History of Flight
On August 9, 2016, at 2035 central daylight time, a Hughes 269C helicopter, registration N9277R, impacted terrain following an autorotation near Howe, Texas. The flight instructor was fatally injured, the student pilot sustained serious injuries, and the helicopter sustained substantial damage. The helicopter was privately owned and operated under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. The local instructional flight had departed Sherman Municipal Airport (SWI) in Sherman, Texas, at an unknown time.
According to the student pilot's report to law enforcement and in a written statement, the helicopter was flying at about 1,100–1,200 ft above ground level when the instructor initiated a practice autorotation by reducing the throttle to idle to simulate an engine failure. When the power was reduced, the engine experienced a total loss of power. The instructor attempted to restart the engine but was unsuccessful. The student stated that the autorotation was initially controlled, but the helicopter then impacted terrain in a high-speed descent. The student recalled starting a flare about 25 ft above ground level but had no further recollection. He felt they did not slow the descent enough before contacting the ground. After the crash, the student exited the helicopter and attempted, unsuccessfully, to extricate the instructor before seeking assistance.
The student reported that both he and the instructor were on the controls during the autorotation. However, according to a Federal Aviation Administration (FAA) inspector who spoke with the student, the student stated that the instructor never touched or manipulated the flight controls during the flight or during the accident sequence.
Personnel Information
The student pilot had accumulated 25 flight hours with a local helicopter flight school before flying with the accident instructor. He had stopped flying with that school in October 2012. Since October 2015, the student flew several flights with the instructor and had accumulated 63.7 total flight hours at the time of the accident. Law enforcement records indicate that on July 12, 2014, the student had been involved in a previous accident in the same make and model helicopter. The student told the FAA inspector that the helicopter "got away from him" during that incident, which was not reported to the NTSB.
Aircraft Information
The helicopter's most recent annual inspection, which included 100-, 200-, 400-, and 24-month inspections, was completed on August 10, 2015, at a total airframe time of 5,624 hours and a Hobbs meter time of 13.0 hours. At the time of that inspection, the engine had accumulated 3,664.6 total hours and 392.6 hours since overhaul. The Hobbs meter time at the accident site was 52.7 hours. Review of maintenance records revealed no entries or comments related to idle or mixture adjustments or settings.
Wreckage and Impact Information
The helicopter impacted downsloping grassy terrain adjacent to wooded areas and residential structures. The main wreckage included the fuselage, a portion of the tail boom, and the main rotor system. The landing gear skids were spread apart and bent up into the fuselage. The instrument panel was partially separated. The fuel boost pump switch was found in the OFF position. Flight control continuity was established from the cockpit to all flight controls. The three main rotor blades were bent and deformed but remained attached. First responders noted fuel draining from the fuel tanks.
A detailed examination on August 30, 2016, revealed extensive damage. The tail boom was fractured at the center bulkhead rivet line. The engine remained partially attached; engine control continuity was established but full motion was restricted due to airframe deformation. Thumb compression and valve motion were noted on all cylinders, and all spark plug leads produced spark. The engine could not be functionally tested due to damage.
Additional Information
The Pilot's Flight Manual found at the accident site was last updated in June 2000, while the manufacturer had released nine revisions since, including a complete re-issue in December 2012 with new warnings on practice autorotations and throttle management. The manual's emergency procedures for engine failure above 450 ft described lowering collective, establishing a steady glide at 52 knots, and beginning a flare at 50 ft with a level landing at 10 ft. The air restart procedure stated that if below 2,000 ft, proceed with autorotation landing and pull mixture to idle cutoff.
The November 2014 revision included warnings such as: "Do not rapidly reduce throttle to idle stop in flight" and "rapid throttle reductions to full idle during flight shall not be conducted at any altitude." It also warned against airspeed and altitude combinations inside the height-velocity curve and recommended ensuring the fuel boost pump was activated before autorotation training.
Medical and Pathological Information
The flight instructor died in the hospital on August 10, 2016. The Dallas County Office of the Medical Examiner performed an autopsy, which determined the cause of death as blunt force injuries. Forensic toxicology by the FAA's Bioaeronautical Sciences Research Laboratory was negative for carbon monoxide and ethanol. Testing identified acetaminophen (31.2 ug/ml) in urine, glucose (160 mg/dl) in vitreous, and glucose (18 mg/dl) in urine; the blood sample was unsuitable for analysis of Hemoglobin A1C.