# NTSB WPR23LA212: Grumman Acft ENG Cor-Schweizer G-164B, N6750K, Colusa, CA, June 4, 2023 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 4 · Limited · Final report - Date: June 4, 2023, 09:05 local (16:05 UTC) - Place: Colusa, CA · crashed in rice field - Coordinates: 39.241597, -121.90951 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.2416&lon=-121.9095&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Western Pacific Region - Parties: SAC FSDO - NTSB case key (mKey): 192307 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR23LA212 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192307/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192307 - Page: https://openairdocs.org/ntsb/WPR23LA212 ## Probable cause The pilot’s failure to maintain clearance from a power line during a low-level aerial application flight. Contributing to the accident was the pilot’s fatigue. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Mental/emotional state: boredom](https://openairdocs.org/ntsb-findings/02022525): Personnel issues › Psychological · Pilot; cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 1 case](https://openairdocs.org/ntsb-findings/02022525/cases.md?model=3952802), [All aircraft, 1 case](https://openairdocs.org/ntsb-findings/02022525/cases.md) - [Alertness/Fatigue: fatigue due to work schedule](https://openairdocs.org/ntsb-findings/02013520): Personnel issues › Physical · Pilot (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 1 case](https://openairdocs.org/ntsb-findings/02013520/cases.md?model=3952802), [All aircraft, 25 cases](https://openairdocs.org/ntsb-findings/02013520/cases.md) - [Object/animal/substance: wire](https://openairdocs.org/ntsb-findings/03022032): Environmental issues › Physical environment · Compliance w/ procedure (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 8 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md?model=3952802), [All aircraft, 588 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md) - [Object/animal/substance: wire](https://openairdocs.org/ntsb-findings/03022032): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 8 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md?model=3952802), [All aircraft, 588 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 6 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=3952802), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Takeoff: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) (defining event); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 4 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=3952802), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot reported this was the eighth aerial application flight of the day spraying rice fields. He had made all takeoff’s flying low under a power line about 3/4 mile from the departure end of the runway. He stated that due to the monotony of the flights combined with fatigue and a bi-plane wing configuration, he lost sight of the power line and struck it. The airplane impacted the ground and cartwheeled sustaining substantial damage to the wings, fuselage, vertical and horizontal stabilizer. The pilot reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operations. ## Aircraft - Registration: [N6750K](https://openairdocs.org/deregistered/N6750K-2023-08-08), registration cancelled 2023-08-08, S/N 449-B (OpenAirDocs) - Reported make and model: GRUMMAN ACFT ENG COR-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: 449-B - Year built: 1978 - Engines: Pratt and Whitney R-1340 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Valley Air - Registered owner: Valley Air - Airworthiness certificate: Special, Restricted (Special) - Departed: O08, Colusa, CA - Destination: Same as departure - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 73; injuries: serious; flight instructor, commercial; airplane ratings: single-engine land, multi-engine sea; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review December 31, 2021; seat: center; restraint: 4-point; flight hours: 28,000 total, 8,000 in this make and model, 225 in the last 90 days, 225 in the last 30 days, 10 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 54 °F - Altimeter: 29.82 inHg - Observed at: KMYV, 20 nm away - METAR: METAR KMYV 041553Z AUTO 00000KT 10SM CLR 24/12 A2982 RMK AO2 SLP100 T02440117 $= ## 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 20230604005819A](https://openairdocs.org/incident/20230604005819A), Jun 4, 2023: Grumman Acft Eng Cor-Schweizer G-164B, Colusa, CA, Substantial damage. In an email from the pilot, he stated "I have flown under that set of wires probably hundreds of times since I considered it safer than trying to go over it… ## Other investigations on N6750K (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 LAX81DVD39](https://openairdocs.org/ntsb/LAX81DVD39), Aug 12, 1981: Grumman G-164B (N6750K), Tracy, CA, destroyed ## Docket (3 files) The files NTSB released with the investigation on October 20, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192307. 24.5 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 7 pages, 23.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15741345&FileExtension=pdf&FileName=6120.1_Redacted-Rel.pdf - Memorandum for record a�� telephone interview, pilot (item 2, PDF, 1 page, 43 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15792305&FileExtension=pdf&FileName=Sam%20Muse%20MOR-Rel.pdf - Photos (item 3, PDF, 2 pages, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15741355&FileExtension=pdf&FileName=Photo%201-Rel.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.