Looks to me that it was a hostage rescue mission, and that they had been locked in an underground bunker, or even buried, and time was running out.

They know the approximate area of the hastages, but not the exact location, perhaps they knew which valley, but not which house, so they go in with FINDER to locate the victim heartbeats.

Hostages are found, rescued, and taken back to be exfiltrated.

Bad actors deploy drones, or hack reaper drones, to destroy aircraft on the ground, to prevent mission success, perhaps kill the hostages as well.

Drones get shot down, additional assets sent in, hostages rescued.

FINDER: Detecting Heartbeats in Rubble and Rescuing Victims of Disasters

https://www.youtube.com/watch?v=u-_qj3AYgmw