Enroute VNAV - Autopilot

[midlifeflyer]

Will the certified version of the HDX autopilot follow an enroute VNAV profile from a Garmin GTN or Avidyne IFD?

 

[Danerazz]

Reading the HDX manual it appears “no”

I might be wrong, but the “VNAV” according to the manual is only for GP/GS on an approach, or skyview internal vs to waypoint.

At least for Garmin, I’m pretty sure enroute VNAV only works with Garmin autopilots/PFD. Not sure about Avidyne.

That said, the airplanes this system would be installed in would very seldom benefit from that. I’ve looked at Big G and Dynon, and the only things I can’t do with Dynon (as far as I know) are smart rudder bias, enroute VNAV, display a DME, and envelope protection with autopilot off.

None of that is worth the price difference to me, and the flexibility of the Dynon system is appealing.

 

[midlifeflyer]

I might be wrong, but the “VNAV” according to the manual is only for GP/GS on an approach, or skyview internal vs to waypoint.

That's what it sounded like to me too -that "VNAV" in Dynon is "APR" in other autopilots. But I wanted to check with Dynon reps or people who might have a navigator/FMS that does feed enroute VNAV data. It's not just a Garmin thing. Avidyne added enroute VNAV to the IFD.

I'm not sure I agree with

the airplanes this system would be installed in would very seldom benefit from that.

While I'm only asking for information (some asked me) and not doing a value comparison, "benefit" is pretty much a personal preference thing. As is having an AP to begin with. Dynon Certified systems are installed is very capable IFR airplanes - Bonanzas and twin-engine Barons come quickly to mind - and the ability of an AP to automatically navigate a STAR vertically as well as laterally or follow a VDI to "cross FXNME at 3,000" might well have valuable to some pilots.

 

[Danerazz]

That's what it sounded like to me too -that "VNAV" in Dynon is "APR" in other autopilots. But I wanted to check with Dynon reps or people who might have a navigator/FMS that does feed enroute VNAV data. It's not just a Garmin thing. Avidyne added enroute VNAV to the IFD.

I'm not sure I agree with

While I'm only asking for information (some asked me) and not doing a value comparison, "benefit" is pretty much a personal preference thing. As is having an AP to begin with. Dynon Certified systems are installed is very capable IFR airplanes - Bonanzas and twin-engine Barons come quickly to mind - and the ability of an AP to automatically navigate a STAR vertically as well as laterally or follow a VDI to "cross FXNME at 3,000" might well have valuable to some pilots.

I agree the ability would be nice, but I fly a Baron and almost never get a STAR that has lends itself to a descend-via. The ability to fly a VDI to make a crossing restriction would be nice, but not a deal breaker for me.

Reading the HDX manual it appears you can use “skyview” guidance (not IFR certified, so VFR) to follow a path to a point X miles from the airport/runway at Y altitude, but no provision I can see that allows it to do complex descents with stepdowns. There does seem to be some language in there that indicates it would follow a VNAV path if the navigator would generate it, but the wording in different sections of the manual is a little ambiguous and contradictory.

The GTN manuals and AFMS seem to indicate the enroute VNAV capability only when connected to Garmin PFDs. Garmin needs to learn that maybe it’s okay to allow more functionality with third-party systems instead of shoehorning everybody into the “go all Garmin or half of the advertised features won’t work” ecosystem.

Now, if you can do this with an IFD and the HDX, I might consider dropping the GTN on principal.

 

[362PC]

My understanding is that baro correction altitude is necessary between the HDX and IFD for en route VNAV to be fully functional. The IFD installation manual specifically calls this out. Dynon has it on the list of future improvements from what I have heard.

 

[midlifeflyer]

My understanding is that baro correction altitude is necessary between the HDX and IFD for en route VNAV to be fully functional. The IFD installation manual specifically calls this out. Dynon has it on the list of future improvements from what I have heard.

Yes, a baro-corrected altitude source is required for enroute VNAV for both the IFD and GTN. It's mentioned in the user manual for both.

 

[Jhlanzillo]

INSTALLED in 2020 - I HAVE A BONANZA V35B WITH TOTAL DYNON HDX SUITE ( EVERY OPTION OFFERED ) WITH 2X10" SCREENS - AS WELL AS AVIDYNE 440 the simplest most intuitive navigator i have ever used.
ALL DYNON

I FLY FULL IFR - ILS -VOR OR GPS APPROACHES WITH AVIDYNE DRIVING THE DYNON SYSTEM
an ipad 4 sits beneath the ifd 440 converting the ifd 440 into a ifd 550 for pennies on the dollar
a wx 500 storm scope is also displayed on the ifd 440
on my yoke there is a small key pad that will drive the ifd 440 if i do not want to reach across to the panel
if i wish to fly vfr with an autopilot -at times -i will select the dynon gps to drive the dynon autopilot for back up / general practice etc
PMA 450B audio panel