I encountered some unexpected behaviour when trying to use the OBS mode in the TBM900 when trying to fly holding patterns. It seems to me that this is a bug, but maybe I'm doing something wrong. Skip down to "PROBLEM DESCRIPTION" if you want to cut to the chase
A little background: I'm a real world, pilot with a PPL-A close to about 75 hours, VFR only. I have used X-Plane 10 and 11 extensively during my flight training. I use the sim to get familiar with new airports, train for specific situations (e.g. engine emergencies). It has helped me tremendously in training and I can only recommend doing so to any student pilot. After obtaining my license I have continued to train with the sim, even honing my landing skills. The Carrenado PA-28 Archer II captures the real PA-28 that I fly very well, once you fiddle with the joystick curves a little.
I have read a few books on instrument flying and I would love to start my IR soon. I have no doubts that sim training will come in especially handy for that! I have logged quite a few hours flying a Mooney on VATSIM and I'm quite confident using the GNS430 for that now. To make things more interesting, I bought a payware TBM850. On that specific product, the G1000 can't be updated with current charts and doesnt work properly on X-Plane 11. Looking for a replacement, I have followed the development of the X-Aviation TBM900 and I was thrilled when it came out recently.
First of all, I am absolutely amazed by how well this plane is made. Everything from the graphical side of things, the modelling of the systems and even the documentation is just on a superb level! The way using h-shape throttle pattern was implemented is very clever and elegant. I am working in jet engine research and have experience in systems modelling - the way the PT6 is modelled in the X-Aviation TBM900 feels very convincing to me. Amazing stuff
PROBLEM DESCRIPTION: I have started to fly various IFR exercises with the TBM900 and X-Plane 11.26. When trying to fly holds on the PINIK wpt near LZSA (Lugano, Switzerland), the problem occurred. The published hold for PINIK is shown below:
I departed from LSZA using the SID. Before arriving at PINIK, I activated OBS mode to stop waypoint sequencing and keep PINIK as the current waypoint. In the screenshot below, I completed the outbound leg (parallel entry) and the outbound arc. I am using HDG mode to intercept the inbound leg to PINIK:
Note that CRS is set to 017°. This should enable me to fly the inbound leg using the NAV autopilot setting. However, when I switch to NAV mode, instead of turning left and intercepting the radial the autopilot will turn right:
If I then leave the autopilot in NAV mode and wait, it will cross the radial and eventually fly away from waypoint, airport and radial:
The described method of flying a the hold has worked for other waypoints enroute and even at PINIK. I am not able to consistently reproduce the error. My suspicion is that there is a bug in the way the X-Plane/X-Aviation G1000 handles OBS mode. Maybe in some part of the code, the current leg (1320)->PINIK is regarded as a current reference for the autopilot, while it should really be the 017° radial of PINIK?
Am I doing something wrong? Any ideas how to fix this? Is this even the appropriate forum?
Slightly off-topic, I can recommend checking out LSZA and its IGS 01 approach: 6.65° degree glide path, relatively short field, unusual go around and mountains in the VC!