Hazard Reporting

I wanted to share a story that I heard from an organization that I think is important.

An agency was doing a training mission at night at an event involving a large group of people. The 1st mission went fine and they completed a battery change. The pilot took off with his M30T and started to fly towards the mission area. At some point he received a battery error/warning. The thought was bring the drone back and see what the issue is. The pilot reversed hastily and slowed down prior to entering the LRZ. The pilot landed and had discovered one of the 2 batteries was completely missing. The crews did a cursory search for the battery without success and decided to return in the morning as inclimate weather was coming in and the exercise was ending. The lead pilot returned in the morning to look for the battery. There was a furniture store in the operations area, so the pilot went in to see if anyone had come across the battery. The employee advised that they had not, however they were investigating a leak in the rubber roof. The employee went to the roof and discovered the battery had embedded itself into the roof causing damage. This prompted a notification to the FAA as there was property damage in excess of $500. The investigation following was interesting. The pilots flight records and training records as well as all of the maintenance records of the drone were scrutenized. The battery clip had somehow failed and the battery had come loose. On the braking part of the return trip the battery was probably ejected. Thankfully they were not flying over the crowd and the only victim was the hole in the roof. Keep accurate records and pre-flight checks for even battery swaps. The story was shared with the region without hesitation. Thanks to that agency for being so transparent.