Moundridge, KS, USA
N863H
BELL 206-L4
While en route to the destination airport, the helicopter impacted terrain in a relatively level attitude at high speed. A review of the helicopter’s Sky Connect flight path showed fluctuations in altitude prior to the helicopter’s impact with terrain. The pilot had severe obstructive sleep apnea known to the FAA and effectively treated it with routine use of a nasal continuous positive airway pressure (CPAP) device, which was found among the pilot’s personal effects in the wreckage. It was not possible to determine whether the pilot had used the device in the days leading up to the accident. Also found among the pilot’s personal effects was a container of nasal swabs marketed for the relief of congestion. It is possible (but could not be conclusively determined) that the pilot had nasal congestion that prevented him from using his CPAP in the day or days leading up to the accident, potentially resulting in severe fatigue on the day of the accident. An examination of the airframe and engine did not detect any anomalies prior to impact. An examination of the helicopter's annunciator panel did not reveal evidence that any lights were illuminated at the time of impact.
HISTORY OF FLIGHT On March 8, 2009, approximately 1426 central daylight time, a Bell 206-L4 helicopter, N863H, was substantially damaged upon impact with terrain near Moundridge, Kansas. The helicopter was owned and operated by Hillcrest Aircraft Company, Lewiston, Idaho. The commercial pilot, the sole occupant of the helicopter, was fatally injured. Visual meteorological conditions prevailed and no flight plan was filed for the Title 14 Code of Federal Regulations Part 91 positioning flight. The helicopter departed Searle Field Airport (KOGA), Ogallala, Nebraska, at 1204 and was en route to the Newton City/County Airport (KEWK), Newton, Kansas. Unless otherwise noted, all times in this report are central daylight time. The helicopter was equipped with a Sky Connect system, which was configured to transmit a position report back to the operator's facility in Idaho every two minutes. The last Sky Connect transmission occurred at 1424 with the helicopter heading 115 degrees, traveling at 113 knots, and at an altitude of 1,749 feet mean sea level (roughly 280 feet above ground level). This last transmission was about 1.38 nautical miles northwest of the accident site. A nearby resident heard the helicopter's engine "rev to a high RPM" twice followed by two to three "thump" or "whump" sounds. There were no reported eyewitnesses to the accident. PERSONNEL INFORMATION The pilot, age 66, held a commercial helicopter pilot certificate with and instrument helicopter ratings. The pilot's most recent flight review was conducted on December 3, 2008 in a Bell 206L-3. On December 4, 2008, the pilot completed the 206B Flight Procedures Training Course conducted by the Bell Helicopter Customer Training Academy. At that time, the pilot reported having accumulated 24,722 total flight hours, all in helicopters. A review of the pilot's experience indicated he had flown various versions of Bell 204s, 205s, 206s, 212s, and 214s. The pilot had reported to the FAA a history of severe obstructive sleep apnea, treated with a nasal continuous positive airway pressure (CPAP) device, and of high blood pressure, treated with lisinopril. He had been granted an Authorization for Special Issuance of Medical Certificate from the FAA for both conditions most recently on December 3, 2008. The pilot’s CPAP device, recovered from the wreckage, did not record actual dates of use, but a report of the data available did document a “90% history of being compliant which includes days of congestion and sleeping quarters with no electricity” and “6.7 hours of usage per night.” AIRCRAFT INFORMATION The seven-seat, single-engine helicopter, serial number 52252, was manufactured in 2000. The airframe had accumulated approximately 2,574.1 hours. The helicopter was powered by a 600 horsepower Allison 250-C30P turbo shaft engine, serial number CAE 895936. The engine had accumulated approximately 2,797 hours. The last inspection was a combined 300-hour/annual inspection accomplished by the operator on January 27, 2009. METEOROLOGICAL INFORMATION At 1415, an automated weather reporting facility at Newton City Airport (KEWK), located about 19 nautical miles southeast of the accident site, reported wind from 260 degrees at 15 knots gusting to 22 knots, visibility 10 miles, clear skies, temperature 55 degrees Fahrenheit, dew point 28 degrees Fahrenheit, and a barometric pressure of 29.94 inches of Mercury. WRECKAGE AND IMPACT INFORMATION The helicopter wreckage was located in a flat, slightly muddy, wheat field. The accident site elevation was approximately 1,476 feet mean sea level. The centerline of the debris path was generally aligned with a 124 degree magnetic heading and was over 100 yards in length. The first wreckage pieces were a damaged right vertical stabilizer along with the “sliced” off portion of the stabilizer; damage appeared consistent with a strike from the main rotor blade. Ground scars consisted of two tail rotor strikes and a gouge following the centerline of the wreckage path. This was followed by four main rotor strikes, pieces of the “red” main rotor blade, and the centerline gouge with two marks resembling the skids contacting the ground. The centerline gouge continues towards the aft cabin section. The tail rotor gearbox was found separated and to the right of the wreckage path, the skids separated from the fuselage, were fractured in multiple places, and were found near the wreckage path centerline. The outer-most portion of the “white” blade was found approximately 50 feet to the right of the wreckage path. Portions of the tail boom and aft fuselage were scattered just prior to the aft cabin portion of the wreckage. Components and personal belongs were scattered throughout the area surrounding the aft cabin and forward cabin sections. The transmission remained attached to the forward cabin section. The engine was the last major component in the wreckage path. The six portions of the tail rotor drive shaft were examined. The coupling closest to the transmission displayed a slight “U” shape bend and was separated from the next portion of drive shaft. The Thomas coupling displayed signs of tearing consistent with rotation at the time of separation. The next four sections of drive shaft were continuous and displayed sign of rotational scoring and gouging in several locations. The sixth portion of drive shaft was separated at the Thomas coupling. This portion of drive shaft displayed signs of rotation and longitudinal scoring. The tail rotor gearbox had separated from the tail boom was found approximately 1/3 of the way down the wreckage path. Both tail rotor blades were still attached to the tail rotor gearbox. One blade was mostly attached while the other was fractured approximately 1/3 span from the blade root. The gearbox and blades were impacted with mud. The tail boom section displayed streaking of mud along the longitudinal axis. The aft cabin section consisted of the floor section from just aft of the pilot’s seat back to the fuel bladder. Although the fuel lines were compromised, the fuel bladder contained approximately five gallons of fuel. The forward cabin section consisted of the flight instruments, pilot’s seat, the left front passenger seat, the pilot’s door structure, and the helicopter’s transmission still mounted to the top of the fuselage. The cabin section was bent, twisted, heavily distorted, and impacted with mud and debris. The roots of both blades remained attached at the main rotor blade hub. The blades were marked as the white blade and the red blade. The white blade broke into four pieces, while the red blade broken into three pieces. When reconstructed, both blades displayed an upward bending tendency, chord-wise scratches, and mud streaks. The engine was located at the end of the wreckage path. An examination of the engine was conducted by a technical representative from Rolls-Royce Engine Company, under the supervision of the National Transportation Safety Board (Safety Board) and the Federal Aviation Administration (FAA). All engine mounts were found fractured in overload. The spragg clutch housing was found fractured with signatures consistent with overload. The governor control arm was found in the “full” position, and when actuated, displayed freedom of movement. The oil tank was breached. Three of the engine’s first stage fan blades were bent in the opposite direction of rotation. Mud intrusion was found throughout the compressor. Fuel was found at both the fuel line at the nozzle and the fuel filter. The fuel spray nozzle was found at least finger tight without the lock wire. Both the gas generator section (N1) and the power turbine section (N2) could be rotated by hand and were found to move free and quiet. Power train continuity was established throughout the engine. The airframe was examined by a technical representative from Bell Helicopters, under the supervision of the Safety Board and the FAA. Cyclic, collective, and anti-torque controls were found fractured in multiple locations with signatures consistent with overload. Extensive impact damage sustained to the cockpit precluded any accurate assessment of switch locations prior to the accident. No pre-impact anomalies were detected with either the airframe or the engine. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the pilot on March 9, 2009, by the Regional Forensic Science Center, Sedgwick County, Kansas, as authorized by the Harvey/McPherson Coroner. The only natural disease noted on the report of autopsy under “Pathologic Diagnoses” was “Moderately stenosing (70% occlusion) atherosclerosis of the left anterior descending artery.” The cause of death was reported as a result of multiple blunt force injuries. Forensic toxicology was performed on specimens from the pilot by the FAA Bioaeronautical Science Research Laboratory, Oklahoma City, Oklahoma. The toxicology report stated no carbon monoxide or ethanol was detected in the blood, and no drugs were detected in the urine. At the accident scene the pilot’s (CPAP) machine was found with condensation in the water tank. Also found was a box of Zicam Cold Relief Gel Swabs. The pilot’s widow reported that the pilot was in good health prior to departing Idaho on March 6. Prior to obtaining his current medical certificate, a sleep study was conducted on the pilot in February 2007. It was determined at the pilot had a sleep latency of 3.5 minutes. On October 25, 2007, the pilot took a Maintenance of Wakefulness Test (MWT). The scoring technician noted that “…this patient did everything, not to fall to sleep....” On October 22, 2008, the pilot’s sleep specialist noted that the pilot “continues to have excellent treatment compliance and is asymptomatic as far as sleep disordered breathing is concerned. He no longer has excessive daytime sleepiness, fatigue or cognitive impairment. A maintenance of wakefulness test conducted a year ago was normal." TESTS AND RESEARCH Pilot Flight History According to company records, on March 6, 2009, the pilot departed Lewiston, Idaho, at 1300 MDT and arrived in Boise at 1500 MDT. On March 7, 2009, the pilot made the following positioning flights: 0811 MDT: departed Boise, Idaho 0949 MDT: arrived Pocatello, Idaho 1057 MDT: departed Pocatello 1321 MDT: arrived Rawlins, Wyoming 1411 MDT: departed Rawlins 1534 MDT: landed in a field near Cheyenne, Wyoming to wait out a snow squall 1626 MDT: departed field 1756 MDT: arrived Ogallala, Nebraska The day prior to the accident the pilot flew almost 7 hour of flight time and was on duty over 9 hours and 45 minutes. The helicopter was on the ground for over 17 hours prior to the accident flight. Light Bulb Analysis The helicopter’s annunciator panel was examined at the Bell Helicopter laboratories in Fort Worth, Texas, under the auspices of the FAA and representatives from the Hillcrest Aircraft Company. All light bulbs were removed, photographed, examined, and returned to their original locations. None of the light bulbs exhibited filament stretching or directional deformation, with the exception of the “low rotor RPM” light bulb. Further examination revealed that the deformation of the filament was consistent with a bulb that was illuminated frequently, but the filament did not exhibit any signs of illumination during the accident sequence. Pilot’s Flight Path The helicopter was equipped with a Sky Connect system which utilizes 66 Iridium low-orbit satellites and an on-board TRACKER-AFF configured to provide position reports every two minutes. While the pilot’s destination was not stated to his company; the helicopter flight path was consistent with a destination of KEWK. Jet-A fuel was available at this airport. A review of the last 12 Sky Connect positions reports show that at from 1400 CDT to 1410 the helicopter descends from 2,100 feet mean sea level (msl) to 1,841 feet msl. At 1412 the helicopter climbed to 1,936 msl, descended to 1,841 feet msl at 1417, and then climbed to 1,867 feet msl. At 1420, the helicopter descended to at least 1,686 feet (approximately 205 feet above ground level), before climbing back to 1,749 msl at 1424. The average speed over these plots is 116.5 knots.
Inflight collision with terrain for undetermined reasons.
Source: NTSB Aviation Accident Database
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