Can someone explain why a sudden ascent during descent?

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Hi there! I couldn't wait any longer for a working camera gimbal assembly to get flying, so I've been flying my P2V+ the past couple of days without the camera installed teaching myself the old stick-and-rudder way (sorta, if only the Wright Brothers had gyroscopic stabilization!). Everything is going great! I've been shocked how similar fixed-wing flying techniques work in the quadcopter world. Coordinated turns especially, I've really found my P2V+ to be a graceful and easily piloted vehicle when you mind your rotor physics. The battery it came with is not in peak health as I'm getting about 8 minutes of active flight time before a full-power bolt will turn the wings red and I bring it back in. I can't wait to get more batteries so I'm not making 3 round-trips back home to charge the battery up for a full afternoon of flying!

One anomaly spooked me that I was curious about whether there was a rational answer for or not. One flight I wound it out to the point I got four wings of red leds at about 200 ft altitude, so I halted my fun and started to bring it in quickly. About 20 feet off the ground it suddenly bolted toward the sky and would not allow my control input to stop it and bring it back into a descent. Again, no up-stick initiated it, it just full-powered upward. About 3 seconds later it returned control to me, but without the camera gimbal attached you can imagine how much height I had gained in 3 solid seconds, now with an even shakier battery situation after that big burst of power, I thought for sure I'd lose the aircraft in a dead tumble. But, I managed to catch it and shut it down before it dropped.

My question is: Is there some environmental trigger that causes this behavior I need to be aware of? Is it indicative of a failing controller battery or receiver interference (lost command link)? Remember, no WIFI extender installed on controller at the moment, purely RX -> P2V+.

Thank you!
 
Sounds like critically low battery, initiated RTH feature, where craft will accelerate to set height ( usually 60-100' up ) then it will stop and then descend down to home point, and land.
You probably noticed all red lights on craft while this was happening.


J Dot
:cool:
 
Sounds like critically low battery, initiated RTH feature, where craft will accelerate to set height ( usually 60-100' up ) then it will stop and then descend down to home point, and land.
You probably noticed all red lights on craft while this was happening.


J Dot
:cool:
I reckon you nailed that one perfectly, the aircraft did exactly as designed. If lsp was looking at the battery level it would have been reading 10% when it went into that sudden ascent to the previously set RTH height.
 
OK, great! Thank you. Anxiety relieved. My over thinking leads me to believe that this would be the ultra-safe logic to follow:

If(BatteryCritical())
{
If(HumanCommandingDescent())
{
AllowTheLandingToCommence();
}
else
{
InitRTH();
}
}


Sent from my XT1254 using PhantomPilots mobile app
 
OK, great! Thank you. Anxiety relieved. My over thinking leads me to believe that this would be the ultra-safe logic to follow:

If(BatteryCritical())
{
If(HumanCommandingDescent())
{
AllowTheLandingToCommence();
}
else
{
InitRTH();
}
}


Sent from my XT1254 using PhantomPilots mobile app
Yes the Phantom should be able to check whether the aircraft is already "returning to home" before initiating the RTH sequence which could (and in your case did) put the aircraft at further risk. It should of course notify the OP that RTH would have been initiated and stop the AC from being manually taken further away from the home point. Pity help the OP and AC if it has been infected with one of those bugs that move the home point as 3.1.2 seems to have done to the P3!!
 

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