Accident Details
Probable Cause and Findings
The pilot's intentional flight into adverse weather conditions, and his failure to maintain altitude/clearance, which resulted in an in-flight collision with terrain. Factors contributing to the accident were the snow and whiteout weather conditions.
Aircraft Information
Registered Owner (Historical)
Analysis
HISTORY OF FLIGHT
On June 21, 2002, about 2319 Alaska daylight time, a Hughes OH-6A helicopter, N345SD, was destroyed during an in-flight collision with terrain while maneuvering, about 15 miles west-southwest of Central, Alaska. The helicopter was being operated as a visual flight rules (VFR) personal flight under Title 14, CFR Part 91, when the accident occurred. The private pilot/operator sustained serious injuries, two of the three passengers aboard were seriously injured, and the third passenger was fatally injured. Instrument meteorological conditions prevailed in the area of the accident, and no flight plan was filed. The flight originated at Eagle Summit, elevation about 4,400 feet msl, and was bound for Circle Hot Springs, Alaska, about 8 miles southeast of Central.
On-site interviews were conducted by the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on June 22. Witnesses said an engaged couple was transported to Eagle Summit in the helicopter for a mountaintop wedding ceremony. Witnesses/wedding guests said when they arrived on Eagle Summit in their personal vehicles, it was windy, but visibility was good, and the clouds were high above the summit. They said they could see worsening weather approaching from the north, and shortly after the helicopter arrived, the weather closed in, and it began to snow. They said visibility was reduced to 100 to 300 feet in wet, heavy, blowing snow. The wedding ceremony was concluded quickly, and the pilot voiced concerns about having to leave the helicopter on the mountaintop over night. The pilot and his wife boarded the helicopter and occupied the front two seats, and the bride and groom occupied the two rear seats. Witnesses said the helicopter lifted off of the ground, made a right turn, and disappeared into the blowing snow en route to Circle Hot Springs. They said they had to remove an accumulation of wet, heavy snow from their cars prior to descending along the summit access road to reach the Steese Highway en route to Circle Hot Springs. About two-tenths of a mile east of the summit access road, on the Steese Highway, the wedding guests spotted the crashed helicopter. It was lying on its belly, facing the highway, in an open, down-sloped area, about 60 yards north of the highway. The tail boom, tail rotors, and main rotor system were separated from the helicopter, and the engine was still running. The occupants of the helicopter were evacuated from the helicopter by the wedding guests, and moved to the highway. Due to the remoteness of the area, the occupants were transported to the hospital by private automobile. The witnesses said the helicopter engine was still running at a high rpm when they left the area.
During an interview with the IIC on July 12, 2002, the pilot said he had flown his wife, and his brother and his brother's fiancée, from Circle Hot Springs to Eagle Summit for a summer solstice wedding ceremony. The ceremony was to be performed about midnight ( midnight in this region of Alaska, at this time of year, is still during daylight hours ). He said he had flown to the area earlier in the day to check the location. He said high ceilings and good visibility had prevailed throughout the day, but the wind was strong when he went to check the area. He said the flight from Circle Hot Springs to Eagle Summit is about 20 minutes. The pilot said when they left Circle Hot Springs for Eagle Summit en route for the wedding ceremony the visibility was greater than 10 miles, and the ceiling was about 8,000 feet msl. He said when they landed on Eagle Summit the winds had died down somewhat from his earlier trip to the summit. He said while they waited for all of the guests to arrive, a line of dark clouds descended on them from the north. He said as the guests arrived it started to snow and the ceiling and visibility decreased. He said the ceremony was concluded rather quickly because of the deteriorating weather conditions. The pilot said after the ceremony everyone was going to meet at Circle Hot Springs. He said as the helicopter lifted off for departure the ceiling was about 600 feet and the visibility was two miles. He said it had stopped snowing. The pilot recalled taking off, making a right turn, and heading downhill toward the road that would lead them back to Circle Hot Springs. He said he could not recall any of the circumstances just prior to, or related to, the accident. He said there were no mechanical problems with the helicopter.
PERSONNEL INFORMATION
The pilot held a private pilot certificate with FAA ratings for airplane single-engine land and helicopter. The pilot did not hold an instrument airplane or instrument helicopter rating. The pilot was issued an FAA Third Class Medical Certificate on July 3, 2001. According to information received from the pilot, he had accumulated 502 total flying hours, 126 of which were in helicopters. All of the 126 helicopter hours were in the make and model of the accident helicopter. The pilot had accumulated 2.2 hours of simulated instrument flying time, and .2 hours of actual instrument flying time. The pilot did not provide information with respect to the date of his last FAA Flight Review.
AIRCRAFT INFORMATION
The accident helicopter was an ex-military OH-6A, which received FAA certification on March 21, 2001. The helicopter was not equipped for instrument flight. At the time of the accident, the helicopter had accrued a total airframe time of 4,388 hours, and 89 hours since the last annual inspection. The engine had accrued a total of 2,466 hours, and 596 hours since overhaul.
METEOROLOGICAL INFORMATION
The closest official weather reporting station is at Fairbanks, Alaska, about 130 miles southwest of the accident location. At 2153 Fairbanks reported winds 300 degrees at 15 knots with gusts to 21 knots. The visibility was 10 statute miles, and the temperature and dewpoint were 51 and 32 degrees F respectively. The sky condition was reported as few clouds at 4,500 feet msl and overcast at 7,000 feet msl. The altimeter setting was 29.81. The altitude of the weather station at Fairbanks is 453 feet msl.
The Fairbanks Next Generation Weather Radar (NEXRAD) loop with a start time of 020621/23:01 and an ending time of 020622/01:02 shows a line of heavy precipitation that transits the area of the accident from west-northwest to east-southeast at the time of the accident.
Numerous wedding guests who saw the helicopter takeoff were interviewed. They all reported high winds and heavy wet blowing snow at the time of the takeoff. Visibility estimates ranged from 50 to 300 feet, with the sky obscured and no discernable cloud bases. All the witnesses said they had to remove an accumulation of heavy wet snow from their cars and proceed with caution down the summit access road to the Steese Highway because of the poor visibility.
A witness, who was not a party to the wedding, was on the summit at the time the helicopter took off. During an interview with the IIC he said that he was a pilot, and when the helicopter landed visibility and sky conditions were good, but the winds were picking up and gusting. He estimated gusts of over 20 knots. He said he watched as the wedding progressed and the weather deteriorated. He said after the wedding ceremony the wedding party got into the helicopter. He said he assumed they got in the helicopter to get out of the weather, which was strong winds, blowing snow, sky obscured, and visibility of less then 100 feet. He said he was surprised when the helicopter's engine started, but thought they were just going to turn the heater on. He said he was more surprised when the helicopter picked up into a hover. He said from inside his camper, about 50 yards from the helicopter, he could only see the red beacon light on the tail, and he could make out the faint outline of the helicopter. He said the helicopter made a hovering right turn and then started forward and disappeared northbound into the blowing snow. The witness provided the IIC with a video tape of the wedding, the deteriorating weather conditions, and the helicopter's departure. The witness said he did not know the helicopter crashed until approximately 40 minutes later. He said the weather cleared and he saw a military helicopter descend toward the highway on the north side of the summit. He said he walked to a point on the summit where he could see the Steese Highway, and the accident site.
Wedding guests said they drove their cars down the summit road northwest bound for about one-quarter mile to the Steese Highway. Once on the Steese Highway they said they drove for less than one-half mile eastbound, and spotted the helicopter on the north side of the highway, about 50 yards from the highway. They said the sky was still obscured and it was snowing.
WRECKAGE AND IMPACT INFORMATION
The terrain sloping down from Eagle Summit to the Steese Highway varies in pitch from gently sloping about 10 degrees to a moderate slope of about 30 degrees in places. The slope is covered with tundra, sparse low growing shrubs about three feet tall, and punctuated with low rock outcroppings. The view from the summit to the highway is unobstructed. The Steese Highway cuts east to west along the north side of the summit hill about 300 feet below Eagle Summit, and extends eastbound along the top of a ridge. The highway is a two lane gravel roadway with shoulders, which is about 30 feet wide. The north edge of the roadway drops off abruptly about 40 degrees for about six vertical feet, and then decreases in pitch angle to about 20 degrees, and then to about 10 degrees where the helicopter came to rest.
The wreckage of the helicopter was located on the north side of the Steese Highway about one-half mile east of the Eagle Summit rest area. The fuselage was on the downhill side of the highway, about 60 feet...
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# ANC02FA057