Bow, WA, USA
N469MD
Beech 58P
Approximately 11 minutes after takeoff on a night instrument flight rules flight plan, the pilot of the twin-engine airplane radioed air traffic control (ATC) that he was climbing out of 7,800 feet. Shortly thereafter, ATC received a "mayday" transmission followed by "lost an engine." Subsequently, radio communications and radar contact with the airplane were lost. Witnesses reported they observed the airplane in an unusually steep descent prior to impacting terrain. One witness stated he heard a high-pitched noise emanating from the airplane as it descended toward the ground. The wreckage was located in an open field adjacent to a highway. The main wreckage was located in the confines of a large impact crater approximately 15 feet in diameter and 6 feet deep. Dark night conditions with low ceilings prevailed at the time of the accident. Post-accident teardown and examination of both engines revealed no evidence of excessive wear or operational failure of internal engine components. Extensive damage, however, was noted to the right turbocharger assembly. Disassembly of the component revealed damage to the compressor wheel and compressor housing shroud. Circumferential scuffing and pockmarks were noted to the inner compressor housing, and impact type damage and smearing were noted to the individual compressor blades. Scuffing type damage was noted to the turbine wheel and corresponding turbine housing. Additional damage was noted to the turbine/compressor input shaft, and associated journals and bearings. Foreign material was found in the compressor housing and turbocharger after cooler. The material consisted of aluminum fragments, a rivet head, a piece of brass, paint chips, rubber, gasket material and dirt. The manufacturer of the turbo assembly examined the unit and reported the damage was consistent with FOD (foreign object damage) and lubricant starvation. The exact sequence of events leading to the failure of the turbocharger was not determined.
HISTORY OF FLIGHT On February 22, 2006, about 1854 Pacific standard time, a Beech 58P Baron, N469MD, was destroyed when it collided with terrain subsequent to a reported loss of engine power during the initial climb out approximately two nautical miles south of Bow, Washington. The airplane was registered to H&W Management Services, Inc, of Carson City, Nevada, and was being operated by the pilot as an instrument flight rules (IFR) cross-country flight under the provisions of Title 14, CFR Part 91, when the accident occurred. The commercial pilot, the sole occupant of the airplane, was fatally injured. Night instrument meteorological conditions prevailed at the time of the accident, and an instrument flight rules (IFR) flight plan was in effect. The flight originated from the Bellingham Regional Airport about 1843 Pacific standard time, and was en route to the Ogden International Airport, Ogden, Utah. Recorded air traffic control (ATC) communications between Seattle Air Route Traffic Control Center, and the pilot of N469MD, indicated the pilot radioed Seattle Center communicating that he was out of 7,800 feet. Seattle Center acknowledged the pilot and cleared the airplane to 15,000 feet. Shortly thereafter, Seattle Center received a "mayday" transmission followed by "lost an engine." Shortly after the transmission, radio and radar contact with the airplane were lost. Witnesses reported they observed the airplane in an unusually steep descent prior to impacting terrain. One witness stated he heard a high-pitched noise emanating from the airplane as it descended toward the ground. The wreckage was located in an open field adjacent to Highway 11. The main wreckage was located in the confines of a large impact crater approximately 15 feet in diameter and 6 feet deep. PERSONNEL INFORMATION The pilot held a private pilot certificate with an airplane single-engine land rating, a commercial certificate with a multi-engine land rating and a commercial instrument airplane rating. The pilot's most recent medical certificate (third-class) was issued on June 26, 2004. The certificate carried a limitation requiring the pilot to wear corrective lenses. Comprehensive flight time logbooks for the pilot were not located. Documentation was located indicating the pilot completed a flight review (FAR 61.56) and an instrument proficiency check (FAR 61.57[d]) on October 22, 2005. On the pilot's latest FAA Application for Airman Medical Certificate (Form 8500-8), dated June 26, 2004, the pilot listed 7,500 hours total pilot time and 150 hours total pilot time in the 6 months preceding the medical. AIRCRAFT INFORMATION The twin engine Beech Baron 58P, serial number TJ-331, was manufactured in 1978 and was certified as a normal category airplane. The airplane was equipped with two Teledyne Continental Motors (TCM) TSIO-520 engines, each rated at 310 horsepower. The airplane was approved for visual flight rules (VFR) and instrument flight rules (IFR) operations, as well as flight in icing conditions. The airplane's last inspection, an annual inspection, was completed on December 16, 2005. Maintenance records showed the airplane's total time at inspection was 9,401 hours. The right engine's total time at inspection was 2,048 hours (621 since major overhaul); the left engine's total time at inspection was 3,476 hours (695 since major overhaul). A top overhaul of both engines was completed during the annual inspection. Maintenance records showed that the last altimeter system and altitude reporting equipment test (in accordance with FAR 91.411) was completed on June 24, 2004. Complete airframe, engine and propeller maintenance logbook records were not located for the accident aircraft. METEOROLOGICAL INFORMATION The closest weather observation facility to the accident site was the Skagit Regional Airport (KBVS), located approximately 4.6 miles south of the accident location at an elevation of 144 feet msl. The airport is equipped with an Automated Weather Observation System (AWOS). The following Meteorological Aerodrome Reports (METARs) were issued surrounding the period of the accident: On February 22, at 1850, the METAR observation was, in part, winds from 180 degrees at 4 knots, visibility 8 statute miles, a few clouds at 2,000 feet, overcast skies at 3,500 feet, temperature 4 degrees C. At 1910, the METAR observation was, in part, visibility 7 statute miles, scattered clouds at 100 feet, broken clouds at 2,500 feet, overcast skies at 3,400 feet, temperature 4 degrees C. COMMUNICATIONS At 1851:02, the pilot of N469MD was instructed by Whidbey Approach to contact Seattle Center on frequency 134.95. The pilot acknowledged the ATC specialist and subsequently contacted Seattle Center stating he was through 7,800 for niner (nine) thousand. The ATC specialist then cleared the aircraft to 15,000 feet, and at 1851:38 the pilot acknowledged the clearance, stating, "we're up to one five thousand for niner mike delta." At 1853:43, ATC received an unintelligible radio transmission containing "lost a" and "niner mike delta." At 1853:48, ATC received a second transmission from the pilot who stated "mayday mayday just lost an engine a." At 1853:53 and 1853:55, ATC received two additional transmissions believed to be from the pilot, however both were unintelligible. This was the last known radio transmission from the pilot of the accident aircraft. A complete ATC communication transcript and radar data are included in the public docket. FLIGHT RECORDERS The airplane was not equipped with flight data or cockpit voice recorders. WRECKAGE AND IMPACT INFORMATION Personnel from the National Transportation Safety Board, Federal Aviation Administration, Teledyne Continental Motors and Raytheon Aircraft accessed the aircraft wreckage on February 23-24, 2006. The crash site was located in an open field adjacent to the intersection of Highway 11 and Sunset Road, at 48 degrees 32.56 minutes' north latitude and 122 degrees 24.28 minutes' west longitude. The elevation at the crash site was approximately 11 feet above mean sea level (msl). The surrounding terrain was relatively flat and featureless. The wreckage debris field encompassed an area approximately 348 feet in length (from south to north). The main wreckage was located in the confines of a large impact crater measuring approximately 15 feet in diameter and 6 feet deep. A majority of the wreckage was located in the immediate area of the impact crater. Numerous small pieces of system components and cockpit instrumentation were scattered from the crater to the end of the wreckage debris path. The main wreckage included engines and propeller assemblies, fuselage, wing assemblies, and tail assembly. Impact forces destroyed the forward section of the fuselage and cockpit. A majority of the cockpit components and instrumentation were located in the crater and were severely fragmented. Both engine assemblies were separated from the airframe and located near the bottom of the crater. Both assemblies sustained extensive impact related damage. The 3-bladed McCauley propeller assemblies were located within the confines of the crater. Both sustained extensive impact related damage. The six propeller blades were separated from their respective hub assemblies and were located in the confines of the impact crater. Forward bending, leading edge damage, chord wise scratches and extensive overall deformation were noted to the propeller blades. The main wing assembly was located with the main wreckage and sustained extensive impact related damage and fragmentation. Extensive accordion type damage was noted to the leading edge of the wing structure. The entire wing assembly was severely fragmented and deformed. Both flap and aileron assemblies were attached to the wing structure and sustained impact related damage. The aileron trim actuator measured 1.5 inches, which equates to 4.75 degrees tab up. Flap actuator measurements indicated the flaps were in the up position at the time of impact. The remains of the empennage assembly were located near the center of the impact crater, atop of the main wreckage. The vertical stabilizer was bent forward and the rudder was separated from the assembly. The horizontal stabilizers remained attached to the empennage assembly, but sustained extensive impact related damage. The right-hand and left-hand elevators were attached to the empennage and extensive bending deformation was noted. The elevator trim tab actuators measured 1.08 inches, which corresponds to 5 degrees tab down. The rudder trim actuator measured 4 inches, which equates to approximately 4 degrees tab left. The landing gear was located in the confines of the impact crater. It was determined that the landing gear was in the up position prior to impact. All primary flight control surfaces and major system components were identified and located at the wreckage site prior to the wreckage being recovered. The impact crater was full of water and oil. There was a strong odor of aviation fuel in and around the accident site. Reexamination of the wreckage on October 3, 2006, by investigators from National Transportation Safety Board and Raytheon Aircraft, focused on the right engine's induction system. The induction system sustained impact related damage and was heavily distorted, however, the alternate air door and hinge assembly were intact. MEDICAL AND PATHOLOGICAL INFORMATION Representatives from the Skagit County Coroner's Office, Mount Vernon, Washington, performed the autopsy on the pilot on February 23, 2006. According to the autopsy report, the pilot's cause of death was determined to be "blunt trauma to head, trunk & extremities." Toxicological testing of specimens from the pilot was performed by the FAA Forensic Toxicology Research Team, Oklahoma City, Oklahoma. The report stated the following was detected in liver specimen: ethanol 22 (mg/dl, mg/hg). See toxicological report included in the public docket for specific test parameters and results. TESTS AND RESEARCH Post accident teardown and examination of both engines was accomplished at Teledyne Continental Motors (TCM), Mobile, Alabama, on April 17-19, 2006. Representatives from the National Transportation Safety Board, Raytheon Aircraft and TCM were in attendance. Both engines sustained extensive impact related damage, however disassembly and examination of the engines revealed no evidence of excessive wear or operational failure of internal engine components. In conjunction with the engine teardowns, both turbo chargers were examined. Extensive damage was noted to the right-hand turbocharger (Garrett model TH08A68 [serial number DIN00014]). Partial disassembly of the component revealed damage to the compressor wheel and compressor housing shroud. Circumferential scuffing and pockmarks were noted to the inner compressor housing and impact type damage and smearing were noted to the individual compressor blades. Scuffing type damage was noted to the turbine wheel and corresponding turbine housing. Foreign material was found in the compressor housing and turbocharger after cooler. The material consisted of aluminum fragments, a rivet head, a piece of brass, paint chips, rubber, gasket material and dirt. The collective weight of the material found in the after cooler was approximately 46 grams; the weight of the material found in the compressor housing was approximately 20 grams. Subsequent to the examination at TCM, the right-hand turbocharger assembly was shipped to Kelly Aerospace for additional evaluation and teardown. On April 24, 2006, the turbocharger assembly was examined at Kelly Aerospace's facility in Montgomery, Alabama. In addition to the before mentioned damage, the examination and disassembly revealed additional damage to the turbine/compressor input shaft and associated journals and bearings. A post examination report (included in the public docket) from Kelly Aerospace stated the shaft journal, on the turbine end of the shaft, "had contacted the journal bearing and displayed markings consistent with insufficient lubricant to the shaft." Additionally, the report stated the journal bearing bores "were out of round and heavily tracked from contact with the shaft." The report stated that lack of lubricant and an imbalance caused by FOD (foreign object damage) to the compressor wheel "may have caused" the contact between the shaft and bearing. The report stated the turbocharger assembly was "Factory Rebuilt" by Garrett in September of 2000. ADDITIONAL INFORMATION On October 5, 2006, the airplane, engine and associated components were released to CTC Services, Aviation (LAD Inc), Renton, Washington.
The pilot's failure to maintain aircraft control during the climb to cruise. Contributing factors included a loss of engine power to the right engine folowing a turbocharger failure, instrument meteorological and dark night conditions.
Source: NTSB Aviation Accident Database
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