N19MTBeech A36 · 1976

On January 19, 2023, about 1729 EST, a Beech A36, N19MT, was substantially damaged when it was involved in an accident near North Castle, New York. The private pilot and one passenger were fatally injured. The airplane was operated as a Title 14?Code of Federal Regulations Part 91 personal flight.

According to ADS-B and air traffic control audio information, the flight departed from runway 4L at John F Kennedy International Airport (JFK), New York, New York, at 1658, and continued on a north-northeast heading.

After takeoff, data from the on-board Graphic Engine Monitor (GEM) indicated the cylinder head temperature (CHT) value for the No. 4 cylinder was generally higher than the values for the other cylinders but all were well within normal limits until 1659:23. At that time, when the flight was about 1 nautical mile north-northeast from the departure end of the runway, the No. 4 CHT value was indicating 463° F, which was above the maximum red line value of 460°F. The CHT values for the No. 4 cylinder continued increasing, reaching a maximum of 711°F at 1700:39 and then falling below the CHT values for the remaining cylinders, which were normal.

The flight continued as instructed by air traffic control with normal communications until 1710:15, at which time the pilot advised the controller he was “…doing my best here…” in response to the controller’s instruction to maintain best rate of climb to 8,000 ft. Normal communications continued again until 1715:54, when the airplane was at 5,100 ft barometric altitude climbing to the assigned altitude of 8,000 ft above mean sea level (msl),;the pilot then asked the controller if he could stop the climb at 6,000 ft msl. The airplane at that time was about 6 nautical miles south-southeast of the Westchester County Airport (HPN), White Plains, New York. The controller approved the request and the pilot informed the controller at 1716:14 and again at 1716:33 about poor aircraft performance and only climbing about 200 feet per minute. Twenty-one seconds after his last transmission about performance, at 1716:54, while south of HPN, the pilot advised the controller that nothing was depicted on the instrumentation to explain the poor climb performance. The controller advised the pilot that HPN was nearby, and he could proceed there to have it checked out. The pilot did not acknowledge that suggestion; at 1718:30, when about 4.8 nautical miles due south of HPN, the pilot informed the controller that the problem was a “…dead cylinder” and requested to proceed to HPN. The controller instructed the pilot to maintain a 340° heading consistent with vectoring the airplane onto the downwind leg on the west side of HPN, but the flight did not proceed on that heading. At 1719:52, the controller asked the pilot if he was declaring an emergency, to which he replied he was not. The airplane remained on a west-northwest (WNW) heading and at 1720:11 the GEM data indicated that the oil pressure decreased below the minimum specified value of 30 psi and continued decreasing to 0 psi.

While on the WNW heading the pilot was informed that the instrument landing system (ILS) runway 16 approach was in-use, then about 1720:58, the pilot turned to the vectored heading issued by the controller 2 minutes 17 seconds earlier. At 1721:18, when the flight was about 6 nautical miles southwest of HPN, the pilot declared an emergency and advised the controller that the oil pressure was dropping. Shortly after that transmission the airplane began a right turn that was not directed by the controller or announced by the pilot. The controller informed the pilot to level the wings and maintain 5,000 ft msl. The flight proceeded on an east-northeast heading. At 1722:58, while about 3 nautical miles southwest of HPN, the pilot again declared an emergency and informed the controller again that they were losing oil pressure.

The controller responded to the pilot’s second emergency call and instructed him to fly heading 070° for vectors to the downwind leg of the airport traffic pattern for runway 16 at HPN. The pilot repeated that he indeed had an emergency, and the flight continued the east-northeasterly heading flying south of HPN while gradually descending. During that time the controller informed the pilot that he intended to vector the flight onto the downwind leg for runway 16 and then cleared the pilot to descend to 3,000 ft msl, which he acknowledged. The flight remained on the east-northeasterly heading until about 1724:22, when about 1.5 nautical miles east-southeast of HPN, the flight turned to a northerly heading. The flight remained on the northerly heading while gradually descending. At 1725:13, while flying at 4,600 ft barometric altitude about 2.5 nautical miles northeast from HPN, the pilot broadcast, “mayday mayday mayday mayday.” At that time the engine rpm was 2,454, the fuel flow was 3.1 gallons-per-hour (GPH), and the No. 3 exhaust gas temperature (EGT) and CHT values had decreased to 892°F from the steady state value of about 1,350°F and to 306°F from the steady state value of about 317° F, respectively.

The controller informed the pilot that HPN was behind him and to turn left or right as necessary. The flight continued briefly on the northerly heading when, at 1725:46, the engine rpm and fuel flow were reading zero. The pilot turned left, flying in a southwest direction while descending, with the controller continually advising the pilot about direction and distance from HPN. The pilot was cleared to land at 1727:48; during that transmission from the controller, the low altitude alert sounded. About 16 seconds later, the controller informed the pilot that he should be clear of the ceiling at 300 ft. The controller continued to point out direction and distance from HPN to the pilot which he acknowledged in his last transmission at 1728:23. The airplane at that time was about 1 nautical mile northwest of the approach end of runway 16 flying at 900 ft barometric altitude. The controller continued to advise the pilot of heading information until, at 1728:56, the controller broadcast on the frequency for the accident pilot that radar contact was lost.

Multiple agencies involved in the air, water, and land searches located the wreckage at 2255.

A review of the pilot’s logbook that began with his 1st logged flight in May 2013 and his last logged flight on December 2, 2022., revealed that including the date of a flight associated with his instrument rating received on May 29, 2017, he logged a total of 3.0 hours actual instrument flight time and 50.5 hours simulated instrument flight time. Since obtaining his instrument rating, he logged about 9 hours of actual instrument flight time and 29 hours of simulated instrument time. His last logged instrument proficiency check flight occurred on October 3, 2021. In August 2022, he flew 5 flights with a flight instructor, logging “holds” and performing a total of 17 instrument approaches and accruing 1.5 hours of actual instrument flight time and 4.4 hours of simulated instrument flight time. His last logged actual instrument flight of 0.2 hour occurred on November 3rd/4th 2022, while his last logged simulated instrument flight time of 2.0 hours occurred on December 2, 2022.

The airplane underwent modifications in accordance with (IAW) Supplemental Type Certificates (STC) covering installation of a different model engine and propeller, overhaul and calibration of the manifold pressure/fuel flow gauge, installation of new cooling air baffles, aileron and wing flap gap seals, and lower cowling access panels.

Section II, Limitations, of the POH/AFM specified that the maximum CHT was 460°F, and the minimum oil pressure was 30 psi. Section III, Emergency Procedures, of the POH/AFM revealed there were no checklists for loss of oil pressure or CHT exceedance.

The engine manufacturer Standard Practice Maintenance Manual specified that the fuel flow at full power be between 24.9 to 26.6 gallons-per-hour (GPH).

Two mobile phones, a tablet computer, two Garmin G5’s, and a Stratus Attitude Heading and Reference System (AHRS) were recovered from the wreckage. No data were recovered from either mobile phone, the tablet computer, or either Garmin G5.

An Insight GEM which was installed in the instrument panel, just above and to the right of the center control yoke, in accordance with installation instructions that specified it was to be installed where it was easily visible by the pilot. Data were successfully recovered from the device following the accident.

Further review of the GEM data associated with the accident flight, correlated with ADS-B data, revealed that the recorded fuel flow values from about takeoff power application to when it decreased and remained at 0 were nearly always above the maximum limit of 26.6 GPH, averaging about 44 GPH with the highest value slightly over 99 GPH. The EGT values, which were not an engine operating limitation, appeared “noisy” and erratic for the No. 4 cylinder and had not trended with the remaining cylinders since December 13, 2022. The oil temperature values from takeoff power application to where the fuel flow decreased to and remained at 0 were above normal, averaging about 693°F.

Data from the GEM for the flight before the accident flight revealed that the CHT values for the No. 4 cylinder were generally equal to or slightly higher than the highest values for the remaining cylinders; however, all CHT readings were below the maximum specified value. The data also indicated that the fuel flow was generally steady and within limits except for a short period about 5 minutes after takeoff power was applied, periodically during the flight, and then again for about 19 minutes before power was reduced. During the times when the fuel flow was erratic and exceeded the maximum specified value, the CHT values for all cylinders were below the maximum value and all trended generally the same. The oil temperature values from takeoff power application to the end of recorded data were above normal, averaging about 1,714°F (these recorded values were likely erroneous).

The engine was rebuilt by Continental Aerospace Technologies (formerly Teledyne Continental Motors) on September 13, 2019, then installed into the accident airplane on November 22, 2019 at tachometer time of 835.34 hours. The engine remained installed to the accident date. An engine maintenance logbook entry dated January 18, 2022, at tachometer time of 1,462.5, indicated that the top and bottom spark plugs of the No. 4 cylinder were removed and replaced with new plugs. The last 100-hour inspection of the engine was performed on November 9, 2022, at tachometer time 1809.6, and the last oil change occurred on December 16, 2022, at tachometer time 1871.3.

At the time of the accident, the tachometer was reading 1889.21 hours. Thus, the engine had accrued about 18 hours since the last oil change, 80 hours since the last 100-hour inspection, 427 hours since the No. 4 top and bottom spark plugs were replaced, and 1,054 hours since major overhaul.

The stockholder of the airplane reported flying it for 12.8 hours during the two days before the accident. He reported he normally operated the airplane at 23 inches of manifold pressure and 2,400 rpm and leaned the fuel-to-air ratio to about 25° rich of peak. He was not sure how the accident pilot flew the airplane with respect to his leaning procedures. He reported no engine related issues during his flights. Earlier on the accident date before the flight departed from CGF, he added one or one and a half quarts of oil to the engine, which brought the total capacity to 10.5 quarts; the full capacity was 12 quarts.

On the accident date the airplane was fueled with 39.2 gallons of 100 low-lead fuel, which filled each main fuel tank. According to the facility that provided the fuel, there were no fuel-related complaints from aircraft that purchased fuel before the accident airplane. Specific gravity testing was performed postaccident and the results were within 0.2 of the value when the fuel was delivered two days before the accident.

According to an FAA Safety Team (FAAST) presentation regarding preignition 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 build-up in the combustion chamber. The presentation recommended prevention by cooling the engine by reducing power, increasing airspeed, enrichening the mixture, and opening the cowl flaps.

A High Resolution Rapid Refresh (HRRR) model sounding was created for the accident time and location, with the modeled surface elevation at 423 ft msl.

Based on the sounding, the freezing level was around 9,500 ft msl with the sounding temperature and dew point of -0.3°C at 9,534 ft msl. The HRRR indicated that the winds aloft at about 6,000 ft msl were from 231° at 48 knots.

The airplane underwent modifications in accordance with (IAW) Supplemental Type Certificates (STC) covering installation of a different model engine and propeller, overhaul and calibration of the manifold pressure/fuel flow gauge, installation of new cooling air baffles, aileron and wing flap gap seals, and lower cowling access panels.

Section II, Limitations, of the POH/AFM specified that the maximum CHT was 460°F, and the minimum oil pressure was 30 psi. Section III, Emergency Procedures, of the POH/AFM revealed there were no checklists for loss of oil pressure or CHT exceedance.

The engine manufacturer Standard Practice Maintenance Manual specified that the fuel flow at full power be between 24.9 to 26.6 gallons-per-hour (GPH).

Two mobile phones, a tablet computer, two Garmin G5’s, and a Stratus Attitude Heading and Reference System (AHRS) were recovered from the wreckage. No data were recovered from either mobile phone, the tablet computer, or either Garmin G5.

An Insight GEM which was installed in the instrument panel, just above and to the right of the center control yoke, in accordance with installation instructions that specified it was to be installed where it was easily visible by the pilot. Data were successfully recovered from the device following the accident.

Further review of the GEM data associated with the accident flight, correlated with ADS-B data, revealed that the recorded fuel flow values from about takeoff power application to when it decreased and remained at 0 were nearly always above the maximum limit of 26.6 GPH, averaging about 44 GPH with the highest value slightly over 99 GPH. The EGT values, which were not an engine operating limitation, appeared “noisy” and erratic for the No. 4 cylinder and had not trended with the remaining cylinders since December 13, 2022. The oil temperature values from takeoff power application to where the fuel flow decreased to and remained at 0 were above normal, averaging about 693°F.

Data from the GEM for the flight before the accident flight revealed that the CHT values for the No. 4 cylinder were generally equal to or slightly higher than the highest values for the remaining cylinders; however, all CHT readings were below the maximum specified value. The data also indicated that the fuel flow was generally steady and within limits except for a short period about 5 minutes after takeoff power was applied, periodically during the flight, and then again for about 19 minutes before power was reduced. During the times when the fuel flow was erratic and exceeded the maximum specified value, the CHT values for all cylinders were below the maximum value and all trended generally the same. The oil temperature values from takeoff power application to the end of recorded data were above normal, averaging about 1,714°F (these recorded values were likely erroneous).

The engine was rebuilt by Continental Aerospace Technologies (formerly Teledyne Continental Motors) on September 13, 2019, then installed into the accident airplane on November 22, 2019 at tachometer time of 835.34 hours. The engine remained installed to the accident date. An engine maintenance logbook entry dated January 18, 2022, at tachometer time of 1,462.5, indicated that the top and bottom spark plugs of the No. 4 cylinder were removed and replaced with new plugs. The last 100-hour inspection of the engine was performed on November 9, 2022, at tachometer time 1809.6, and the last oil change occurred on December 16, 2022, at tachometer time 1871.3.

At the time of the accident, the tachometer was reading 1889.21 hours. Thus, the engine had accrued about 18 hours since the last oil change, 80 hours since the last 100-hour inspection, 427 hours since the No. 4 top and bottom spark plugs were replaced, and 1,054 hours since major overhaul.

The stockholder of the airplane reported flying it for 12.8 hours during the two days before the accident. He reported he normally operated the airplane at 23 inches of manifold pressure and 2,400 rpm and leaned the fuel-to-air ratio to about 25° rich of peak. He was not sure how the accident pilot flew the airplane with respect to his leaning procedures. He reported no engine related issues during his flights. Earlier on the accident date before the flight departed from CGF, he added one or one and a half quarts of oil to the engine, which brought the total capacity to 10.5 quarts; the full capacity was 12 quarts.

On the accident date the airplane was fueled with 39.2 gallons of 100 low-lead fuel, which filled each main fuel tank. According to the facility that provided the fuel, there were no fuel-related complaints from aircraft that purchased fuel before the accident airplane. Specific gravity testing was performed postaccident and the results were within 0.2 of the value when the fuel was delivered two days before the accident.

According to an FAA Safety Team (FAAST) presentation regarding preignition 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 build-up in the combustion chamber. The presentation recommended prevention by cooling the engine by reducing power, increasing airspeed, enrichening the mixture, and opening the cowl flaps.

Examination of the accident site area revealed initial impact marks beginning in a tree about 100 ft above ground level (agl). Multiple tree contacts at slightly generally decreasing heights were noted along the energy path between the first impacted tree and the resting position of the main wreckage 250 ft away; the energy path was oriented on magnetic heading of 179°. The accident site was located about 0.8 nautical mile and 301° from the approach end of runway 16.

The main wreckage, consisting of the fuselage with attached aft empennage and a 4-ft inboard section of the left wing, came to rest wedged near the base of two trees. Separated sections of both wings consistent with tree contacts were located away from the main wreckage. The engine without propeller was located about 33 ft forward of the main wreckage; the propeller came to rest in close proximity to the engine and fuselage. Both vertical and horizontal stabilizers and the primary and secondary flight control surfaces remained attached.

Elevator and rudder flight control cable continuity was confirmed from the cockpit attach points to each control surface. The landing gear drive depicted the landing gear in the retracted position matching the landing gear selector position in the cockpit. Examination of the aileron flight control system revealed both direct and the balance cable exhibited tension overload with no evidence of preimpact failure or malfunction. Both flap actuators were extended about 1.7 inches, which equated to flaps retracted.

Fresh oil was noted on the bottom of the fuselage beginning about at the wing leading edge location to the tail cone. The oil appeared to be coming from behind the left cowl flap area. The interior surface of the outlet of the lower aluminum tube of the crankcase breather system contained fresh oil.

Examination of the cockpit revealed that the control yokes, pilot, and co-pilot seats were separated but found in the immediate vicinity of the fuselage. The right horn of the pilot’s control yoke was fractured, while both horns of the co-pilot’s control yoke were intact. Although the engine was separated, the throttle quadrant was examined and the throttle control was 1/4 inch from full forward, while the mixture and propeller controls were full forward. The cowl flap handle was extended (open) and bent slightly up.

Examination of the separated engine revealed a hole in the engine crankcase above the No. 6 cylinder position. A deformed connecting rod cap with two entrapped fractured connecting rod bolts was found inside the engine below the hole opening. The rod-oil gauge and cap assembly was in-place. No oil was noted on the engine exterior on the bottom or left sides of the engine. The oil filter adapter was in place, but the oil filter was impact separated from the oil filter adapter but remained attached by safety wire.

Examination of the engine lubrication system following engine recovery revealed minimal oil remained in the oil sump with no failure or malfunction of the oil pump or oil path to the main and connecting rod bearings. The damage to the connecting rod bearings and connecting rods was consistent with oil exhaustion. Both spark plug heli-coils of the No. 4 cylinder appeared to be properly installed and did not extend into the cylinder. Examination of the No. 4 piston revealed erosion damage to the perimeter, consistent with pre-ignition/detonation that produced a gap between the piston side and compression rings. Examination of the air induction system for the No. 4 cylinder revealed no evidence of preimpact failure or malfunction. Operational testing to production standards of the fuel injector lines, distributor valve, and 5 of the 6 fuel injector nozzles (one nozzle was impact damaged, which precluded testing) revealed the assembly passed all test points. Following removal of internal contamination in the engine-driven fuel pump consistent with impact damage to several fittings, testing at full rpm was performed twice. During the first and second tests, the discharge pressure was about 3.7 psi and about .7 psi greater than the upper specified limit, respectively. Operational testing of the throttle body and metering valve revealed that at full throttle, the unit flowed about 1 pound-per-hour greater than the specified maximum limit. Although magneto-to-engine timing could not be determined because the crankshaft flange was impact separated from the engine, the magnetos were operationally tested and functioned normally. While chafing was noted in several areas of the No. 4 bottom ignition lead, both ignition leads of the No. 4 cylinder passed high-tension testing.

The No. 4 cylinder top and bottom spark plugs exhibited extensive material at the firing end and were sent to the manufacturer’s facility for operational testing and examination. Because of bridging of material from the center to both ground electrodes of both plugs, resistance testing could not be performed. Although both plugs were placed in a machine to test to production standards, neither plug produced spark at the firing end. Testing of the deposits at the core nose and ground electrode of the cylinder No. 4 top plug were positive for lead, aluminum, and nickel. The deposits at the core nose of the cylinder No. 4 bottom plug were positive for lead and aluminum, while deposits on the ground electrode were positive for lead, aluminum and nickel. Disassembly inspection of the top spark plug revealed a piece of the insulator/ceramic core nose was separated, while a crack in the core nose insulator of the bottom plug was noted. The spark plug manufacturer representative reported that detonation in the cylinder was enough to cause the core nose to crack. The representative also reported that detonation in a cylinder can be caused by a defective spark plug, use of an incorrect heat range, lead fouling, and the core nose being broken, though in that condition misfiring may not occur. If the crack in the core nose were present and a misfire was also present, the spark plug could get deposits from running cold.

Examination of the separated propeller revealed all three blades remained secured in the hub, but two of the three blades were rotated in the hub. The final blade exhibited a slight forward bend.

Internal postmortem examination of the pilot was not performed due to religious concerns. According to the Office of the Medical Examiner, County of Westchester, New York, the cause of death was multiple blunt force trauma, and his manner of death was accident.

The Westchester County Department of Labs and Research, Division of Forensic Toxicology, performed toxicological testing of postmortem urine and subclavian blood from the pilot. 7-aminoclonazepam was detected in blood at 24 ng/mL and in urine at less than 125 ng/mL. Clonazepam was not detected. Sertraline, acetaminophen, salicylic acid, and naproxen were presumptively detected in blood.

Forensic toxicology was performed by the FAA Forensic Sciences Laboratory, Oklahoma City, Oklahoma, on specimens of the pilot obtained from syringe only. 7-aminoclonazepam was detected in subclavian blood at 25 ng/mL and urine at 94 ng/mL. Sertraline was detected in blood at 78 ng/mL and was also detected in urine. Desmethylsertraline was detected in blood at 214 ng/mL and was also detected in urine, while Famotidine was detected in both blood and urine.

7-aminoclonazepam is a metabolite of clonazepam, which was not detected in this case. Clonazepam is a prescription benzodiazepine commonly used to treat seizures, panic attacks and anxiety, and which generally carries warnings regarding risks of impaired judgement, thinking and motor skills with use. It also usually carries warnings regarding abuse, misuse, addiction, and withdrawal. Operating a motor vehicle or hazardous machinery while using clonazepam is not advised until the effects of the medication can be determined by the user.

Sertraline is a prescription selective serotonin-reuptake inhibitor (SSRI) medication commonly used to treat depression, anxiety, panic disorders, and post-traumatic stress disorder. A pilot on sertraline (not in combination with other psychiatric drugs) may be considered for FAA medical certification via an Authorization for Special Issuance, depending on a detailed evaluation of the individual pilot’s condition, including assessment of the pilot’s response to treatment.

Famotidine is an over-the-counter stomach acid suppressing medication commonly used to treat heartburn, gastroesophageal reflux, and peptic ulcer disease. Acetaminophen is an over-the-counter medication used to treat minor aches, pains as well as reduce fever. Salicylic acid is the primary active metabolite of aspirin, a widely available over-the-counter medication that can be used to control pain and fever and to reduce cardiovascular risk. Salicylic acid can also be found in over-the-counter medication used topically to treat skin conditions. It is often found in acne treatments. Naproxen is an over-the-counter non-steroidal anti-inflammatory medication used to treat minor aches and pains from arthritis. Famotidine, acetaminophen, salicylic acid, and naproxen are not generally considered impairing.