SkyMaster 337 trim Erratic

[ThomasAH 61]

6 hours ago, lewblok said:

I was wondering if the pitch wheel down on the console on the AP has a neutral position or if it should be neutralized someway before turning on AP.

No, (at least in the sim) this is an endless scrolling wheel and will only make relative changes, just like your mouse wheel on long web pages 🙂

[FDEdev 955]

4 hours ago, ThomasAH said:

No, (at least in the sim) this is an endless scrolling wheel and will only make relative changes, just like your mouse wheel on long web pages 🙂

Don't know where you've got this 'info' from.  Again, upon loading the aircraft the trim is centered and of course it does have an up/down limit. 

[ThomasAH 61]

31 minutes ago, FDEdev said:

Don't know where you've got this 'info' from.  Again, upon loading the aircraft the trim is centered and of course it does have an up/down limit. 

In the part I quoted and answered the OP asked about the AP pitch wheel, not the trim wheel.

[FDEdev 955]

32 minutes ago, ThomasAH said:

In the part I quoted and answered the OP asked about the AP pitch wheel, not the trim wheel.

Oops, sorry. Talk about target/trimwheel fixation.

Concerning carb heat/anti-ice.  That's not necessarily a bug. The 337 does have a prop deice switch and AFAIR the default carb heat/engine/prop anti-ice command is H.

[ThomasAH 61]

19 minutes ago, FDEdev said:

Oops, sorry. Talk about target/trimwheel fixation.

Concerning carb heat/anti-ice.  That's not necessarily a bug. The 337 does have a prop deice switch and AFAIR the default carb heat/engine/prop anti-ice command is H.

Unfortunately the prop anti-ice switch is not modeled in the Carenado C337, otherwise it might be possible to wire that function to it 🙂

(and it would still be a bug, in the real C337 only the front propellers are equipped with anti-icing boots, but I have seen both engines turning off in the simulated C337 due to icing until I press H)

[lewblok 8]

Thanks for all of the responses regarding the 337 AP.  My original problem of just flying along for 1 to 2 hours and all of a sudden the AP puts nose down and I turn off and then flight controls do not repond has not happened again.  After some thought, I think it may have more to do with FSX and not with the 337 program.  So will cruise along and see if it happens again,  Will put up with the big trim fluctuations and continue flying this fun aircraft.  Thanks again!

 

Lewblok

[HighBypass 2,339]

One further question did this erratic AP behaviour only happen at high altitudes? Could there be some kind of hypoxia condition modelled as the 337 is unpressurised?I say "some kind" as I believe real hypoxia doesn't take 1-2 hours to occur.

Yes, even a hypoxic autopilot??  FSX can be a strange beast.

[ThomasAH 61]

Maybe the AP's oxygen supply ran out after 1-2 hours 🙂

But the Carenado C337 has no hypoxia condition modeled. It might be nice to have a generic add-on (or FSUIPC lua script) for this to be used with any unpressurized aircraft.

[lewblok 8]

No hypoxia involved.  This has happened at 8000 ft or that time at 17000 feet.  Just flying along and starts descending without any reason.  No loss of airspeed, no loss of rpm, nor any other problem except for the loss of altitude and then turning off AP and then flight controls are unresponsive.  I still think it has something to do with FSX itself somewhat like a CTD.  Has not happened again so far.

 

Lewblok

[lewblok 8]

Another crazy flight.  I was flying my A2A Cessna 182 on an IFR flight from KSPS to KDAL to practice overcast breakout at minimums with about 50 miles from KDAL with AP set on heading at 5000 ft.  When all of a sudden the stall warning starts sounding and the plane turns upside down, disconnected AP but plane was not responding to any kind of flight controls input.  Of course crashed trying everything I knew and no response.  So evidently my problem is with FSX and not the Skymaster 337 has I had thought.  Now if someone can tell me what to do to resolve this AP problem I would greatly appreciate it.  Thanks for the help!

 

Lewis

 

[FDEdev 955]

If the controls don't respond despite the AP being disconnected something else must be going on.

[ThomasAH 61]

Another possibility is an add-on that wants to display a message in the FSUIPC message bar that is longer than 127 characters:

Add-ons have to write the message text to offset 0x3380, if an add-on writes more than the 128 character buffer (including zero byte at the end) can fit, it may overwrite offset 0x3412 (spoiler axis input value), or even 0x3414 (flaps axis input value), which sounds like a good way drop airspeed.

I have seen this problem with PF3 before version 3.1.33 (from 2016) when displaying ATIS messages while having some debug information enabled, but this is an error that can easily happen in other add-ons, too.