If I flight straight and level. Then enable AP it is in ROL and PIT mode. My understanding is that the autopilot should maintain the currently set roll and pitch. Garmin say this is a way to set a climb or descent at a constant angle. Now, If the AP is active and I roll the plane to the LEFT and turn maybe 50 degrees using a 15 degree bank then let go of the yoke what should happen?
- Should the AP maintain my 15 degree bank? This is what I thought would happen going by the Garmin docs and input from other real pilots though then we were talking pitch not roll…
- Right now the AP will do a 90+ degree roll to the right causing a dive that it often wont recover from. It tries to get back to the original heading it was on when the AP was activated. That seems wrong.
Hi @Yuudai5178, PIT and ROL mode together are never really used. At least not intentionally or on purpose. And any time the autopilot is on, adding control inputs will just fight the autopilot and get you in a mis-trim situation.
Recommended method would be to set up the autopilot prior to engaging it. In other words, set the desired altitude using the preselector knob. Select a vertical mode (such as VS), select a rate of climb / descent using the pitch wheel or up/dn buttons, and then select a lateral mode (HDG, NAV, etc). Once all that is done, then engage the autopilot.
(There is a function in planes like the Baron / Bonanza called control wheel steering, or CWS. It will allow what you mentioned, but is not modeled in the sim)
2 Likes
Thanks. I normally do set it up before hand but I am attempting to find the bug where on occasion the aircraft does a 90+ degree roll with massive loss of height. I can recreate the behaviour using PIT and ROL modes but I think it can happen on other AP mode changes too. It has only happened to me once just yesterday though I’ve seen others complain about it too.
As for “never really used”. That may be but they are features listed in the Garmin manual. PIT seems OK in the current patch (I’m fairly sure it insisted on level flight before) but ROL doesn’t seem to match the manuals definition.
Sweet, so for the Garmins, the yoke should not be used while AP is on, ever. By the sounds of it they really only connect to trims, there is no yoke integration. I would have thought that either:
- The AP would disconnect.
- The AP would use the new patch and roll attitudes.
But I don’t like assuming hence the posts 
Sure thing. And you are correct, the autopilot will disconnect once it detects enough resistance in the servos. 
Sweet, thanks. I have three AP bugs listed and I think they are fairly easily reproducible so hopefully they will get sorted soon. I had to change some of my fix suggestions because they were wrong for this kind of AP but that’s OK. There was still a bug, just the solution is a little different.
I can see how if we operate the AP properly there are so few issues and that would be why it would pass testing. It’s been an interesting learning experience.
We may need an Autopilot wiki we can refer people to if they have trouble.
1 Like
Sounds like a good suggestion. I will put one together. (May wait until after the next patch however)
1 Like
I’ve noticed this most often occurs when the trim wheel is being manually controlled and having already set up the AP, upon engaging AP for climb and if your attitude is beyond ~10 deg from what the flight director is wanting, you’ll get the aggressive autopilot correction which overshoots the preselected VS.
You should always be in stable flight prior to engaging automation (IE, if you want 800FPM, you should already be attaining 800 FPM or nearest rate of climb). I can’t reproduce the issue under these circumstances.
1 Like
Thanks and very true, that is similar to what I just wrote to someone else. I rarely have an issue myself because I usually hand fly to get on the right vector or where the AP just has a minor intercept to manage. If that is what the real AP requires then that is fine. But if the real AP is more robust then we should expect the sim to be just as robust, no more no less.
My summary.
- AP can work very well if you limit your demands on it. I think that is good piloting myself, but we shouldn’t use it as a workaround for bugs, if any.
- We should expect no more or less than the behaviour of the real devices. Part of this is correct AP (and not assume a Garmin is the same as an airliners FMC) knowledge and part of this fixing bugs.
- Fairly minor bugs like AP not disconnecting when it should lets a player get the aircraft in a position where the AP will make the aircraft lose control. So a minor and maybe simple bug can have a big outcome. If AP doesn’t disconnect people will assume it shouldn’t.
2 Likes
I fully agree. In general, and in my experience (I’m by no means a test pilot but have my share of hours with Garmin, Honeywell and Collins systems), they all have the capability to intercept a vector from any angle and correct appropriately within not only the flight envelope, but pilot/pax comfort. The complexity and capability increases with the systems involved (G1k, 3k, 5k, Primus), but the overlapping factor is the ability to provide a robust level of safe, comfortable flight.
1 Like
Just to document this. I was flying and AP disconnected. I don’t know why because I had another app in the foreground. So I disable NAV mode (only ALT) is selected then level the aircraft so it will intercept the course line. I then click AP to re-enable the AP. The AP then rolled to an angle I had set earlier. Not what I was currently on when I pressed the button.
I used HDG mode after that but it confirms a suspicion I had and that is that the AP ROL and PIT modes sometimes use a previous roll and pitch, not the one the aircraft is following when the AP is enabled.
Seeing this is not common, I am wondering if there is a way AP can be disconnected that does not reset the current pitch and roll values when it is re-enabled. It might be a hint.
1 Like
PIT and ROL mode together are never really used. At least not intentionally or on purpose.
Directly from the G1000 cockpit reference:
AP Key – Engages/disengages the Autopilot and
Flight Director. Pressing the AP Key activates the Flight
Director and engages the Autopilot in the default pitch axis
and roll axis modes.
The game’s G1000 should not behave unpredictably when engaged in what is a basic two-axis autopilot mode that is the default mode in real life aircraft and manages not to put the aircraft at risk of departure, and whether or not the game models CWS. CWS differs from basic two-axis ROL+PIT in that CWS allows manual input corrections to the two-axis setting.
That said, there are traps to be aware of when making AP adjustments. From a GFC700 supplement:
Selected Altitude Capture (ALTS)
… a vertical mode specifically for capturing altitudes, called Selected Altitude
Capture (indicated by an ALTS annunciation).
During level-off, the active vertical mode will transition from the climb/descent mode, to the
altitude capture mode, and then to ALT mode. The pilot cannot activate ALTS mode directly.
Instead, it is automatically armed when the pilot selects other vertical modes.
Nevertheless, pilots should still be aware of ALTS mode, due to a potential trap.
While Selected Altitude Capture mode is active (indicated by a green ALTS and a white ALT**
annunciation), if the pilot changes the Selected Altitude,
the flight director will revert to Pitch Hold mode and hold its current pitch angle.
This angle may or may not “intersect” with the new selected altitude,
which could lead to an uncapped climb or descent. To avoid this, wait for the flight director to
enter ALT mode (indicated by a green ALT annunciation), then program a second climb/descent
as necessary.