Baring, WA, USA
N55NW
Agusta A109A II
The pilot aborted his mission due to snow, rain and foggy conditions and the aircraft remained overnight in an open field. The following morning the pilot departed to return to his base and shortly after takeoff he radioed that he had lost power in the #1 engine. He returned to the departure site and about 200-300 feet above ground lost power in the #2 engine. The rotorcraft pitched nose down and landed hard. A witness reported a mix of rain-snow, freezing temperatures and low ceilings at the time of the accident. Post-crash examination of the aircraft revealed no mechanical malfunctions. A laboratory examination of fuel from several sources within the rotorcraft as well as both airframe fuel filters revealed no significant anomalies. Both engines were test run at the manufacturer's facility with no indication of any mechanical problem and the #2 fuel control unit was flow checked and examined. The RPM WARN CB was observed to be tripped at the accident site and tests demonstrated that with this CB out, the engine failure and low rotor RPM lights and horns were inoperative. The engine DEICE locking toggle switches (engine anti-ice system switches) were observed in the off position at the accident site. The Flight Manual contained no Height-Velocity Diagram for a two-engine inoperative condition.
HISTORY OF FLIGHT On January 20, 2002, approximately 0750 Pacific standard time, an Agusta SpA A109A II rotorcraft, N55NW, registered to Aero Incorporated, being operated by C. J. Systems Aviation Group, and being flown by an airline transport rated helicopter pilot, was substantially damaged during a hard landing after the sequential loss of power in both engines one and two shortly after takeoff. The aircraft crashed a short distance from its takeoff point near Baring, Washington. The pilot, who was the only occupant aboard, sustained serious injuries, and there was no post crash fire. Variable meteorological conditions existed at the time of the accident. The aircraft was being operated as a positioning flight under 14CFR91, and had just departed from a landing site near Baring, approximately 0745. The operator reported that the helicopter had been dispatched under a contract with Airlift Northwest as a medical evacuation flight late on the previous day operating under 14CFR135, but had aborted the mission due to weather, landing in a field near Baring. The pilot reported upon landing that it was "...pitch black, snowing, raining, and fog..." (refer to attachment ADS-I). N55NW remained parked over night in an open field and the pilot remained at the Skykomish Fire House for the night. He contacted Airlift Northwest Dispatch at 0607 on the morning of the accident and advised that he "...would head out to [the] aircraft when it was light and see if they could get out...." The pilot radioed Command 50 (the county fire department radio frequency for Fire District 50) shortly after takeoff that he had lost power on the number one engine and was returning to land. Shortly thereafter he radioed that he had lost power on the number two engine and he attempted to execute an autorotation landing. A witness reported that the aircraft was approximately 200-300 feet above ground and that the nose dropped from a hover and the rotorcraft went right on over the trees and impacted the terrain. PERSONNEL INFORMATION The Operator reported that the pilot's total flight experience was in excess of 7,400 hours of which more than 6,900 were as pilot-in-command (PIC) and more than 7,200 hours were in rotorcraft. The Operator provided the following flight time for the pilot: Total* Night Day IFR (actual/simulated) Last month: 007.8 004.5 003.3 000.0 Last six months: 110.6 038.9 071.7 004.0 Last 12 months: 188.2 063.9 124.3 004.0 *all in the Agusta A109A The pilot holds an airline transport rating in helicopter and a commercial certificate with an instrument rating in aircraft single engine land. His last medical (first class) was accomplished on October 9, 2001, and contained the limitation that the "Holder must possess corrective lenses for intermediate and near vision." The pilot accomplished a recurrent flight check in an Agusta A109A rotorcraft on October 22, 2001. The check flight documentation sheet showed that the pilot started the aircraft with a circuit breaker out and forgot to turn the pitot heat on (refer to attachment FC-I). The pilot reportedly had no recall of the accident scenario following the accident. AIRCRAFT INFORMATION The Flight Manual for the Agusta A109A II rotorcraft contained a reference in Section II "Normal Operating Procedures" which stated under 'ENGINE START' the following caution: "If the OAT is 4 [deg] C (40 [degrees] F) or below and if visible moisture is present the anti-icing must be ON" (refer to attachment FM-I). This constraint was not a part of the FAA approved CJ Systems abbreviated checklist (refer to attachment CL-I). The air intakes for the left and right engines on the A109A II are situated on the left and right sides of the rotor pylon and centered roughly between the leading and trailing edge of the pylon. The intakes were covered with open multiple panels attached by screws and covered with an approximate one-quarter inch mesh screen (refer to photographs 1 and 2). The engines on the rotorcraft were not equipped with particle separators. The individual engines were equipped with a de-ice (bleed air anti-ice) system. The rotorcraft was not equipped with an auto-ignition or continuous ignition system. A test of another one of the Operator's Agusta A109A rotorcraft revealed that when the "RPM WARN" (low rotor RPM) circuit breaker was pulled the engine failure and low rotor RPM lights and horns were inoperative. Although the Flight Manual contained Height-Velocity Diagrams for one-engine inoperative conditions and two different weights, there was no Height-Velocity Diagram for a two-engine inoperative condition. METEOROLOGICAL INFORMATION An Inspector from the Federal Aviation Administration (FAA) interviewed the Skykomish Fire Chief who witnessed the rotorcraft's takeoff and the accident. The Fire Chief reported that the temperature at the aircraft upon his arrival (with the pilot) was 38 degrees F. and that at the time of takeoff the weather was clear with no blowing snow, rain or snow falling, but there was a little mist at the time (refer to attachment EI-I). The Inspector also reported that in a telephone conversation with the Skykomish Fire Chief he "...asked him about any covers on the air intakes and he [Fire Chief] said that he had not noticed any...." Another FAA Inspector interviewed a Washington State Patrolman who was at the accident site immediately following the crash but did not witness the accident. The Trooper noted, "...the weather at the time of the accident was around 32 degrees F., overcast, with mixed rain and snow..." (refer to attachment RV-I). A special weather observation taken at Stampede Pass (SMP), Washington, (30 nautical miles southeast of the accident) at 0746 reported in part 0.25 statute miles visibility in light snow and freezing fog, indefinite sky condition 100 feet, temperature and dew point both -1 degrees C. SMP is located 3,964 feet above sea level. WRECKAGE AND IMPACT INFORMATION The aircraft crashed within a small clearing of blackberry brush in a wooded area approximately one-quarter mile west of Baring, Washington. The accident was approximately 47 degrees 46.4 minutes North latitude and 121 degrees 29.3 minutes west longitude and about 750 feet above sea level (refer to Chart I). An FAA Inspector assigned to the Seattle Flight Standards District Office (FSDO) examined the rotorcraft at the accident site. The airframe remained intact and the rotorcraft was observed in an upright attitude. There was no post-crash fire and all major components (tail rotor assembly, main rotor blades, main rotor head) were accounted for (refer to photographs 3 through 5). On site examination revealed the engine #1 power lever in the "IDLE" detent and the engine #2 power lever in the "FLIGHT" detent (refer to photograph 6). Additionally, both the #1 and #2 engine "DEICE" locking toggle switches were found in the "OFF" position (refer to photograph 7). Also, the "RPM WARN" (low rotor RPM) circuit breaker was observed to have an orange collar on it and the circuit breaker was in the out position (refer to photograph 7). TESTS AND RESEARCH Following its recovery from the accident site, two FAA Inspectors examined the rotorcraft. The lead Inspector reported that continuity was established for all flight and engine controls as well as from the engines to the rotor. He also reported that fuel was present at the fuel nozzles of both engines and that both airframe fuel filters were full of clean fuel and that oil was present in both engines. Additionally, he found fuel in both engine driven fuel pump filters. Both engine chip detectors as well as the transmission chip detector were clean. Fuel samples taken from the rotorcraft's right fuel sump and both the left and right fuel filter chambers were submitted to the Department of the Air Force's Aerospace Fuels Laboratory, Mukilteo, Washington, for examination and testing. No detectable contamination was noted and all samples met or exceeded the Department of Defense standards. Additionally, both the left and right fuel filters were subjected to microscopic evaluation at the same facility and neither filter displayed any evidence of plugging by either particles or formation of film (refer to attachment LTR-I, II, III, IV, and V). Both #1 and #2 Allison 250-C20B turboshaft engines were shipped to Rolls Royce (parent company) in Indianapolis, Indiana, where both were run in a test cell. Both engines ran normally and there was no indication of any mechanical malfunction with the exception of possible fuel scheduling issues on the number two engine fuel control unit (refer to pages 1, 2, 4, and 5 of Rolls Royce Engine Investigation Engine Report [attachment RR-I]). The Main Fuel Control (MFC) for the #2 engine was removed and taken to Honeywell, South Bend, Indiana, where the MFC was subsequently bench checked. The test results indicated that aside from a shallow governor slope (the required RPM to reduce fuel flow at 104% was higher than required), no anomalies were noted that would have resulted in a loss of power, flameout or sudden overspeed condition (refer to attachment AR149). ADDITIONAL INFORMATION Written wreckage release to the Global Aerospace, Inc. adjustor of the rotorcraft and all associated records and items retained by the Safety Board was executed on February 12, 2003, (refer to NTSB Form 6120.15).
The sequential non-mechanical total loss of power in both engines 1 and 2 for undetermined reasons and the pilot's failure to maintain adequate rotor RPM to prevent a hard landing. Contributing factors were the tripped "RPM WARN" circuit breaker which disabled the engine failure and low rotor warning lights and aural warnings.
Source: NTSB Aviation Accident Database
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