The Charity
Aviation
Maritime
The flight crew were wearing gloves to install batteries into a Mavic 2 Enterprise Advanced. The battery powered-on the UA but when it came to take off, an error was displayed stating that the battery was not inserted correctly. The flight was cancelled. Upon visual inspection, the battery looked as if it was installed correctly, but when it was firmly depressed, 2 audible clicks were heard, and the battery was then secure. It was about 1°C and the flight crew were wearing gloves that would have meant loss of dexterity.
Lessons Learned:
Be aware that wearing gloves will mean that the sense of touch will be less sensitive than normal. This could lead to perception being misled, i.e. the perception that the battery has been installed correctly, when in fact, it has not. The safety of the system was robust enough to give a warning to the Remote Pilot and safety was not compromised at any time. Internal procedural changes to the pre-flight checks are deemed sufficient to prevent a repeat occurrence. An Internal Safety Notice was created to inform all Remote Pilots of the failure.
Procedural changes:
The following improvements are to be made to the pre-flight checklists every time a battery is installed onto a Mavic:
Figure 1 – Battery not clicked into place (note gap)
Figure 2 – Battery securely clicked into place (gap reduced)
This was a well caught and handled incident, that may well have had consequences if it had been any different. If a battery is not properly fitted into the aircraft and contact between the battery and airframe is lost, even momentarily, the motors will stop and the aircraft will descend vertically to the ground. We would recommend: