# NTSB WPR15LA267: Cessna 177, N3416T, Thermal, CA, September 24, 2015 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 24, 2015, 15:15 local (22:15 UTC) - Place: Thermal, CA - Coordinates: 33.626667, -116.159721 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.6267&lon=-116.1597&mi=10 - Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping) - Defining event: [Standing-engine(s) start-up: Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report January 21, 2016 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 92055 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR15LA267 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/92055/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=92055 - Page: https://openairdocs.org/ntsb/WPR15LA267 ## Probable cause A fire in the engine compartment due to the pilot overpriming the hot engine. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine starting: cranking](https://openairdocs.org/ntsb-findings/01058010): Aircraft › Aircraft power plant · Incorrect use/operation (probable cause); cases with it: [Cessna 177, 1 case](https://openairdocs.org/ntsb-findings/01058010/cases.md?model=2073704), [All aircraft, 3 cases](https://openairdocs.org/ntsb-findings/01058010/cases.md) - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Cessna 177, 7 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=2073704), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) - [Engine fuel and control: fuel control/carburetor](https://openairdocs.org/ntsb-findings/01057322): Aircraft › Aircraft power plant · Capability exceeded (probable cause); cases with it: [Cessna 177, 1 case](https://openairdocs.org/ntsb-findings/01057322/cases.md?model=2073704), [All aircraft, 195 cases](https://openairdocs.org/ntsb-findings/01057322/cases.md) - [Temp/humidity/pressure: high temperature](https://openairdocs.org/ntsb-findings/03031015): Environmental issues › Conditions/weather/phenomena · Effect on equipment; cases with it: [Cessna 177, 2 cases](https://openairdocs.org/ntsb-findings/03031015/cases.md?model=2073704), [All aircraft, 30 cases](https://openairdocs.org/ntsb-findings/03031015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Standing-engine(s) start-up: Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150) (defining event); cases with it: [Cessna 177, 1 case](https://openairdocs.org/ntsb-events/150/sequence.md?model=2073704), [All aircraft, 504 cases](https://openairdocs.org/ntsb-events/150/sequence.md) ## Analysis The pilot reported that, after flying several legs of a cross-country flight, he landed the airplane to purchase fuel. After shutting down the engine and then topping off the wing tanks with fuel, the pilot attempted to start the engine; however, it would not turn over. He pumped the primer and then continued to crank the starter. He then observed a fire in the muffler area and continued to crank the starter in an attempt to suck the fire through the muffler. The engine never started, and the propeller did not turn. A postaccident examination revealed no catastrophic failures with the engine. However, white discoloration and excessive heat damage to the lower right firewall were found, indicating that the fire likely originated in this area. The fire was likely due to the pilot overpriming the induction system, which would have filled the carburetor air box with fuel and resulted in a fire starting in the lower firewall area. ## Factual narrative On September 24, 2015, about 1515 Pacific daylight time, a Cessna 177 Cardinal, N3416T, experienced an on-ground fire while the pilot attempted to start the engine at the Jacqueline Cochran Regional Airport, Thermal, California. The owner, who was additionally the passenger, was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The private pilot and passenger were not injured; the airplane sustained substantial damage. The cross-country personal flight was to originate from Thermal with a planned destination of Boulder Municipal Airport, Colorado. Visual meteorological conditions prevailed and no flight plan was filed.The pilot reported that the airplane was based out of Boulder, Colorado and earlier in the morning, he and his passenger completed a flight from there to Palm Springs, California. They departed from Palm Springs and landed in Thermal with the intent of purchasing fuel at the airport. He shut the engine down and then decided not to get fuel at that location on the field. He started the engine and then moved to the other side of the field. At that point, they topped off the wing tanks with 25 gallons. After fueling, the pilot attempted to start the engine however it would not turn over. With the mixture in the full rich position he then pumped the primer once and continued to crank the engine. They observed a fire start in the muffler area. He proceeded to crank the starter in an attempt to suck the fire through the muffler. The passenger egressed the airplane and discharged the entire contents of a fire extinguisher on board. The pilot exited out of the rear of the airplane. At no time did the engine actually start and the propeller was not turning. The pilot noted that the engine was running very hot that day as seen from the oil temperature gauge. He thought this was due to the outside air temperatures reaching over 100 degrees Fahrenheit and the duration of the flight. A certified airframe and powerplant mechanic (A&P) completed a post-accident teardown examination under the auspice of Federal Aviation Administration (FAA) inspectors. Fuel system continuity was established from the firewall to each of the engine's cylinders. The boost pump was activated with no anomalies noted. Removal of the spark plugs revealed that all were uniformly dark in color an indication of an oil fouled operating condition however a compression check revealed normal operations. The cylinders' combustion chambers were examined through the upper spark plug holes utilizing a lighted borescope. The combustion chambers remained mechanically undamaged, and there was no evidence of foreign object ingestion or detonation. There was no evidence of valve to piston face contact observed. The gas path and combustion signatures observed at the spark plugs, combustion chambers, and exhaust system components displayed coloration that was consistent with a rich operation. There was no oil residue observed in the exhaustsystem gas path. The fire appeared to have started on the lower right side of the engine where there was white coloration and excessive heat damage to the firewall and belly skin in that area. The mechanic opined that the source of fuel that ignited the fire was likely due to the pilot over priming the induction system which would have filled the carburetor air box with fuel located in that position. According to the airframe Pilot's Operating Handbook, "No priming is required when the weather is warm," and that "weak intermittent firing followed by puffs of black smoke from the exhaust stack indicates over-priming or flooding." It further states that "excess fuel can be cleared from the combustion chambers by the following procedure: Set the mixture control full lean and the throttle full open; then crank the engine through several revolutions with the starter," and to "repeat the starting procedure without any additional priming." ## Aircraft - Registration: [N3416T](https://openairdocs.org/deregistered/N3416T-2018-05-30), registration cancelled 2018-05-30, S/N 17700716, built 1967 (OpenAirDocs) - Reported make and model: CESSNA 177 - Registry model: [Cessna 177](https://openairdocs.org/model/cessna-177) (registry code 2073704) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17700716 - Year built: 1967 - Engines: LYCOMING O-320 SERIES 180 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Departed: TRM, Thermal, CA - Destination: BDU, BOULDER, CO - Airport: TRM, Jacqueline Cochran Rgnl ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 72; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; seat: left; restraint: none; flight hours: 500 total ## Weather - Conditions: Visual (VMC), Day - Wind: 150° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 108 °F, dew point 52 °F - Altimeter: 29.70 inHg - Observed at: TRM ## Docket (2 files) The files NTSB released with the investigation on December 14, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=92055. 818 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 723 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40434956&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Record of Conversation - Mechanic (item 2, .PDF, 96 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40434957&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Mechanic-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.