I’m currently trying to find reproductions for some issues people complain about.
If we set the autopilot to climb 4000 feet at 500fpm then take off at YPPF in the C172, and “forget” to lean the mixture, the aircraft will stall. Does the Garmin actually allow that?
It is something a pilot wouldn’t normally do but maybe someone knows from manuals or training.
If an aeroplane stalls to an extent the autopilot can no longer maintain control it should disconnect itself.
That matches other APs I’ve seen. I guess we should have a stall warning horn going off so that would be the alarm.
I had wondered if it might provide a bit of prior notice though.
I’ve honestly never tried putting a real world aircraft into a stall in a Garmin with the autopilot engaged. Of the times I’ve put one into a stall, it was all manual flight, and there wasn’t much indication other than the usual buffet and a stall horn (if I remember correctly). No prior notice.
The Garmin should disconnect the autopilot when it isnt able to maintain flight parameters though.
As an aside, a real 172 shouldn’t be stalling at 4000’ even with mixture full rich at normal climbs speeds, and using VS in a climb isn’t generally a good practice (due to lack of low airspeed protection, although people who know what they are doing sometimes do use it).
Thanks, I did wonder if it should lose power that quickly because it seemed a bit fast but I’ve not flown an aircraft with a mixture control, or an autopilot for that matter and while I’ve used them in other sims I don’t like to assume they are doing things accurately.
My AP did not disconnect so that is a bug.
That’s two AP issues that are replicable that I logged today. One more to try and replicate is where my 4 year old grandson caused my AP to disconnect while I was out of the room and when I re-enable it the aircraft tried to do a wing-over and hit the ground. I’d love to know what he did.
The last is where the aircraft pitched up massively withe AP in altitude hold mode. On one occasion it was because the flaps went to full down all by themselves and the AP couldn’t cope. That should be easy to confirm.
I’ve had lights turn on without touching anything too but that’s less dangerous!
If you are using VS (vertical speed) hold at 500fpm, the real G1000 will try to hold that VS up to the selected altitude, and yes, if it does not have enough power to maintain that, the AP will continue to increase the angle of attack to try to maintain the 500fpm climb until the aircraft stalls. In fact, there have been a few real life accidents that resulted from this. Some of the newer G3000 models have envelope protection to prevent this from happening.
For that reason, the way most pilots use the G1000 to change and capture altitudes while climbing is with the FLC (flight level change) function. In FLC mode, the autopilot holds the airspeed constant through the climb, reducing the rate of climb as the aircraft ascends and loses power, thus preventing a stall as the airplane climbs to higher altitudes.
I’m not sure either mode, however, is being modeled correctly in MSFS2020.