Ascent / Descent speed

Apologies for launching straight into a question, Ive had a look around but cant see the answer.

I would like to have a switch on my Tx (I have plenty of spare channels etc) to slow the ascent / descent rate down to 1 metre per second or some other figure. I have considered a flight mode on the transmitter to limit the maximum up / down but if I can do it on Pixhawk I should then be able to set in metres or cm’s the rate (I hope).

Thanks in anticipation - John

Thanks Matt, thats the sort of thing but both directions and not in landing mode, a selectable speed limiter…


I thought of the Ch 6 tuning, but couldn’t figure out exactly how to set it up for what you want.
There are some likely looking paramaters but they’re separated out into UP and DOWN velocities, not combined into a single vertical velocity value.

“to have a switch on my Tx (I have plenty of spare channels etc) to slow the ascent / descent rate down to 1 metre per second or some other figure.”

It seems to me you’d need a flight mode as in open tx that would allow you to set a specific pwm value or % that would be high enough to keep the vehicle from falling (as with zero throttle) but low enough to descend slowly instead of maintaining or increasing altitude (as with full or midpoint throttle) This mode would then be mapped to a switch on the transmitter (and probably the stabilize flight mode in ardupilot as alt or POS hold would maintain altitude which is not what you want)

If you try this, I’d be interested in hearing how you do it

Good luck!

Hi. In Mission planner you can set the maximum descent rate / ascend rate (for example 6m/s)
If you then fly in Loiter, PosHold or AltHold mode throttle 0% means you descent with 6m/s and throttle 100% means you ascend with 6m/s.
Depending on the TX you are using (I use a Taranis X9D, and with that it works) you can assign a switch that the min and max limits of throttle are reduced to for example 50%. So you would then speed up / down with 3m/s when the switch is up.
You can also programm one of the knobs S1/S2 to set a GV in Taranis which is then used as the limit for the throttle. With that you can adjust the min max limit of the throttle and therefor the ascend/descend rate stepless from 0% to 100% = 0m/s to 6m/s in that example.

So yes it is possible.

Best regards


Thanks Harald,

I had considered the approach on the Tx which is relatively straight forward to do (its a Jeti duplex DC 24, but wondered if I could do it withing PixHawk to get a more accurate rate, I have to get to 0.5m/Sec. I’ll have a look at the loiter parameters and will give it a try.