So today while flying on my third battery, everything was going good until it decided to just fall out of the sky.  Spark was loosing power, sputtering, surging, and couldn't hold altitude.  Like a car running out of gas but the battery was still at 75%.  Anyone got any ideas on this one?  Looking back at the flight record it doesnt show that it hit the ground but in the video you can clearly see it do a bounce on the grass (got lucky no damage).  Checked it out and it seemed fine physically but flew it around the yard still same issue.  And yes I was in Sprot mode, it's sunny, clear, no wind, 80 degrees, perfect day for ripping around the neighborhood.  LOL

Hmmm, my first thought was maybe icing on the props since the forum shows you are in Canada, but then I got to the 80 degrees and sunny part and noticed your username (Texas?).  You might try posting a link to your video and uploading your flight record to the following site and posting the resulting URL here.  Maybe someone will spot something that will help you out.

http://www.phantomhelp.com/LogViewer/Upload/

Yeah I have no idea why it says I'm in Canada and I've never found a way to change it.  But you're right I'm in Texas not that bein in Canada would be a bad thing.  But I can throw a log up and a video clip.

Maybe propwash?
Logs or video would help for sure for analyzing.

Here is the log
http://www.phantomhelp.com/LogViewer/368M0ZG8YH2CYO0ZKEPQ/

The only thing interesting I noticed was a 'GPS Position NoMatch" message at 1m 11s into the flight.  Otherwise nothing really interesting.

So is there anywhere I can look to find out what battery I was running at the time of the flight?  I’ve been digging around and I don’t see any battery info such as serial number etc.

Looks like vortex ring state.. Log shows it coming down at over 4ft per second.. even on the video , I have never seen a spark descend that quickly. But, it did recover... not sure it could recover from vortex ring if it really got into that.   Was it just that one time or is the spark still acting strange.  in other words.. does it fly normal except when it is coming straight down?

LouisP Posted at 2018-3-13 10:41
Looks like vortex ring state.. Log shows it coming down at over 4ft per second.. even on the video , I have never seen a spark descend that quickly. But, it did recover... not sure it could recover from vortex ring if it really got into that.   Was it just that one time or is the spark still acting strange.  in other words.. does it fly normal except when it is coming straight down?

Was zippin along until it just came to a halt and fell out of the sky. Did a bounce and then somewhat recovers but was still having trouble staying in the air like the power was cutting out. I landed it checked it out everything looked fine. No cracked props or anything loose. Did a little test flight around the yard between 5 to 30 feet of altitude and 100 foot distance still having trouble staying in the air sputtering around.  So I did a refresh of v.900 took it out on a flight before sundown anything d everything seemed fine.  That’s what made me think of a possible battery problem,  but with 5 batteries I was hoping to narrow it down a little easier. But you’ll notice when it falls it shakes and flutters. I’ve never seen any video before like that.