Ground/Air speed variance with VTOL


Today, I transited and flew my freeman 2100 VTOL in fixed-wing mode for more than about 5 seconds. Firstly, I transited it in the sea direction, and stopped it with multicopter mode, and I turned yaw at sea, and planned to test its roll and pitch axis control when I flew from the sea to the land (home position) direction. I observed that the airspeed was 12m/s, but the ground speed was 22m/s during this flight. I calibrated my airspeed sensor properly with Mission Planner, and there was no wind; the wind speed was about 1~2m/s as the sea was very calm. I would appreciate anyone’s opinion on this symptom.

When I transited from the sea to the land (home position), it was very fast and frightened me because the speed did not seem to decrease quickly, when I saw it in very long distance. There was a tall building near the landing site. Nonetheless, I changed to QHover mode very early, and its speed was stopped safely and smoothly, landing well in the designated spot. However, I suspect there may be an issue with the airspeed sensor. before take off, after calibration, I noticed the airspeed value was 1~2m/s, which is normal.

Here is the flight log (bin) file:

I use Pixhawk Cube Orange Plus.

Thank you for anyone’s assistance

@Truth_T , Iam as newbie not able to read your logs but you write an airspeed and a groundspeed which is much faster. and you write that your drone is coming in very fast. So are this values you posted above are the values measured on the inbound course or on the outbound course or the values of outbound and inbound are the same? I assume you are going first straigth outbound and Than same way back inbound.

Oh, Thank you for reminding important thing to write.

I omitted in my post that airspeed was always slower than ground speed, so it was obiously sensor’s problem