Strange TBM850 MSFS2020 VLOC Problem
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All of a "sudden", VLOC does not seem to be working. If while setting on the runway I tune in the ILS or a nearby VOR, the CDI in the HSI just drifts back and forth kind of from one side of the display to the other. This happens no matter what "radio" I use for NAV1 -- I have tried the GNS 530, PMS 750, TDS GTN750Xi and the KX155. This does not happen with other aircraft I have tried.
I have tried re-installing the TBM850, and with essentially an empty Community folder, but that didn't help. I don't use any "addon" liveries. BTW, same thing happens when using NAV2 and the VOR2 gauge display. The tablet indicates there are no active failures.
Thanks for any ideas.
Al -
You have discovered one of the many advanced features I've created for the Black Square fleet. In the manuals, you can find a section on "VOR & ADF Signal Degradation" that describes how the feature works.
The perfectly aligned and low resolution navigation signals from the default flight simulator system (unchanged since the 90's) has always been a disappointment to me, so I created my own system that solves many of these problems. As soon as you're off the ground, or get much closer to a navigation aid located on the airport property, the signal strength will become stronger, and the indication will become more reliable. Take note that the NAV flags on the instruments are actuated by the derivative of the interpreted signal, which is a stochastic process; therefore, the NAV flag may become visible again momentarily when signal strength is poor.
I hope that answers your questions! Let me know if you have any more.
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The effect is overdone, though--when dialed in to a navaid on the same airfield, you're easily within the range of the transmitter's ground wave, even if it's just a low power "T" (terminal) navaid. If a localizer really wobbled as it is being simulated, a Cat II/III autoland in aircraft so-equipped would be absolutely impossible, as those systems use the localizer during the ground rollout phase of the autoland. Additionally, many airports have navaid checkpoints on the taxiway near the approach end, e.g. a sign with bearing/distance to the navaid so pilots can cross-check their receivers. That would not be possible with the bearing wandering around like it's doing.
It's an interesting idea, but based on my r/w flying experience (ATP-rated ex-military pilot), the degradation effect is excessive. Would appreciate it if you could dial down the effect, or alternatively give us an option to scale it back or remove it entirely.
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@Black-Square said in Strange TBM850 MSFS2020 VLOC Problem:
I hope that answers your questions! Let me know if you have any more
Thanks very much for the help, and I do applaud the effort to increase the realism. I also agree with the comment above suggesting the degradation effect be moderated a bit.
Al -
Unfortunately, there is only so much that I can do within the limitations of the simulator, and most "workaround" features that I produce for my aircraft are the result of an embarrassing amount of trail and error to thread a fine needle between one rock and another hard place. What you're seeing here when sitting on the ground observing an ILS from the centerline is the result of MSFS's lack of easily accessible variables for navigation aids without querying a database. It forces me to treat many navigation aids as the same type of antenna, or directionally agnostic, for instance. For another example, the VOR's treatment close to the ground is a result of not using a terrain database and computationally expensive ray-tracing algorithms, but instead comparing the altitude of the aircraft to the receiver and applying various curves based on antenna radiation patterns and attenuation constants to arrive at a believable solution that is also light on performance.
All that being said, the reason I am often so delighted to have this forum is that it allows me to add requested features and changes to a never-ending list of items to revisit during future development. Next time I am doing work near my signal degradation code (likely for the Baron and Bonanza Professional), I will see if I can come up with some more clever tricks to improve signal integrity while operating on the airfield's surface for you. As is so often the case, I may already have some ideas of what can be done after looking at the code again while writing this.
