Government UAS crews reported system failures with two UAS during a mission. In the first failure the crew experienced a lost link and fly away which resulted in the UAS crashing and being recovered. In the second failure the UAS lost link and initiated automated return to home where it landed without damage.
Synopsis
Government UAS crews reported system failures with two UAS during a mission. In the first failure the crew experienced a lost link and fly away which resulted in the UAS crashing and being recovered. In the second failure the UAS lost link and initiated automated return to home where it landed without damage.
Narrative
On Day 0; Person A with the Police Department was alerted to an active call to search for a wanted subject who was evading police. Person B requested assisted with the drone so Person A and Person C responded to the scene.Person C assembled Aircraft X sUAS while Person A obtained information on where the Officer In Charge (OIC) wanted officers to concentrate their search. After Person C assembled Aircraft X; Person A verified it was all put together correctly. Person A started up Aircraft X and everything appeared to be working as usual. Person A took off and flew straight up to an altitude of about 100 feet. The drone briefly lost connection but it regained signal after about 2 seconds and the sUAS started responding again. Person A then started flying Aircraft X north. While flying north; Person A was also increasing the altitude. After flying for about 100 yards; Person A observed the sUAS stopped moving forward. Person A looked down at the controller and it indicated the sUAS had lost connection with the controller. This is a common occurrence but the sUAS is programmed to hover in place for a few seconds and if it still does not regain connection; it is programmed to fly straight up to around 400 feet and the return to the place it took off from. Instead of hovering in place; Person A observed the sUAS start to loose altitude despite no input from Person A's controller. After a short time; the sUAS had lost enough altitude that Person A lost sight of the sUAS behind a building. The controller continued to indicate no signal with the sUAS. Person A immediately informed Person B of the issue. Person A and Person C then went looking for the sUAS in the last known location. It was ultimately located about 100 yards from the starting point stuck in a tree. The sUAS was on north side of the tree; the opposite side from where Person A had started from indicating it did not fly straight into the tree; rather; it would have had to land or come from the top to get into that position. There were other sUAS in the area at the time of the flight as well as numerous first respond vehicles and equipment; however; we have never had issues before with having these in the area.
Second reporter narrative
On Day 0; Person A; Chief Pilot with [the] Police Department; flew the agencies Aircraft Y in support of the Police Department; Location A as they searched for a suspect. First two flights were uneventful. During the third flight Person A experienced an sUAS system failure that cause the sUAS to climb to 400 feet AGL and fly away to a distance of 1;406 feet before the link was lost. After the designated wait time the sUAS initiated its programmed return to home flight. It landed without incident. Person A grounded the sUAS until system checks are performed.Aircraft Y communicates with the remote controller using 2.4 GHz and 5.8GHz. The sUA automatically selects between the frequency to ensure the best transmission channel and it does this without latency.The following software and firmware versions were in use:App vX.X.X.XXAircraft Version XX.XX.XXXXRemote Controller XX.XX.XXXXGimbal XX.XX.XX.XXCamera XX.XX.XX.XXBattery XX.XX.XX.XXThese were not the most recent updates. [Approximately one month later] drone company issued firmware updates for Aircraft Y; the Remote Controller; and the App to fix some minor bugs according to drone company's release notes.The Failsafe Return to Home (RTH) feature automatically activates after the remote-control signal is lost for more than two seconds. When Failsafe RTH is activated; the sUAS starts to retrace its original flight route home. If the remote-control signal is re-established within 60 seconds the Failsafe RTH being activated; the sUAS hovers at the present location for 10 seconds and waits for pilot commands. If no commands are received after the 60 seconds; the sUAS stops retracing its original flight route and flies to Home Point in a straight line.For several minutes it appeared the sUAS was losing the signal then reacquiring it. The sUAS was in a hover at 6 feet AGL less than 10 feet from the pilot. The sUAS was not obeying commands from the pilot. After the several minutes had passed the sUAS began an uncommanded climb to more than 400 feet AGL then flew away to a distance of more than 1;400 feet. Another one to two minutes passed when signal reacquired and the sUAS began RTH to Home Point where it landed without further incident.Two days after the event; the Maintenance Chief for aviation section conducted several test including flights without a repeat of this incident.
NASA callback
The reporter had no additional information to share.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.