# NTSB WPR24LA121: Kitfox Series 5, N743JT, Yucca Grove, CA, April 5, 2024 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: April 4, 2024, 20:00 local (Apr 5, 2024, 03:00 UTC) - Place: Yucca Grove, CA - Coordinates: 35.436962, -115.69038 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.4370&lon=-115.6904&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: FAA FSDO - NTSB case key (mKey): 194060 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR24LA121 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194060/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=194060 - Page: https://openairdocs.org/ntsb/WPR24LA121 ## Probable cause The pilot’s improper repair of the oil sump, which resulted in a loss of oil pressure and collision with terrain during a precautionary landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng oil sys](https://openairdocs.org/ntsb-findings/01058550): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Anderson Thomas C KITFOX SERIES 5, 1 case](https://openairdocs.org/ntsb-findings/01058550/cases.md?model=05605CB), [All aircraft, 130 cases](https://openairdocs.org/ntsb-findings/01058550/cases.md) - [Engine (reciprocating): recip eng oil sys](https://openairdocs.org/ntsb-findings/01058550): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Anderson Thomas C KITFOX SERIES 5, 1 case](https://openairdocs.org/ntsb-findings/01058550/cases.md?model=05605CB), [All aircraft, 130 cases](https://openairdocs.org/ntsb-findings/01058550/cases.md) - [Maintenance: repair](https://openairdocs.org/ntsb-findings/02062015): Personnel issues › Task performance · Pilot; cases with it: [Anderson Thomas C KITFOX SERIES 5, 1 case](https://openairdocs.org/ntsb-findings/02062015/cases.md?model=05605CB), [All aircraft, 99 cases](https://openairdocs.org/ntsb-findings/02062015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Anderson Thomas C KITFOX SERIES 5, 1 case](https://openairdocs.org/ntsb-events/340/sequence.md?model=05605CB), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Anderson Thomas C KITFOX SERIES 5, 1 case](https://openairdocs.org/ntsb-events/096/sequence.md?model=05605CB), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported the engine run-up and takeoff were normal. While in cruise flight the pilot noticed a slight drop in oil pressure. With no increase in oil temperature or other engine warnings he decided to continue the flight while monitoring the engine parameters. A short time later the oil pressure began to drop at a faster rate. He decided to perform a precautionary landing. He shut down the engine and configured the airplane for landing on a highway service road, but while on approach he noticed the landing area was obstructed by light poles. He maneuvered the airplane towards an adjacent dirt field; however, the terrain was much rougher than anticipated, and the airplane nosed over during roll out after striking scrub brush. The engine’s oil sump had a crack in its mounting flange that resulted in a loss of oil on previous flights, but not at a significant rate. The crack was then improperly repaired by the pilot, who used epoxy putty to seal it rather than having it welded or replaced. During the accident flight, which was the first since the repair, the crack propagated beyond the putty fill area and the putty unbonded, resulting in most of the engine oil being expelled out of the crack. ## Factual narrative On April 4, 2024, about 2000, a Kitfox Series 5, N743JT, was substantially damaged when it was involved in an accident near Yucca Grove, California. The experimental, amateur-built airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot was relocating the airplane from California to Colorado, and this was the first leg of the trip. He departed from Cable Airport (CCB), Upland, California, with a destination of Henderson, Nevada. While en route at an altitude of 9,500 ft mean sea level, the pilot noticed a slight reduction in engine oil pressure. With no increase in oil temperature or other engine warnings he decided to continue the flight while monitoring the engine parameters. The engine appeared to be operating normally, but a short time later the oil pressure began to drop at a faster rate. He decided to perform a precautionary landing rather than risk continuing the flight towards inhospitable terrain as the sun began to set. He shut down the engine and configured the airplane for landing on a highway service road, but while on approach he noticed the landing area was obstructed by light poles. He maneuvered the airplane towards an adjacent dirt field; however, the terrain was much rougher than anticipated, and the airplane nosed over during roll out after striking scrub brush. The airplane sustained damage to both wings and the vertical stabilizer, and post-accident examination revealed the belly of the airplane was completely covered in engine oil. The airplane was equipped with a Continental C90 engine that was fitted with a steel “kidney” style oil sump. Examination of the engine compartment revealed that the oil sump and surrounding components and fittings, including the back side of the carburetor, were coated in oil. No anomalies were noted to the engine oil system lines, filter, or cooler. The oil drain plug remained in place and closed. One quart of oil was drained from the sump; the oil was brown in color, and free of visible debris. A 3-inch-wide bead of grey filler had been applied to the forward neck of the oil sump mounting flange. When the sump was pushed forward and aft by hand it became apparent that the filler was not properly bonded and appeared to be covering a crack. The filler could be easily pried off with a screwdriver, revealing a 4-inch-long crack at the weld that joined the sump to the mounting flange. The crack had propagated beyond the filler contact area (see Figure 1). The area of the sump where the filler had been installed showed evidence of abrasive marks consistent with bonding preparation, but most of the paint remained. Figure 1 - Oil sump flange The pilot, who was a Federal Aviation Administration-certified airframe and powerplant mechanic with inspection authorization, later confirmed that a crack had been there since December 2023, but the leak was a nuisance and not significant, with a total oil consumption of about 1 quart every 4-6 hours. He decided torepair the crack with “Steelstik” epoxy putty, manufactured by J-B Weld. After the repair he performed multiple engine ground test runs. The accident was the first flight since he had made the repair. Review of the data stored on the airplane’s engine monitor revealed a gradual loss of oil pressure as described by the pilot. ## Aircraft - Registration: [N743JT](https://openairdocs.org/aircraft/N743JT), registered now, S/N S9501-0091, built 1998 (OpenAirDocs) - Reported make and model: Kitfox Series 5 - Registry model: [Anderson Thomas C KITFOX SERIES 5](https://openairdocs.org/model/anderson-thomas-c-kitfox-series-5) (registry code 05605CB) (OpenAirDocs) - Registry engine: [Subaru ALL MDLS A/B](https://openairdocs.org/engine/subaru-all-mdls-a-b) (registry code 59050, 4 cycle) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: S9501-0091 - Year built: 1998 - Airframe hours: 838.4 - Engines: Continental C90-12F 90 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, September 11, 2023, 13.7 hours before - Departed: CCB, Upland, CA - Destination: HND, Las Vegas, NV - Equipment: Electronic flight bag or handheld device, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 37; injuries: none; airline transport; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review March 16, 2024; seat: left; restraint: 4-point; flight hours: 5,370 total, 69 in this make and model, 3,050 as pilot in command, 90 in the last 90 days, 49 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 230° at 16 knots, gusting 30 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 68 °F, dew point 28 °F - Altimeter: 29.57 inHg - Observed at: KLAS, 46 nm away - METAR: METAR KLAS 050156Z 23016G30KT 10SM VCBLDU FEW120 FEW250 20/M02 A2957 RMK AO2 PK WND 18036/0124 SLP000 T02001022= ## 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 20240404003599A](https://openairdocs.org/incident/20240404003599A), Apr 4, 2024: Anderson Thomas C KITFOX SERIES 5, Nipton, CA, Substantial damage. The FAA was not at the scene of the accident. The pilot provided photographics of the accident scene. Total of four photographics were taken showing the… ## Other investigations on N743JT (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 CHI02LA260](https://openairdocs.org/ntsb/CHI02LA260), Aug 26, 2002: Anderson Kitfox Series 5 (N743JT), Garden Prairie, IL, substantial damage. Probable cause: The pilot's miscalculation of fuel consumption and his operation of the fuel system beyond its limitation, which resulted in fuel exhaustion. Contributing factors were transmission wires and dark… ## Docket (6 files) The files NTSB released with the investigation on November 26, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=194060. 18.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 4.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17783789&FileExtension=pdf&FileName=r_6120_Redacted-Rel.pdf - Accident site photo (item 2, PDF, 2 pages, 1 photo, 180 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17780111&FileExtension=pdf&FileName=Accident%20Site%20Photo-Rel.pdf - NTSB engine examination report (item 3, PDF, 6 pages, 5 photos, 971 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17783991&FileExtension=pdf&FileName=Engine%20Examination%20WPR24LA121-Rel.pdf - Video attachment to the NTSB engine examination report (item 4, MOV, 12.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17779905&FileExtension=MOV&FileName=Video%20Attachement%201-Rel.MOV - Jpi engine monitor data (item 5, CSV, 146 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17783918&FileExtension=csv&FileName=Flt292-Rel.csv - Engine logbook excerpts (item 6, PDF, 2 pages, 121 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17779427&FileExtension=pdf&FileName=r_N743JT_RJS_Logbook_Entry_005_Cond_Insp_2023_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.