History of Flight
On May 4, 2016, at 1002 central daylight time, an MD Helicopters 369E helicopter, registration N629JK, impacted trees and terrain near Reedsville, Wisconsin. The commercial-rated pilot, who was the sole occupant, sustained fatal injuries, and the helicopter sustained substantial damage. The helicopter was registered to Padgett Ag Air, LLC, of Pawleys Island, South Carolina, and operated by Rotor Blade, LLC, of Georgetown, South Carolina, under 14 Code of Federal Regulations Part 133 as an external load operation. Visual meteorological conditions prevailed, and no flight plan was filed. The flight departed from Manitowoc County Airport (MTW), Manitowoc, Wisconsin, about 0730.
The helicopter was used to transport personnel and equipment for a power line construction project to replace a shield wire with a fiber optic cable. The project began on March 10, 2016, with a basic helicopter and landing zone (LZ) safety course provided by Rotor Blade for construction employees. The project had continued without interruption except for weather delays. On the accident morning, the helicopter arrived at the LZ about 0800. Two job briefings were conducted, and the helicopter was to transport linemen, equipment, and materials to power line tower structures about 125 ft tall using a 50 ft long line attached to the cargo hook. The helicopter flew from 0842 to 0906 and returned to the LZ.
At 0949, the helicopter departed the LZ and transported two linemen from tower 9903 to neighboring tower 9904. After the linemen detached from the long line, the helicopter proceeded east and hovered for 2 to 3 minutes. The linemen requested the helicopter return to tower 9904 to pick up equipment and return to the LZ. The helicopter approached from the southwest, facing northeast into the wind, as the linemen presented hand signals. The linemen reported that the end of the long line was about 20 ft laterally and 15 ft vertically from their reach when they noticed the helicopter's sound change and it descended suddenly. The helicopter veered right away from the tower, and the main rotor blades slowed noticeably. It continued into trees and terrain south of the tower. The linemen climbed down and heard the engine still producing noise; one pulled the emergency fuel shutoff valve and turned off the battery.
Two other project employees about 150 yards north of tower 9904 stated that, as the helicopter approached for the final time, the main rotor blades slowed, the engine sound decreased, and the helicopter veered right toward the ground.
Personnel Information
The pilot's logbooks were not found. Company flight log reports showed the pilot flew the accident helicopter from March 8 to May 3, 2016, for 67 hours, plus an estimated 2.5 hours on the accident morning.
Aircraft Information
The MD 369E has a fully articulated five-bladed main rotor and a four-bladed semi-rigid tail rotor. It was configured to be flown from the left pilot seat. The helicopter had 7,688.4 total time (TT) at the accident. An annual inspection was completed on December 4, 2015, at 7,522.6 hours TT. The engine, a Rolls-Royce 250-C20B, had 1,048.7 hours TT since new. On April 3, 2016, at 987.4 engine hours, a 150-hour inspection was completed, and a fuel control tube was replaced; also replaced were the engine combustion case, combustion liner, and engine bleed valve due to a power transient over-temperature of 850°C for 2 seconds. On April 16, 2016, an inoperative power turbine speed (N2) dual tachometer was replaced. On April 26, 2016, a video showed the dual tachometer indicating about 475 rotor rpm and about 60% N2 rpm. A ground crewman stated the pilot wanted to send the video to a mechanic; the mechanic said he told the pilot not to fly if there was a problem, but they discussed it likely being an indicating issue. The engine was installed new on November 21, 2007. Its accessories, including the power turbine governor (PTG) model AL-AA2, part number 2549170-1, serial number HR48214, were installed new with 0.0 hours TT. No maintenance records indicated work on the PTG after installation. All applicable FAA Airworthiness Directives had been completed. Weight and balance showed the center of gravity within limits; gross weight at accident was 2,097 lbs, maximum 3,550 lbs. The operator was authorized for Class A, B, and C external loads. The helicopter had an Onboard Systems hydraulic hook kit and Rotor Blade H500 side hook assembly. On May 3, 2016, the fuel truck was fueled with 211.3 gallons of Jet-A at MTW. Before the 0800 departure, the helicopter was refueled and departed with 260 lbs of fuel; before the final departure at 0949, it departed with 240 lbs (35.29 gallons), estimated to provide 1 hour 10 minutes of flight.
Wreckage and Impact
The helicopter came to rest in a wooded area about 125 ft south of tower 9904. Surrounding trees were 50 to 75 ft tall, several broken or scarred consistent with impact. All major components were present; the long line remained attached to the cargo hook trailing north. Fuel odor and leakage were noted. On May 5, 2016, a postaccident examination was completed. The main transmission and mounting showed no exterior impact damage; transmission fluid level was full; chip detectors clear; gearbox rotated freely; drive continuity from engine to main rotor and tail rotor verified; overrunning clutch functional. All five main rotor blades remained attached, showing impact damage with minimal preimpact rotation signatures. The aft tail boom was fractured but attached by wiring; forward section remained attached. No evidence of main rotor blade strike to tail boom. Tail rotor gearbox and swashplate operated smoothly; chip detector clear; tail rotor blades and controls responded appropriately. Right horizontal stabilizer crushed inward. Lateral cyclic continuity established through main rotor head; longitudinal cyclic continuity established to fractures in interconnecting torque tube and one-way lock; beyond fractures, continuity to rotor head. Trim actuators near center; could not be electrically tested due to circuit breaker damage. Collective control continuity established; anti-torque control continuity from upper bellcrank to fractures under cockpit floor and to tail rotor control tube. All breaks consistent with impact damage. The instrument console and slant panel were in place but damaged on right side. Battery power applied to test caution/warning panel lights; they illuminated on push-to-test; engine out warning functioned; trim motors and N2 beep did not function due to impact damage. Engine fuel vacuum check showed slow leak on engine side; airframe side held vacuum. Fuel start pump inlets and tank sump area clean; fuel noted in pump inlet port and at nozzle; fuel sender wire verified wrapped around fuel line. About 6 gallons of fuel drained from tank sump; fuel appeared clean. Low fuel warning light functional. The engine and accessories had minimal external damage; mounts undamaged. Pneumatic, oil, and fuel lines showed no damage or leakage; all B-nut connectors at least finger tight. Compressor inlet and visible stages free of foreign object debris. Manual rotation of gas generator drive train free and continuous; power turbine drive train free and continuous from power takeoff to stage four turbine wheel. Upper and lower engine chip detectors clear.
Medical and Pathological Information
The Manitowoc County Coroner's Office completed an autopsy; cause of death was blunt force trauma to the head and chest. The pilot wore an MSA LH250 flight helmet. Toxicology testing by the FAA's Civil Aerospace Medical Institute revealed amlodipine and atorvastatin, both previously reported to the FAA, and negative for other substances.
Tests and Research
The engine was shipped to a Rolls-Royce facility for functional testing. Several start attempts were unsuccessful; fuel was present up to the nozzle with normal spray patterns and pressures. The fuel control unit was replaced, but starts remained unsuccessful. The governor servo pressure (Py) line between the PTG and fuel control was removed and capped; a successful start was made. The PTG was removed and found to have a fractured main drive shaft. With a new PTG and original fuel control, the engine started normally and met production test specifications. On August 9, 2016, the PTG was examined at a Honeywell facility. The governor pressure (Pg) lever clevis fork was bent; the spool bearing assembly was loose within the drive body cavity; the drive shaft guide post was fractured and trapped; metallic debris present; internal bearing elements seized; one flyweight bent; drive shaft fractured at guide post and drive spline. On September 16, 2016, NTSB examination showed a portion of the fractured drive shaft embedded in the spool bearing spindle; fracture surfaces consistent with overstress. The outer cap of the spool bearing was removed; ball bearings and spacers were coated with powdery black particulate; no grease observed; ball retainers fragmented; inner bearing surfaces rough and frosted.