Is Skyview Autopilot a "reasonably modern Autopilot"?

WingedFrog · #1 03-03-2016, 07:09 AM

My question is inspired by a quite interesting story from the March 2016 Issue of Sport Aviation by J Mac Mcclellan (Title "Pilot in Command"). It is all about cockpit automation. In the article section discussing all what can go wrong in the autopilot control, McClellan says:
"Every reasonably modern autopilot that I know of requires the human pilot to test the clutches as part of the preflight checks"
Of course he is talking about commercial airplanes way bigger and more complex than our RV-12 and I am being a little facetious in the title of this thread. Still, I have this question: Everyone of us using the Skyview autopilot has experienced instances of slippage of the pitch server. These slips are subject to warning and solved by adjusting the trim (or doing nothing if produced by a sudden strong turbulence). In the case of failure of the clutch, i.e. undetected stucked clutch, what would be the consequence? I assume that we would not get the warning but we also could get unusual attitudes. Should we (or better, Vans) not add this test of the clutches in the preflight check list?
And by the way, I have no idea how we could do that

redbaron · #2 03-03-2016, 08:59 AM

Ck out the Garmin Autopilot as it has a different design.

Dgamble · #3 03-03-2016, 08:59 AM

It seems that if you really wanted to do it, you could test roll by moving the heading bug away from the current heading and putting the AP in Trk/Hdg mode. If you can keep the stick from moving (and feel the "clicking" of the clutch), it's working.

Pitch would be similar.

dynonsupport · #4 03-03-2016, 09:38 AM

There are no clutches in a Dynon servo. They are inherently safe in that the internal drive motors are torque limited. Every time you "slip" the servos you are experiencing the maximum torque it can exert in a failure.

bruceh · #5 03-03-2016, 09:45 AM

You also get a nice "ROLL SLIP" or "PITCH SLIP" annunciation on the EFIS when it happens. That's usually my cue to disconnect and hand fly when the skies are too bumpy.

Raymo · #6 03-03-2016, 09:53 AM

Dynon has a nice video on how to set up the servos during install for proper operation and will swap out a lighter torque servo for higher torque as needed.

https://www.youtube.com/watch?v=oVrfeAZaXZ0

myrv6180 · #7 03-04-2016, 07:49 AM

MGL's autopilot, if you use their servos, is accurate, is digital and the digital servos give you a force feedback on your screen for manual or auto trim function. I have an Iefis touch screen and it is wonderful.

cactusman · #8 03-04-2016, 05:06 PM

Quote:

Originally Posted by WingedFrog

McClellan says:
"Every reasonably modern autopilot that I know of requires the human pilot to test the clutches as part of the preflight checks"

I haven't read the article, but I don't have a clue what he is talking about. I have never flown an airplane with an autopilot, (inc. g/a, commuter, Boeing, Airbus, etc.) that required me to preflight or otherwise test the autopilot as part of the preflight checks.

It either works or doesn't, is MEL'd or inop.

Most PTS state clearly that that you may be required to demonstrate proficiency using the automation installed in the aircraft used for the practical test, which means you may be required to intervene if it is not working correctly by responding to inputs.

I tuned mine per the guide and it works pretty good. Set an altitude and waypoints, hit GPS, climb at 75-85 IAS, and she will level off and trim and maintain alt within a few feet.

MikeyDale · #9 03-04-2016, 06:34 PM

It's been a while but I remember when calibrating and setting up the Dynon auto pilot, the instructions ask you to use break out force on each servo once. I assume to make sure you can over ride the servos if needed. My auto pilot has worked great for 10 months! I think it was on my second flight, I hit the AP button and SHAZAM! It worked perfect! I don't know why I was so surprised but i was!

Jesse · #10 03-04-2016, 08:25 PM

I have installed many Dynon servos both driven by the D series and Skyview systems. I just installed a 2-axis system (as well as a full Skyview system) in a -9A and on the first flight, I turned on the A/P at 500' and it worked absolutely flawlessly. Nothing to adjust. Nothing to tweak. It just worked.

I have a Dynon A/P in my IFR RV-10 and my IFR RV-6A and love them. They are as modern and feature rich as it gets.