# NTSB WPR25LA004: Cessna 172L, N7869G, El Monte, CA, October 7, 2024 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: October 6, 2024, 20:39 local (Oct 7, 2024, 03:39 UTC) - Place: El Monte, CA - Coordinates: 34.086898, -118.03438 - Nearby events: https://openairdocs.org/map.md?lat=34.0869&lon=-118.0344&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Fuel contamination](https://openairdocs.org/ntsb-events/193) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 10, 2025 - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 195265 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR25LA004 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/195265/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=195265 - Page: https://openairdocs.org/ntsb/WPR25LA004 ## Probable cause A total loss of engine power due to contaminated fuel. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Cessna 172L, 11 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=2072432), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Cessna 172L, 24 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2072432), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid condition (probable cause); cases with it: [Cessna 172L, 4 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=2072432), [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 · Inadequate inspection; cases with it: [Cessna 172L, 4 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=2072432), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Fuel contamination](https://openairdocs.org/ntsb-events/193) (defining event); cases with it: [Cessna 172L, 1 case](https://openairdocs.org/ntsb-events/193/sequence.md?model=2072432), [All aircraft, 225 cases](https://openairdocs.org/ntsb-events/193/sequence.md) ## Analysis The pilot was conducting a night cross-country flight when, about 35 miles from the destination airport, the engine lost total power. The pilot diverted to a nearby airport but overshot the runway during the forced landing and impacted a drainage culvert parallel to the runway as well as a fence, resulting in substantial damage to the fuselage and left-wing spar. A combination of blue-colored fuel, consistent with 100LL aviation fuel, and yellow-colored fuel, consistent in odor and color with fouled automotive fuel, was recovered from the airplane’s fuel tanks. Samples from both fuels tested negative for water contamination. Continuity of the fuel system was established from the main fuel tanks to the carburetor. An external fuel tank was attached to the fuel supply line, and the engine was subsequently started and operated through various power settings for about five minutes with no anomalies. Although the airplane was equipped with a supplemental type certificate that permitted the use of automotive fuel, the owner stated that he only used aviation fuel. It is likely that some of the fouled fuel entered the fuel delivery system and did not support combustion, which resulted in a total loss of engine power; however, the source of the automotive fuel could not be determined. The pilot refueled the airplane with 100LL aviation fuel before departing on the flight, and the manager from that airport reported no anomalies with the fuel supply or delivery system. The pilot did not provide any information regarding his preflight inspection of the airplane before departure. ## Factual narrative On October 6, 2024, about 2039 Pacific daylight time, a Cessna 172L, N7869G, was substantially damaged when it was involved in an accident near El Monte, California. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that he departed Modesto City-County Airport-Harry Sham Field (MOD) Modesto, California, with a destination of Chino Airport (CNO), Chino, California. While at MOD, the airplane was refueled with about 24 gallons of 100LL aviation fuel. ADS-B data showed the airplane departed MOD about 1710, climbed to about 5,800 ft mean sea level (msl), and proceeded to Meadows Field Airport (BFL), Bakersfield, California, where the pilot landed and subsequently departed about 1928. The airplane then climbed to a cruise altitude between 7,500 and 7,700 ft msl and proceeded toward CNO. The pilot stated that he was northeast of Burbank, California, about 7,500 ft when the engine lost power. He declared an emergency and turned to the nearest airport, which was San Gabriel Valley Airport (EMT), El Monte, California. The pilot stated that multiple attempts to restart the engine were unsuccessful, and during the forced landing, he “veered off course of the runway” and impacted terrain. ADS-B data and video of the airplane showed the airplane overflying the runway until about midfield. The airplane turned slightly to the right, then turned 180° while descending. The airplane overflew the runway and landed in the Rio Hondo Wash, a concrete drainage that ran parallel to runway 1. During the landing, the left wing impacted a chain-link fence, which substantially damaged the left wing spar and undercarriage near the engine firewall. The airplane was equipped with two 19-gallon wing-mounted fuel tanks. Both fuel tanks were drained by recovery personnel, who reported that about 8 gallons of fuel were recovered from the left wing fuel tank, and about 6 gallons of fuel from the right wing fuel tank. Fuel samples revealed a combination of blue-colored liquid, consistent with 100LL aviation fuel, and a yellow-colored liquid, as seen in the figure. The yellow-colored sample tested negative for water and had the smell of fouled automotive fuel. The blue-colored liquid also tested negative for water. Figure. Samples of fuel recovered from the wing-mounted fuel tanks, fuel lines and fuel strainer. According to the owner, the airplane was always stored in a hangar, and he did not use automotive gasoline, despite the airplane being modified by a supplemental type certificate for automotive gasoline. Examination of the fuel system revealed worn rubber seals on both fuel caps. Continuity of the fuel system was established from the wing fuel tanks throughout the system to the carburetor. Visual inspection of the airframe fuel strainer revealed a blue-colored fuel consistent with 100LL, and minor debris. The drain plug from the carburetor bowl was removed and no fuel was observed in thecarburetor bowl. The fuel line from the airframe fuel strainer to the carburetor was removed and no fuel was observed. The fuel selector lever was moved to the left fuel tank position, and blue-colored fuel was observed coming from the airframe fuel strainer. The fuel selector lever was then moved to the right fuel tank position, and blue-colored fuel was observed coming from the airframe fuel strainer. The fuel was collected in a clear glass container and tested for water with negative results. Examination of the recovered airframe and engine revealed no preaccident mechanical malfunctions or failures that would have precluded normal operation. An external fuel tank with 100LL fuel was attached to the engine fuel supply line. The engine was primed and started on the first attempt. The engine ran normally throughout various power settings for about 5 minutes. Both magnetos were checked and operated within normal parameters. The throttle was advanced to full forward, and the engine produced a static speed of about 2,300 rpm. According to the Pilot’s Operating Handbook for a similar Cessna 172L, with about 38 gallons of fuel, at 7,500 ft msl and engine speed of 2,300 rpm, the airplane had an endurance of about 6.1 hours, and about 640-mile range without reserve, with a fuel consumption rate of about 6.2 gallons per hour. Given the same consumption rate, 24 gallons equated to about 3.8 hours endurance and about 403-mile range. ADS-B data revealed that the accident flight was about 300 miles in distance and about 3.5 hours duration. A fuel receipt from MOD showed that the pilot purchased 21.9 gallons of 100LL fuel. The airport manager reported no customer complaints of the 100LL fuel around the time of the accident airplane’s refueling. Additionally, the routine testing of the 100LL fuel delivery systems revealed no reports of anomalies either before or after the accident airplane’s refueling. The pilot did not provide any information regarding his preflight inspection of the airplane before departure. ## Aircraft - Registration: [N7869G](https://openairdocs.org/aircraft/N7869G), registered now, S/N 17259569 (OpenAirDocs) - Reported make and model: CESSNA 172L - Registry model: [Cessna 172L](https://openairdocs.org/model/cessna-172l) (registry code 2072432) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17259569 - Year built: 1971 - Airframe hours: 11105 - Engines: Lycoming O-320-E2D 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Mls Aviation LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, September 12, 2024, 85 hours before - Departed: BFL, Bakersfield, CA - Destination: CNO, Chino, CA - Airport: EMT, San Gabriel Valley Airport, runway 1/19, 3,995 × 75 ft, asphalt - Equipment: ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 25; injuries: none; private; airplane ratings: single-engine land; medical: class 1, without waivers/limitations; last flight review September 10, 2024; seat: left; restraint: 3-point; flight hours: 118 total, 118 in this make and model, 52 as pilot in command, 84 in the last 90 days, 34 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night - Wind: 230° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 61 °F - Altimeter: 29.89 inHg - Observed at: KEMT - METAR: KEMT 070245Z 23003KT 10SM CLR 22/16 A2989 ## 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 20241006020199A](https://openairdocs.org/incident/20241006020199A), Oct 6, 2024: Cessna 172L, El Monte, CA, Substantial damage. On October 6, 2024, about 2039 pacific daylight time, a Cessna 172L, [privacy data omitted], was Substantially damaged when it was involved in an accident near… ## Other investigations on N7869G (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 MKC75DCQ50](https://openairdocs.org/ntsb/MKC75DCQ50), Jun 2, 1975: Cessna 172U (N7869G), Goodland, KS, substantial damage ## Docket (14 files) The files NTSB released with the investigation on December 10, 2025, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=195265. 83.7 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 10 pages, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18804418&FileExtension=pdf&FileName=NTSB%20Form%206120_Signed_Redacted-Rel.pdf - Emailed pilot's statement (item 2, PDF, 2 pages, 414 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19597867&FileExtension=pdf&FileName=Pilots%20Statement_Redacted-Rel.pdf - Interview with the airplane owner (item 3, PDF, 2 pages, 80 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18844197&FileExtension=pdf&FileName=Interviews_All-Rel.pdf - Fuel receipt (item 4, PDF, 1 page, 59 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18844473&FileExtension=pdf&FileName=N7869G%20fuel%20invoice%20-%2010-06-2024_Redacted-Rel.pdf - Cessna 172L pilot's operating handbook excerpt (item 5, PDF, 2 pages, 77 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18844217&FileExtension=pdf&FileName=Cessna%20172L%20Operator%27s%20Manual-Rel.pdf - ADS-B kml data (item 6, KMZ, 668 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18844493&FileExtension=kmz&FileName=20241007_AAAA6A_567420212-Rel.kmz - ADS-B excel data (item 7, XLSX, 30.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18845228&FileExtension=xlsx&FileName=20241007_AAAA6A_567420212_ADSB-Rel.xlsx - Photos (item 8, PDF, 4 pages, 875 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18877026&FileExtension=pdf&FileName=Photos%20for%20WPR25LA004-Rel.pdf - Video file of airplane over airport (item 9, MOV, 47.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18804905&FileExtension=MOV&FileName=IMG_1653%202024-10-08%2013_46_05-Rel.MOV - Fuel system illustration (item 10, PDF, 1 page, 130 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18860580&FileExtension=pdf&FileName=Fuel%20System-Rel.pdf - Email fuel examination (item 11, PDF, 1 page, 104 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18858212&FileExtension=pdf&FileName=Fuel%20Examination_Redacted-Rel.pdf - Airframe and engine examination report (item 12, PDF, 9 pages, 955 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18844483&FileExtension=pdf&FileName=Airframe%20and%20Engine%20Examination-Rel.pdf - FAA form 337 for automotive fuel STC (item 13, PDF, 2 pages, 234 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18844207&FileExtension=pdf&FileName=FAA%20Form%20337%20Auto%20Fuel%20STC_Redacted-Rel.pdf - Email from mod regarding fuel quality checks (item 14, PDF, 2 pages, 244 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18844324&FileExtension=pdf&FileName=Fuel%20Quality%20Checks%20from%20MOD_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.