# NTSB CHI96LA287: Grumman-Schweizer G-164B, N6966K, Wellfleet, NE, August 9, 1996 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 9, 1996, 12:00 local (17:00 UTC) - Place: Wellfleet, NE - Coordinates: 40.749214, -100.729057 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.7492&lon=-100.7291&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 23, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 10353 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI96LA287 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10353/pdf - Page: https://openairdocs.org/ntsb/CHI96LA287 ## Probable cause failure of the pilot to maintain aircraft control, while maneuvering at low latitude. The hilly (rolling) terrain and unfavorable wind were related factors. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, maneuvering - aerial application - terrain condition - mountainous/hilly (contributing factor) - weather condition - unfavorable wind (contributing factor) - low altitude flight/maneuver - performed, pilot in command (contributing factor) - aircraft control - not maintained, pilot in command (cause) - In flight collision with terrain/water, maneuvering - aerial application ## Analysis While conducting aerial spraying over rolling terrain, the pilot experienced a violent nose down motion of the airplane, followed by the airplane going into a left wing down attitude. He recovered from the left wing down attitude, but experienced a right wing and nose down situation. The airplane struck the rolling terrain with the right wing, which subsequently resulted in extensive damage. The pilot reported no mechanical deficiencies or operational problems prior to impact. He believed that he may have encountered a windshear condition. About 21 miles west (at North Platte), the wind was from 180 degrees at 10 gusting 17 knots. ## Factual narrative On August 9, 1996, at 1200 central daylight time (cdt), a Grumman-Schweizer G-164B, N6966K, registered to Wallace Flying Service, Inc., of Wallace, Nebraska, piloted by a commercial pilot, impacted terrain, while maneuvering during the aerial application of a herbicide. The airplane was destroyed. The pilot reported no injuries. The local CFR Part 137 flight was operating in visual meteorological conditions. No flight plan was on file. The flight originated from Wallace, Nebraska, at 1150 cdt. According to the pilot's written statement, after making six agriculture spraying passes over rolling terrain, the pilot turned downwind over trees and experienced a violent nose down followed by a left wing down. He recovered from the left wing down and experienced a right wing down and nose down attitude. The airplane struck the terrain with the right wing. A Federal Aviation Administration Principal Maintenance Inspector (PMI) represented the NTSB on-scene. The PMI said the pilot reported no mechanical deficiencies or operational problems prior to impact. The pilot believes he may have experienced a severe wind shear condition. ## Aircraft - Registration: [N6966K](https://openairdocs.org/aircraft/N6966K), registered now, S/N 530B (OpenAirDocs) - Reported make and model: Grumman-Schweizer G-164B - Registry model: [Grumman Acft ENG Cor-Schweizer G-164B](https://openairdocs.org/model/grumman-acft-eng-cor-schweizer-g-164b) (registry code 3952802) (OpenAirDocs) - Category: Airplane - Serial number: 530B - Airframe hours: 6496 - Engines: P&W R-1340-AN1 600 horsepower reciprocating - Damage: Destroyed - Flight: Aerial application, Part 137 - Registered owner: Wallace Flying Service, Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, April 10, 1996, 387 hours before - Departed: 64V, WALLACE, NE - Destination: 64V ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 41; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, unknown; seat: center; flight hours: 8,278 total, 6,994 in this make and model, 8,146 as pilot in command, 215 in the last 90 days, 197 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 10 knots, gusting 17 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 55 °F - Altimeter: 30.00 inHg - Observed at: LBF, 21 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 19960809022219A](https://openairdocs.org/incident/19960809022219A), Aug 9, 1996: Scwzer G164B, Wellfleet, NE, Destroyed. Aircraft crashed while turning during aerial application. (.4)while conducting aerial spraying over rolling terrain, the pilot experienced a violent nose down… 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.