DUAS 0034 - DJI Mavic 4 screen freeze
Initial Report
When flying drones, it is not only the aircraft that has limitations; the controller itself can become overloaded if too many functions are run at the same time. This report highlights the importance of understanding controller capacity when combining multiple functions such as waypoint flying and screen recording.
Report Text
A DJI Mavic 4 Pro was being flown using the ‘Waypoint Mission’ functionality, with a mission comprising 87 waypoints.
Midway through the flight the pilot switched to the ‘Map View’ screen to check progress. At this point the DJI Fly App froze, and the drone paused in flight at its current position.
Attempts to switch modes on the controller or return to the camera view were unsuccessful. The pilot then initiated a manual ‘Return to Home’ (RTH) using the controller button. The aircraft responded, and control was regained during the RTH operation. However, the Fly App remained frozen until the controller was powered down after landing.
Subsequent investigation suggested a potential issue with the DJI Fly App (running on the dedicated RC2 controller). If a large number of waypoints are used and the view is switched to ‘Map View’, the system may freeze.
The reporter noted that on re-running the same waypoint file the following day, the mission completed without incident. One possible contributing factor was that screen recording had been enabled during the problem flight; this feature was not used during the successful rerun. The reporter’s assessment was that running both screen recording and a large waypoint mission may have exceeded the processing capacity of the RC2 controller. By comparison, they regularly use both features in parallel on enterprise drones such as the M30T/M300 without issue, but those controllers are significantly more capable.
Reporter’s Observations
- No on-screen notice was displayed about a waypoint limit.
- No “Resume” button appeared when the app froze.
- The mission remained wholly within Class G airspace.
- Obstacle avoidance was set to default (on).
- The reseller has not yet been contacted.
- The reporter’s experience suggests the issue was not the number of waypoints per se, but the RC2 being overloaded by simultaneous tasks (screen recording, waypoint mission management, C2 data/video feed).
CHIRP Comment
The Advisory Board made the following observations:
- If there is a maximum number of waypoints, or a CPU processing limit when running multiple tasks, this should be clearly stated in the User Manual. On-screen alerts should also warn the pilot if limits are exceeded.
- In the absence of such guidance, pilots are left to discover operational limits by trial and error.
- Human Factors considerations apply as much to system design and documentation as to pilot behaviour; in this case, the lack of clear limits has created unnecessary risk.
- The Mavic 4 Pro with the Fly App may be more optimised for filming tasks than for complex waypoint mapping.
CHIRP will contact DJI to highlight this report and the concerns raised.