NTSB Factual Report

HISTORY OF FLIGHT

On November 24, 2011, approximately 1830 central standard time, a Robinson R44 II helicopter, N821JV, sustained substantial damage when it impacted water while maneuvering near Hackensack, Minnesota. The private pilot was fatally injured as a result of the accident sequence, and the passenger sustained minor injuries. The helicopter was registered to Four Winds Leasing, LLC, Walker, Minnesota, and operated by the pilot. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The flight departed Alexandria, Minnesota, at an unknown time.

According to the passenger, she and her husband were returning from Alexandria after celebrating the Thanksgiving holiday. The pilot was maneuvering the helicopter for a landing near his residence, which was located on a lake, where he was going to drop off his wife and then fly to his hangar at his office.

Prior to the landing, the pilot decided to maneuver the helicopter into a low hover over the lake approximately 200 yards from shore. The passenger was not sure why the pilot decided to do that maneuver before landing. While in the low hover over the water, the passenger saw a yellow/orange flash and water splash on the windscreen. The helicopter yawed to the right and went into the water. The pilot and passenger exited the helicopter, and the passenger was able to swim to shore. The pilot was found the following day by divers approximately 75 feet in front of the helicopter.

PERSONNEL INFORMATION

The pilot held a private pilot certificate with airplane single-engine land and rotorcraft helicopter ratings. His most recent Federal Aviation Administration (FAA) third class medical certificate was issued in February 2010. According to the pilot's logbook, he had accumulated 1,659 helicopter flight hours.

AIRCRAFT INFORMATION

The four-seat, single main rotor, single-engine helicopter, serial number 10155, was constructed primarily of metal, and manufactured in 2003. The primary structure of the fuselage was welded steel tubing and riveted aluminum sheet. The tail boom was a monocoque structure in which aluminum skins carried most of the primary loads. Fiberglass and thermoplastics were used in the secondary structure of the cabin, engine cooling system, and in various other ducts and fairings. The helicopter was powered by a 260-horsepower Lycoming IO-540-AE1A5 engine (serial number L-28866-48A) with a maximum continuous rating of 205-horsepower at 2,718 rpm.

A review of the helicopter's maintenance logbooks revealed its most recent annual inspection was completed June 24, 2011, at a total time of 1,142.9 hours. The helicopter's recording hour-meter showed 1,210.5 hours at the time of the accident.

METEOROLOGICAL INFORMATION

At 1917, the Longville Municipal Airport, Longville, Minnesota, automated weather observing system, located approximately 9 miles east of the accident site, reported the wind from 150 degrees at 4 knots, clear sky, visibility 10 miles, temperature minus 1 degree Celsius, dew point minus 2 degrees Celsius, and an altimeter setting of 29.68 inches of Mercury.

According to the sun and moon data, 0 percent of the moon was illuminated. The passenger reported there were possibly two lights that would have been illuminated at their residence at the time of the accident.

WRECKAGE AND IMPACT INFORMATION

The helicopter was recovered from the lake on November 25th and placed in the pilot's hangar. On December 12th, the helicopter was examined by the NTSB investigator-in-charge (IIC), a FAA inspector, a representative from the Robinson Helicopter Company, and a representative from Lycoming Engines.

According to the recovery divers, the helicopter came to rest upright on the lake bottom in 27 feet of water and displayed minimal structural damage. Both doors were open and instrument back lighting was illuminated on the instruments. The landing light was off. The divers turned off the master battery and alternator switches.

Postaccident examination of the helicopter showed the fuselage and landing gear skids sustained minor damage during the water recovery efforts. No evidence of hydraulic deformation was noted on the fuselage. Both main rotor blades were bent, and the main spars were bent aft with compression wrinkles noted on the blade skins. No crush damage was noted on the forward seats.

Examination of the airframe and flight control system components revealed no evidence of a preimpact mechanical malfunction. Flight control continuity was established from the cockpit to the main rotor and tail rotor controls. Several instruments contained moisture and water. The instrument panel caution and warning light bulbs, which lenses were orange and red in color, were examined for filament stretch. The "Low RPM" bulb displayed minimal stretch and no stretch was noted on the other bulbs. The cockpit clock installed on the instrument panel was stopped and read approximately 1830.

Examination of the main gearbox, forward flex coupler, overrunning clutch, intermediate flex coupler, tail rotor drive shaft, aft flex coupler, main gearbox and tail rotor gear box chip detectors revealed no evidence of a preimpact mechanical failure or malfunction. Drive continuity was established from the main rotor hub to the belt pulley. The tail rotor drive shaft was separated aft of the damper bearing and displayed signatures of a rotational fracture. Rotational scoring marks were noted on the upper sheave, clutch alignment strut, and clutch actuator.

The engine was examined and contained water in the engine cylinders, crankcase, intake and exhaust components, and ignition system. Investigators attempted to start and functionally test the engine. The fuel pump functioned properly and pumped fuel to the engine; however, attempts were unsuccessful due to the amount of water in the engine and its accessories. Investigators decided to remove as much water as possible, and then attempt another functional test at a later date.

When power was applied to the helicopter during the postaccident examination, the governor circuit breaker popped and continued to pop when power was applied. The DC to DC converter was then removed for further testing.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was performed on the pilot on November 26, 2011, by the Ramsey County Office of the Medical Examiner. The autopsy reported the cause of death as drowning. There was no evidence of personal flotation devices on board the helicopter, nor were they required.

Forensic toxicology testing was performed on specimens from the pilot at the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The tests were negative for all screened substances.

TEST AND RESEARCH

On February 14, 2012, the engine was examined by the NTSB IIC and a representative from Lycoming Engines at the Wentworth Aircraft facility in Minneapolis, Minnesota. An auxiliary power source was applied to the helicopter and an engine start was attempted using the helicopter's controls. After unsuccessful starts, it was determined that the engine fuel pump was not functioning properly. The fuel pump was removed and replaced with a slave pump. Another engine start was performed, and the engine started. A functional test at various power settings was accomplished for approximately 5 minutes.

On May 15, 2012, the KGS Electronics DC to DC converter was examined by a NTSB investigator, and a representative from Robinson Helicopter Company at KGS Electronics, Inc. facility in Arcadia, California. Examination of the converter revealed the unit was inoperable due to the short-circuit failure of the Q1 power output transistor. The Q1 and Q2 transistors were replaced and the unit operated as designed during the functional test.

NTSB Probable Cause

The helicopter's sudden yaw and subsequent impact with the water for reasons that could not be determined during postaccident examination of the helicopter and its systems.