GTN 650 Xi VNAV AGL limitations

[iamtheari]

I feel like this is a new thing but I’m not sure. I have noticed that I occasionally cannot choose AGL when entering an altitude in my GTN 650 Xi flight plan. Does anyone know what the specific preconditions are for the Xi to allow flight plan entry of altitudes in AGL?

 

[Avanza]

A valid three-D position seems to be a logical requirement for AGL presentation.
Also if the aircraft is below "safe altitude" at various flight conditions I recall that AGL can not be displayed.

From the Pilot guide:
The system automatically uses altitudes loaded with arrival and approach procedures (up to and including the FAF) for computing vertical deviation guidance. These values, accompanied by an altitude restriction bar(s), display in cyan. Constraint values display in MSL or flight level (FL). Constraints at airports may be specified as MSL or AGL.

Good luck

 

[iamtheari]

I seem to recall being able to enter a constraint for an airport in AGL, with or without a lateral offset (like 3 nm before the airport be at 1,000 AGL for pattern entry). And now it seems like it's inconsistent. I can always enter things in MSL, it's just that the Above Ground Level option is not shown.

 

[mburch]

In my experience, VNAV altitude constraints can only be defined using AGL if the flight plan waypoint is an airport. If you're trying to do this for an intersection, VOR, etc, then it won't work.

 

[iamtheari]

In my experience, VNAV altitude constraints can only be defined using AGL if the flight plan waypoint is an airport. If you're trying to do this for an intersection, VOR, etc, then it won't work.

I'm always doing this for an airport or for a lateral offset before an airport. And I recall both of those working in the past.

 

[Traash]

Work Left to Right (1,2,3).

If you do the offset first you won't have an AGL option.