# NTSB WPR12CA271: Grumman Acft ENG Cor-Schweizer G-164B, N6861K, Okanogan, WA, June 20, 2012 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Data collection · Final report - Date: June 20, 2012, 08:33 local (15:33 UTC) - Place: Okanogan, WA - Coordinates: 48.359722, -119.540557 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=48.3597&lon=-119.5406&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report October 4, 2012 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 84041 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR12CA271 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/84041/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=84041 - Page: https://openairdocs.org/ntsb/WPR12CA271 ## Probable cause The pilot's failure to maintain clearance from power lines while maneuvering. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Object/animal/substance: wire](https://openairdocs.org/ntsb-findings/03022032): Environmental issues › Physical environment · Response/compensation (probable cause); cases with it: [All aircraft, 588 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md) - [Attention/monitoring: task monitoring/vigilance](https://openairdocs.org/ntsb-findings/02021520): Personnel issues › Psychological · Pilot (probable cause); cases with it: [All aircraft, 330 cases](https://openairdocs.org/ntsb-findings/02021520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Maneuvering-low-alt flying: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that, while establishing the second boundary along the eastern edge of a field where he was conducting an aerial application, the airplane struck power lines. Following the collision with the power lines, the airplane turned to the left and impacted the ground in a flat attitude, which resulted in structural damage to all four wings and fuselage. The pilot stated that there were four sets of power lines near the field; however, the upper right wing blocked his view of the power lines that the airplane struck. No preimpact mechanical malfunctions were reported that would have precluded normal operation of the airplane. ## Factual narrative The pilot reported that while establishing the second boundary along the eastern edge of a field where he was conducting an aerial application, the airplane struck power lines. Following the collision with the power lines, the airplane turned to the left and impacted terrain in a flat attitude, which resulted in structural damage to all four wings and fuselage. The pilot stated that there were four sets of power lines near the field; however, the upper right wing blocked his view from the power lines the airplane struck. No preimpact mechanical malfunctions were reported that would have precluded normal operation of the airplane. ## Aircraft - Registration: N6861K (not matched to a registry record) - Reported make and model: GRUMMAN ACFT ENG COR-SCHWEIZER G-164B - Category: Airplane - Serial number: 506B - Engines: P&W R1340 SERIES 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Smith & Murdock LLC - Registered owner: Smith & Murdock LLC - Airworthiness certificate: Special, Restricted (Special) - Departed: Okanogan, WA - Destination: Okanogan, WA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 41; injuries: serious; commercial, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; seat: center; flight hours: 10,941 total, 273 in this make and model, 231 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 110° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 61 °F, dew point 43 °F - Altimeter: 30.14 inHg - Observed at: OMK, 7 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 20120620011499A](https://openairdocs.org/incident/20120620011499A), Jun 20, 2012: Grumman Acft Eng Cor-Schweizer G-164B, Okanogan, WA, Destroyed. Pilot was conduct a survellience pass over a new field and did not see a power l ine crossing the field. The powerline was blocked from view by the upper wing.… ## Docket (2 files) The files NTSB released with the investigation on August 1, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=84041. 179 KB in all. - Pilot Statement (item 1, .PDF, 31 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40373236&FileExtension=.PDF&FileName=Pilot%20Statement-Master.PDF - Photo 1: View of the main wreckage. Courtesy of local law enforcement. (item 2, .PDF, 148 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40373703&FileExtension=.PDF&FileName=Photo%201%3A%20View%20of%20the%20main%20wreckage.%20%20Courtesy%20of%20local%20law%20enforcement.-Master.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.