noticed the AoA setting was in % and did not read the the fine print below that defined % in terms of the bar color range.
 
Dynon AOA

Where is ONSPEED with Dynon AOA?

I calibrated my Dynon HDX AOA and expected to hear a steady tone around the ONSPEED speed which I thought would be around 70 kts with beeping tones before and after. Not happening and generating questions:

1) What is the approximate ONSPEED speed of a RV-7A?
2) Where on the AOA spectrum of green, yellow, red is ONSPEED?
3) Where on the AOA spectrum of green, yellow, red is stall?
4) How is it suppose to work?
5) Is AOA 's primary purpose to warn of stall?
6) Or is AOA's primary purpose to give you an audio tone at ONSPEED so you can fly it without looking down at the indicator?
7) Is AOA trying to get me to fly a speed? or a pitch?

thanks
 
HDX AOA settings

Go to SETUP MENU > SYSTEM SETUP > AUDIO SETUP to configure audio output settings. Most of the items in this menu control whether the audio output for a particular alert or alert category is played or not. The settings that can be adjusted here that are not voice alert toggles are:

o In this menu only, audio is only outputted from the actual display that is in the setup menu.

? ANGLE OF ATTACK ? This sets a pulsing, progressive tone that increases in frequency, similar in nature to a conventional reed type aircraft stall warning sound to a reed-type stall warning sound, although it is much more predictable in its progression. It can be set to start its pulsing tones at either the border of the yellow/green marks on the AOA bars, the middle of the yellow, or the yellow/red border. The pulsing tones start at the level selected and get progressively quicker and closer together until a solid tone is played at critical AOA (in the red.)

o INHIBIT AOA BELOW AIRSPEED ? Allows you to set an airspeed below which no AOA tones are played. This helps prevent nuisance alarms while on the ground and taxiing, especially in tail draggers.

Fine but what percentages do you set in order to get the AOA tones using Dynon HDX to come on in yellow thru red? I'm hearing tones only at about stall speed 50 kts in RV-7A.
 
I set mine at the widest range possible and was still not happy with the onset of tones. While working with VAC, I re-did the calibration and set it at 3 knots above actual stall speed. It now works as I expect and with the beeps starting around 55 knots dirty. Many others have done the same.
 
Dynon AOA

I set mine at the widest range possible and was still not happy with the onset of tones. While working with VAC, I re-did the calibration and set it at 3 knots above actual stall speed. It now works as I expect and with the beeps starting around 55 knots dirty. Many others have done the same.

Ray
Thanks for the update and call. So I see, in summary Dynon AOA warns of impending stall, but doesn't do ONSPEED. Okay. thanks I will recalibrate slightly above stall. thanks much
 
Mine starts beeping just before 1.3Vs. So when you hear the first beep it is about the same as ONSPEED.

Besides the Skyview menu you can also change values in the USER_CONFIG.dfg file. Look for "aoa" and change values, e.g.;

audio_aoa_vol=70
audio_aoa_ias_min=10.2889
audio_sound_aoa_v15=1
audio_sound_aoa_start_thld=62
audio_sound_aoa_solid_thld=95

ONSPEED is at 60% lift. With my config the beep starts at 62%
 
You guys must be flying business jets?

My early S/N 12 has D-180 with stall warning. I pull two notches of flap, set min power, and trim stabilator for hands-off (literally) glide slope at 60 knots. I bleed speed down to 55 over the fence and remain in ground effect until almost a full-stall landing with just a peep from the stall warning.
 
Jim, the D-180 has the AOA feature. DOWNLOAD the instructions from Van's. The only thing that you need from the instructions is where to drill the hole in the wing for the AOA port. That port is just a rivet which is the same as those used for the static ports. Connect tubing from the rivet to the D-180. A quick connect fitting at the wing root is optional. I ran the tubing along the inside of the fuselage where it is out of sight.
- The wings can stall at any airspeed when in a turn. But they will always stall at the same angle of attack for a specific flap setting.
 
The wings can stall at any airspeed when in a turn. But they will always stall at the same angle of attack for a specific flap setting.

Thanks Joe... I think I'll stay with nice quiet solitude and just continue to remain vigilant for airspeed / bank angle. Shallow bank (always) for the base-to-final turn with constant attention to airspeed.
 
Jim,

I switched to AOA a couple years back. It's really nice to have, especially to build more awareness of one's AOA during more "sporting" flying. I don't miss the old vane-switch stall warning one bit. That said... if you're happy with it, great!
 
So, when you install AOA you removed the stall warning vane?

My friend's one-year old Synergy RV-12 with dual Dynon HDX has both stall warning and AOA. Lots of sirens as you slow for landing...
 
No, the stall warning is not removed. Keep both AOA and stall vane. The AOA audio starts ticking as stall is approached, kind of like Morse Code. As the AOA increases, so does the length of the audio tones, from ticks, to dits, to dahs, and to a solid tone at stall. After flying with AOA for awhile, you will wonder how you ever got along without it. One time I made a steep turn from downwind to base and the AOA stated ticking, even though the airspeed was well above normal stall speed. So I relaxed back pressure on the stick.
 
I big safety benefit of AOA is in situations that are not normal flight operations.... such as a forced landing after an engine failure.
It can be a high stress situation.... possibly with some last minute maneuvering at low airspeed. AOA could prevent an inadvertent stall.
 
So, when you install AOA you removed the stall warning vane?
I did not remove it, but I did disconnect it. Figured I may want it again some day. After the thing tore a hole in another pair of jeans, I think during the next CI we'll remove the vane.
 
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