# NTSB CHI96LA217: Air Tractor AT-301, N8883S, Ness City, KS, June 26, 1996 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 26, 1996, 09:00 local (14:00 UTC) - Place: Ness City, KS - Coordinates: 38.450527, -99.899909 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.4505&lon=-99.8999&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 16, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 10288 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI96LA217 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10288/pdf - Page: https://openairdocs.org/ntsb/CHI96LA217 ## Probable cause the failure of a counterweight bolt in the propeller for reasons undetermined. Factors were the wet landing area and the encounter with unsuitable terrain during 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, maneuvering - aerial application - propeller system/accessories,counterweight - loose part/bolt/nut/clamp/etc (cause) - Forced landing, emergency descent/landing - Nose over, landing - roll - terrain condition - none suitable (contributing factor) - terrain condition - wet ## Analysis The pilot stated that during a swath run the engine began to vibrate. He reduced engine power, then applied power again, but the vibration continued. He elected to conduct a forced landing. During the landing the airplane encountered wet terrain and nosed over. Subsequent examination revealed that a bolt in the propeller counterweight had broken. Source of the break in the bolt was not determined. ## Factual narrative On June 26, 1996, at 0900 central daylight time, an Air Tractor AT-301, N8883S, sustained substantial damage during a forced landing following a loss of engine power, near Ness City, Kansas. The pilot reported no injuries. The 14 CFR Part 137 flight was operating in visual meteorological conditions. No flight plan was on file. The flight departed from a private strip on the local flight near Ness City, Kansas. The pilot stated that that during his third spray run the engine began to vibrate. He said that he initially reduced power, but then tried to advance the throttle again. He then found that the vibration was continuing. He elected to execute a forced landing; however, he overflew the intended field and touched down in a wheat field. The touchdown was in mud and the airplane nosed over. Subsequent to the accident an examination was conducted to determine the source of the vibration. A counterweight bolt on the propeller was found broken. The pilot was unable to account for the reason the bolt broke and did not have any record of the time in service for that component. ## Aircraft - Registration: [N8883S](https://openairdocs.org/deregistered/N8883S-2021-02-12), registration cancelled 2021-02-12, S/N 301-0226, built 1979 (OpenAirDocs) - Reported make and model: Air Tractor AT-301 - Registry model: [Air Tractor AT-301](https://openairdocs.org/model/air-tractor-at-301) (registry code 0390103) (OpenAirDocs) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 301-0226 - Engines: P&W R-1340 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Steve J. Blocker - Airworthiness certificate: Special, Restricted (Special) - Departed: NONE, KS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 8,526 total, 900 in this make and model, 8,496 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 4 knots - Visibility: 15 statute miles - Lowest ceiling: none - Temperature: 81 °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 19960626015179A](https://openairdocs.org/incident/19960626015179A), Jun 26, 1996: Airtrc AT301, Ness City, KS, Substantial damage. Engine vibrated on spray run. Elected land. Overshot open field. Into wheat. Nosed over. Prop counter weight broke. 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.