Hughes 369D N8688F accident near Ackerly, Texas

Probable cause

The pilot’s failure to identify and maintain adequate clearance from a shield wire that was suspended between power transmission line towers.

NTSB analysis

The helicopter was being used to hoist linemen onto power transmission towers. The helicopter was equipped with a 100-foot external cargo long-line. Shortly after departure, as the helicopter was climbing toward the transmission tower, the long-line collided with a shield wire suspended between transmission towers. The operator reported that the long-line severed about 5 feet above the linemen. The two linemen, who were being hoisted on the long-line, were fatally injured after falling about 200 feet to the ground after the collision. The pilot returned to the landing zone and made an uneventful landing. The operator did not report any malfunction or failures with the helicopter that would have prevented normal operation. The pilot stated that the shield wire installed on the tower had not been identified or discussed during the preflight briefing. He reported that the clear sky condition and the morning light made the shield wire impossible to see from the ground. Additionally, he stated that it was uncommon for shield wire to be installed on the upper tower structures before the lower line work had been completed.

Text from the NTSB. Open the NTSB docket for CEN13LA461 for the full record.