History of Flight
On July 22, 2009, about 1125 eastern daylight time, a Hughes 369D (registration N61735) was substantially damaged during a forced landing in an open field in Forbes State Forest, near Franklin, Pennsylvania, while en route to a temporary landing location. The certificated commercial pilot was fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed. The flight was conducted under 14 CFR Part 133.
The helicopter had arrived in Pennsylvania from California on July 4, 2009, and was under contract to gather 200-250 pound bags of seismic monitoring equipment from remote locations in heavily wooded areas and reposition them. Since arrival, it had logged approximately 72.9 flight hours moving equipment within a 20-square mile area.
On the morning of the accident, the pilot attended a safety briefing at 0600. Around 0730, the pilot and operator departed for the day's operations. The pilot performed a pre-flight inspection, started the engine at 0934, and departed at 0939. The flight returned to the temporary landing area about 1010 to refuel. The accident flight departed about 1030 to retrieve four bags of equipment. During the return, personnel heard the pilot over the communication frequency, with some hearing him say he was "going into the tree[s]."
The helicopter was discovered in a clearing about 250 feet from a paved highway by a passer-by, who reported no noise from the helicopter at that time.
Personnel Information
The pilot, age 33, held a commercial pilot certificate with a rotorcraft-helicopter rating. His most recent FAA second-class medical certificate was issued March 24, 2009, at which time he reported 2,600 total flight hours. According to company records, he had 2,844 total hours, including 1,876 hours as pilot-in-command in turbine-powered rotorcraft and 1,252 hours in the accident make and model. He was hired as a contract pilot on February 25, 2009, and had flown approximately 161 hours with the company, all in the accident helicopter.
Aircraft Information
The helicopter (N61735) was issued an FAA airworthiness certificate on March 10, 1993, and registered to the owner on January 4, 2002. It was equipped with an Allison 250-C20R2 engine. The 100/200/300-hour yearly inspection was completed on June 29, 2009, at which time the Hobbs meter indicated 1,658.3 total hours, airframe 11,621.5 hours, and engine 1,237.2 hours with 852 cycles.
Meteorological Information
An observation at Garrett County Airport (2G4), Oakland, Maryland, about 22 nautical miles southeast, at 1130 included winds from 140 degrees at 7 knots, visibility 10 miles, scattered clouds at 2,100 feet, temperature 22°C, dew point 15°C, and altimeter 30.19 inches of mercury.
Wreckage and Impact Information
The helicopter impacted the ground in an open field 104 feet from a wooded area with trees approximately 60 feet high. It came to rest upright, leaning slightly left on a heading of 170 degrees. The five main and two tail rotor blades showed little leading-edge damage. Two main rotor blades had slight positive coning; one was bent negatively. The aft left tail boom showed deformation, orange paint transfer, and contact marks consistent with main rotor blade strikes. The anti-torque control linkage was continuous. Main rotor drivetrain continuity was confirmed. The tail rotor gearbox rotated freely with oil present. The under-seat collective control rod was fractured; continuity from the fracture to upper flight controls was confirmed.
The right horizontal stabilizer was bent downward. The right landing skid separated and was found 2 feet away; the left skid separated and lay next to the fuselage. The left side and belly exhibited extensive crush damage, consistent with a high vertical descent rate. The left pilot seat box was crushed. All other seats had been removed for increased payload.
The main fuel tank bladder was breached; no residual fuel was found in either bladder or on the ground. The auxiliary fuel tank shut-off valve handle was found in the "CLOSED" position. The main fuel shut-off valve was "OPEN." Fuel lines were inspected; approximately three drops of fuel were found in the line to the fuel nozzle. Lines from the fuel control to check valve and from tank to filter were void of fuel. Battery power was applied, and the "low fuel" indicator illuminated. A functional test of the fuel sending unit could not be performed due to impact damage.
The engine remained attached. The gas producer throttle lever indicated 90 degrees on the quadrant, but rigging continuity could not be verified due to impact damage. The power turbine governor throttle lever indicated a maximum fuel flow condition. Collective rigging to the power governor could not be verified. The 5th stage compressor bleed valve was in the "OPEN" position. Oil was present and clean. The gearbox vent line was separated. N1 rotated continuously; N2 could not rotate. The engine auto-relight system was in the auto position.
The external load and line were located in the wooded area 281 feet at 076 degrees from the helicopter. The load consisted of three orange and one yellow bag, each weighing approximately 250 pounds, totaling an estimated 1,150 pounds. The line was about 200 feet of braided nylon rope and electrical cord. A four-hook metal assembly attached to the external cargo hook weighed about 150 pounds.
Medical and Pathological Information
An autopsy performed on July 23, 2009, indicated the pilot sustained multiple blunt force traumas. Forensic toxicology detected no drugs of abuse.
Tests and Research
A GPS unit from the helicopter was downloaded. Data showed departure at 0936:36, return at 1032:57, and final departure at 1039:42, with recording ending at 1129:19 near the accident location.
The fuel control unit and power turbine governor were tested and found to be functioning normally, with no abnormalities.
The engine was examined and disassembled. The N1 system was continuous; N2 could not rotate due to deformation of the exhaust collector tunnel precluding No. 5 bearing rotation. The bearing was removed and rotated with little resistance. Compressor damage was consistent with vertical axis forces. A longitudinal fracture in the 3rd stage turbine wheel shroud was examined and showed fatigue progression with no mechanical damage or metallurgical abnormalities.
Additional Information
The operator reported requiring pilots to land with at least 70 pounds of fuel on board, noting one instance where fuel was very low. The helicopter was usually loaded with 150 pounds of fuel for flights lasting 30-40 minutes. No load sheet was calculated for each flight.
Employees of the seismic monitoring company stated bags weighed 200-250 pounds, and the individual who attached the last bags reported no problems or changes in helicopter sound.
A GPS log from the owner recorded position every 5 minutes. On the accident morning, the helicopter started at 0934:34 at 2,630 feet GPS altitude. The first speed change was at 0941:49 at 2,727 feet. Flights ranged from 2,091 to 2,768 feet altitude. The accident flight departed at 1044:25. Previous days included 10 flights lasting 18 to 59 minutes.
According to the Rolls-Royce 250-C20R Series manual, cruise fuel consumption varied from 211.1 to 239.8 pounds per hour, not including takeoff power burn of up to 23 pounds in 5 minutes.