# NTSB SEA93LA198: Grumman-Schweizer G164A, N9536, Dayton, WA, September 13, 1993 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: September 13, 1993, 09:10 local (16:10 UTC) - Place: Dayton, WA - Coordinates: 46.310176, -117.899925 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.3102&lon=-117.8999&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report August 1, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 41766 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA93LA198 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41766/pdf - Page: https://openairdocs.org/ntsb/SEA93LA198 ## Probable cause THE PILOT IN COMMAND'S FAILURE TO MAINTAIN PROPER CLEARANCE FROM THE POWER LINES. THE UNMARKED POWER LINES WERE A FACTOR. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, maneuvering - object - wire,transmission (contributing factor) - clearance - not maintained, pilot in command (cause) - In flight collision with terrain/water, descent - uncontrolled ## Analysis THE PILOT REPORTED THAT WHILE 'DODGING TREES' FOLLOWING A SPRAY RUN IN A CANYON, THE AIRCRAFT IMPACTED AN UNMARKED POWER LINE AND THEN COLLIDED WITH TERRAIN. ## Factual narrative On September 13, 1993, at approximately 0910 hours Pacific daylight time (PDT), a Grumman/Schweizer G-164A, N9536, registered to and operated by Cropland Air Service, Inc., and being flown by Val Woodworth, a certificated commercial pilot, was destroyed during a collision with power lines and terrain while maneuvering during a crop dusting operation approximately five nautical miles south of Dayton, Washington. The pilot sustained minor injuries. Visual meteorological conditions prevailed at the time and no flight plan had been filed. The flight, which was engaged in aerial application of a chemical, was to have been operated in accordance with the requirements set forth in 14CFR137 and originated from the operator's private airstrip near Waitsburg, Washington, at approximately 0900 hours. The pilot reported that following a spray run the aircraft's airspeed began to diminish and that he "added full power (and) pulled out of the canyon." He began a "gradual right hand turn down the canyon" during which a loss of altitude occurred. The pilot reported that "by now I was at tree top level (and) was dodging trees when the aircraft hooked a Bonneville power line." The aircraft collided with terrain immediately thereafter. The aircraft came to rest almost directly beneath the unmarked power lines (refer to photographs 1 & 2). The pilot reported no mechanical malfunction with the aircraft during the event. ## Aircraft - Registration: [N9536](https://openairdocs.org/deregistered/N9536-2000-06-12), registration cancelled 2000-06-12, S/N 1191 (OpenAirDocs) - Reported make and model: Grumman-Schweizer G164A - Registry model: [Grumman Acft ENG Cor-Schweizer G-164A](https://openairdocs.org/model/grumman-acft-eng-cor-schweizer-g-164a) (registry code 3952801) (OpenAirDocs) - Category: Airplane - Serial number: 1191 - Engines: P&W R-1340 600 horsepower reciprocating - Damage: Destroyed - Fire: On-Ground - Flight: Aerial application, Part 137 - Operator: Cropland Air Service, Inc. - Registered owner: Cropland Air Service, Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, July 7, 1993 - Departed: WAITSBURG, WA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 37; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: front; flight hours: 2,292 total, 1,838 in this make and model, 2,235 as pilot in command, 110 in the last 90 days, 40 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 240° at 5 knots - Visibility: 30 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 39 °F - Altimeter: 30.00 inHg - Observed at: ALW, 14 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 19930913052229A](https://openairdocs.org/incident/19930913052229A), Sep 13, 1993: Scwzer G164A, Dayton, WA, Destroyed. Unable to climb after spray run. Turned away from trees but caught a powerlilne. Terrain down draft were factors. ## Other investigations on N9536 (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 SEA83LA143](https://openairdocs.org/ntsb/SEA83LA143), Jun 29, 1983: Grumman G-164A (N9536), Waitsburg, 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.