# NTSB SEA98LA125: Rockwell S-2R, N4996X, Pasco, WA, July 9, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 9, 1998, 10:00 local (17:00 UTC) - Place: Pasco, WA - Coordinates: 46.409225, -118.899787 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.4092&lon=-118.8998&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 15, 1999 - Report: Approved by Office Director - NTSB case key (mKey): 43218 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA98LA125 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/43218/pdf - Page: https://openairdocs.org/ntsb/SEA98LA125 ## Probable cause Separation of the throttle linkage which resulted in the loss of power. Factors include worn throttle linkage parts and the furrows in the plowed field which was the available field for the forced landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, takeoff - initial climb - throttle/power lever,push/pull rod - separation (cause) - throttle/power lever,push/pull rod - worn (contributing factor) - Forced landing, descent - emergency - Nose over, landing - roll - terrain condition - none suitable (contributing factor) ## Analysis The pilot reported that while taking off to the west and climbing through about 40 feet above ground, the engine went to idle. He stated that he dropped his chemical load and immediately landed in an open potato field. The landing roll was crosswise to the furrows and the aircraft ultimately nosed over. FAA on-site inspection revealed a disconnect of the throttle linkage just forward of the firewall where it attaches to a 90 degree bell-crank designed to translate forward/aft motion into left/right lateral motion. The threads on the bell-crank attach end of the longitudinal throttle tube were found to be heavily worn. ## Factual narrative On July 9, 1998, approximately 1000 Pacific daylight time, a Rockwell "Thrush" S-2R, N4996X, owned by Gerald Titus and being operated by Air-Trac, Inc., and being flown by a commercial pilot, sustained substantial damage when it nosed over during the landing roll following a near total loss of power on takeoff, seven nautical miles east-northeast of the Pasco airport, Pasco, Washington. The pilot was uninjured. Visual meteorological conditions existed and no flight plan had been filed. The flight, which was for the aerial dispensation of chemicals, was to have been operated under 14CFR137, and was departing from a private airstrip when it crashed. The pilot reported that while taking off to the west and climbing through about 40 feet above ground, the engine went to idle. He stated that he dropped his chemical load and immediately landed in an open potato field. The landing roll was reported to be crosswise to the furrows and the aircraft ultimately nosed over. FAA on-site inspection conducted by an inspector from the Spokane FSDO revealed a disconnect of the throttle linkage just forward of the firewall where it attaches to a 90 degree bell-crank designed to translate forward/aft motion into left/right lateral motion. The threads on the bell-crank attach end of the longitudinal throttle tube were found to be heavily worn. ## Aircraft - Registration: [N4996X](https://openairdocs.org/deregistered/N4996X-2012-02-07), registration cancelled 2012-02-07, S/N 2138R, built 1975 (OpenAirDocs) - Reported make and model: Rockwell S-2R - Registry model: [Rockwell International S-2R](https://openairdocs.org/model/rockwell-international-s-2r) (registry code 7630202) (OpenAirDocs) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 2138R - Airframe hours: 14000 - Engines: P&W R-1340 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Titus, Gerald, R. - Airworthiness certificate: Special, Restricted (Special) ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 15,000 total, 8,000 in this make and model, 15,000 as pilot in command, 350 in the last 90 days, 179 in the last 30 days, 9 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 63 °F - Altimeter: 29.00 inHg - Observed at: PSC, 7 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 19980709024399A](https://openairdocs.org/incident/19980709024399A), Jul 9, 1998: Ayres S2R, Pasco, WA, Substantial damage. Lost power on liftoff. Dumped load landed potato field. Nosed over. Throttle connector worn out failed. (.4)the pilot reported that while taking off to the… ## Other investigations on N4996X (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 WPR11CA229](https://openairdocs.org/ntsb/WPR11CA229), May 18, 2011: Rockwell International S-2R (N4996X), Kahlotus, WA, substantial damage. Probable cause: The pilot's failure to maintain directional control during takeoff. 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.