Hi All - This thread started discussing the VNAV feature that came with the version 6.5 upgrade to GTNs: http://advanced-flight-systems.com/f...highlight=vnav . I just took the time to do this upgrade and couldn't get my AFS 5600 and tru trak AP to respond to the altitudes entered in the flight plan of the GTN or the waypoint altitudes automatically specified for approaches. VNAV is activated on the AFS unit, and the EFIS, AP, and GTN couple correctly to glideslopes on various approach types. The GTN shows a Message: "VNAV ... Unavailable: Barometric altitude lost". I'm not sure if this is indicating that the unit temporarily lost the baro altitude at some point, and this is a residual (but irrelevant) message, or if I need to change some setting. Any info is appreciated.

Cheers,
Jeff