Lost P4P+

PhantomWetSuits · Apr 21, 2018

sar104 said:
I'm a little suspicious that this event might have been due to a loss of power. There were some minor signal issues prior to the end of the log, but nothing that suggested an imminent disconnect. On the other hand, the end of the recorded flight coincides with a maneuver that caused a rapid and large change in aircraft pitch:

View attachment 97695

At 368 s the aircraft was flying in sport mode 18 m/s (40 mph) with full forward elevator, when the pilot applied nearly full throttle. As a result the pitch changed from -34° to -7° in one second, and was still rising when the log ended. That maneuver has, in the past, caused poorly secured batteries to disconnect/eject.

It's not conclusive at all but the coincidence of the maneuver with the abrupt end of the log is certainly suggestive.

We have to agree , with all the research we have done on the battery, sport mode does have the ability to jar the battery , we made a video of it on are site phantomrain.org as we explain why the wet suit locks the battery in .

its worth looking at , but really its more of a sales pitch for the Phantom Rain Wet Suit but supports the disconnect

sar104 · Apr 21, 2018

aPpYe said:
Heh ... actually the drone was found several days ago. Check out a few posts up. I actually did find a guy who lives near me and he came up to try and find it with his Mavic, but we didn't have much luck. What actually helped me the most was the telemetry data from the log. Sar104's red line projection and wind data (a few more posts up) was the most help. I found it just to the right and about 70 yards beyond the end of the yellow line, just as the telemetry predicted... Some strenuous hiking and that fantastic moment when I found it was all worth it. I have my drone back now!

I noticed some weirdness there as well. There is a gap somewhere in the middle with motor speeds of 0 as well... As you indicated, the file may be corrupted somewhat. I am happy to see that the data confused you as well. I did notice that the GPS data does extend perhaps 30 feet beyond what is seen in the txt file. I am glad you know how to decipher the timestamps ... I couldn't figure out how to correlate them with the txt file. It seems the power did indeed go out on it for some reason, and it more or less traveled and landed as predicted given that scenario.

While I am feeling somewhat vindicated as to my poor flying choices, I am now unsure if I can trust it not to do the same thing... Perhaps it powered off because I pushed it too hard? It was in sport mode for several minutes with the sticks more or less jacked up to the tops? I don't know. Wouldn't the electronics have some sort of failsafe for this? After the first crash a few weeks ago, I inspected the esc boards (and every other board) pretty closely and there was no sign of impact or any other damage.

The recorded motor voltage does fall, but it does not look like previous power loss cases, where the inductance of the motor circuit slows the voltage drop at the motor. Here the voltage drops discontinuously from normal (~ 14 V) to around 6.7 V. Voltage and other data continue to be recorded for another 0.02 s. I'm not certain that these data are real, although clearly something did cause it to fall out of the sky at this point.

aPpYe · Apr 21, 2018

sar104 said:
The recorded motor voltage does fall, but it does not look like previous power loss cases, where the inductance of the motor circuit slows the voltage drop at the motor. Here the voltage drops discontinuously from normal (~ 14 V) to around 6.7 V. Voltage and other data continue to be recorded for another 0.02 s. I'm not certain that these data are real, although clearly something did cause it to fall out of the sky at this point.

View attachment 98014

I think I am gonna go with the not being careful about the latch thing... I guess I will fashion some straps or something...

Russ43Phantom · Apr 22, 2018

In my opinion, VLOS means you can see your drone (not just the air space where it is flying) so that you know where it is relative to any manned aircraft and take evasive maneuvers. If you fly beyond your VLOS (meaning you can't see the drone), the guideline is to have spotter along the way with radio communication. Most lost drones seem to be a consequence of feeling that VLOS does not apply. Whether or not you are a US citizen under FAA rules, the guideline is worth honoring.

chazzm · May 2, 2018

aPpYe said:
the main question I have at this point would be where a good point to find the craft would be. Flying at 40mph, with perhaps a 5-8mph tailwind, and considering it is 524 feet above the ground, how far beyond the last known position would you suggest looking? I went perhaps a couple hundred feet beyond the flight path, but perhaps I should have gone further? Honestly, I am loath to make that hike again!

You’d have to take wind direction into consideration at that point as well due to being in Atti mode! Drift

aPpYe · May 2, 2018

I don't remember anything about atti mode. I did find the drone a couple weeks ago though, based on sar104's wind data and that beautiful red and yellow line...