Almost a 'fly-away'. What do you think?

[HacKiwi]

Think I almost had a ‘fly-away’ today, but got VERY lucky. Thought I’d share my experience and maybe someone can advise what may have happened.

I've been flying without a glitch or crash since getting my P2V+ in May. Originally it suffered from major TBE but that was corrected.

On the weekend I noticed an odd behavior; while ~100% forward, ~80% down, 80% yaw if I release the yaw/throttle stick the Phantom just stopped dead even though I was still full forward. This was in GPS mode. Releasing forward and pushing forward again returned to normal flight. It was intermittent so I didn't think anything of it - probably unrelated.

Today I was trying to fly over a river through town. I was at 300m range, 50m elevation with full FPV and good line of sight. I titled the camera down and started time-lapse photos and the thing stopped responding and banked hard right disappearing behind a building. I feared the worst, but after a minute I heard it coming home. I figured possibly it lost control signal but that was no excuse for the hard right.

As I was bringing it home it went completely nuts (on-board clip below) what I can only assume full manual control feels like. It was at 40-50m away, clear line of sight (but trees and buildings around) so i don't think it was a control signal. After fighting to get control I gave up and flicked to RTH and it settled instantly. Flicking S1 back to GPS I was able to land – so probably not loss of GPS.

[youtube]https://www.youtube.com/watch?v=piK45x1xrms[/youtube]

Any ideas? Loose connections / interference (flying in the city) / Manual control triggered somehow?

I was Flying in NAZA – GPS mode. Went back out this evening to a nice open park - no problems.

Any ideas?

 

[4wd]

I'd be doing a full calibation of sticks and IMU, and look at the figures in the software to see if anything seems out - before and after.
It does almost look like a sudden interference to your signal, always possible in an urban location.
Since it came back promptly on RTH it must still have had good satellites (K index has been up a bit the last 24 hours)

 

[Panamon Creel]

Also replace the batteries in your Remote Control

 

[flyNfrank]

You wouldn't happen to have a flight logger recording your data would you? I ask because it would be nice to use to see what is shown at the point of doing what it did.

I have had this happen to me a couple of times and each was of a different situation. The spin is caused from the quad searching for a gps signal. The wacky flying is a result of not locating a gps signal and the quad has no idea where it's at. My guess is this is either a loose connection, or a grounding short from a bad aluminum foil gps mod.

My situation took place due to a bad S1 switch that if you barely touched it, it would jump from gps mode to atti mode repeatedly over & over. The other was a loose connection from the gps plug-in point on top of the main board. The plug was all the way in, but the plug itself was loose and wobbled.