Flight and Incident
An instructor and a passenger departed on an introductory flight, initial instructional flight, or a combination of both. During the flight, the aircraft was flown down a canyon that the instructor had navigated previously.
Collision with Transmission Lines
As the aircraft approached transmission lines spanning the canyon, it entered an unexplained abrupt nose-down maneuver. The pilot in command did not or was unable to maintain adequate clearance with the lines, resulting in a collision.
Descent
Following the collision, the aircraft descended out of control to the base of the canyon.