Odd, the video does not play in Canada. Says not available... must be due to the music (copy write).
Time to use Tunnel Bear
On the OP I don't usually get into these discussions, but this appears to be another case of pushing the copter to the absolute out limits of the battery particularly when the battery is practically new and wonder why after 17 minutes it runs out of juice.
The YT author stated:
(I watched the landing gear come down and it started heading "HOME")
In fact, it did not start heading "HOME" according to the telemetry data.
My memory isn't what it used to be, but I thought (after testing RTH a few times yesterday) the landing gear goes down after the copter reaches the point above where it lands once RTH is activated, correct if wrong, and I very well could be.
However, after looking at his telemetry map and recreating the lon/lat locations according to the telemetry data shown on the video, they don't match. Only the takeoff and crash locations match. For the '1st low battery warning" I took the first lon/lat visible at the top of the telemetry data sheet, then the 'error' line, then the last visible entry. I did the same for the '2nd low battery warning'. With that a rough flight path can be seen.
Location and flight path based on telemetry data in the video:
Pilot's version. He says RTH was activated by the pilot at ~1700 ft at 1st low battery warning, yet by his own picture it is nearly 3000 ft. The picture above is 1700 feet when the 1st low battery warning came on.
Something is not adding up. Then there is the incomplete video and no link to the full telemetry data.
At no time does the data show the flight mode was changed from Angle mode to RTH. It was in Angle mode (3) the entire flight until it crashed, then went to flight mode 12 (crash).
If it's like Arducopter, there should be two sets of data; telemetry from the GCS and flight logs from the FC. How does Yuneec handle it?