Using VS mode on Autopilot...

[hawgdrvr]

Did some work with the autopilot to explore functionality today and further my familiarization. Did a RNAV approach today, finally a successful one but one question regarding descents. I learned from watching various YouTube videos (CitationMax is a good one) set the altitude first then set your descent mode. So I set my altitude and then pressed VS but nothing happened. I realized I had to use the up/down wheel to set the descent rate, which I then set to 500 fpm which is fine.

My question is should there be a default descent rate already configured such that when pressing VS it will start a descent at that time? Or is it preferred, as is, to always have to dial in a descent rate?

[Clay Hammond]

That's how the Garmin logic is set up. Its that way in the GFC700's at the top of the GA heap also. Hit VS and then roll in the rate you want.

All of my time in Cubcrafter's equipment is pre Garmin for the most part, and I don't have experience flying anything but bootleg approaches in them that I had to plug in myself, but usually with an RNAV in a Garmin set-up with any kind of Glide Path component (GP in the scorebox) the autopilot initiates the descent down the approach glide path when the unit is put into Approach mode (APR) and the aircraft is steered to intercept the glidepath. Maybe that option isn't present in the CC installations, I don't know. So specific to what you are asking, for the purposes of an approach, unless it is absolute non-precision with lateral guidance only, then there is a self initiated descent profile by the autopilot following the programmed glidepath in most cases if it is flown in Approach mode.

[hawgdrvr]

Thank you and yes, when it captures glidepath with APR armed, as I did, it does fly down. I've been flying the approach until the FAF which is where that seems to happen. It took me a few attempts at it as it's new to me, mainly the autopilot work, but I think I'm getting it. It is amazing to have this capability in a cub. The autopilot is amazing as well as the other Garmin components. So cool.

[Narwhal747]

Engaging V/S will hold your present vertical speed at the moment you press the switch. That's the way every V/S mode equipped autopilot I've ever flown behaves. It's probably designed that way to prevent abrupt pitch changes. I'm glad you're enjoying flying some approaches in your FX3! Can't wait to try some myself! In some airplanes V/S is the default mode that engages when you turn on the F/D after flying raw data; the Garmin autopilot uses PIT (pitch) mode for this.

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