FS 2019: Auto-/Co-Pilot messing up - now reproducable!

  • As mentioned in another thread about the copilot / autopilot interfering massivly although switched off, this happened again today and I figured out the pattern. I tried it three times afterwards with different planes (Dash8, LearJet, Cessna), and it happend everytime! Following is a description how to reproduce. The actual error is the autopilot still trying to keep altitude although switched off. The first few steps are just to make it reproducable quickly.

    • Select plane from the menu
    • Select a starting point in the air, lets's say 5,000 feet
    • start flight
    • Activate autopilot, press CTR for level flight (speed setting does not matter)
    • select a lower designated autopilot altitude, let's say 2,500 feet
    • select a V/S for descent, let's say 1,000 fpm
    • Before reaching the altitude, I change my mind and deactive the autopilot by touching that on/off button - all buttons are white now
    • Flaps 1, steady descent, zero throttle (depends on plane, of course)
    • AND NOW IT GETS HAIRY: When approaching the selected altitude, I see that the V/S of the autopilot (although switched off!) increases (see instruments or HUD view), until it even reaches positive values.
    • I do not move the device, but elevator goes back (can't see whether it's trimming or autopilot moving)
    • Result: Plane pitches up when reaching the altitude or is already below - but thrust is still idle, or at least way too low for achieving these V/S values - results in unusual attitudes or bevahviour.
    • Flaps are also retracted and extracted by copilot
    • It's quite a fight to get the plane under control again, it feels completely out of trim, but at a certain stage, autopilot is not messing up any more.

    Would be good of you could reproduce - and solve - this.



  • Hi Patrick, thanks for the bug report, that is indeed unintended behavior. It seems that the copilot is turning itself on again when you capture the selected altitude. I'll fix that!

    Can you confirm that it also happens in the reverse direction, when you turn the copilot off before reaching the selected altitude?

  • Yep, if you mean try the same with climbing to an altitude - same behaviour. When reaching the altitude in manual mode, plane pitches down, although autopilot off. Not so dangerous though, because thrust is usually higher and no flaps. Disturbing nevertheless. With glass cockpits, I think ALTSEL becomes highlighted.

  • Ok, there was indeed a single line of code missing and as soon as you select an altitude via the copilot overlay it will capture it, regardless weather it was off or not. But it doesn't engage fully, only the trim seems to be affected and other things that depend on the vertical mode only.

    I'll hand it over first thing on Monday.

  • The 737 is quite bad, if you pull power 15 miles out to get 180 knots and flaps 5 ... all in manual, the mutinous virtual copilot opens up the throttles again. No autoflight involved from fresh boot and 2019 start.

    How can I reproduce this?

    Place myself 15 nm out with the location dialog and then fly it towards the runway?

  • Feels like the same behaviour as described by me, but here, thrust is also affected. And the plane trims in very very high speed. Trim wheels almost fall off8o

    For reproducing, I just set autopilot altitude to a lower one than currently flying at, then descend and slow down manually. It helps to be rather slow when approaching the selected altitude, then it goes all haywire.

    I'm not a pilot, but I could imagine this it what it feels like if an MCAS or other stall protection system kicks in unintentionally. Guess I will try this at night with zero visibilty, this will be fun.

    BTW: Thrust levers move in the 737 when this happens, but not the control slider.

  • How can I reproduce this?

    Place myself 15 nm out with the location dialog and then fly it towards the runway?

    The mutinous copilot was active if a similar flight path route was present in the navigation page even though the 737 was flown manually. This uncommanded throttle activity was present in repeat manual flights which shared the destination runway with the inactive route.

    With the route deleted and a (clearing?) Cessna flight carried out from a new airport followed by a 737 flight from a third airport the throttles were perfectly normal in an all manual flight.

    A repeat no-route 737 flight into the original airport runway also had normal throttles.

  • We hoped it would be self explanatory, up/down, left/right, takeoff, landing, route.... center to stabilize...

    But I guess we should add some form of a guide.

    It is but I found some anomalies which I will need to retest. I assumed CTR would have set everything to the current attitude i.e., altitude, heading, speed etc. but the aircraft seems to continue to climb or descend. Will test more and feedback.

  • When you depress the center button for a bit longer it will always go to level off and wings level.

    If you press it short it centers one thing after another (keep tapping it): first bank hold and flight path angle hold, then wings level and fpa hold, then wings level and level off. I found that that was more useful during an actual manual flight than always leveling off, e.g. climbing turn or descending turn, where you just want to roll out on present heading.