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Dynon Skyview AOA calibration problem

KayS

Well Known Member
Hi All,

today was my third attempt to calibrate the skyview's AOA. i open the inflight setup and go to AOA. i do what Dynon tells me to do... cruise with 140 KTAS or so, pitch the aircraft several times up and down with around +-5°, stall that baby, recover, press STALL, repeat process with flaps and later push the SAVE button. but still no AOA indication. the bar stays emty with a question mark.

first possible root cause: the guys from the supplier did something wrong (never happened yet). second option: it's me.

could somebody give any hints? would be very appeciated. i also want that shiny AOA indication!

Best Regards
Kay
 
Kay

The calibration process for me was straightforward, so I too am guessing something mechanical is amiss.

When you say the "bar stays empty" you're referring to the AOA indication on the HDX? The question mark is a sure sign as well.

Talk to Dave Weber or Michael at Dynon, I'm sure they'll recognize the issue right away.

Good luck
 
Trying to throw out all possible ideas

Did you enable the Angle of Attack indication in the PFD SETUP Menu?

Dynon calls it is an ICON, not a bar, so just trying to figure it out.

If not, go to the PFD SETUP menu, the ANGLE OF ATTACK menu – Enter this page to enable/disable display of the Angle of Attack indicator, or ICON.

Then try the calibration again.

Brian
 
Did you enable the Angle of Attack indication in the PFD SETUP Menu?

Dynon calls it is an ICON, not a bar, so just trying to figure it out.

If not, go to the PFD SETUP menu, the ANGLE OF ATTACK menu – Enter this page to enable/disable display of the Angle of Attack indicator, or ICON.

Then try the calibration again.

Brian

I agree with Brian. Check to be sure the hardware is enabled.

You may also want to do the Zero Presure IAS/AOA Calibration first (but probably not the cause of your problem).

ZERO PRESSURE IAS/AOA CALIBRATION
This calibration routine samples Pitot, Static, and AOA pressures in a windless environment to allow SkyView to provide the best possible Indicated Airspeed (IAS) readings at very low airspeeds, and the best possible Angle of Attack (AOA). Ideally, perform this calibration before performing an (in-air) AOA calibration. After performing these two steps, in the future, performing a ZERO PRESSURE IAS/AOA CALIBRATION should restore both airspeed and AOA performance without requiring a full AOA calibration.

It is important that this calibration is done in an absolutely windless environment, such as a closed hangar. Additionally, before performing this calibration, cover the Pitot, Static, and AOA ports with a sock or cloth to minimize airflow WITHOUT putting any air pressure on the Pitot, Static, or AOA ports.
 
Hi All,

today was my third attempt to calibrate the skyview's AOA. i open the inflight setup and go to AOA. i do what Dynon tells me to do... cruise with 140 KTAS or so, pitch the aircraft several times up and down with around +-5°, stall that baby, recover, press STALL, repeat process with flaps and later push the SAVE button. but still no AOA indication. the bar stays emty with a question mark.

first possible root cause: the guys from the supplier did something wrong (never happened yet). second option: it's me.

could somebody give any hints? would be very appeciated. i also want that shiny AOA indication!

Best Regards
Kay

My D6 instructions are different……..after the +-5 deg pitch excursions, push the stall button. A 45 sec countdown timer starts. Stall and recover. Wait for timer to hit zero. Repeat. When all done push finish. Note: if countdown timer gets to zero before you have stalled, you need to start over.
 
thanks for the replies so far!

the AOA-tube is definatley connected to the ADAHRS.

i'm sure that angle of attack indicator is enabled in the PFD SETUP, otherwise the empty AOA indication would not appear on the screen. but i will check.

the zero pressure test was performed but i have to redo it anyway. i did the test prior first flight but later my skyview went south and i had to send it do dynon for repair. i got the skyview back in default configuration. good to be reminded that way.

if all fails i will give dynon a call.
 
Dynon AOA

Did the Dynon AOA procedure and evaluated the resultant AOA indications and tone - not impressed. Redid the calibration and did further evaluation at different weights and CG. Not only not impressed but didn't feel like trusting it in gusty turbulent conditions (like quite often occur at home airfield). Built and installed the "Onspeed AOA" system and very impressed (runs off the Dynon probe). Both the display and tone work well and reliably. I still have to fine tune the calibration (in work) but definitely worth the effort to build and install. Big problem is with getting electronic parts - like oil filters, they are really hard to source so for those contemplating building you may have to wait a while to get all the component parts.

KT
 
Did the Dynon AOA procedure and evaluated the resultant AOA indications and tone - not impressed. SNIP

This is exactly opposite of my experience with the SkyView AOA I’ve installed on RVs. Dirt simple to calibrate and consistory repeatable results during operation. On landing I get the steady tone at just the right point. Doing stalls I get almost to the steady tone when the first buffets start.

I never look at the AOA display, just listen to the tones. When I need the AOA most I’m looking out the window.

Carl
 
This is exactly opposite of my experience with the SkyView AOA I’ve installed on RVs. Dirt simple to calibrate and consistory repeatable results during operation. On landing I get the steady tone at just the right point. Doing stalls I get almost to the steady tone when the first buffets start.

I never look at the AOA display, just listen to the tones. When I need the AOA most I’m looking out the window.

Carl

I'm with Carl on this one, the Dynon AOA has worked remarkably well for me, and is something I listen for, never look for.
 
On speed

This is exactly opposite of my experience with the SkyView AOA I’ve installed on RVs. Dirt simple to calibrate and consistory repeatable results during operation. On landing I get the steady tone at just the right point. Doing stalls I get almost to the steady tone when the first buffets start.

I never look at the AOA display, just listen to the tones. When I need the AOA most I’m looking out the window.

Carl

My impression of the Dynon AOA is that it is pretty good as a progressive stall warning indicator but doesnt have AOA characteristics. OnSpeed condition for approach or maneuvering should occur at max L/D which is not where the first stall buffeting occurs (or shouldnt be). Try doing 2,3 and 4 g turns and pull ups at different aircraft weights,altitudes and speeds through stall and see what results you get- you might be surprised. The benefit of a reliably accurate AOA system in a departure turnback maneuver is in providing a consistent dynamic stall margin indication under high workload stressful conditions. Most of us with a few thousand hours under our belts can manage a standard approach to landing even without a reliable airspeed indication or stall warning indicator but turnback at low altitude with power failure is a totally different story. An added benefit of an accurate AOA system is the indication of Carson speed flight conditions for best range (especially with the price of gas these days). As an aside- stall in my RV-7A occurs all at once - no buffet or warning and at higher g levels, quite suddenly with a lot of roll off. Not usually survivable when performed below pattern altitude in an RV as a number of accident reports would indicate. In my view having an accurate reliable AOA system in an RV is essential kit. I do agree - the two frequency tone with solid Onspeed tone is all that is needed.


KT
 
I'm with Carl on this one, the Dynon AOA has worked remarkably well for me, and is something I listen for, never look for.

+2. Whenever someone has trouble with anything related to pitot static, first thing I ask is, ‘Did you use the Vans hollow rivet for the static port, or something else?’
 
My impression of the Dynon AOA is that it is pretty good as a progressive stall warning indicator but doesnt have AOA characteristics. OnSpeed condition for approach or maneuvering should occur at max L/D which is not where the first stall buffeting occurs (or shouldnt be). Try doing 2,3 and 4 g turns and pull ups at different aircraft weights,altitudes and speeds through stall and see what results you get- you might be surprised. The benefit of a reliably accurate AOA system in a departure turnback maneuver is in providing a consistent dynamic stall margin indication under high workload stressful conditions. Most of us with a few thousand hours under our belts can manage a standard approach to landing even without a reliable airspeed indication or stall warning indicator but turnback at low altitude with power failure is a totally different story. An added benefit of an accurate AOA system is the indication of Carson speed flight conditions for best range (especially with the price of gas these days). As an aside- stall in my RV-7A occurs all at once - no buffet or warning and at higher g levels, quite suddenly with a lot of roll off. Not usually survivable when performed below pattern altitude in an RV as a number of accident reports would indicate. In my view having an accurate reliable AOA system in an RV is essential kit. I do agree - the two frequency tone with solid Onspeed tone is all that is needed.


KT

Approaching a stall is all it is designed to do. You’re correct, it won’t indicate max L/D.
PS. ‘Carson speed’ is definitely not max range speed.
 
Approaching a stall is all it is designed to do. You’re correct, it won’t indicate max L/D.
PS. ‘Carson speed’ is definitely not max range speed.[/
Agreed - but it is the cheapest place on the Airspeed indicator as far as fuel burn for each knot of airspeed. (optimizing AOA for cost per knot of airspeed given aircraft weight, air density, and temperature for the particular aircraft)

Don't all RV drivers like to optimize speed against cost with todays price of fuel?

KT
 
Don't all RV drivers like to optimize speed against cost with todays price of fuel?

KT

Life is short. Go Fast.

I climb to the low "Teens", WOT, lean as best I can in my carbureted plane, and dial the RPM back to about 2100, and find the smoothest RPM.

Unless you are out for a DDA flight, sightseeing and returning to base, that is. Then you can go as slowly as you want.

DDA: Day "Richard" Around. Old term from my military days. :rolleyes:

Flame suit on.............
 
Don't all RV drivers like to optimize speed against cost with todays price of fuel?
KT

Nope. Most want to go fast.
‘Carson’s speed’ doesn’t even use the cost of fuel as a variable. It specifically minimizes the combination of dry Hobbs hours and fuel burn, giving equal weight to each. If the cost of gas goes up, you would want to go slower, if your goal was to minimize the cost of dry Hobbs and fuel, on a given flight.
 
Nope. Most want to go fast.
‘Carson’s speed’ doesn’t even use the cost of fuel as a variable. It specifically minimizes the combination of dry Hobbs hours and fuel burn, giving equal weight to each. If the cost of gas goes up, you would want to go slower, if your goal was to minimize the cost of dry Hobbs and fuel, on a given flight.

I dont think I implied that the cost of fuel was a variable in the determination of Carson speed. However as costs go up we all look to trim our sails to get the most performance out of the dollars available ( at least those of us on a fixed retirement income). Since Carson speed is minimization of fuel flow / knot of airspeed one could look at it as getting the best bang for the buck in terms of going fast. And as we all know, in an RV the “Yea Haa” bit is the most fun.

KT
 
Don't all RV drivers like to optimize speed against cost with todays price of fuel?

KT

Some of us just buy cheap fuel. I outfitted my plane to eat a steady diet of 93E10, which is currently selling well under $4. I didn't build a fast plane to fly it slow. 90 knots is for the climb and the Fisk approach.
 
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My Advanced Flight 5400 EFIS calibrates AoA differently. A little odd since they’re a component of Dynon and the whole rig uses an SV ADAHRS and Skyview network. AoA calibration requires a “parabolic-type” weightlessness maneuver….push the record button when things start to float. Got some great tips on that maneuver from Paul Dye and an informative YouTube video.

Otherwise, same findings…the increasing tones are more useful to me than the display, and at 1.15 x stall I get an annunciation “angle angle push”. I rarely watch the gauge since AFS software version 16 implemented the tones.
 
We struck a similar problem when we calibrated an RV12 with a Skyview HDX. We were puzzled by the fact that the calibration seemed to go ok but the AOA indicator remained blank. The solution was that the tube from the probe, or rivet in our case, had become trapped and closed off. Releasing the tube fixed the issue.
When the calibration goes correctly there is a lot more feedback on the indicator which may be a clue.
 
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update: i disconnected the AOA tube from the ADAHRS and blowed into it. there was a blockage at the fitting connecting the pitot tube and the blue AOA line. some bug decided that this would be a nice place to build some kind of nest for raising bug kids.

calibration procedure works now and that shiny AOA bar blinks and beeps as it should.

thank you for all the inputs!

Kay
 
Dynob AOA calibratioon problem

I have been flying my RV-8 with dual 10" HDX systems for several years. Did the AOA calibratioin soon after installation and it has worked fine - until...

I installed the latest system update and to my recollection the AOA was still functional - but when I ran a new AOA calibration sequence (3 times) the AOA is not operative. No sound, no ICON on the display.

I've check the audio setup for AOA as well as the PFD setup for AOA. Everything seems to be set to work fine.

It seems that running an AOA calibration after the latest system uppdate has disabled the AOA system.

Dynon says to run thexero pressure IAS/AOA Calibration and then do the AOA calibration again - but I have a feeling that is not going to fix the problem...

Thoughts?

Thanks
Jay
RV-8 N312FM
 
I also check the pitot and AOA ports on the heated pitot tube and all apprea clear - no bug residue or other blockages visible...
 
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