# NTSB SEA98LA069: Bell 47G3B2A, N7965J, Stanwood, WA, May 3, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 3, 1998, 12:00 local (19:00 UTC) - Place: Stanwood, WA - Coordinates: 48.210353, -122.279144 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=48.2104&lon=-122.2791&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report February 11, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 42780 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA98LA069 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42780/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=42780 - Page: https://openairdocs.org/ntsb/SEA98LA069 ## Probable cause The failure of the number two connecting rod, which led to additional internal engine damage and a complete loss of power. Factors include soft terrain in the area where the pilot found it necessary to execute his forced landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, maneuvering - engine assembly,connecting rod - failure (cause) - Forced landing, descent - emergency - autorotation - performed, pilot in command - Hard landing, emergency descent/landing - terrain condition - soft (contributing factor) ## Analysis While reducing power in the initial climb in order to establish cruise flight, the pilot of the helicopter experienced a partial engine power loss, followed by a complete loss of power about 15 seconds later. The pilot executed an autorotation to an emergency landing in a freshly plowed field, whereupon the main rotor flexed downward and contacted the tail boom during the touchdown. A post-accident inspection of the engine revealed that the number two connecting rod had failed near where it attaches to the crankshaft, ultimately leading to a total engine failure. Because both relevant fracture surfaces of the connecting rod were severely damaged and disfigured by repeated rotational impact pounding, the rod was not submitted for metallurgical failure mode examination. ## Factual narrative On May 3, 1998, approximately 1200 Pacific daylight time, a Bell 47G3B2A helicopter, N7965J, experienced a hard landing after an inflight total loss of engine power near Stanwood, Washington. The commercial pilot and his two passengers were not injured, but the aircraft, which was owned and operated by the pilot, sustained substantial damage. The 14 CFR Part 91 sightseeing flight, which departed the Stanwood Fairgrounds about one minute earlier, was being operated in visual meteorological conditions. No flight plan had been filed, and there was no report of an ELT activation. According to the pilot, he had just taken off and had been airborne for less than a minute when he reduced power in order to establish level flight at about 300 feet above the ground (AGL). As he reduced the power, he heard a loud bang and felt a "high-speed" vibration. Believing that he had experienced a partial power loss, the pilot entered an autorotation and checked to make sure he still had tail rotor authority. About 15 seconds into the autorotation, the engine quit and the vibration "dissipated." The pilot then continued his autorotation to a point where he could complete an emergency landing in a freshly plowed field. According to the pilot, he exaggerated his flare to bring his forward speed to nearly zero, in order to keep the aircraft from rolling over if a skid were to sink into the soft dirt. As the helicopter touched down, the contact with the ground was hard enough that the main rotor flexed downward and impacted the tail boom. A post-accident inspection of the engine revealed that the number two connecting rod had failed near where it attaches to the crankshaft, leading to a catastrophic failure of other internal engine components. Because the two relevant fracture surfaces on the number two connecting rod were severely damaged and disfigured by repeated rotational impact pounding, the rod was not submitted for metallurgical failure mode examination. ## Aircraft - Registration: [N7965J](https://openairdocs.org/aircraft/N7965J), registered now, S/N 6859, built 1973 (OpenAirDocs) - Reported make and model: Bell 47G3B2A - Registry model: [Bell 47G3B2A](https://openairdocs.org/model/bell-47g3b2a) (registry code 1181025) (OpenAirDocs) - Registry engine: [Lycoming TVO-435-GIA](https://openairdocs.org/engine/lycoming-tvo-435-gia) (registry code 41526, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: 6859 - Airframe hours: 5596 - Engines: Lycoming TVO-435-F1A 280 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Other work use, Part 91 - Registered owner: Stephen L. Gable - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 4, 1998, 47 hours before - Departed: WA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 52; commercial, flight instructor; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 5,300 total, 900 in this make and model, 4,968 as pilot in command, 62 in the last 90 days, 20 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 3 knots - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 61 °F ## 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 19980503008229A](https://openairdocs.org/incident/19980503008229A), May 3, 1998: Bell 47G3B2A, Stanwood, WA, Substantial damage. Sightseeing tours from Stanwood fairgrounds when the engine caught fire and the acft made an emerg landing. (.4)while reducing power in the initial climb in… ## Other investigations on N7965J (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 DEN84LA260](https://openairdocs.org/ntsb/DEN84LA260), Aug 5, 1984: Bell 47G (N7965J), West Glacier, MT, substantial damage ## Docket (2 files) The files NTSB released with the investigation on August 11, 1998, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=42780. 428 KB in all. - Supplement S (item 1, .PDF, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40090398&FileExtension=.PDF&FileName=Supplement%20S-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 371 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40413139&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF 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.