It's not really clear what happened. The log for this case is #00015. The matching sensor file is Sensor_00030.txt. It contains the MAVlink messages sent from the drone down to the controller.
I have cut the last 52sec from the flight. It was flown in Angle mode. Then at 11:08:31 switched to RTH for 14sec. This explains the climbing from 10m to 20m.
View attachment 25269
Then again Angle mode and at the last part for 7sec Sports mode with full pitch. Then there is a drop of all telemetry data for 2.5sec. Telemetry came back as the drone was already down. It came back with only invalid data.
View attachment 25268
This is indicated by strange values as for example the 5V values that are not really 5V but an initial value if no data is available. Before the dropout we have had a stable altitude ~23,8m, no descent. Also voltage is not bad. It goes down but this is as expected in Sports mode with full pitch. Speed of the drone is increasing from 4m/s up to 12m/s. At this point we lost telemetry and at least the drone. What happen inbetween, I don't know.
At the location according GoogleMaps there are no obstacles. The H+ is very stable if it windy but maybe a gust of wind or a bird has made the things wrong. Another explanation is total power loss during flight due to battery contact problem. However, signs of live came back when the drone was on the ground.
There are two data sets where the voltage drops to 9.2V for a very short time. This may an be an indicator for contact problems. But this is not seen in the sensor file.
The sensor file shows the same. At the end the current goes high from fair 14-16A up to 32A I think this caused by Sports mode:
65742 00:17:07 voltage: 15.0V current: 15.83A Batt used: 3774.74mAh
onboard_control_sensors_present: 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
onboard_control_sensors_enabled: 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
onboard_control_sensors_health : 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
65891 00:17:10 voltage: 15.0V current: 14.96A Batt used: 3785.31mAh
onboard_control_sensors_present: 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
onboard_control_sensors_enabled: 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
onboard_control_sensors_health : 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
66012 00:17:12 INFO: '(3,25)SPORT MODE'
66013 00:17:12 INFO: '(2,87) not angle mode obs not available'
66043 00:17:12 voltage: 15.0V current: 13.30A Batt used: 3794.84mAh
onboard_control_sensors_present: 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
onboard_control_sensors_enabled: 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
onboard_control_sensors_health : 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
66191 00:17:14 voltage: 14.9V current: 24.56A Batt used: 3811.42mAh
onboard_control_sensors_present: 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
onboard_control_sensors_enabled: 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
onboard_control_sensors_health : 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
66338 00:17:16 voltage: 14.7V current:
32.31A Batt used: 3832.77mAh
onboard_control_sensors_present: 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
onboard_control_sensors_enabled: 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
onboard_control_sensors_health : 3D_GYRO 3D_ACCEL 3D_MAG ABSOLUTE_PRESSURE GPS
Sensor file also stops suddenly and never came back.
The flight review from the ULOG file gives no clear picture for me:
Battery voltage looks normal in ULOG file so far:
View attachment 25270
regards HE