Incident Overview
A flight instructor and a student pilot were conducting a training flight focused on confined area and pinnacle landings. The student had practiced several confined area landings in the local area and along a river. After the last landing and takeoff, the instructor took control of the helicopter to give the student a break.
The instructor flew north of the previous landing areas to review the lesson, then turned south and flew along the river, commenting on potential landing sites. The student, looking over his right shoulder at a previous landing area, turned forward and saw wires directly ahead. He exclaimed, "Wires!" and observed the instructor pull up on the collective and apply left cyclic input.
The helicopter pitched up and rolled left, subsequently impacting trees and terrain on the left side of the river.
Accident Site Examination
Investigators found a set of three unmarked wires at the accident site. One wire remained suspended across the river at approximately 40 feet above the water, below the tops of the trees along the banks. The other two wires were lying on the west bank. The helicopter came to rest on its left side among trees about 100 yards from the wires.
Helicopter Damage
Examination of the helicopter revealed that the mast cowling exhibited two marks and tears perpendicular to the mast. The aircraft sustained substantial damage.
Injuries
No injuries were reported by either the flight instructor or the student pilot.