On November 17, 1989, a Mcdonnell Douglas 369 (registration N1097G) operated by Helicopters International was involved in an aviation accident near Barstow, CA. Investigators recorded the probable cause as: IMPROPER PLANNING/DECISION BY THE PILOT, AND HIS DELAY IN JETTISONING THE LOAD. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 1 related events involving the same aircraft type or operator are linked below.
A helicopter crashed after its external sling load conductor became entangled with a transmission stanchion crossbar, causing the aircraft to spin and descend.
Accident Overview
A helicopter conducting an external sling load operation crashed after the suspended conductor became entangled with a transmission line stanchion. The accident occurred during a flight to string wire conductors.
Sequence of Events
The pilot began the external sling load operation approximately 1 hour and 15 minutes before the accident. After flying for 1 hour and 5 minutes, the pilot landed and refueled the helicopter at a landing area located 2 miles west of the accident site. Following refueling, he departed on the accident flight.
Video footage showed the helicopter hovering over a transmission stanchion with the conductor attached to the long line. The conductor became entangled with the stanchion's crossbar. The helicopter then began to climb while the conductor remained attached and entangled with the crossbar. Subsequently, the helicopter began to spin to the left in a nose-down attitude and crashed.