I have an ongoing issue with the above mentioned aircraft.  I’ve been working their support channels but today support basically said, “…it works as we designed it.  As intended” along with a chart of the AP panel that provided no solution.  Here is the problem as I described in my ticket.

TRANSITIONING TO AUTOFLIGHT WHILE CLIMBING:   Hello, I’m having challenges when turning on the auto pilot while established in climb.  No matter what I try, including dialing up Pitch Hold aftet AP activation I find that the minute I turn on AP the plane immediately switches to Vertical Speed and zeros pitch out to zero feet per minutes.  At that point I have to dial up a vertical speed (3000fpm) to reestablish climb. How can I turn on AP without this dipsey-doodle maneuver?
TIA,

The Official FSS solution was, “try to switch to IAS mode as quickly as possible”. Any here have a better method or workaround?

Thanks,

-B

5 hours ago, btacon said:

Any here have a better method or workaround?

Thanks,

-B

In the real 727, when the AP is/was engaged, initially, it will maintain the present attitude. From there, you select whatever mode you need. It could be an issue that some entries are missing in the systems.cfg at the AUTOPILOT section, see if you have the following entries: 

pitch_pid_reset_mode=2 

roll_pid_reset_mode=2. 

What you described, the airplane was not doing that in real life. I hope it will work, or they will fix it. 

This is a known problem and the developers are working on it. Hopefully it will be fixed in the next update. If you follow their discord you will find that numerous folk have experienced this problem.

49 minutes ago, TrevorS said:

This is a known problem and the developers are working on it. Hopefully it will be fixed in the next update. If you follow their discord you will find that numerous folk have experienced this problem.

I do follow their discord and I was told today to by a member of the FSS staff that it works like it should. Official trouble ticket and all.

But I would be well pleased to be proven wrong.

-B

15 hours ago, btacon said:

support basically said, “…it works as we designed it

Hope they will not walk 'arrogant way' with customers, i have high hopes about 727...

7 hours ago, btacon said:

I do follow their discord and I was told today to by a member of the FSS staff that it works like it should. Official trouble ticket and all.

But I would be well pleased to be proven wrong.

-B

The assertion is incorrect. When the autopilot system is engaged, the aircraft will maintain the heading and vertical speed at the time of engagement. There will be no leveling off, increase, or decrease in the rate of climb or descent. The aircraft will maintain that attitude until an alternative mode is chosen. Actually, the explanation is in the FCOM, which I don't have anymore; it was a long time ago.

I just found that even on FSS Documentation HUB they mention:

The autopilot holds the heading and vertical speed existing at the time of engagement. If the airplane is in a turn, the autopilot will level the wings and hold the heading assumed at the time the wings are leveld.

Typical mentality of blowing off the customer instead of acknowledging the bugs.  Like other developers on the market. So discouraging. 

If you want to learn how to operate the aircraft correctly check out https://www.youtube.com/@A330Driver

 

Ben

I have the same issue, plus the altitude capture never works properly, always hundreds of feet off. Anyone know how to fix that?

48 minutes ago, Overload said:

I have the same issue, plus the altitude capture never works properly, always hundreds of feet off. Anyone know how to fix that?

What Nav are you using?  GNS, GTN, OR GTNxi?

-B

Itˋs a shame - such an interesting and beautiful plane - but so buggy - I hope FSS takes their courage in both hands and wipes off these unpleasant issues.

4 hours ago, btacon said:

What Nav are you using?  GNS, GTN, OR GTNxi?

-B

GTNxi, could that be the issue? But generally not using it in gps mode. 

 

30 minutes ago, Overload said:

GTNxi, could that be the issue? But generally not using it in gps mode. 

 

So it seems. In testing I have found all the other AP navigators (GNS, GTN, CIVA) aquire and hold PITCH/VS when AP is activated.  Only the GTNxi delivers the anomalous behavior I describe as OP.

Try for yourself with the GNS.  Pitch should grab and stick.  Let me know.

Let me add that I’ve shared my findings with TDSSim and they are actively investigating.

-B

Edited August 22, 20241 yr by btacon

Thanks for that, I'm away from the sim for a few days, but will test it when I come back.

Been away longer than expected, but fired up the sim today, updated the GTNxi, and the 727 (V 1.03) so had high hopes of a fix, but altitude capture still hundreds of feet off. Disabled the GTNxi and altitude capture fine.  No a big problem for me, I mostly fly the 727 old school, but surprised it isn't fixed.