WPR18FA188

The pilot's failure to maintain clearance above the surface of the ocean.

The pilot was employed by a US company that leased the helicopter and the pilot's services to a Taiwanese fishing ship. The pilot and the turbine-powered, float-equipped helicopter were stationed on the ship, and a Taiwanese observer provided fish-spotting services. No helicopter maintenance personnel were stationed on the ship. Most of the brief flight was captured by a shipboard surveillance camera. The camera faced forward, with a field of view that included the helicopter on the landing platform, as well as the ocean surface forward of and on both sides of the ship. The ocean surface appeared glassy, with only slight swells and no waves. According to the Federal Aviation Administration, the visual aspects of glassy water make it difficult to judge an aircraft's height above the water, and the smooth, reflecting surface can lead to confusion. The helicopter lifted off and immediately entered a right descending turn, flying out of view on the right side of the image. Several seconds later, the helicopter re-entered the field of view via the upper right image frame. The helicopter was traveling nearly horizontal from right to left at an altitude that was sufficiently low for visible ripples to form on the water surface behind the helicopter. The helicopter struck the water, overturned, and remained afloat inverted. Skiff boats responded to the accident location within minutes, and both helicopter occupants, who were still strapped into their seats, were recovered but unable to be resuscitated Most of the helicopter, absent the tail boom and several main rotor blades, was recovered from the water, transported to shore, and examined two months later. Subsequent recovery and examination of the helicopter revealed no evidence of any mechanical anomalies that would have prevented continued flight above the water surface. Main rotor blade damage signatures indicated that the engine was providing significant power at the time of water impact. Two days before the accident, the helicopter, which had been parked outside on the ship's landing platform, was exposed to a significant storm. Afterward, the pilot initially had some difficulty starting the engine because it had too much water in it. These difficulties, which included the expulsion of oil and smoke from the engine during the start attempts were resolved, and the pilot conducted a subsequent flight (before the accident flight) that lasted 1.5 hours. The oil and smoke were likely the result of a stuck check valve in the engine oil system, which would not have affected engine operation. The pilot's toxicology results indicated the presence of a sedating antihistamine that can reduce reaction time. The pilot's impairment, if any, from this medication could not be determined given the detected level of medication. However, it is possible that the medication affected the pilot's reaction time, which was especially critical given that the glassy, nearly featureless ocean surface could have hampered the pilot's ability to visually determine the helicopter's height above the water surface. This ocean surface condition, either alone or along with a decreased reaction time, could have compromised the pilot's ability to recognize and correct the helicopter's descent toward the water.

Federal Aviation Administration (FAA) records indicated that the US pilot held a commercial pilot certificate with rotorcraft-helicopter and instrument helicopter ratings and a flight instructor certificate with a rotorcraft-helicopter rating. Records and information provided by VSC were incomplete. As of November 2016, the pilot had accumulated about 650 hours of total flight experience, including about 428 hours in turbine-powered helicopters. According to information provided by VSC, the pilot began flying for VSC in 2017. VSC did not provide any information regarding the pilot's flight time at VSC. The pilot's most recent VSC "Annual Competency Check" flight review was completed in March 2018, and his most recent FAA second-class medical certificate was issued in October 2017. No autopsy was conducted on the pilot prior to embalming and transport back to the US. An autopsy was performed by the US Armed Forces Medical Examiner Office at Dover Air Force Base, Delaware. The autopsy report concluded that there was no significant natural disease or trauma, and that the pilot's cause of death was "probable drowning." Toxicology testing detected the presence of chlorpheniramine, (brand name Chlor-Trimeton) a sedating antihistamine, in the pilot's liver. This over-the-counter antihistamine helps control cold and allergy symptoms and may be used as a sleep aid. This medication can slow reaction times and may impair the mental and/or physical ability required for the performance of potentially hazardous tasks. Because this medication has a long elimination half-life (12 to 48 hours), the FAA recommends waiting 5 days after the last dose to perform airman duties. No other screened drugs of abuse or medications were detected in the pilot's specimens. FAA records indicated that the accident helicopter was manufactured in 1978 and was equipped with a Rolls-Royce (Allison) 250-C20B turboshaft engine. VSC records indicated that as of June 30, 2018, the helicopter had accrued a total time in service of about 17,560 hours, and the engine had a total time of about 15,645 hours. The records also indicated that the accident engine had been removed from another VSC helicopter and installed in the accident helicopter on that date. On July 5, 2018, about 0914 local time (coordinated universal time [UTC] + 12 hours), an MD Helicopters (Hughes) 369D helicopter, N8648F, impacted the Pacific Ocean near the Republic of Nauru in the Marshall Islands about 20 seconds after liftoff from a Taiwan-registered fishing ship. The commercial pilot and the non pilot-rated observer (who was the designated fish-spotter) received fatal injuries. The helicopter was destroyed by impact forces and salt water immersion. The helicopter was registered to Vertol Systems Company (VSC) of Hillsboro, Oregon, and operated as a Title 14 Code of Federal Regulations Part 91 aerial observation flight. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed for the flight, which was originating at the time of the accident. There were no known recorded communications between the helicopter and the ship before or during the accident flight. A forward-facing surveillance video camera on the ship captured the helicopter's liftoff and water impact. The permanent-type float-equipped helicopter was positioned on the ship's landing platform, which was about 40 ft above the waterline. The sky was clear, the sea state was calm, and the water surface was glassy in appearance, with no waves and minimal swells. While on the platform, the helicopter faced about 45° to port (left). The left-side of the helicopter was visible and revealed that the left cockpit door was not installed. The helicopter lifted off and began an immediate descending right turn of about 90° heading change and disappeared off the right edge of the image frame. It then re-entered the image frame, traveling from right to left, well ahead of the ship's bow. The helicopter was sufficiently low that it left visible disturbances on the water surface behind it. While still flying forward, the helicopter contacted the surface of the water and immediately nosed over into an inverted position. The wreckage remained afloat, but the low resolution of the image prevented any determination of its condition. The ship captain's statement indicated that two "skiff boats" were dispatched to "rescue" the helicopter occupants. Both occupants were recovered from inside the helicopter, but they were not able to be resuscitated. The wreckage was recovered and secured on the deck of the ship. No other significant details were provided in the ship captain's statement or accompanying incident report. Subsequent documentation showed that the helicopter was placed lying on its right side for transport to shore. About 4 days after the accident, the helicopter was delivered to the VSC facility on the atoll of Majuro in the Marshall Islands. VSC personnel righted and then partially disassembled the helicopter for storage in a temperature- and humidity-controlled shipping container, where it remained until examined by investigators a few months later. The wreckage was examined in Majuro about 2 months after the accident. The fuselage was mostly intact, but most of the tailboom was absent. All four landing gear struts and braces were attached to the fuselage. Crush and skin deformation were observed along the upper portions of the aft fuselage, tailboom fairing, and the upper aft left side of the cockpit. Both aft (cabin) doors were present and attached. Both front (cockpit) doors were absent, and damage patterns were consistent with those doors not being installed for the accident flight. Most windscreen and cabin Plexiglas were absent. The cockpit retained most of its original volume. The "OFF/ON" key, battery switch, and start pump switch were all set to their respective "ON" positions, and the fuel valve handle was found in its open, fuel on position. No seat pan deformation of either forward seat was observed. Both seats were equipped with four-point harnesses. Both lap belts had been cut, presumably by ship personnel during rescue/recovery efforts. The harness webbing remained connected to the inertia reels, which operated normally. Flight controls were installed only at the left cockpit station. Collective control continuity was verified to the top of the tunnel-routed control tube. The cyclic stick was connected to the lateral lower control tube and the lower bell crank, but the upper ends of the control tubes were fractured. The antitorque pedals remained attached and free to move. Continuity was established from the pedals to the upper end of the control tube. Most of the tailboom, including the tail rotor, tail rotor transmission, and vertical and horizontal stabilizers, had separated from the helicopter and were not recovered. Both the tail rotor drive shaft and the tail rotor pitch control tube were truncated at the location of the tailboom separation. The main rotor hub remained attached to the main rotor drive shaft, which remained splined into the main transmission. The helicopter had five main rotor blades. The red and white main rotor blades were wrapped around the rotor head multiple times. A 32-inch section of the yellow main rotor blade remained attached to the hub; the remaining section of the blade was absent. The blue and green main rotor blades were absent. The main transmission was securely attached to the airframe, but was damaged by saltwater corrosion, and mechanically seized. No metal particles were observed on the transmission chip detectors. The engine-to-transmission drive shaft remained connected at both ends. The tail rotor drive shaft remained connected to the main transmission. No distortion or other abnormalities of the KAflex couplings were found. The freewheel unit was removed, and it manually rotated smoothly in one direction and locked in the other direction, consisten