# NTSB WPR21LA200: Grumman Acft ENG Cor-Schweizer G-164C, N6596K, Glenn, CA, May 12, 2021 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 3 · Limited · Final report - Date: May 12, 2021, 10:30 local (17:30 UTC) - Place: Glenn, CA · rice field - Coordinates: 39.479139, -122.06213 - Nearby events: https://openairdocs.org/map.md?lat=39.4791&lon=-122.0621&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Fuel exhaustion](https://openairdocs.org/ntsb-events/192) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 103110 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA200 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103110/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103110 - Page: https://openairdocs.org/ntsb/WPR21LA200 ## Probable cause The pilot’s fuel mismanagement, which resulted in fuel exhaustion, a total loss of engine power, and an off-airport hard landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid management (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164C, 2 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=3952803), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164C, 2 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=3952803), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164C, 1 case](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=3952803), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Fuel exhaustion](https://openairdocs.org/ntsb-events/192) (defining event); cases with it: [Grumman Acft ENG Cor-Schweizer G-164C, 2 cases](https://openairdocs.org/ntsb-events/192/sequence.md?model=3952803), [All aircraft, 804 cases](https://openairdocs.org/ntsb-events/192/sequence.md) - [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Grumman Acft ENG Cor-Schweizer G-164C, 1 case](https://openairdocs.org/ntsb-events/092/sequence.md?model=3952803), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The pilot reported that, he departed for the aerial application flight with the fuel gauge indicating a half-full tank of fuel and a full load of product. About 100 ft above ground level the engine lost total power. The pilot elected to make a forced landing to a narrow dirt frontage road. The airplane landed hard and came to rest upright. The wings and fuselage were substantially damaged. Postaccident examination of the airframe revealed that no usable fuel was present in the center fuel tank nor from the wing fuel tanks. Maintenance personnel reported that they checked the fuel gauge in the cockpit, and it revealed that the center fuel tank was indicating half full. When the float connected to an arm in the center tank was manipulated, the fuel gauge in the cockpit moved but not in a manner coincident with the placement of the float, and that the fuel gauge may have been reporting false quantities of fuel. An engine inspection revealed no preaccident mechanical failures or malfunctions that would have precluded normal operation. The pilot reported that he did not refuel the airplane based on the fuel gauge indications that the fuel tank was half full. Thus, the pilot did not properly manage the airplane’s fuel, which resulted in fuel exhaustion and the total loss of engine power. ## Factual narrative On May 12, 2021, about 1030 Pacific daylight time, a Grumman ACFT ENG COR Schweizer G-164C, N6596K, was substantially damaged when it was involved in an accident near Glenn, California. The pilot was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 agricultural flight. The pilot reported that the airplane had just departed with the fuel gauge indicating a half-full tank of fuel and a full load of product (2,200 pounds of rice seed). About 100 ft above ground level the engine lost total power. He saw a narrow dirt frontage road in between rice fields and made a forced landing, during which the airplane landed hard and came to rest upright, causing substantial damage to the wings and fuselage. The pilot reported that he did not refuel the airplane before the accident flight based on the fuel gauge indications. The operator reported that the center fuel tank, which draws fuel from the two wing tanks was empty of fuel. About 1 gallon of fuel was recovered from the fuel sump. The engine and the fuel systems remained intact and uncompromised. Maintenance personnel reported that they checked the fuel gauge in the cockpit, and it revealed that the center fuel tank was indicating half full. When the float connected to an arm in the center tank was manipulated, the fuel gauge in the cockpit moved but not in a manner coincident with the placement of the float, and that the fuel gauge may have been reporting false quantities of fuel. The engine was sent to a repair facility for overhaul with no discrepancies identified. Further testing of the fuel gauge was not accomplished. ## Aircraft - Registration: [N6596K](https://openairdocs.org/aircraft/N6596K), registered now, S/N 6C, built 1978 (OpenAirDocs) - Reported make and model: GRUMMAN ACFT ENG COR-SCHWEIZER G-164C - Registry model: [Grumman Acft ENG Cor-Schweizer G-164C](https://openairdocs.org/model/grumman-acft-eng-cor-schweizer-g-164c) (registry code 3952803) (OpenAirDocs) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 6C - Year built: 1978 - Airframe hours: 22400 - Engines: Pratt & Whitney PT-6-41 turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Jones Aviation Inc. - Registered owner: Jones Aviation Inc. - Airworthiness certificate: Standard, Utility - Destination: Same as departure - Flight plan: Company VFR - Airport: N/A - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; injuries: serious; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review November 16, 2020; seat: center; flight hours: 1,550 total, 350 in this make and model, 100 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 4 knots - Visibility: 10 statute miles - Temperature: 82 °F, dew point 43 °F - Altimeter: 29.98 inHg - Observed at: KOVE, 21 nm away - METAR: KOVE 121753Z AUTO 13004KT 10SM CLR 28/06 A2998 RMK AO2 SLP151 T02830056 10283 20150 53009 ## 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 20210512021199A](https://openairdocs.org/incident/20210512021199A), May 12, 2021: Grumman Acft Eng Cor-Schweizer G-164C, Butte City, CA, Substantial damage. While maneuvering during a agricultural flight, the aircraft engine stopped running, the pilot made a forced landing in an agricultural field. The aircraft… ## Other investigations on N6596K (2) 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 LAX99LA040](https://openairdocs.org/ntsb/LAX99LA040), Nov 25, 1998: Grumman-Schweizer G-164C (N6596K), Oroville, CA, substantial damage. Probable cause: The pilot's decision to attempt readjustment of the rudder pedal in-flight. - [NTSB LAX92LA219](https://openairdocs.org/ntsb/LAX92LA219), May 26, 1992: Grumman G-164C (N6596K), Butte City, CA, substantial damage. Probable cause: THE PILOT'S FAILURE TO FOLLOW NORMAL PROCEDURES BY SELECTING THE WRONG RUNWAY. CONTRIBUTING TO THIS ACCIDENT WAS THE PILOT'S PREMATURE LIFT OFF AND THE EXISTING TAILWIND. ## Docket (5 files) The files NTSB released with the investigation on June 8, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103110. 10.5 MB in all. - Mpolit roc WPR21LA200 (item 1, PDF, 3 pages, 195 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15425988&FileExtension=pdf&FileName=MPolit%20RoC_Redacted-Rel.pdf - Memorandum for record a�� telephone interview, dom (item 2, PDF, 1 page, 88 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15421186&FileExtension=pdf&FileName=MoR%20(NTSB)-Rel.pdf - Record of conversation jburg jones aviation (item 3, PDF, 1 page, 66 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15425446&FileExtension=pdf&FileName=JBurg%20RoC%20WPR21LA200-Rel.pdf - Photos (item 4, PDF, 3 pages, 467 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15420580&FileExtension=pdf&FileName=Photo%20Array-Rel.pdf - Video of damaged airplane (operator) (item 5, MOV, 9.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15420590&FileExtension=mov&FileName=Video%20Operator-Rel.mov 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.