History of Flight
On October 30, 2018, at about 1611 eastern daylight time, an Aerospatiale AS355F2 helicopter, registration N372CA, was destroyed when it collided with a wooden utility pole and power lines while conducting power line construction operations near Beekmantown, New York. The airline transport pilot and a lineman were fatally injured; the pilot-rated passenger and another lineman sustained serious injuries. The helicopter was registered to and operated by Catalyst Aviation, LLC, operating under 14 CFR Part 133 for an external load operation. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight that departed from a designated landing zone near Plattsburgh, New York, at 1602.
The power lines being worked on were supported by two 75-ft-tall wooden utility poles connected by a wooden horizontal bar and two wooden cross bars. The horizontal bar was installed about 6.5 ft below the top of the poles. The lines were oriented northwest/southeast.
The helicopter was equipped with an external bench on the right side of the right landing gear, used by a lineman. The pilot, seated in the front right seat, positioned the helicopter on the left side of the pole so the lineman could work.
Survivors included the pilot-rated passenger (front left seat, observing for training) and one lineman (aft left seat). Two ground witnesses also provided accounts. The pilot-rated passenger stated the pilot was solely controlling the helicopter; it approached the pole, got caught in power lines, struck the pole twice, and rolled inverted. He recalled being upside down with the helicopter on fire and jumping out.
The surviving lineman reported that earlier that day, the pilot had difficulty hovering due to wind during a previous flight. During a tailboard meeting, the pilot noted it was too windy to hover 5-7 minutes for a full block installation but acceptable for a 30-second temporary hang. The team agreed. On the accident flight, the helicopter hovered about 5 seconds for the lineman to place a block on the line, then the skid hit the pole three times, with the third hit hard, causing the helicopter to roll inverted into wires and catch fire.
The linemen's foreman stated that at the meeting, a weight and balance calculation was performed. He observed the approach: the right skid was nearly even with the pole top; the lineman connected the static line and placed the block, then the right skid struck the pole. After a second strike, a third strike caused the helicopter to roll right, main rotor blades hit the adjacent static line and pole top, and the helicopter became entangled in energized 115 KVA power lines and caught fire.
The owner's husband, also a witness, saw the helicopter make a slow approach, engines normal; the lineman began installing the block; the helicopter slid left and right; he thought the right skid struck the pole, causing immediate right roll. The main rotor blades struck the pole top, and the helicopter entangled in power lines and caught fire. He saw all four occupants jump from the burning wreckage.
Personnel Information
The pilot held an airline transport pilot certificate with rotorcraft ratings. His most recent first-class medical was issued August 22, 2018; he reported 16,500 total flight hours. His last flight review was October 16, 2018, in the same make/model. The pilot-rated passenger held a commercial pilot certificate with rotorcraft ratings, second-class medical issued January 19, 2018, with 2,000 total hours, 300 in the accident make/model.
Aircraft Information
The Aerospatiale AS355F2 is a twin-engine light-utility helicopter with two Rolls-Royce 250-C20F engines. The last 100-hour inspection was completed October 28, 2018, at 9,904.3 total airframe hours. Left engine: 11,611.4 total hours, 1,640.9 since overhaul. Right engine: 8,114.9 total hours, 1,684.2 since overhaul. The helicopter had flown less than 1 hour since inspection.
Meteorological Information
At 1553, Plattsburgh International Airport, about 6 miles southeast, reported wind from 290° at 7 knots, visibility 10 miles, overcast ceiling at 3,100 ft, temperature 4°C, dew point -2°C, altimeter 30.06 inHg.
Wreckage and Impact Information
A postimpact fire consumed most of the helicopter. Sections fell from the power lines as the helicopter burned. Found below the lines were cockpit portions, pilot and copilot seats, main rotor system (three blades), combiner gearbox with main transmission, tailboom, and both engines. Seats were extensively fire-damaged; aft seating area consumed. Main rotor system: red and blue pitch change links attached; yellow blade detached from swashplate; blue blade separated three-quarters out; red blade full-length but outer skin separated; yellow blade separated five-eighths out; starflex arm sheared; scissor link and collective collar attached. Main transmission and combiner gearbox separated, undamaged; left-side combiner input sheared. Hydraulic reservoirs crushed, fluidless; fluid at transmission base. Tailboom separated, impact and fire damage. Tail rotor blades attached; one embedded 2 inches in ground, other undamaged. Vertical fin attached with impact damage. Right horizontal stabilizer partially embedded. Landing gear remained in power lines, fire-damaged but mounting sleeves intact.
No. 1 engine: engine bay consumed by fire; combustor impact-damaged; fuel control unit intact but control arm immovable; compressor heat-damaged, liner melted, minor blade tip bending; N1/N2 rotors not rotatable. No. 2 engine: partially buried, fire-damaged; compressor with FOD and rotational scoring; turbine modules showed no FOD or thermal degradation; fuel spray nozzles had small fuel, no debris. Examination revealed no mechanical deficiencies precluding normal operation.
Additional Information
The FAA Helicopter Flying Handbook describes dynamic rollover: a helicopter can roll laterally if a skid contacts a fixed object while hovering sideward, leading to unrecoverable roll if critical angle exceeded. Once started, opposite cyclic alone cannot stop it.
Medical and Pathological Information
An autopsy determined the pilot's cause of death as multiple organ trauma due to a fall. Toxicology testing was negative for carbon monoxide, ethanol, and all tested drugs.