Government UAS pilot reported the UAS struck a tree and crashed while they were diagnosing an automation issue. The UAS was damaged as a result.

Narrative

I was acting as a Remote Pilot in Command of the listed unmanned aircraft for a public safety operation. I was using the unmanned aircraft's automated flight program to fly a grid pattern; which is part of the manufacturer's remote-control software. While the aircraft was maneuvering to take photographs; the aircraft came close to a tree with bare branches. This caused the aircraft's collision avoidance system to engage and stop the aircraft. I switched to manual control of the aircraft; but due to the close proximity of other tree branches; the collision avoidance system on the aircraft would not let the aircraft move from its position. I attempted to move the aircraft forward; reverse; left; right; up and down; but it would only rotate in place. I started walking toward the aircraft's position; but while the aircraft was hovering; the propellers struck a branch; causing the aircraft to fall to the ground. This resulted in propeller damage and damage to the left side landing gear. No other damage was apparent at this time. The area that this occurred was rural; and no other people were in the area; other than public safety personnel. Factors that could have been taken into consideration was the base of the tree in question was approximately 25 - 30 feet higher than all the other trees in the area; due to it being up on an embankment that was higher than the area we were documenting. There were also other trees behind the tree in question that still had their leaves on; making the branches of the bare tree difficult to see. At no point was the aircraft out of the view of the RPIC or other Visual Observers on site. The altitude for the mission was limited to 100 feet AGL; due to the Class C grid. All efforts will be made for future flights to be launched from the highest point in the mapping area; to ensure clearance of all objects.