History of Flight
On October 16, 2017, about 1918 Hawaii-Aleutian standard time, a Robinson Helicopter R44, N820DF, impacted the Pacific Ocean near Molokai, Hawaii. The flight instructor and commercial pilot receiving instruction are missing. The helicopter was registered to Stasys Aviation Leasing LLC and operated by Hawaii Pacific Aviation, doing business as Mauna Loa Helicopters, as a Title 14 Code of Federal Regulations Part 91 instructional flight. Instrument and visual meteorological conditions existed in the area, and an instrument flight rules (IFR) flight plan was filed. The flight originated from Daniel K. Inouye International Airport (PHNL), Honolulu, Hawaii, at an undetermined time.
Air traffic control (ATC) cleared the flight for a practice RNAV (GPS)-B instrument approach to Molokai Airport (PHMK), after which the pilots requested a pop-up IFR clearance to PHNL. The controller instructed the pilots to depart via the published missed approach to 4,000 ft. The pilots acknowledged. The controller subsequently terminated radar service, approved a frequency change, and informed the flight to return to that frequency after conducting the missed approach.
The flight executed the missed approach and reestablished radio contact with ATC about 1 mile north of PHMK while climbing through 1,700 ft. The controller issued a clearance to PHNL with instructions to fly a heading of 260° and climb to 4,000 ft. About 4 minutes later, the controller issued a heading change to 240°, which the pilots acknowledged. About 2 minutes later, the controller advised that radar contact was lost. No further radio transmissions were received.
Radar data showed the helicopter's track started about 1.3 nautical miles northeast of PHMK and remained on a north-northeasterly heading while climbing from 1,700 ft to 3,500 ft for about 3 minutes. It then entered a left turn to a westerly heading while continuing to climb to 4,000 ft. The track continued westerly for about 2 minutes before beginning a right turn to an east-southeasterly heading. About 35 seconds later, it entered a left turn to a northwesterly heading and began descending from 4,000 ft to 3,700 ft over about 35 seconds. The track then turned left to a southeasterly heading for about 19 seconds while climbing to 3,900 ft. It then turned to a westerly heading and had descended to about 2,700 ft when radar contact was lost about 6 miles northwest of PHMK.
A United States Coast Guard representative reported that after the helicopter was reported missing, debris and a red chemlight were found floating in the ocean northwest of Molokai. The following day, an uninflated life jacket was located along the northwest shoreline of Molokai by the Maui Fire Department. The search was suspended on the evening of October 19, 2017. Water depths in the vicinity of the last radar target varied between 348 ft and 1,812 ft.
Personnel Information
The flight instructor, age 24, held a commercial pilot certificate with rotorcraft-helicopter and instrument helicopter ratings, and a flight instructor certificate with rotorcraft-helicopter and instrument-helicopter ratings. He was issued a second-class FAA medical certificate on January 5, 2017, with the limitation "must wear corrective lenses." He reported a total flight experience of 630 hours, with 300 hours in the previous 6 months.
The pilot receiving instruction, age 27, held a commercial pilot certificate with a rotorcraft-helicopter rating. He was issued a second-class FAA medical certificate on June 2, 2017, with the limitation "must wear corrective lenses." He reported a total flight experience of 139 hours. Flight training records showed that as of October 12, 2017, he had accumulated 186.9 hours, with 18.5 hours in the previous 30 days.
Aircraft Information
The accident helicopter was a Robinson R44 II, four-place, two-bladed, single main rotor, single-engine helicopter with skid-type landing gear. It was equipped with a Lycoming IO-540-F1B5 engine, rated at 260 horsepower but de-rated to a 5-minute takeoff rating of 245 horsepower and a maximum continuous rating of 205 horsepower. The helicopter was certified for day and night visual flight rules operations only.
The most recent annual inspection was completed on September 28, 2017, at an airframe total time of 4,209 hours and engine total time since major overhaul of 2,009.2 hours.
Meteorological Information
At 1854, recorded weather at PHMK (6.3 miles southeast of the last radar target) included wind from 030° at 8 knots gusting to 21 knots, 10 statute miles visibility, light rain, few clouds at 3,300 ft agl, a broken ceiling at 6,000 ft agl, another broken layer at 7,000 ft agl, temperature 24°C, dew point 20°C, and altimeter 30.04 inches of mercury.
WSR-88D radar at Molokai captured base reflectivity at 1917 and 1918, showing moderate-to-heavy reflectivity within the vicinity of the last radar target. The National Weather Service Area Forecast Discussion at 1600 mentioned strong gusty northeast winds and temporary moderate turbulence (AIRMET Tango). Scattered rain showers were forecast with reduced ceilings and visibility. Neither pilot requested an official weather briefing, but one pilot requested ForeFlight weather information at 1803.
Wreckage and Impact Information
In October 2018, a private company located the wreckage submerged about 2 miles offshore of Molokai at a depth of 298 ft. A portion of the wreckage was recovered on January 24, 2019.
Video recordings from a remotely-operated vehicle showed the fuselage severely fragmented and partially embedded in the ocean floor. Both main rotor blades remained attached to the hub; one blade tip was damaged. The tailboom and tail rotor gearbox were separated. The engine exhibited various damage but no pre-impact mechanical failure was evident. Detailed examination of components revealed overload signatures and corrosion from the marine environment.