What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The class b external load operation was using a 100 foot long-line to perch 2 workers on the 230 foot tall transmission towers at CR4501 and CR4200, in Lenorah, Texas (martin county). The pick-up site was bounded by 50 foot tall power lines on the east and south. Prevailing winds in the area were 13 with gusts to 17 from the south. There was a 90 degree direction change in the transmission line under construction: the 230 foot towers to the north were behind the helicopter and the towers to the west were to the right of the helicopter, the west towers were being serviced. There were two static wires (lines) connecting the top of the 230 foot tower behind the helicopter (north), to the top of the first 230 foot tower to the right of the helicopter (west). The pilot was in the left seat facing south looking down at the 100 foot long-line with two workers attached. As he lifted the workers, he had to avoid sliding left (east) into the 50 foot power lines and gaining more altitude and airspeed as he avoided the 50 foot power lines in front of him (to the south). He started a right turn toward the west and spotted the 230 foot transmission tower, so he continued his climbing turn to west-north-west.
At an airspeed of above 35 knots, the last 5 feet of the 100 foot long-line struck one of the top static lines and was severed. The two workers fell 230 feet to the ground, sustaining fatal impact injuries. The pilot felt only a slight tug on the long-line as it was being severed by the static wire between the towers.
The pilot did not see the static wires between the towers. When he realized that the long-line was severed, he landed and parked the helicopter at an oil well pump-jack site just east of the pick-up site, past the 50 foot power lines.
As the FAA filed it
THE CLASS B EXTERNAL LOAD OPERATION WAS USING A 100 FOOT LONG-LINE TO PERCH 2 WORKERS ON THE 230 FOOT TALL TRANSMISSION TOWERS AT CR4501 AND CR4200, IN LENORAH, TEXAS (MARTIN COUNTY). THE PICK-UP SITE WAS BOUNDED BY 50 FOOT TALL POWER LINES ON THE EAST AND SOUTH. PREVAILING WINDS IN THE AREA WERE 13 WITH GUSTS TO 17 FROM THE SOUTH. THERE WAS A 90 DEGREE DIRECTION CHANGE IN THE TRANSMISSION LINE UNDER CONSTRUCTION: THE 230 FOOT TOWERS TO THE NORTH WERE BEHIND THE HELICOPTER AND THE TOWERS TO THE WEST WERE TO THE RIGHT OF THE HELICOPTER, THE WEST TOWERS WERE BEING SERVICED. THERE WERE TWO STATIC WIRES (LINES) CONNECTING THE TOP OF THE 230 FOOT TOWER BEHIND THE HELICOPTER (NORTH), TO THE TOP OF THE FIRST 230 FOOT TOWER TO THE RIGHT OF THE HELICOPTER (WEST). THE PILOT WAS IN THE LEFT SEAT FACING SOUTH LOOKING DOWN AT THE 100 FOOT LONG-LINE WITH TWO WORKERS ATTACHED. AS HE LIFTED THE WORKERS, HE HAD TO AVOID SLIDING LEFT (EAST) INTO THE 50 FOOT POWER LINES AND GAINING MORE ALTITUDE AND AIRSPEED AS HE AVOIDED THE 50 FOOT POWER LINES IN FRONT OF HIM (TO THE SOUTH). HE STARTED A RIGHT TURN TOWARD THE WEST AND SPOTTED THE 230 FOOT TRANSMISSION TOWER, SO HE CONTINUED HIS CLIMBING TURN TO WEST-NORTH-WEST.
AT AN AIRSPEED OF ABOVE 35 KNOTS, THE LAST 5 FEET OF THE 100 FOOT LONG-LINE STRUCK ONE OF THE TOP STATIC LINES AND WAS SEVERED. THE TWO WORKERS FELL 230 FEET TO THE GROUND, SUSTAINING FATAL IMPACT INJURIES. THE PILOT FELT ONLY A SLIGHT TUG ON THE LONG-LINE AS IT WAS BEING SEVERED BY THE STATIC WIRE BETWEEN THE TOWERS.
THE PILOT DID NOT SEE THE STATIC WIRES BETWEEN THE TOWERS. WHEN HE REALIZED THAT THE LONG-LINE WAS SEVERED, HE LANDED AND PARKED THE HELICOPTER AT AN OIL WELL PUMP-JACK SITE JUST EAST OF THE PICK-UP SITE, PAST THE 50 FOOT POWER LINES.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.