20110526013449A

On may 26th, 2011, at approximately 1445 local time (1945 UTC), an airline transport pilot was involved in an aircraft accident while attempting to conduct a run-on landing following an intentional autorotation; this flight operation was in conjunction with a maintenance evaluation of the rotor track and balance. The accident occurred 6.1 nautical miles (NM) northwest of the newton city county airport (kewk), newton, Kansas; actual location of the accident site is in close proximity to Walton, Kansas. The aircraft involved in this accident is owned and operated by a title 14 code of federal regulations (CFR) part 135 on-demand helicopter emergency medical services (hems) operator. Visual meteorological conditions (VMC) prevailed at the time of the accident; clear skies, 10 statue miles of visibility and northeasterly winds at 8 knots were reported via the newton city county airport automated weather observation system. Per the airman's statement, the helicopter was conducting a maintenance flight to complete a track and balance check; this was the eighth (8th) maintenance flight of this particular day. Per the operator, in order to complete the remaining track and balance check, an autorotation was planned with a powered recovery. The autorotation, per the airman, was initiated at approximately 3,000 ft. MSL by reducing the power and down collective; a field was chosen in the event of an emergency landing. Upon initiating the autorotation, the helicopter was flying at approximately 60 knots; initial engine indications were normal. At approximately 500 ft AGL, the airman stated that he elected to initiate the powered recovery by slowly adding power. As the helicopter was descending through 300 ft AGL, the airman indicated that the low rotor RPM annunciator light illuminated, and an audible warning horn was heard. The airman stated that the rotor RPM indicated 80 %. Additional down collective was applied and power was slowly added to initiate the powered recovery; however, based upon the helicopter's current altitude and descent rate, he elected to conduct a run-on landing in the field. The helicopter's approach to the down-sloping, terraced wheat field was in a north-northwesterly direction; approximate heading was 340 degrees magnetic. The helicopter's skids initially contacted the wheat field and traveled approximately 63 feet prior to the front right skid, impacting the terraced, soft ground. Upon the right skid impacting the ground, the helicopter firmly landed; the resultant touchdown caused the tail section to be separated from the fuselage by the main rotor blade. The helicopter's subsequent nose-low attitude caused the low-mounted wire cutter to penetrate into the soft earth, ultimately causing the helicopter to roll inverted, resting approximately 21 feet from the initial skid impact point. An inspection of the wreckage revealed that all flight control surfaces and engine controls were operating properly, with continuity to each system established. Several attachment points and rotor transmission parts displayed overload indications. The helicopter's main rotor remained attached with minimal leading edge damage. Initial investigation indicates that there were no aircraft maintenance issues prior to the accident. Upon recovery, 31 gallons of jet a fuel were strained from the helicopter's fuel tank; additional fuel remained within the helicopter's main fuel bladder. A fuel sample was retrieved from the helicopter's fuel system for additional testing. Additional testing of the helicopter's engine by the manufacturer did not reveal the presence of any anomaly that would have contributed to, or would have been indicative of, an engine failure. The airman and the airframe & powerplant mechanic on-board the helicopter sustained minor injuries as a result of the accident.