I had an 'incident' yesterday which thankfully only cost me a prop, and a little time carefully bending my zenmuse arm straight again but it could have been much worse. I want to get to the bottom of why it happened, but at the moment the info seems unclear. Hopefully I can blame it on pilot error, ensure I don't repeat in future, and therefore trust the phantom again.
I'd been flying my P2 LOS very close for about 10 minutes at most, with gimbal and gopro, and a TK102 tracker (about 40g) attached.
Behaved perfectly and I tested out the failsafe return home by switching off the TX, and it worked perfectly.
Flew it again and it was getting a bit breezy so I moved downhill slightly to a sheltered spot.
That's when there was a problem.
After maybe a minute in the air, the P2 switched into Evil mode (fast red flashing indicating low voltage, but the battery lights were still good), stopped responding, and started to climb rapidly.
I couldn't get any input so I switched to manual and did a heavy landing that caused minor damage (a prop, and a ding on the gimbal).
I have two specific questions about the behaviour of my P2 if anyone can clarify, as this will help put my mind at rest:
1) Low voltage auto landing -
When the low voltage auto landing sequence is invoked (NOT the failsafe return home ie lost signal etc), does the P2 climb to a fixed height first before landing, or does it just descend from wherever it is when the low voltage condition is met?
All the videos I've seen on youtube appear to show that the phantom just descends from the height/position it's current at, and this makes sense to me because if you're at a critical voltage there may not be enough power remaining to climb first before landing, like the failsafe return home function does.
I haven't seen any videos of the P2 or P1 where there is an ascent under the low voltage auto landing, but I really need to clarify if this should be the case or not? Ideally a link to something DJI have written that describes whether this happens or not, or videos demonstrating where it's very evident.
2) GPS home lock (rapid green flashes) -
I've seen it a few occasions now when running the startup sequence of my P2 that it will display the home lock rapid flashing, change to normal operation steady green flash, then some seconds later repeat the home lock rapid flashing a second time.
It then continues with the normal steady green flash and works fine, but I haven't seen other people describe this second home lock behaviour so it makes me slightly nervous that it's not normal and could indicate a problem?
The bottom line is that I think possibly I have a battery problem (I only have one pack so I can't compare), as it still appeared to have good power but also looked like a low voltage incident was triggered (ie the flashing red lights).
Fair enough if that's the case (although I'd still be very upset if I have to pay for a new battery when it's not old at all), but why then did the bird start rapidly climbing at this point instead of landing? All the stuff I've found shows them just landing where they are in low voltage emergency, so it 'seems' more like a flyaway but maybe I'm wrong? Happy to admit to pilot error if that's the case but I want to be able to clearly show that's what happened to give myself reassurance that it wasn't bad behaviour from the P2.
Here are some other details that will get asked I'm sure:
*Compass calibrated immediately before flight.
*Wifi disabled on gopro and phone.
*TX and P2 on latest firmware.
*Battery has only been used approx 11 times.
*Home lock was definitely acquired before lift off.
One other thing I wanted to ask is re' the compass calibration.
A mate has told me that it's important to ensure the P2 is pointing North when you begin compass calibration. I haven't heard/read this until he said it, and non of the videos I've seen suggest this must be done so I'm not convinced, but he says it's important to ensure it works correctly and that it solved a problem he had with his gimbal drifting. Like I say, I'm a bit skeptical about this as it's not the most practical thing that you have to strictly know which way north is every time etc (I know it's not that difficult but still)...
Thanks guys!
I'd been flying my P2 LOS very close for about 10 minutes at most, with gimbal and gopro, and a TK102 tracker (about 40g) attached.
Behaved perfectly and I tested out the failsafe return home by switching off the TX, and it worked perfectly.
Flew it again and it was getting a bit breezy so I moved downhill slightly to a sheltered spot.
That's when there was a problem.
After maybe a minute in the air, the P2 switched into Evil mode (fast red flashing indicating low voltage, but the battery lights were still good), stopped responding, and started to climb rapidly.
I couldn't get any input so I switched to manual and did a heavy landing that caused minor damage (a prop, and a ding on the gimbal).
I have two specific questions about the behaviour of my P2 if anyone can clarify, as this will help put my mind at rest:
1) Low voltage auto landing -
When the low voltage auto landing sequence is invoked (NOT the failsafe return home ie lost signal etc), does the P2 climb to a fixed height first before landing, or does it just descend from wherever it is when the low voltage condition is met?
All the videos I've seen on youtube appear to show that the phantom just descends from the height/position it's current at, and this makes sense to me because if you're at a critical voltage there may not be enough power remaining to climb first before landing, like the failsafe return home function does.
I haven't seen any videos of the P2 or P1 where there is an ascent under the low voltage auto landing, but I really need to clarify if this should be the case or not? Ideally a link to something DJI have written that describes whether this happens or not, or videos demonstrating where it's very evident.
2) GPS home lock (rapid green flashes) -
I've seen it a few occasions now when running the startup sequence of my P2 that it will display the home lock rapid flashing, change to normal operation steady green flash, then some seconds later repeat the home lock rapid flashing a second time.
It then continues with the normal steady green flash and works fine, but I haven't seen other people describe this second home lock behaviour so it makes me slightly nervous that it's not normal and could indicate a problem?
The bottom line is that I think possibly I have a battery problem (I only have one pack so I can't compare), as it still appeared to have good power but also looked like a low voltage incident was triggered (ie the flashing red lights).
Fair enough if that's the case (although I'd still be very upset if I have to pay for a new battery when it's not old at all), but why then did the bird start rapidly climbing at this point instead of landing? All the stuff I've found shows them just landing where they are in low voltage emergency, so it 'seems' more like a flyaway but maybe I'm wrong? Happy to admit to pilot error if that's the case but I want to be able to clearly show that's what happened to give myself reassurance that it wasn't bad behaviour from the P2.
Here are some other details that will get asked I'm sure:
*Compass calibrated immediately before flight.
*Wifi disabled on gopro and phone.
*TX and P2 on latest firmware.
*Battery has only been used approx 11 times.
*Home lock was definitely acquired before lift off.
One other thing I wanted to ask is re' the compass calibration.
A mate has told me that it's important to ensure the P2 is pointing North when you begin compass calibration. I haven't heard/read this until he said it, and non of the videos I've seen suggest this must be done so I'm not convinced, but he says it's important to ensure it works correctly and that it solved a problem he had with his gimbal drifting. Like I say, I'm a bit skeptical about this as it's not the most practical thing that you have to strictly know which way north is every time etc (I know it's not that difficult but still)...
Thanks guys!