Drone Manufacturer: 3DR
Drone Model: Solo
Country: United States of America
Type: Incident
Date: 2019-07-11
Applies: Daytime
Pilot Qualifications: Unknown Status
Pilot Flight Experience: Unknown Hours
Link to External Information About This submission: https://www.safecom.gov/safecom/19-0340
File Uploaded: None
Description
Took off and conducted cross section surveys via Tower app as GCS. Aircraft making way back towards LZ under low power and pilot took over controls {paused Tower, selected “fly mode”}. Pilot began flying towards landing location at 13battery. The aircraft was making a slow return and began acting erratically and not responding to pilot input. AC was confirmed not in RTL. The AC yawed 180 degrees and pitched forward, heading towards a tree. AC appeared to be traveling at max speed. Pilot applied full aft pitch with no response from AC. Pilot attempted to kill power on the AC when it contacted the tree but the rotors remained turning until AC crashed into the ground upside down. AC was powered off and inspected for damage. On the next flight the AC was flying in auto via Tower app. Data link was lost between AC and controller in the same general area of the first flight issue. The AC performed as expected and initiated an RTL back to launch site. Pilot expected to reconnect to AC after RTL was initiated but was never able to reestablish a connection. Aircraft landed under RTL with no issue. 3 power cycle attempts were made on controller to reconnect to AC with no effect. No WiFi signal was detected from the controller after the loss of link. Tower GCS used for the third flight with the same AC. Pause sent to AC to suspend progress and send to another waypoint. AC began acting erratically when trying to send it from one WP to another, and was not moving towards the correct WP. Pilot took over manual control and landed aircraft safely.
Reported Cause
No damage was discovered during the post-crash inspection and the controller link issue was resolved through re-pairing. The AC““s jerky response during waypoint selection is not unusual, however the AC““s flight direction seemed fixed towards the same problematic area of the programmed flight path. AC GNSS was slow to acquire more than 10 satellites though at the time of the third flight, more than 20 satellites were being tracked.There““s no clear issue though the crew will implement the following procedural changes to evaluate the issues: Flight crew plans to repeat the mission after conducting a foot reconnaissance of the targeted building““s roof to ensure there are no obvious sources of interference. AC will remain on the ground, under power, until more than 12 GNSS satellites are being tracked. AC will be calibrated without the FLIR camera attached to reduce the potential for compass errors.