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0 votes
asked by (40 points)
I have a question for you more seasoned X plane pilots.  I use a Rift for VR and fly the Cirrus Vision.  Since the latest beta update as of 12/27/18, I can not get the plane to hold its altitude.  I use to be able to set my altitude and my VS and when it reached altitude it would level off.  Or I could hit the ALT button and it would level off.  Now when it reaches the altitude I set it will level off then begin to roller coaster up and down and slowly start gaining altitude.  Has anyone else had this issue?  I have not tried another plane since the problem and the latest update and the only other thing I have done during that time was purchase another plane and install it in the plane folder.  Does anyone have any idea what is going on?

1 Answer

0 votes
answered by (22 points)
As far as I can tell they changed the VNE (Velocity Never Exceed) from 350Kts to 250Kts in either 11.30 RC1 or RC2. This means if you exceed about 240kts on autopilot, it will nose up to bleed off speed gaining altitude in the process. If this is your problem, you can fix it. Navigate to the Aircraft > Laminar Research > Cirrus SF-50 folder and open the file CirrusSF50.acf with a text editor. Search for an entry "P acf/_Vne_kts". If this is set to 250, change it to 350 and save. Hopefully this will fix your problem.
commented by (40 points)
Thank you for the response.  I have changed it to what you said and will try it out later this evening!  It did say 250.
commented by (40 points)
I tried a flight after changing the value.  It did not seem to help, although if I slow the plane down the problem of going up and down does go away.
commented by (22 points)
hmmmm. Sorry it didnt work for you.Here are my settings for VNE and VNO that fixed it for me.

P acf/_Vne_kts 350.0

P acf/_Vno_kts 250.0

With that in place, on the airspeed indicator you should see a green bar up to 250 and a yellow bar between 250 and 350, then a red bar above 350. I dont fly VR, but dont see any VR setting that would overide this.
asked Jun 2, 2020 by (24 points)
0 votes
Changing the Vne Values Worked - Thanx!