# NTSB CEN21LA211: Piper PA-28-161, N54MC, Spring, TX, May 6, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: May 6, 2021, 17:07 local (22:07 UTC) - Place: Spring, TX · on DWH airport - Coordinates: 30.061779, -95.552788 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=30.0618&lon=-95.5528&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: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Flight Standards District Office - NTSB case key (mKey): 103051 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA211 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103051/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103051 - Page: https://openairdocs.org/ntsb/CEN21LA211 ## Probable cause An engine fire that resulted from a fuel leak into the carburetor air box due to the electric fuel pump over-pressurizing the carburetor needle/seat assembly. Contributing to the severity of the fire was the flight instructor’s failure to turn off the electric fuel pump before exiting the airplane. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine fuel and control: fuel control/carburetor](https://openairdocs.org/ntsb-findings/01057322): Aircraft › Aircraft power plant · Capability exceeded (probable cause); cases with it: [Piper PA-28-161, 4 cases](https://openairdocs.org/ntsb-findings/01057322/cases.md?model=7102803), [All aircraft, 195 cases](https://openairdocs.org/ntsb-findings/01057322/cases.md) - [Action: forgotten action/omission](https://openairdocs.org/ntsb-findings/02041035): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Piper PA-28-161, 1 case](https://openairdocs.org/ntsb-findings/02041035/cases.md?model=7102803), [All aircraft, 440 cases](https://openairdocs.org/ntsb-findings/02041035/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: [Piper PA-28-161, 9 cases](https://openairdocs.org/ntsb-events/150/sequence.md?model=7102803), [All aircraft, 504 cases](https://openairdocs.org/ntsb-events/150/sequence.md) ## Analysis The flight instructor and student pilot were landing the airplane during an instructional flight when they noticed a loss of engine power during landing rollout. After exiting the runway, the flight instructor was able to restart the engine on the second attempt. The pilots subsequently noticed that an engine fire had developed, shut down the engine, and exited the airplane. The fire substantially damaged the engine mount and firewall before it could be extinguished. The flight crew turned the electric fuel pump on before landing in accordance with normal operating procedure, and the flight instructor did not turn it off before exiting the airplane [as called for by the emergency procedure for an engine fire]. Postaccident examination revealed that with the electric fuel pump turned on, fuel leaked from the carburetor into the air box. The carburetor was disassembled with no anomalies observed. The fuel leaking from the carburetor was likely due to the electric fuel pump over-pressurizing the carburetor needle/seat assembly, which allowed the carburetor bowl to overfill. The leaking fuel likely came in contact with hot exhaust pipes and ignited, which resulted in the engine fire. ## Factual narrative On May 6, 2021, about 1707 central daylight time, a Piper PA-28 airplane, N54MC, was substantially damaged when it was involved in an accident at David Wayne Hooks Memorial Airport (DWH), Spring, Texas. The flight instructor and student pilot were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. During landing rollout, the flight instructor noticed a loss of engine power. After exiting the runway, the flight instructor was able to restart the engine on the second attempt. The flight instructor and student pilot subsequently noticed a fire that produced smoke and extreme heat in the cabin compartment. The flight crew shut the engine off and egressed the airplane. The electric fuel pump was turned on before landing, which is normal operating procedure, and remained on after the fire was observed and when the flight crew egressed the airplane. Per the emergency procedures checklist, it should have been turned off. The fire substantially damaged the engine mount and firewall before airport fire department personnel were able to extinguish it. Postaccident examination revealed that fuel leaked from the carburetor into the air box when the electric fuel pump was turned on. Carburetor disassembly by a carburetor repair station revealed no anomalies with the needle/seat assembly, mixture control shaft, nozzle, idle tube, accelerator pump, or throttle lever. Repair station personnel noted that if the electric fuel pump pressure is greater than 6 pounds per square inch, the carburetor needle/seat assembly will allow fuel to enter the carburetor bowl and overflow into the air box. ## Aircraft - Registration: [N54MC](https://openairdocs.org/deregistered/N54MC-2023-04-01), registration cancelled 2023-04-01, S/N 28-7816208, built 1977 (OpenAirDocs) - Reported make and model: PIPER PA-28-161 - Registry model: [Piper PA-28-161](https://openairdocs.org/model/piper-pa-28-161) (registry code 7102803) (OpenAirDocs) - Category: Airplane - Serial number: 28-7816208 - Year built: 1977 - Airframe hours: 7535 - Engines: Lycoming O-320-D3G 160 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Instructional, Part 91 - Operator: Hoffman Aviation Services LLC - Registered owner: Hoffman Aviation Services LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 15, 2021, 56 hours before - Departed: DWH, Spring, TX - Airport: DWH, David Wayne Hooks Meml, runway 17R/35L, 7,009 × 100 ft, asphalt - Equipment: ADS-B, Auto-pilot, Electronic multifunction display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 25; injuries: none; flight instructor, commercial; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review April 10, 2021; seat: right; restraint: 3-point; flight hours: 728 total, 45 in this make and model, 682 as pilot in command, 14 in the last 90 days, 14 in the last 30 days, 0 in the last 24 hours - Student pilot; age 18; injuries: none; seat: left; restraint: 3-point; flight hours: 5 total, 5 in this make and model, 5 in the last 90 days, 5 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 40° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 84 °F, dew point 55 °F - Altimeter: 30.11 inHg - Turbulence: Unknown - Observed at: KDWH - METAR: KDWH 062153Z 04006KT 10SM CLR 29/13 A3011 RMK AO2 SLP193 T02940133 ## 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 20210506009299A](https://openairdocs.org/incident/20210506009299A), May 6, 2021: Piper PA-28-161, Houston, TX, Substantial damage. On 5/06/2021 at around 4:30 local CST N54MC entered kdwh airspace for work in the traffic pattern. After the 3rd lap around they landed with the intent of… ## Docket (7 files) The files NTSB released with the investigation on June 21, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103051. 7.3 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 4.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13620505&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Correspondence with FAA inspector (item 2, PDF, 1 page, 128 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13620345&FileExtension=pdf&FileName=Correspondence%20with%20FAA-Rel.pdf - Photo of engine (item 3, PDF, 1 page, 712 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13623989&FileExtension=pdf&FileName=Photo%20of%20Fire%20Damage-Rel.pdf - Carburetor exam (item 4, PDF, 3 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13620144&FileExtension=pdf&FileName=Carb%20exam_Redacted-Rel.pdf - Correspondence with the carburetor repair station (item 5, PDF, 2 pages, 195 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14033244&FileExtension=pdf&FileName=Correspondence%20with%20carburetor%20repair%20station-Rel_Redacted-Rel.pdf - PA-28-161 normal procedures, approach and landing (item 6, PDF, 1 page, 124 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14033471&FileExtension=pdf&FileName=PA-28-161%20Approach%20and%20Landing%20Procedures-Rel.pdf - PA-28-161 emergency procedures, engine fire during start (item 7, PDF, 1 page, 93 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14034644&FileExtension=pdf&FileName=PA-28-161%20Emergency%20Procedures%20Engine%20Fire%20During%20Start-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.