16.4 Update Feedback

CRW

I love flying!
Joined
Mar 26, 2017
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15
Any feedback from the installation of his update?
I have been waiting for this and plan to install it tomorrow but I am very interested in hearing from someone who has done the install and what you have experienced. Hopefully no new "bugs" will show themselves with this update.

Best regards,
Chuck
 

RV8JD

Active Member
Joined
Dec 17, 2017
Messages
232
Location
WA State
I have not loaded or flown v16.4.0, but I am flying a "Release Candidate", v16.4.RC0.9553 (for the Classic models) awhile back. Some problems fixed and no new problems noted. It included the fix for the aggressive autopilot roll behavior and the fix for the Tach time issue when the ignition sources used different pulse/revolution settings. See this post for what I found:

https://forum.flydynon.com/threads/...-like-a-fighter-pilot.14071/page-4#post-83737
 
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jsalak

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Apr 29, 2013
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30
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FL
Did the 16.4.0 upgrade today and will test fly it tomorrow. Looking forward to not hearing "BANK ANGLE" anymore. Hopefully I can get a better AP tune with the new guide, the altitude hunting in any kind turbulence is getting old (hysteresis in pretty bad). Not sure why the AP allows such large VSI numbers that contribute to the overshooting in both directions.
 
Joined
Sep 24, 2007
Messages
133
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Tehachapi, CA 93561
...Hopefully I can get a better AP tune with the new guide, the altitude hunting in any kind turbulence is getting old (hysteresis in pretty bad). Not sure why the AP allows such large VSI numbers that contribute to the overshooting in both directions.
THIS. I was very pleased to see that there's now a way to take the play in the system into account, although I don't know that the hysteresis is a function of my pitch control system (there's very little play) or a software issue. I've played with the VSI gain to no avail. It'll hold altitude great when smooth - within 5 ft - but in turbulence (and it doesn't have to be bad turbulence - just light chop) I can hand fly within 20 ft., while the AP will oscillate a few hundred ft. No safety issue, but very annoying, and can be nausea producing. Here's hoping...
 

jsalak

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Joined
Apr 29, 2013
Messages
30
Location
FL
Went out and flew for a couple of hours today to check out the 16.4 SW. No improvement in the pitch control with a light chop, I was seeing 700-800 FPM in the VSI and speed changes of 10-15 knots with the pitch up and down hunting around the altitude bug. I tried some of the adjustments suggested in the AP tuning guide with no apparent improvement. Maybe it's time to reset to the defaults numbers and start over on the tuning. Flew a coupled approach (LP+V) with the IDF540 and did not see any issues with VNAV holding the glideslope.
 

Solana

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Mar 26, 2017
Messages
51
Went out and flew for a couple of hours today to check out the 16.4 SW. No improvement in the pitch control with a light chop, I was seeing 700-800 FPM in the VSI and speed changes of 10-15 knots with the pitch up and down hunting around the altitude bug. I tried some of the adjustments suggested in the AP tuning guide with no apparent improvement. Maybe it's time to reset to the defaults numbers and start over on the tuning. Flew a coupled approach (LP+V) with the IDF540 and did not see any issues with VNAV holding the glideslope.
Are you sure you don’t have a broken shear pin? Or maybe a cracked capstan in the pitch servo? You can put your autopilot on altitude hold (in the hangar) and see how much play you have when you push the elevator up and down.
 

jsalak

I love flying!
Joined
Apr 29, 2013
Messages
30
Location
FL
Are you sure you don’t have a broken shear pin? Or maybe a cracked capstan in the pitch servo? You can put your autopilot on altitude hold (in the hangar) and see how much play you have when you push the elevator up and down.
I went out today in smooth air to try some more adjustments, the Lost Motion Compensation was interesting setting it to 2 resulted in a short period pitch oscillation, 1 reduced it some, and zero stopped it. I already reduced the G-Error-Limit and G-Error-Gain with not much of an observable change in some light bumps. Perhaps a better approach would be to start near the minimum on the sensitivity for gains other than the glideslope related items. The stabilator on my RV-12 is very sensitive to minor inputs and it appears the AP reaction to minor turbulence is just over controlling it, somewhat similar to a PIO. The new AP Tuning Guide is a lot more useful than the previous version in defining what the coefficients are.
 
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