# NTSB NYC03LA137: Cessna 150F, N8517G, Williamson, NY, June 26, 2003 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 26, 2003, 14:30 local (18:30 UTC) - Place: Williamson, NY - Coordinates: 43.083332, -77.120277 - Nearby events: https://openairdocs.org/map.md?lat=43.0833&lon=-77.1203&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report September 1, 2004 - Report: Approved by Office Director - Parties: FAA - ADs cited in the narratives: [AD 94-05-05 R1](https://openairdocs.org/ad/94-05-05-R1) (OpenAirDocs) - NTSB case key (mKey): 57318 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC03LA137 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/57318/pdf - Page: https://openairdocs.org/ntsb/NYC03LA137 ## Probable cause The failure of a rocker arm shaft boss, which resulted in a partial loss of power and subsequent forced landing. A factor was the unsuitable terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, takeoff - initial climb - engine assembly,rocker arm/tappet - failure (cause) - Forced landing, descent - emergency - On ground/water collision with object, emergency descent/landing - object - tree(s) - unsuitable terrain or takeoff/landing/taxi area - performed, pilot in command(cfi) (contributing factor) ## Analysis As the airplane was climbing, with the student pilot at the controls, the engine began to run rough. The certified flight instructor (CFI) took over the controls and elected to perform a forced landing to an apple orchard. During the forced landing, the left and right wings struck trees. The airplane came to rest upright. Examination of the engine revealed a fractured cylinder rocker shaft boss to the number one cylinder. The fracture was consistent with fatigue. An Airworthiness Directive, published in 1994, was issued to prevent possible engine power loss and subsequent engine failure. The AD required that maintenance personnel inspect the cylinder rocker shaft bosses for cracks at the next cylinder removal from the engine or engine overhaul, whichever occurs first, after the effective date of the AD. A revised AD became effective in 1996. Review of the airplane's engine maintenance records indicated that the last engine overhaul and cylinder removal was accomplished in 1977. ## Factual narrative On June 26, 2003, about 1430 eastern daylight time, a Cessna 150F, N8517G, was substantially damaged during a forced landing after experiencing a partial loss of engine power near Williamson, New York. The certified flight instructor (CFI) and student pilot were not injured. Visual meteorological conditions prevailed and no flight plan was filed for the local instructional flight conducted under 14 CFR Part 91. According to the pilot, the flight had departed the Williamson-Sodus Airport (3G7) in Williamson, about 1330, and remained in the traffic pattern with the student pilot at the controls. After conducting a fourth touch-and-go, as the airplane was climbing, the engine began to run rough. The CFI took the controls and elected to perform a forced landing to an apple orchard. During the forced landing, the left and right wings struck trees. The airplane came to rest upright. A Federal Aviation Administration (FAA) inspector examined the airplane after the accident and observed substantial damage to both wings. The inspector also noted that when the engine was rotated using the propeller blades, the number one cylinder did not develop compression. The valve box cover was removed, and a fractured cylinder rocker shaft boss was observed. The inspector added that the fracture on the boss was consistent with fatigue. Airworthiness Directive (AD) 94-05-05 R1, published in 1994, was issued to prevent possible engine power loss and subsequent engine failure. The AD required that maintenance personnel inspect the cylinder rocker shaft bosses for cracks at the next cylinder removal from the engine or engine overhaul, whichever occurs first, after the effective date of the AD. A revised AD became effective in 1996. Review of the airplane's engine maintenance records indicated that the last engine overhaul and cylinder removal was accomplished in 1977. The engine had accumulated about 2,003 hours of operation since it's manufacture in 1966, and about 700 hours of operation since the overhaul. An annual inspection of the airframe and engine was performed during September 2002. ## Aircraft - Registration: [N8517G](https://openairdocs.org/deregistered/N8517G-2006-06-12), registration cancelled 2006-06-12, S/N 15062617, built 1966 (OpenAirDocs) - Reported make and model: Cessna 150F - Registry model: [Cessna 150F](https://openairdocs.org/model/cessna-150f) (registry code 2071814) (OpenAirDocs) - Registry engine: [Continental 0-200 series](https://openairdocs.org/engine/continental-0-200-series) (registry code 17020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 15062617 - Airframe hours: 2003 - Engines: Continental O-200 100 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Williamson Flying Club Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 4, 2002 - Departed: 3G7, Williamson - Destination: 3G7 - Airport: 3G7, Williamson-Sodus Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 23; injuries: none; commercial, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; last flight review November 1, 2002; seat: right; flight hours: 1,100 total, 50 in this make and model, 1,027 as pilot in command, 160 in the last 90 days, 80 in the last 30 days, 3 in the last 24 hours - Student pilot; injuries: none; seat: left; flight hours: 2 total, 2 in this make and model, 2 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 250° at 11 knots, gusting 19 - Visibility: 7 statute miles - Lowest ceiling: none - Temperature: 90 °F, dew point 64 °F - Altimeter: 29.85 inHg - Observed at: ROC, 25 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20030626017729A](https://openairdocs.org/incident/20030626017729A), Jun 26, 2003: Cessna 150F, Williamson, NY, Substantial damage. (-23) On June 27, 2003, at 1415 EST, a Cessna 150, N8517G, registered to Williamson flying club inc., did an emergency landing in an apple orchard, east of… ## Other investigations on N8517G (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB NYC67F0377](https://openairdocs.org/ntsb/NYC67F0377), Nov 8, 1966: Cessna 150 (N8517G), Hiladelphia, PA, substantial damage From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.