# NTSB WPR24LA214: Grumman Acft ENG Cor-Schweizer G-164B, N6793K, Pleasant Grove, CA, June 25, 2024 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: June 25, 2024, 05:54 local (12:54 UTC) - Place: Pleasant Grove, CA - Coordinates: 38.907455, -121.49334 - Nearby events: https://openairdocs.org/map.md?lat=38.9075&lon=-121.4933&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: No injuries - Injuries: 1 uninjured - Status: Completed, report April 29, 2026 - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Honeywell Aerospace, Hartzell Aviation, Federal Aviation Administration - NTSB case key (mKey): 194552 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR24LA214 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194552/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=194552 - Page: https://openairdocs.org/ntsb/WPR24LA214 ## Probable cause The pilot’s delayed recognition of the extent of the airplane’s increased takeoff roll. Contributing to the accident was the pilot’s lack of experience operating the airplane at a high gross weight. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Experience/qualifications: total experience w/ equipment](https://openairdocs.org/ntsb-findings/02031025): Personnel issues › Experience/knowledge · Pilot (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 1 case](https://openairdocs.org/ntsb-findings/02031025/cases.md?model=3952802), [All aircraft, 269 cases](https://openairdocs.org/ntsb-findings/02031025/cases.md) - [Aircraft capability: takeoff distance](https://openairdocs.org/ntsb-findings/01061025): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 1 case](https://openairdocs.org/ntsb-findings/01061025/cases.md?model=3952802), [All aircraft, 67 cases](https://openairdocs.org/ntsb-findings/01061025/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 6 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=3952802), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [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 operator hired the pilot to reposition the turbopropeller-engine equipped airplane from the seller’s private airstrip to the job location. Although the pilot had experience flying reciprocating engine-equipped models of the airplane, he did not have any previous experience flying the turbopropeller-engine equipped model until he started preparing for the repositioning flight. His preparations included attending ground training and making four familiarization flights (about 2.5 hours total) in the accident airplane with progressively increased loading but at weights less than that of the loading for the accident flight. For the accident flight, the pilot loaded the airplane to about 6,011 lbs, which was below the Civil Aeronautics Manual (CAM) Part 8 operational gross weight of 6,075 lbs listed in an exemplar Pilot’s Operating Handbook (POH) for the airplane model. The POH did not list performance data for the turbopropeller engine or provide performance charts for calculating required runway distances. No performance charts for the turbo-propeller equipped Ag Cat were available to the pilot; however, the ground/flight instructor was confident that the airplane could take off from the 2,100 ft asphalt runway. The pilot’s pretakeoff checks revealed normal operation of the engine. During the takeoff roll, the airplane accelerated at a significantly lower rate than during the pilot’s previous flights in it. Once the tailwheel came up, the pilot saw that most of the runway had been used. The pilot elected to continue the takeoff and pulled back on the control stick to climb. The airplane climbed slowly but struck a gate and then a pickup truck before impacting terrain, which substantially damage the fuselage, wings, and empennage. Any advantage to braking, rather than electing to takeoff, could not be determined due to the lack of performance charts. Postaccident examination of the airframe and engine revealed no mechanical malfunction or anomaly that would have precluded normal operation. An anomaly identified in the fuel control bellows would not have reduced engine power. ## Factual narrative On June 25, 2024, about 0554 Pacific daylight time, a Grumman-Schweizer G-164B, turbopropeller-engine equipped airplane (current type certificate held by Allied Ag Cat Productions Inc.), N6793K, was substantially damaged when it was involved in an accident near Nicolaus, California. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 positioning flight. According to the pilot, the operator had just purchased the airplane and hired him to reposition it from the seller’s private airstrip in Pleasant Grove, California, to a job location in Amana, Iowa. His previous experience flying Ag Cat airplanes involved only models equipped with a reciprocating engine. To prepare for the repositioning flight, the pilot attended 3 hours of ground training provided by a pilot/mechanic who had about 7,000 hours experience flying Ag Cat airplanes, including both turbopropropeller- and reciprocating-engine equipped models. The pilot also conducted four “operational check flights” to familiarize himself with the accident airplane that totaled about 2.5 hours. For each successive flight, the pilot increased the amount of fuel in the hopper to increase the load, and he observed that the airplane departed the runway quickly with no performance issues. The pilot reported that he did not use a load as heavy as that of the accident flight. On the day of the accident flight, the airplane was loaded with 60 gallons of jet fuel in the wing tank and 270 gallons of jet fuel in the hopper. According to the pilot, the airplane’s empty weight of 3,600 lbs, the fuel weight of 2,211 lbs, the pilot’s weight of 190 lbs, and the baggage weight of 10 lbs equated to a gross takeoff weight of about 6,011 lbs. According to an exemplar POH for G-164B airplanes, the design gross weight for the airplane was 4,500 lbs, and the Civil Aeronautics Manual (CAM) Part 8 operational gross weight was 6,075 lbs. According to the pilot, another reference (Jane’s Civil and Military Aircraft Upgrades) listed the airplane’s CAM 8 maximum takeoff weight as 7,020 lbs. The POH did not list performance data for the turbopropeller engine or provide performance charts for calculating required runway distances. According to the ground instructor, he had flown the accident airplane in the past and from the airstrip where the accident flight departed, and he was confident that the airplane could take off with the load and in the environmental conditions of the accident flight. Based on weather conditions reported about the time of the accident from the nearest automated weather reporting station at Lincoln Regional Airport/Karl Harder Field (LHM) Lincoln, California, the calculated density altitude was about 978 ft msl. The pilot reported that, for the accident flight, he used a ground start pack to start the engine and monitored the engine system instruments. After the engine started, he had the start pack removed. He turned on the generator and confirmed that itwas operating normally. He then moved the power lever up and over the back gate to reduce engine speed and ensure the propeller stops were disengaged. He checked the engine instruments and confirmed that they were in the normal ranges. After checking the navigation equipment, the pilot then taxied to the north end of the 2,100 ft asphalt runway, again checking the engine instruments and confirming that they were still in the normal ranges. He then advanced the red engine speed control lever all the way forward and felt the engine speed increase. He then released the wheel brakes to depart. According to the pilot, the airplane did not accelerate as it had on previous flights with less weight. During the takeoff roll, once the tail came up, he noted that about 90% of the runway had been used, and the airplane was failing to gain lift. The pilot applied an aft control stick to clear a gate located near the end of the runway, but the airplane struck the gate and then a pickup truck that was traveling on a road that ran perpendicular to the end of the runway. The airplane then impacted terrain, spun about 180°, and came to rest upright. Postaccident examination of the airframe revealed damage to the fuselage, empennage, and the upper and lower wings, consistent with impact of multiple objects. Flight control continuity was confirmed from the flight controls to their respective control surfaces. Examination of the airframe, engine, and propeller governor identified no evidence of preaccident malfunction or anomaly that would have precluded normal operation. According to the manufacturer of the airplane, the TPE-331 engine was not a factory installation and therefore did not have performance charts for the TPE-331 in the Pilot’s Handbook. Testing of the fuel control unit (FCU) using test specification procedure (TSP)-8519, revision A1, revealed no leaks or other anomaly when the FCU was pressurized. Fuel flow readings were collected at the lower power settings of the acceleration schedule but once Ps3 pressure reached about 95 psi, an air leak could be heard and felt coming from the main air section cover. Removal of the Ps3 (static pressure at station 3.0) bellows cover revealed that the Ps3 diaphragm had a circumferential tear over about 90° adjacent to the plate. According to the FCU manufacturer, “The Ps3 rolling diaphragm is subject to wear. Extreme wear can result in a hole in the diaphragm sidewall. The hole allows air to leak to Pt2 (total pressure at station 2.0), causing the FCU to sense an increased Pt2 pressure. An incorrect Pt2 pressure can result in higher than desired power lever schedule fuel flows and a reduction in acceleration schedule fuel flows.” ## Aircraft - Registration: [N6793K](https://openairdocs.org/aircraft/N6793K), registered now, S/N 487B, built 1978 (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) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 487B - Year built: 1978 - Airframe hours: 7815.3 - Engines: Honeywell TIE-331-1-157A 665 horsepower turbo prop - Damage: Substantial damage - Flight: Positioning, Part 91 - Operator: Cajuncats LLC - Registered owner: Cajuncats LLC - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, November 1, 2023 - Departed: Nicolaus, CA - Destination: C11, Amana, IA - Airport: PVT, Moe's Crop Dusting Service, runway 18, 2,100 × 26 ft, gravel - Equipment: Electronic flight bag or handheld device, Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 69; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review February 16, 2024; seat: single; restraint: 4-point; flight hours: 11,000 total, 620 in this make and model, 11,000 as pilot in command, 13 in the last 90 days, 6 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 5 knots - Lowest ceiling: none - Temperature: 60 °F, dew point 46 °F - Altimeter: 29.86 inHg - Observed at: LHM, 5 nm away - METAR: METAR KLHM 251255Z AUTO 14009KT 10SM CLR 22/05 A2984 RMK AO1 ## 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 20240625009519A](https://openairdocs.org/incident/20240625009519A), Jun 25, 2024: Grumman Acft Eng Cor-Schweizer G-164B, Pleasant Grove, CA, Substantial damage. According to the pilot he slowly advanced the power lever all the way forward and monitored the aircraft’s position on the runway as the tail was still down.… ## Other investigations on N6793K (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 ATL84LA171](https://openairdocs.org/ntsb/ATL84LA171), May 9, 1984: Grumman G-164B (N6793K), Rosedale, MS, substantial damage ## Docket (11 files) The files NTSB released with the investigation on April 22, 2026, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=194552. 14.4 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 15 pages, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19917121&FileExtension=pdf&FileName=6120_Narr_Rec_Redacted-Rel.pdf - Instructors statement (item 2, PDF, 2 pages, 124 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19940322&FileExtension=pdf&FileName=ROC_Instructors%20Statement_Redacted-Rel.pdf - Pilots operating handbook excerpt (item 3, PDF, 1 page, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19937946&FileExtension=pdf&FileName=G-164A%20POH%20Pg%2016-Rel.pdf - Airframe and engine examination report (item 4, PDF, 15 pages, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19939650&FileExtension=pdf&FileName=A%26E%20Exam%20Report%20for%20WPR24LA214-Rel.pdf - Powerplants examination report (item 5, PDF, 15 pages, 6.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19939930&FileExtension=pdf&FileName=Powerplants%20Examination%20Report-Rel.pdf - Mfr engine manufacturer email (item 6, PDF, 1 page, 85 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19938727&FileExtension=pdf&FileName=MFR%20EMail%20from%20Engine%20Manufacturer-Rel.pdf - Satloc data report (item 7, PDF, 4 pages, 856 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20336867&FileExtension=pdf&FileName=WPR24LA214%20Email%20Report_Redacted-Rel.pdf - Memo for record owner of allied ag cat (item 8, PDF, 1 page, 95 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20199292&FileExtension=pdf&FileName=ROC%20-%20Owner%20Allied%20Ag%20Cat_Redacted-Rel.pdf - Memo for record moe's crop-dusting private strip information (item 9, PDF, 1 page, 94 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20199878&FileExtension=pdf&FileName=ROC%20-%20Moe%27s%20Crop%20Dustin%20Runway%20Information_Redacted-Rel.pdf - Photos (item 10, PDF, 5 pages, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19939821&FileExtension=pdf&FileName=Photos%20of%20N6793K-Rel.pdf - Party member certificates (item 11, PDF, 2 pages, 411 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19938101&FileExtension=pdf&FileName=Party%20member%20certificates_All_Redacted-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.