Descending Quickly...

[TheTanger]

Is anyone else scared to descend full throttle (like pull the left stick all the way down past the "click")? It looks like my P3S wobbles slightly when I descend too fast. Firmware updated (to address the speed issue in descent I believe-it used to go faster?) but I still am not 100% comfortable pulling the stick ALL the way down in a straight descent. I sometimes do spirals, or small right stick input while dropping faster.

Am I just being paranoid and too worried about Vortex Ring State? I USED to have the prop guards on but rarely fly with them now (the snap on/off type), and I know those can sometimes contribute to VRS a bit more. Just wondering what all your thoughts are on a full speed descent straight down?

 

[msinger]

Full speed straight down is fine -- only if you watch for the wobble. If it starts wobbling, you should back off the throttle.

I find it easier to just never descend at full stick down. I only descend at full stick down when my Phantom is also moving horizontally.

 

[BigAl07]

I descend with some degree of forward motion until ready for the final last few feet but even then I've not had any wobble with the P3. As noted above if you indeed see wobble address it but do so with finesse.

 

[EnterLeftDownwind]

Full speed straight down is fine -- only if you watch for the wobble. If it starts wobbling, you should back off the throttle.

I find it easier to just never descend at full stick down. I only descend at full stick down when my Phantom is also moving horizontally.

If you're already in VRS, "backing off the throttle" would cause the prop RPM to increase in an attempt to arrest the descent. In that case, you can possibly increase the effects of VRS. The safest course of action would be to move forward, backward, or laterally.

Like you, I typically have some forward or lateral movement when descending. If I have a long way to come down, I'll just descend in circles.

 

[msinger]

If you're already in VRS, "backing off the throttle" would cause the prop RPM to increase in an attempt to arrest the descent

A slight wobble does not indicate you're already in VRS. If you're not watching though, then sure, your Phantom might already be wobbling out of control. And, at that point, all you can do is attempt to move horizontally and hope it helps.

 

[EnterLeftDownwind]

A slight wobble does not indicate you're already in VRS. If you're not watching though, then sure, your Phantom might already be wobbling out of control. And, at that point, all you can do is attempt to move horizontally and hope it helps.

Agreed - which is why I prefaced it with "already in VRS"

Easiest solution, like you said, is just to have some forward, backward, or lateral movement while descending.

 

[msinger]

Agreed as well. I was just clarifying my statement so nobody else is confused

 

[TheTanger]

Ok, thanks...glad I'm not the only one nervous about this.

Wonder what the likelihood is for one of these P3's to get into VRS with full stick down...but I THOUGHT there was a firmware out in December that arrested the descent speed-which IMPLIES that DJI is comfortable/programmed in a safe level of descent even with full throttle down?

Obviously YMMV and it would be foolish not to pay attention to wobble...but just wondering if their limiter addressed that and some wobble is fine now? (Even though I would still be careful-as any wobble scares me).

 

[msinger]

VRS is not common with the P3. It's not something you should totally ignore though. Anything is possible.

 

[TheTanger]

So I found it...DJI Forum|New Firmware for the Phantom 3 Series

It was really because of the low voltage battery scares (overtaxing battery) of people taking off with 70% full batteries. In doing so, they decreased the up and down speeds as well.

1. In cold environments, propulsion output is automatically adjusted based on battery temperature and cell voltage. Horizontal and vertical speed is also decreased to avoid triggering battery protection.
2. Optimized battery management.