ASN Wikibase Occurrence # 131529
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information.
If you feel this information is incomplete or incorrect, you can submit corrected information.
| Date: | Saturday 18 June 2011 |
| Time: | 13:06 |
| Type: |  Cessna T210N Turbo Centurion II |
| Owner/operator: | Private |
| Registration: | N210KW |
| MSN: | 21064181 |
| Year of manufacture: | 1980 |
| Total airframe hrs: | 2791 hours |
| Engine model: | Continental TSIO-520 SER |
| Fatalities: | Fatalities: 4 / Occupants: 4 |
| Aircraft damage: | Substantial |
| Category: | Accident |
| Location: | Armonk, 1 mile from Westchester County Airport - KHPN, NY -
 United States of America
|
| Phase: | Initial climb |
| Nature: | Private |
| Departure airport: | White Plains, NY (HPN) |
| Montauk, NY (MTP) | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
Witnesses observed the pilot perform multiple engine run-ups both on the parking ramp and at the end of the runway prior to departure. Both witnesses reported that the engine initially idled rough. Shortly after takeoff from runway 34, the pilot informed the air traffic controller that he needed to return to the airport and requested runway 16. The pilot declared an emergency but did not state the reason why. The airplane impacted trees and terrain about 1 mile from the approach end of runway 16. The cockpit and cabin sections were found inverted and mostly consumed by a post-crash fire. The wreckage path through the trees indicated that the airplane was established on a shallow glide angle when the impact occurred, with the landing gear and flaps retracted. A disassembly and examination of the engine revealed that the No. 2 cylinder piston head exhibited severe thermal deterioration consistent with a pre-ignition or detonation event. The electrodes of the No. 2 cylinder spark plugs were fully imbedded with aluminum and appeared incapable of producing a spark. The other five cylinders appeared to be functional and were undamaged. The left magneto was set to 30 degrees before top dead center (BTDC); the manufacturer's specification was 22 degrees BTDC. The right magneto was broken at its mount and its timing could not be verified. Examination of the engine maintenance records revealed that the magnetos were last retimed during an annual inspection about 27 months before the accident. The airplane was flown infrequently since the engine was installed in 2007.
The airport was equipped with noise abatement monitoring microphones that captured the airplane on the outbound and inbound (return) legs during the accident sequence. Although the engine appeared to be running just prior to impact, the engine sound pressure recorded on the outbound leg was significantly greater than on the inbound leg, suggesting that the pilot was approaching the airport at a reduced power setting. Although the amount of engine power available could not be determined, it is likely that additional power was available had the throttle been advanced.
Probable Cause: The pilot's decision to depart on the flight with a suspected mechanical deficiency and his subsequent decision to fly the final approach at a reduced power setting. Contributing to the accident was the improper timing of the magneto(s) that resulted in a severe detonation event.
Accident investigation:
 |
|
Sources:
NTSB
Location
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 18-Jun-2011 23:17 | gerard57 | Added |
| 19-Jun-2011 04:18 | RobertMB | Updated [Time, Aircraft type, Registration, Cn, Operator, Other fatalities, Departure airport, Destination airport, Source] |
| 19-Jun-2011 04:57 | Alpine Flight | Updated [Time, Aircraft type, Location, Narrative] |
| 19-Jun-2011 11:40 | RobertMB | Updated [Time, Location, Phase, Source, Narrative] |
| 25-Nov-2015 08:32 | Anon. | Updated [Narrative] |
| 21-Dec-2016 19:25 | ASN Update Bot | Updated [Time, Damage, Category, Investigating agency] |
| 27-Nov-2017 16:55 | ASN Update Bot | Updated [Operator, Other fatalities, Departure airport, Destination airport, Source, Narrative] |
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:
©2024 Flight Safety Foundation