N113CF

History of the Flight

On June 3, 1996, about 1600 Alaska daylight time, a float equipped Robinson R-22 Mariner helicopter, N113CF, crashed on the surface of a small lake about 32 miles southeast of Mekoryuk, Alaska, located on Nunivak Island. The helicopter was being operated as a visual flight rules (VFR) local area business flight under Title 14 CFR Part 91 when the accident occurred. The helicopter, registered to and operated by Bearing Sea Reindeer Products, was destroyed. The certificated commercial pilot, the sole occupant, received fatal injuries. The flight originated at Mekoryuk about 1500.

A company representative reported that the pilot departed for Cape Corwin located on the southeast corner of the island to pick up a company worker. The helicopter did not arrive and did not return to Mekoryuk. The flight was reported overdue at 2313. Search airplanes located the wreckage on June 4, 1996, about 1300, along the south edge of a small lake, about 1/2 mile north of the coastline.

The accident occurred during the hours of daylight at latitude 59 degrees, 54.170 minutes north and longitude 165 degrees, 43.614 minutes west.

Crew Information

The pilot held a commercial pilot certificate with airplane single engine land, airplane multi-engine land, instrument airplane, and rotorcraft helicopter ratings. The most recent second-class medical certificate was issued to the pilot on May 9, 1996, and contained the limitation that the pilot must wear corrective lenses.

According to the pilot's logbook and aircraft logs, his total aeronautical experience consisted of about 1,411.6 hours, of which 890.4 were accrued in helicopters. In the preceding 90 and 30 days prior to the accident, the logs lists a total of 24.5 and 35.3 hours respectively.

On April 14, 1995, the pilot received a biennial flight review that included Robinson R22/R44 Helicopter Awareness Training specified in Special Federal Aviation Regulation (SFAR) 71.

Aircraft Information

The helicopter and engine had accumulated a total time of 1094.3 service hours. The most recent annual inspection of the engine and airframe was accomplished on April 13, 1996, 29.2 service hours before the accident. During the annual inspection, the number 4 engine cylinder was replaced. The helicopter airframe and engine logbooks and daily log sheets found in the helicopter were examined. The maintenance records indicated that on May 14, 1996, ignition noise filters were installed on both engine magnetos. On the same date, an emergency locator transmitter (ELT) was installed and included a remote activation switch installed on the instrument panel.

On May 28, 1996, a certified airframe and powerplant mechanic inspected and repaired the left magneto. In an interview with the National Transportation Safety Board (NTSB) investigator-in charge (IIC), he reported that the pilot called him and requested his services due to a drop in engine RPM. The mechanic indicated that he found the left magneto "P" lead disconnected. The exposed end of the wire was covered by a piece of black tape. He replaced the left magneto's timing gear, points, and coil. He re-timed the engine, performed an engine run-up, and the helicopter was test flown. The mechanic also stated that on June 1, 1996, he called the pilot to check on the status of the helicopter. The pilot informed him that the engine had "lots of power". The mechanic did not make any notation in the engine logbook concerning his work on the magneto. He did produce an invoice that detailed his work. Written on the invoice was "permanete aircraft record". On May 29. 1996, 4.8 hours before the accident, the helicopter daily log sheet noted that the engine oil was changed.

No records of fueling for the helicopter were located. The Executive Officer of the IRA Council, Native Village of Mekoryuk, reported that the helicopter was last fueled before the accident flight from a 50 gallon barrel of 100LL octane aviation fuel. The pilot normally obtained fuel from barrels that are shipped to Mekoryuk by air cargo or barge. Fuel is then hand pumped from the barrels into the helicopter. The hand pump has a spin-on filter and a water separator installed between the pump and the delivery hose. Examination of the water separator revealed water and sediment in the filter bowl.

The operator indicated that the company's supply of fuel had been exhausted. Fuel for the accident flight was obtained from reserve supplies maintained on the island by the U.S. Fish and Wildlife. The specific barrel that the helicopter was fueled from was not initially located during the examination of the wreckage.

Meteorological Information

The closest official weather observation station is Mekoryuk, Alaska, which is located 32 nautical miles northwest of the accident site. At 1600, an automated weather observation system (AWOS) was reporting, in part: Sky condition and ceiling, measured 400 feet overcast; visibility, 3 1/2 miles; temperature, 38 degrees F; dew point, 34 degrees F; wind, 320 degrees at 13 knots; altimeter, 30.54 inHg.

The company worker that the pilot was planning to pickup from the area of the accident reported that the weather conditions on the afternoon of June 3, 1996, were clear without any strong winds.

On the morning of June 4, 1996, the 0655 AWOS observation at Mekoryuk was reporting, in part: Sky condition and ceiling, partially obscured, ceiling measured 100 feet overcast; visibility, 2 miles; temperature, 34 degrees F; dew point, 32 degrees F; wind, 330 degrees at 13 knots; altimeter, 30.45 inHg.

When the Alaska State Trooper arrived at the accident scene on June 4, 1996, at 2100, he indicated that the weather was clear, temperature 58 degrees F, and the wind was from 310 degrees at 17 knots. He indicated that a thick fog bank was located about 20 miles to the north of the accident site.

Wreckage and Impact Information

The NTSB IIC examined the airplane wreckage at the accident site on June 5, 1996. The helicopter was resting on its landing gear floats, partially submerged, against the south shore of a small lake. The nose of the helicopter at the point of rest was observed on a magnetic heading of 238 degrees. The helicopter was floating with the right side about 15 degrees lower than the left. (All heading/bearings noted in this report are oriented toward magnetic north.)

All of the helicopter's major components were found at the point of rest. The float assembly consists of 4 chambers enclosed in a cylindrical tube. The left gear skid assembly was bent in an upward direction at the forward and aft upper attach points. The left float assembly was attached to the skid tube and the internal float chamber adjacent to the left door was punctured. The right gear skid assembly was also bent upward at the upper attach points. The float assembly remained attached to the skid tube and the two interior chambers adjacent to the right door and engine compartment were punctured. The aft section of each landing gear skid tube was bent upward about 10 degrees at their respective aft cross tube attach points.

The helicopter had external cargo racks installed on each side and were mounted between the fuselage and the floats. The racks were buckled in an upward direction and a vertical/diagonal brace at the aft edge of each rack was buckled in an outward direction. Wooden platforms that formed the bottom portion of each rack were found floating in the water near the helicopter.

The cockpit was crushed in a downward direction. The main rotor mast was displaced slightly forward and the forward edge of the mast fairing was wrinkled adjacent to the upper cabin roof. The floor, forward and aft of the front lateral landing gear cross tube assembly, was displaced in a downward direction. The front windshield bow, dividing the left and right sides of the forward windshield, was separated at its upper attach point with the cabin. The windshield Plexiglas was broken out of the frame and only one small portion of the windshield was present at the wreckage point of rest. The forward cabin door posts are both buckled about mid-height in a forward and outward direction. The left and right doors were broken at their respective lower attach points. Both door latch mechanisms were in the latched position but not retained in the airframe latch points. The outer portions of the cabin, below the left and right door sills, were crushed and distorted in a upward direction.

The collective control friction is adjusted by tightening a toggle lever against a vertical metal tab. The lever is installed through the collective handle near the aft end. The friction was found loose and the collective handle was found to be raised about 1/2 inch from full down as measured by the position of the lever against the metal tab.

The tail boom was attached to its appropriate attach points. Minor wrinkling was noted at the tail boom attach point with the cabin. The vertical stabilizer displayed a slight twist to the right with a wrinkle noted beginning just forward of the tail rotor gear box attach point, oriented on about a 45 degree angle from the top of the tail boom toward the right side of the tail boom and progressing in a forward direction. The tail rotor assembly and tail rotor blades were undamaged. The right side of the horizontal stabilizer located on the lower end of the vertical stabilizer was broken and missing. A white paint smear was noted on the top, aft end of the tail boom, just forward of the top tail rotor gearbox bolt, on the top of the bolt and, and also on the top of the tail rotor gearbox.

The main rotor blades were attached to the mast. One rotor blade displayed a small, upward indentation on the underside of the blade at the blade tip. No scratching or gouging of the paint was evident at the dent. The blade also displayed trailing edge wrinkling about mid-span. The second main rotor blad...