OBS mode oddities

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   I tried out OBS mode today (coincidentally using a VOR as a waypoint, but I was using GPS) and found a couple of interesting things.
1) When flying TO a waypoint in the flight plan in OBS mode, the IFD switches back to GPS mode at the waypoint and commences flying the next leg in the flight plan. This is probably useful behaviour in most cases, but...

2) I wanted to set up flying FROM a waypoint in OBS mode to see what the MFD would show. The good news is that the MFD correctly shows the FROM radial as a magenta line. The interesting part is that it's surprisingly fiddly to get that set up - you can't just fly TO the waypoint and continue on the same (or a different) radial outbound, as the IFD switches back to GPS (unless there is some way of telling it not to do that.)

I ended up waiting until I crossed the waypoint, switching the A/P to HDG mode, to stop it turning me back, selecting the waypoint I had just crossed in the flight plan, pressing Direct Enter Enter, which has the IFD paint a 180 degree turn to intercept a course back to the waypoint, selecting OBS and turning the course pointer back (almost 180 degrees) to the outbound course I wanted.  Then reselect NAV mode on the A/P.

Is there another way to do this or is there a way to prevent the OBS-GPS sequencing at the waypoint?

Clyde

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
clydeps Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 05 Sep 2015 Location: Australia Status: Offline Points: 72	Post Options Post Reply Quote clydeps Report Post Thanks(0) Quote Reply Topic: OBS mode oddities Posted: 25 Mar 2016 at 12:31am
	I tried out OBS mode today (coincidentally using a VOR as a waypoint, but I was using GPS) and found a couple of interesting things. 1) When flying TO a waypoint in the flight plan in OBS mode, the IFD switches back to GPS mode at the waypoint and commences flying the next leg in the flight plan. This is probably useful behaviour in most cases, but... 2) I wanted to set up flying FROM a waypoint in OBS mode to see what the MFD would show. The good news is that the MFD correctly shows the FROM radial as a magenta line. The interesting part is that it's surprisingly fiddly to get that set up - you can't just fly TO the waypoint and continue on the same (or a different) radial outbound, as the IFD switches back to GPS (unless there is some way of telling it not to do that.) I ended up waiting until I crossed the waypoint, switching the A/P to HDG mode, to stop it turning me back, selecting the waypoint I had just crossed in the flight plan, pressing Direct Enter Enter, which has the IFD paint a 180 degree turn to intercept a course back to the waypoint, selecting OBS and turning the course pointer back (almost 180 degrees) to the outbound course I wanted. Then reselect NAV mode on the A/P. Is there another way to do this or is there a way to prevent the OBS-GPS sequencing at the waypoint? Clyde

DavidBunin Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 20 May 2015 Location: Rockwall, TX Status: Offline Points: 742	Post Options Post Reply Quote DavidBunin Report Post Thanks(0) Quote Reply Posted: 26 Mar 2016 at 6:26pm
	I think the simpler way (in this case) would be to just navigate in VOR mode instead of GPS mode. David Bunin

clydeps Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 05 Sep 2015 Location: Australia Status: Offline Points: 72	Post Options Post Reply Quote clydeps Report Post Thanks(0) Quote Reply Posted: 26 Mar 2016 at 9:53pm
	VOR mode would have worked in this case, but not if the waypoint wasn't a VOR.

brou0040 Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 13 Dec 2012 Location: KIYK Status: Offline Points: 720	Post Options Post Reply Quote brou0040 Report Post Thanks(0) Quote Reply Posted: 26 Mar 2016 at 10:35pm
	GPS guidance is much smoother so I'd prefer it to a VOR in this case.