Drone Manufacturer: DJI
Drone Model: Phantom
Country: United States of America
Pilot Qualifications: Unknown Status
Pilot Flight Experience: Unknown Hours
Link to External Information About This submission: https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/98099/pdf
File Uploaded: None
The sUAS was operating under the provisions of Part 107 within Class G airspace. The pilot was appropriately certificated for the flight.
Examination of the drone data logs revealed no anomalies with the aircraft or software. The drone responded to control inputs as expected. The pilot erroneously believed that the “down and in” CSC input would result in a landing or in-flight shutdown of the motors. The Phantom 4 user manual specifies that the “down and in” CSC shuts down the motors only when the drone is on the ground. Inputting that command in flight would result in the drone yawing right, pitching backward, and banking left. Logs indicated that the drone maneuvered consistently with the stick inputs. Further, the pilot indicated the drone would not land. Logs indicate that he used the Autoland feature, which scans the landing surface with optical sensors (Visual Positioning System or VPS) to determine if the surface is suitable. Logs indicate the VPS did not calculate a suitable landing surface. This is consistent with the pilot’s report of trying to land on a plastic table, which likely created excessive reflections. In order to conduct a normal landing, the pilot would need to switch out of Autoland, or override it by holding the throttle (left stick) fully back for 2 seconds. Logs indicate the aircraft remained in Autoland mode, and the stick was not pulled fully back for more than ½ second at any time.
The demonstration flight was conducted in a small area, confined by trees, and within close proximity of the observers, 10 feet or less according to witness statements. Although there is no evidence that the pilot flew directly over unprotected persons, or purposely in a hazardous manner, at the time that he perceived a problem with the drone and decided to crash it, the close proximity to the observers should have been accounted for either by warning them to clear away, having an assistant do the same, or to conduct the forced landing in an area clear of the observers.
At the time of the incident, the university and CMI did not have any documented procedure for conducting such demonstrations. Although not required by regulation, the incident pilot did not have any documented aircraft-specific training that might have included the flight manual procedures noted above.
The National Transportation Safety Board determines the probable cause(s) of this incident to be:
the drone pilot’s incorrect control inputs due to insufficient knowledge of the aircraft flight manual procedures.
Contributing to the incident was the close proximity of the observers, and the decision to conduct a demonstration near the observers in a confined area with no assistance.