# NTSB SEA98LA133: Beech 23, N8719M, Oakville, WA, July 13, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 12, 1998, 17:26 local (Jul 13, 1998, 00:26 UTC) - Place: Oakville, WA - Coordinates: 46.830768, -123.28057 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.8308&lon=-123.2806&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report January 11, 2000 - Report: Approved by Office Director - ADs cited in the narratives: [AD 63-23-02](https://openairdocs.org/ad/63-23-02) (OpenAirDocs) - NTSB case key (mKey): 43222 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA98LA133 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/43222/pdf - Page: https://openairdocs.org/ntsb/SEA98LA133 ## Probable cause Loss of power due to the failure of an exhaust valve, and overloading of the landing gear. Factors include the failure of maintenance personnel to verify proper compliance with an Airworthiness Directive related to the exhaust valve, and soft terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, cruise - engine assembly,valve,exhaust - failure (cause) - maintenance,compliance with ad - not verified, other maintenance personnel (contributing factor) - information insufficient, other maintenance personnel - Forced landing, descent - emergency - Gear collapsed, landing - roll - landing gear - overload (cause) - terrain condition - soft (contributing factor) ## Analysis The engine began vibrating violently and losing power without warning while in cruise flight. Unable to maintain altitude, The pilot-in-command executed a forced landing in a soft, open field. During the roll-out, the nose landing gear separated and the left main landing gear collapsed. Post-crash engine examination revealed that the 7/16' exhaust valve on the number 3 cylinder had failed. Reconstructed log books (engine) noted that previous log books had been lost, and that the engine had been overhauled in 1966, about 978 hours before the accident. The Airworthiness Directives (AD) listing in the reconstructed log books for the engine noted that an AD requiring recurrent inspection and replacement of 7/16' valves and/or valve guides (depending upon which camshaft was installed) did not apply due to the serial number of the engine. The associated service bulletin did, however, list the serial number of the engine as requiring compliance. No record of compliance with this AD note prior to the reconstruction of the log books was found, and no record was found as to which camshaft was installed at the time of the reported overhaul. ## Factual narrative On July 12, 1998, approximately 1726 Pacific daylight time, a Beech 23, N8719M, registered to and being flown by a private pilot, was substantially damaged during an off airport forced landing following an abrupt loss of engine power three nautical miles northwest of Oakville, Washington. The pilot and his two passengers were uninjured. Visual meteorological conditions prevailed and a VFR flight plan had been filed. The flight, which was personal, and destined for Elma, Washington, was to have been operated under 14CFR91, and originated from Aurora, Oregon, approximately 1620 The pilot reported that while about ten miles southeast of Elma, the engine started vibrating violently and losing power without warning. He had no success at restoring power using emergency procedures. He stated that he declared an emergency and, unable to maintain altitude, he executed a forced landing in a soft open field of 12 inch high corn. During the roll-out, the nose landing gear separated and the left main landing gear collapsed. The engine was inspected at a maintenance facility at Olympia, Washington. During teardown of the engine, it was determined that the exhaust valve on the number 3 cylinder had failed, with the valve head broken off just below the tulip. This valve was of the hollow sodium-filled type. The aircraft's engine logbook (kept with the airplane) contained a note dated September 11, 1995, at a tachometer reading of 1790 hours, and reporting that the previous log books had been lost. An annual inspection was performed that date, and there was a note that the O-320-D2B engine, serial number L-5772-39, was 790 hours past its major overhaul. A later log entry (May 7, 1996) indicated that this time since overhaul had been corrected from 790 hours to 867 hours at a tachometer reading of 1817. This log entry indicated that the engine was overhauled on December 2, 1966, by Flightcraft, Portland, Oregon. The stem of the failed exhaust valve was dimensionally checked at .433 inches in diameter, or a nominal dimension for 7/16 inch valves (measured at the valve stem). The Airworthiness Directives (AD) listing in the reconstructed log books for the engine noted that AD 63-23-02 "Exhaust valves and guides DNA (does not apply) by SN (serial number)." AD 63-23-02 requires recurrent inspection and replacement of valves and/or valve guides at intervals of a maximum of 500 hours, depending upon the operational environment of the airplane, and depending upon the part number of the camshaft in the engine. That AD refers to Lycoming SB (service bulletin) 293B, which lists, in part, that the applicability of this AD included -D series engines with serial numbers of 5086-39 and up. No record of compliance with this AD note prior to the reconstruction of the log books was found, and no record was found as to which camshaft was installed at the reported overhaul. ## Aircraft - Registration: [N8719M](https://openairdocs.org/deregistered/N8719M-2002-05-01), registration cancelled 2002-05-01, S/N M-503, built 1963 (OpenAirDocs) - Reported make and model: Beech 23 - Registry model: [Beech 23](https://openairdocs.org/model/beech-23) (registry code 1151202) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: M-503 - Airframe hours: 1928 - Engines: Lycoming O-320-D2B 160 lbs thrust reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Waggoner, David, F. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 5, 1998, 8 hours before - Departed: AUO, AURORA, OR - Destination: WA22, ELMA, WA - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 533 total, 121 in this make and model, 443 as pilot in command, 8 in the last 90 days, 7 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: 4,200 ft overcast - Temperature: 64 °F, dew point 55 °F - Altimeter: 30.00 inHg - Observed at: OLM, 17 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 19980712016549A](https://openairdocs.org/incident/19980712016549A), Jul 12, 1998: Beech 23, Elma, WA, Substantial damage. (-23)Pilot experienced rough engine during cruise power, with a following loss of power. Could not maintain altitude. Declared emergency landed in corn field.… ## Other investigations on N8719M (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 SEA66F0024](https://openairdocs.org/ntsb/SEA66F0024), Jun 23, 1965: Beechcraft 23 (N8719M), Anacortes, WA, 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.