Lexington, NC, USA
N58LF
BEECH 58
The pilot was initiating takeoff following completion of an annual inspection, which included replacing and repairing components of the right engine’s No. 1 cylinder, likely due to detonation that occurred during the flight before the accident flight. During the takeoff on the accident flight, witnesses noted significant smoke trailing the right engine at rotation. The witnesses noted that, as the airplane continued over the runway, the right engine lost power and the right propeller feathered. The landing gear retracted and, at the departure end of the runway, white/blue or white smoke was noted trailing the left engine, followed by a perceived loss of power from that engine. The airplane continued off-airport, encountered an aerodynamic stall, and impacted a tractor-trailer travelling on a nearby highway, resulting in a postimpact fire. Postaccident examination of the airframe revealed no evidence of preimpact failure or malfunction of the flight controls or flaps, and there was no evidence of an in-flight left engine fire. Examination of the engines revealed early signs of detonation on the No. 1 piston of the right engine. In addition, the No. 3 cylinder fuel injector nozzle of the left engine was not installed in the cylinder but remained attached to the fuel injector line throughout the flight. Given these findings, it is likely that both engines sustained a partial loss of engine power during takeoff. The witness reports of seeing smoke trailing the left engine when at the departure end of the runway were likely the result of the No. 3 cylinder fuel injector nozzle that was not installed on its respective cylinder. Based on blade impact angles and performance estimates from the propeller manufacturer, it is likely that the left engine exhibited about a 15% power reduction from full rated power during the takeoff. The reduction of left engine power and corresponding rpm would likely have been evident to the pilot from the moment of full power application until about 60 knots, at which point the airflow over the left propeller would have been sufficient for the propeller to operate at full rated rpm. The witness report of the right engine’s power loss and the feathering of the right propeller was likely the pilot’s response to the start of detonation in the No. 1 cylinder. Causes for detonation include improper ignition timing, high inlet air temperature, engine overheating, oil in the combustion chamber, carbon build-up in the combustion chamber, an issue with the fuel octane, or a lean fuel to air mixture. Although the position of the right mixture control at the start of the takeoff could not be determined from the available evidence, it is unlikely that the pilot would have leaned the fuel to air ratio, especially since it was the first takeoff after repairs due to detonation damage following a flight for which he was the pilot. In addition, operating the engines with the fuel to air ratio leaned during the accident takeoff would have been contrary to the takeoff procedure specified in the Pilot’s Operating Handbook and FAA-approved airplane flight manual. Aside from signs of detonation, the No. 1 cylinder and piston, spark plugs, fuel injector nozzle and line, manifold valve, and engine-driven fuel pump of the right engine were eliminated as having any evidence of preimpact failure or malfunction. Impact and/or heat damage, along with impact-separated components of the ignition system, including both magnetos and ignition harness, baffling, cowling, air induction, and fuel metering systems, as well as there being no remaining fuel due to the postimpact fire, precluded determination of preimpact failure or malfunction for these components. Although the root cause of detonation could not be determined from the available evidence, had maintenance facility personnel thoroughly investigated the fuel metering, ignition, and air induction systems and reviewed data from the engine monitor from the previous flight in which the No. 1 cylinder of the right engine exhibited detonation, it is likely that they could have identified and addressed any mechanical reason for the detonation. While moderate atherosclerosis was detected in one segment of the pilot’s left anterior descending coronary artery, there was no evidence to suggest an acute cardiac event occurred; from medical records, he was in good cardiovascular health. Although a disqualifying stimulant used to treat attention deficit hyperactivity disorder (ADHD) was detected during postaccident toxicological testing, the circumstances of this accident do not suggest inattention or fatigue. Thus, the pilot’s cardiovascular medical condition, the effects of his use of methylphenidate, and his ADHD were likely not factors in this accident.
HISTORY OF FLIGHTOn February 16, 2022, about 1707 eastern standard time, a Beech 58 airplane, N58LF, was destroyed when it was involved in an accident near Lexington, North Carolina. The private pilot was fatally injured, and the driver and passenger of an impacted tractor-trailer sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot arrived at Davidson County Airport (EXX), Lexington, North Carolina, that afternoon to pick up his airplane after completion of an annual inspection. Witnesses observed the pilot performing engine runs to varied rpms before departure, then an aborted initial takeoff attempt, followed by a taxi back to the maintenance facility for corrective action due to a reported door latch issue. The pilot then returned to the runway to initiate takeoff. Three witnesses who were on the airport ramp observed a portion of the takeoff roll, rotation, and initial climb before losing sight of the airplane just before impact. One witness reported seeing smoke trailing the right engine when the airplane rotated. Airport security video captured white smoke trailing the airplane about the time the airplane rotated and continued until the airplane went out of sight of the camera, about halfway down the runway. The second witness, who was also a pilot, reported that the right engine was spewing dense white smoke that the airport video did not accurately depict. The witnesses noted the airplane leveled off or decreased the nose-up pitch attitude, with one reporting hearing engine gyrations that he either associated with one engine losing power or the engines being out of sync. A photograph taken by one of the witnesses when the airplane was about 2,664 ft down the 5,004-ft-long runway depicted the airplane in a climb attitude with the landing gear extended and smoke trailing the right engine. As the airplane continued the landing gear retracted and, about that time, the right engine lost power and the propeller stopped rotating. When the airplane was at the departure end of the runway, either white or white/blue smoke was noted trailing the left engine and the airplane was described as not having power. The airplane was observed banking to the left, stalling, and pitching nose down before disappearing behind terrain. Another witness, who was located about 1/4 mile north of the accident site, observed the airplane departing, and an “…engine wasn’t turning.” He observed the airplane descend, heard a loud sound, then saw smoke. The airplane subsequently impacted a tractor-trailer. The driver of the impacted tractor-trailer reported that he was travelling at 65 mph at the time of the collision. After the tractor-trailer turned over and came to rest, the driver and passenger evacuated the vehicle’s cab. A video recording from a tractor-trailer that was traveling behind the impacted tractor-trailer showed the airplane in a very slight nose-up attitude before impact. Although the impact with the tractor-trailer was not recorded, the video did show the tractor-trailer rolling onto its side and an eruption of flames. AIRCRAFT INFORMATIONThe airplane was equipped with two 285-horsepower engines when operated at 2,700 rpm, and each engine was equipped with a two-blade, constant speed, manually feathering, single-acting propeller. The airplane was also equipped with a graphic engine monitor (data from the engine monitor was not available due to extensive heat damage). By design with the installed propellers, at full throttle application and static conditions, the propeller blades would be on the low pitch stop and the rpm would be slightly less than the full rated rpm value. During the takeoff roll, with the propeller low pitch stop position properly set, as the airspeed increased the propeller would remain on the low pitch stop until the propeller/engine rpm reached 2,700, at which time the governor would maintain 2,700 rpm by changing the propeller blade angle. According to the propeller manufacturer, assuming sea level, standard temperature, and the propeller blades on the low pitch stop setting of 14.5°, the propeller would be absorbing about 8% less than full rated rpm at 40 knots true airspeed (KTAS). Using the same sea level and standard temperature conditions but with the propeller blade angle about 1.5° above the low pitch stop setting, or 16°, the propeller would be absorbing full rated power at about 60 KTAS. At about 81 knots calibrated airspeed, which was the published air minimum control airspeed (Vmca), and 16° propeller blade angle, the propeller was absorbing about 243 horsepower, which was about 15% less than full rated power. According to maintenance records and maintenance personnel at EXX, while inbound to their airport in October 2021 for an annual inspection, the No. 1 cylinder of the right engine exhibited “excessively high” cylinder head temperature (CHT) and exhaust gas temperature (EGT) readings. Witnesses at the airport on that date reported seeing the accident pilot land uneventfully with the right propeller feathered and the right engine secured. The pilot later reported on an internet forum that during cruise flight when flying the airplane to the maintenance facility for an annual inspection, he suddenly noted the No. 1 CHT of the right engine was 540°F, which was 80°F above the maximum continuous CHT limit specified in the Pilot’s Operating Handbook and Federal Aviation Administration-approved airplane flight manual. He reported reducing throttle and the mixture control, then pushed them in before noting the EGT increase for 5 cylinders but not for the No. 1 cylinder. He then feathered the right propeller and continued to his destination. During the annual inspection, maintenance personnel identified no compression in the No. 1 cylinder of the right engine. Borescope inspection of the cylinder revealed damage to the cylinder walls and extensive damage to the piston. Repair station personnel attributed the cylinder and piston damage to be detonation caused by pilot-reported excessive leaning of the fuel to air ratio. No troubleshooting was done by the maintenance facility to determine the root cause of the detonation. Further, no engine data from the on-board engine monitor was downloaded for the October 2021 right engine event to identify the reason for the damage. Repairs to the right engine consisted of removing internal contamination; cleaning, flushing, and inspecting components; installing a serviceable cylinder and connecting rod; and installing a piston with untraceable origin. The damaged cylinder, piston, and non-ferrous material found in the oil sump and oil filter were scrapped and not available for the investigation. In addition, new fuel injector nozzles were installed in the right engine in accordance with (IAW) Supplemental Type Certificate (STC) SE09217SC. Following repairs, the engine was test run with the cowling off to check for leaks, then run with the cowling on for 20 to 30 minutes, at times to full power, with no discrepancies noted and with reported normal engine parameters including fuel pressure/fuel flow, manifold pressure, and rpm. Following “extended ground runs,” the right engine oil filter was cut open and the records reflected “only trace amounts of metal found. Will check again after test flight. After engine run, cut open filter to inspect, found no defects at this time. Installed new filter.” The airplane was not test flown following the annual inspection, nor was it required to be. During the annual inspection, there was no discrepancy reported for the right engine baffling. The maintenance facility did not download data from the on-board engine monitor for any post-maintenance engine runs. The airframe and powerplant mechanic with inspection authorization who had performed most of the annual inspection refused to return the airplane to service because he believed the engine should have been removed and sent out for inspection. Another mechanic (who held airframe and powerplant ratings and an inspection authorization) with the maintenance facility researched the engine manufacturer Standard Practice Maintenance Manual Spark Ignited Engines, section 6-5.7, Foreign Object Contamination, and subsequently returned the airplane to service after removing all internal contamination to his satisfaction. The EXX airport manager reported that there was no record of the pilot purchasing any fuel from them since arriving near the middle of October. According to a Federal Aviation Administration Safety Team Presentation regarding pre-ignition and detonation, detonation is an explosion of the fuel/air mixture inside the cylinder and occurs near or after top dead center. It causes the fuel/air charge to explode rather than ignite smoothly. Because of the explosion the charge exerts a much higher force on the piston and cylinder, causing a reduction in power. The presentation further indicated that detonation can be caused by improper ignition timing, high inlet air temperature, engine overheating due to bent baffles, or oil or carbon buildup in the combustion chamber. Additionally, a lean fuel to air ratio can cause detonation. The airplane’s Pilot’s Operating Handbook and FAA-approved airplane flight manual specified that for takeoff the mixture control was to be full rich unless required to be leaned for field elevation. AIRPORT INFORMATIONThe airplane was equipped with two 285-horsepower engines when operated at 2,700 rpm, and each engine was equipped with a two-blade, constant speed, manually feathering, single-acting propeller. The airplane was also equipped with a graphic engine monitor (data from the engine monitor was not available due to extensive heat damage). By design with the installed propellers, at full throttle application and static conditions, the propeller blades would be on the low pitch stop and the rpm would be slightly less than the full rated rpm value. During the takeoff roll, with the propeller low pitch stop position properly set, as the airspeed increased the propeller would remain on the low pitch stop until the propeller/engine rpm reached 2,700, at which time the governor would maintain 2,700 rpm by changing the propeller blade angle. According to the propeller manufacturer, assuming sea level, standard temperature, and the propeller blades on the low pitch stop setting of 14.5°, the propeller would be absorbing about 8% less than full rated rpm at 40 knots true airspeed (KTAS). Using the same sea level and standard temperature conditions but with the propeller blade angle about 1.5° above the low pitch stop setting, or 16°, the propeller would be absorbing full rated power at about 60 KTAS. At about 81 knots calibrated airspeed, which was the published air minimum control airspeed (Vmca), and 16° propeller blade angle, the propeller was absorbing about 243 horsepower, which was about 15% less than full rated power. According to maintenance records and maintenance personnel at EXX, while inbound to their airport in October 2021 for an annual inspection, the No. 1 cylinder of the right engine exhibited “excessively high” cylinder head temperature (CHT) and exhaust gas temperature (EGT) readings. Witnesses at the airport on that date reported seeing the accident pilot land uneventfully with the right propeller feathered and the right engine secured. The pilot later reported on an internet forum that during cruise flight when flying the airplane to the maintenance facility for an annual inspection, he suddenly noted the No. 1 CHT of the right engine was 540°F, which was 80°F above the maximum continuous CHT limit specified in the Pilot’s Operating Handbook and Federal Aviation Administration-approved airplane flight manual. He reported reducing throttle and the mixture control, then pushed them in before noting the EGT increase for 5 cylinders but not for the No. 1 cylinder. He then feathered the right propeller and continued to his destination. During the annual inspection, maintenance personnel identified no compression in the No. 1 cylinder of the right engine. Borescope inspection of the cylinder revealed damage to the cylinder walls and extensive damage to the piston. Repair station personnel attributed the cylinder and piston damage to be detonation caused by pilot-reported excessive leaning of the fuel to air ratio. No troubleshooting was done by the maintenance facility to determine the root cause of the detonation. Further, no engine data from the on-board engine monitor was downloaded for the October 2021 right engine event to identify the reason for the damage. Repairs to the right engine consisted of removing internal contamination; cleaning, flushing, and inspecting components; installing a serviceable cylinder and connecting rod; and installing a piston with untraceable origin. The damaged cylinder, piston, and non-ferrous material found in the oil sump and oil filter were scrapped and not available for the investigation. In addition, new fuel injector nozzles were installed in the right engine in accordance with (IAW) Supplemental Type Certificate (STC) SE09217SC. Following repairs, the engine was test run with the cowling off to check for leaks, then run with the cowling on for 20 to 30 minutes, at times to full power, with no discrepancies noted and with reported normal engine parameters including fuel pressure/fuel flow, manifold pressure, and rpm. Following “extended ground runs,” the right engine oil filter was cut open and the records reflected “only trace amounts of metal found. Will check again after test flight. After engine run, cut open filter to inspect, found no defects at this time. Installed new filter.” The airplane was not test flown following the annual inspection, nor was it required to be. During the annual inspection, there was no discrepancy reported for the right engine baffling. The maintenance facility did not download data from the on-board engine monitor for any post-maintenance engine runs. The airframe and powerplant mechanic with inspection authorization who had performed most of the annual inspection refused to return the airplane to service because he believed the engine should have been removed and sent out for inspection. Another mechanic (who held airframe and powerplant ratings and an inspection authorization) with the maintenance facility researched the engine manufacturer Standard Practice Maintenance Manual Spark Ignited Engines, section 6-5.7, Foreign Object Contamination, and subsequently returned the airplane to service after removing all internal contamination to his satisfaction. The EXX airport manager reported that there was no record of the pilot purchasing any fuel from them since arriving near the middle of October. According to a Federal Aviation Administration Safety Team Presentation regarding pre-ignition and detonation, detonation is an explosion of the fuel/air mixture inside the cylinder and occurs near or after top dead center. It causes the fuel/air charge to explode rather than ignite smoothly. Because of the explosion the charge exerts a much higher force on the piston and cylinder, causing a reduction in power. The presentation further indicated that detonation can be caused by improper ignition timing, high inlet air temperature, engine overheating due to bent baffles, or oil or carbon buildup in the combustion chamber. Additionally, a lean fuel to air ratio can cause detonation. The airplane’s Pilot’s Operating Handbook and FAA-approved airplane flight manual specified that for takeoff the mixture control was to be full rich unless required to be leaned for field elevation. WRECKAGE AND IMPACT INFORMATIONExamination of the accident site revealed the airplane impacted on grass immediately adjacent to a three-lane highway. Marks in grass adjacent to the edge of the highway were oriented on a southerly heading and were nearly perpendicular to the highway in that area. The accident site was slightly less than 2,000 ft south-southwest of the departure end of runway 24. Further examination of the accident site revealed the cockpit and cabin were upright about 394 ft south-southwest from the initial ground impact location. The impacted tractor-trailer was resting on i
Inadequate maintenance, which led to a partial loss of both right and left engine power during takeoff, and the pilot’s subsequent failure to maintain airspeed while maneuvering with one engine at low altitude. Contributing to the accident was the pilot’s failure to detect the partial loss of left engine power during the early part of the takeoff.
Source: NTSB Aviation Accident Database
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