# NTSB WPR11CA229: Rockwell International S-2R, N4996X, Kahlotus, WA, May 18, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: May 18, 2011, 16:15 local (23:15 UTC) - Place: Kahlotus, WA - Coordinates: 46.639999, -118.551109 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.6400&lon=-118.5511&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report August 3, 2011 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 79159 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11CA229 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/79159/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=79159 - Page: https://openairdocs.org/ntsb/WPR11CA229 ## Probable cause The pilot's failure to maintain directional control during takeoff. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Rockwell International S-2R, 6 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=7630202), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Wind: crosswind](https://openairdocs.org/ntsb-findings/03034040): Environmental issues › Conditions/weather/phenomena · Contributed to outcome; cases with it: [Rockwell International S-2R, 2 cases](https://openairdocs.org/ntsb-findings/03034040/cases.md?model=7630202), [All aircraft, 1,008 cases](https://openairdocs.org/ntsb-findings/03034040/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Rockwell International S-2R, 7 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7630202), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Rockwell International S-2R, 8 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=7630202), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Takeoff: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Rockwell International S-2R, 4 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=7630202), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) - [Takeoff: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Rockwell International S-2R, 2 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=7630202), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that he attempted to take off with a strong crosswind. During the takeoff sequence, the airplane veered off the airstrip onto soft dirt and subsequently nosed over. The pilot reported that there were no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal flight. ## Factual narrative The pilot reported that he attempted to takeoff with a strong crosswind. During the takeoff sequence, the airplane veered off the airstrip onto soft dirt and subsequently nosed over. Weather reporting stations within 30 nautical miles (nm) of the airstrip reported wind from 324 degrees, varying from 6 to 7 knots and gusting up to 16 knots. The pilot reported that there were no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal flight. ## 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 INTERNATIONAL 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: 23000 - Engines: P&W R1340 SERIES 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Air-Trac Inc. - Registered owner: Air-Trac Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, March 1, 2011, 200 hours before - Departed: 4WA6, Kahlotus, WA - Destination: 4WA6, Kahlotus, WA - Airport: 4WA6, Hille-Kimp Airstrip, runway 02, 2,600 × 26 ft, gravel ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 68; injuries: none; commercial; airplane ratings: single-engine land; medical: class 2, with waivers/limitations; last flight review January 15, 2010; seat: center; flight hours: 26,500 total, 22,000 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 300° at 12 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 34 °F - Altimeter: 29.81 inHg ## 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 SEA98LA125](https://openairdocs.org/ntsb/SEA98LA125), Jul 9, 1998: Rockwell S-2R (N4996X), Pasco, WA, substantial damage. 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… ## Docket (1 files) The files NTSB released with the investigation on May 27, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=79159. 592 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 592 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348374&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.