Problem with Dynon SkyView

[igor113]

good afternoon! The plane spent a year on the ground in the process of modernization. Equipment did not touch Dynon. After the first start, the instrument is constantly filled with a horizon of several degrees. In addition, the device shows a height of one and a half times more real, while zero is set. There is a feeling that the speed is also more than 10 to 15 percent. I compare everything with the remaining native devices. Previously, this was not. What to do?

 

[Dynon]

Hi Igor - Can you send some pictures of what you are seeing to support at dynonavionics dot com? A few other thoughts: Is altitude wrong on the ground after setting the BARO setting for the airport correctly? For speed, make sure you have your units set to either mph, knots, or kph as you're expecting. Knot and mph are about 15% different.

 

[igor113]

At this photo you can see angle of horizon in flight. And you can see on altitude. Baro setting correctly for both devices and on the ground zero.

 

[igor113]

Foto of another devices

 

[igor113]

For speed, both devices the same units. Once again I checked everything carefully. The greatest difference at low speeds, where it reaches 50 percent, then the difference decreases and gradually almost completely disappears to 260 kilometers per hour.

 

[Dynon]

What are the pitot and static sources for the analog instruments and the SkyView ADAHRS?

Are the altimeters the same on the ground? I'm wondering if static is being routed somewhere differently on the SkyView ADAHRS, and it is seeing some pressure that is different than the static ports that the analog instruments are measuring from (this will DEFINITELY cause discrepancies).

 

[igor113]

1. Analogue instruments use original pitot-static sources on left wing. SkyView uses Dynon's pitot/AOA and static tubes. Pitot is installed under right wing.

2. Altimeters show same values on the ground. Airborne SkyView shows about 150% higher than analogue altimeter. Airspeed is up to 25km/h different at speeds below 100km/h but shows almost same at 260km/h.

3. Horizon is 1° banked on the ground, slip-skid indicator (ball) is half-centered. This fact definitely doesn't depend on pitot-static routing and this makes us think that there may be fault in the electonic system.

We are going to switch ADAHRS blocks with my another airplane (be-23) that has same SkyView system.

 

[igor113]

After switch ADAHRS blocks we see all withour change!!

 

[William_Ince]

After switch ADAHRS blocks we see all withour change!!

Is it okay or not okay now?

 

[igor113]

We suspect that the problem is that something is giving tip-offs to the block. Well, or some other block gives such distortions? We have installed a system for injection of a water-methanol mixture, maybe its electromagnetic valves or a tank, for this year?

 

[igor113]

Not okay

 

[Dynon]

Answers to your questions:

1/2) Our AOA/Pitot probe does not have a static port on it, so this is concerning.. Where does the Dynon static line connect to? I think you have a static source issue here. If the pitot and/or static ports are not in aerodynamically-suitable locations for the aircraft (these are determined by the aircraft characteristics, not the avionics), you can have substantial errors in both altitude and airspeed readings. If you changed your SkyView Pitot and static sources to the ones that provide pressures to your analog instrumentation, I suspect that you'll find that they match. This does not sound like a problem with the avionics. Also, make sure that your AOA port on the probe is not connected to the static port on your ADAHRS. This will cause gross errors in both altitude and airspeed.

3) This is likely due to an ADAHRS which is not installed completely level with respect to the roll and pitch axes of the aircraft.