Incident Overview
A pilot was conducting an external load operation with a helicopter, carrying an external basket loaded with seismic wire bundles weighing approximately 300 to 400 pounds. The load was attached to a 100-foot long-line cable. The pilot flew the load to a staging field and approached a landing area into the wind. He placed the basket on the ground but did not release it.
Maneuver and Sequence of Events
After placing the basket on the ground, the pilot moved the helicopter to the left side of the basket. He then descended laterally to the left by approximately 20 feet, bringing the helicopter to a hover height of about 10 feet. While hovering forward about 10 to 15 feet, the pilot felt a jolt. The helicopter subsequently nosed down to the left and came to rest on its right side.
Company Procedure
The company's procedure for repositioning the helicopter to land with an external load attached specified that "the cable must remain in visual contact with the pilot at all times." The pilot was instructed to "lay the cable out in front of or to the side of the pilot position in full view of the pilot."
Pilot Experience
The pilot had successfully completed a Part 133 evaluation on June 18, 1997. At the time of employment, the pilot had 42 hours of experience in long-line external load operations. Since then, he had accumulated approximately 25 additional flight hours of experience.