You can contribute by submitting additional or updated information.
| Date: | Thursday 19 January 2023 |
| Time: | 17:29 |
| Type: |  Beechcraft A36 Bonanza |
| Owner/operator: | Daviation Inc |
| Registration: | N19MT |
| MSN: | E-798 |
| Year of manufacture: | 1976 |
| Total airframe hrs: | 9135 hours |
| Fatalities: | Fatalities: 2 / Occupants: 2 |
| Other fatalities: | 0 |
| Aircraft damage: | Destroyed |
| Category: | Accident |
| Location: | near White Plains-Westchester County Airport (HPN), North Castle, NY -
 United States of America
|
| Phase: | Manoeuvring (airshow, firefighting, ag.ops.) |
| Nature: | Private |
| Departure airport: | New York-John F. Kennedy International Airport, NY (JFK/KJFK) |
| Cleveland-Cuyahoga County Airport, OH (CGF/KCGF) | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
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.
About 18 minutes after takeoff, while on an instrument flight rules (IFR) flight, the pilot requested a lower altitude, advising the controller that the airplane’s climb performance was degraded. As the flight continued the pilot recognized a “dead cylinder” and requested a heading to a nearby airport. The controller vectored the flight to the airport, but the pilot delayed turning onto the vectored heading for over 2 minutes. When the flight was about 6 nautical miles from the airport the pilot declared an emergency and advised the controller that the oil pressure was dropping. After turning onto the vectored heading, 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 change in the airplane’s heading resulted in the controller providing a new vector, which increased the distance and flight time to the intended runway. Recorded data showed the engine then lost all power. The airplane continued to descend and subsequently collided with trees and the ground less than 1 mile from the intended runway threshold.
According to recorded data, shortly after takeoff, when the flight was about 1 nautical mile from the departure end of the runway, the No. 4 cylinder head temperature (CHT) value exceeded the highest allowed value. The flight continued while the No. 4 CHT continued to increase. The CHT for that cylinder then began to decrease, consistent with non-firing of the fuel air mixture, and the flight continued.
Postaccident examination of the engine revealed damage to the top and sides of the No. 4 piston that were likely the result of pre-ignition/detonation that pressurized the crankcase, pushing oil out of the breather assembly and depleting the oil supply. This ultimately resulted in oil exhaustion and subsequent catastrophic internal engine failure. Both spark plugs of the No. 4 cylinder had extensive deposits and one had a separated section of core nose insulator while the other only had a cracked core nose insulator, though it could not be determined from the available evidence if those conditions existed before or were the result of preignition/detonation.
Causes for detonation include improper ignition timing, high inlet air temperature, engine overheating, carbon build-up or oil in the combustion chamber, an issue with the fuel octane, or a lean fuel-to-air mixture.
Although the magneto-to-engine timing could not be determined postaccident, there were no postaccident anomalies noted with either the magneto or the ignition harness. High inlet air temperature, engine overheating, or carbon build-up/oil in the combustion chamber were not likely or not observed. There was no report of any fuel-related issue from the facility that last fueled the accident airplane. While the position of the mixture control during the flight and the pilot’s leaning procedures were unknown, it is unlikely that the pilot would have leaned the fuel-to-air ratio to CHT exceedance as that would have been contrary to the published limitations and takeoff procedures.
Probable Cause: The pre-ignition/detonation damage to the No. 4 piston for reasons that could not be determined, which allowed the crankcase to become pressurized and resulted in oil exhaustion and subsequent catastrophic internal engine failure.
Accident investigation:
 |
|
Sources:
https://www.cbsnews.com/newyork/news/plane-crash-white-plains-single-engine-beechcraft-a36/
https://pix11.com/news/local-news/small-plane-from-jfk-to-ohio-crashes-near-white-plains-faa/
https://abc7ny.com/plane-crash-missing-westchester-county-airport-jfk/12719639/
https://www.nbcnewyork.com/news/local/plane-goes-missing-en-route-to-westchester-county-airport-sources/4057439/
https://data.ntsb.gov/Docket?ProjectID=106608
https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=19MT
https://globe.adsbexchange.com/?icao=a166f7&lat=41.081&lon=-73.733&zoom=13.0&showTrace=2023-01-19&leg=2
https://flightaware.com/live/flight/N19MT/history/20230119/2100Z/KJFK/KHPN
https://www.tandgflying.com/beechcraft-bonanza-a36---19mt.html
https://cdn.jetphotos.com/full/5/42413_1664070821.jpg (photo)
Location
Media:
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 19-Mar-2025 22:21 | Captain Adam | Updated [Location, Phase, Source, Embed code, Narrative, Accident report, ] |
Corrections or additions? ... Edit this accident description
The Aviation Safety Network is an exclusive service provided by:
Quick Links:
| ASN Home | Send Correction / Feedback |
| FSF Home | Disclaimer | Copyright |
| Contact Us | Privacy Policy |
| Press / Media |
CONNECT WITH US:
©2025 Flight Safety Foundation