Question about RNAV capabilities
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Hello, I'm just wondering if the BAE146 equipped with the UNS1 is supposed to be able to conduct rnav turns such as the one in the image below. This is a 270 degree left turn towards a waypoint. The main question is what is the rnav capability of the aircraft with the UNS1 retrofitted? I am aware that it is incapable of conducting RNP procedures.
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I haven't found any documentation on the supposed capabilities of the UNS-1 as simulated in the 146 (the current UNS-1 units are pretty complete packages for modern environments it appears), but with the way it behaves I'd assume it does pure point-to-point GNSS without any augmentation, DME/DME, or INS support, supporting "track to fix" legs. So basically anything that's straight lines between waypoints. The whole field is a confusing mix of terminology where RNAV and RNP with various pre- and suffixes as well as numerical designators come and go and sometimes change meaning altogether.
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I suspect the root cause of this particular SID is that there is no information in the UNS-1s Navdata to dictate which direction the turn should be made for that SID. So once the aircraft flies over the 3,000ft fix the UNS-1 is calculating that the shortest direction of turn to the ZB100 fix is a right turn, so it turns to the right.
I have logged this with the UNS-1s development team to take a look into and we'll see if there's anything that can be improved for a future update.
Mark - Just Flight