# NTSB ERA23LA347: Piper PA28, N15417, Knoxville, TN, July 27, 2023 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: July 27, 2023, 14:41 local (18:41 UTC) - Place: Knoxville, TN - Coordinates: 35.963833, -83.873667 - Nearby events: https://openairdocs.org/map.md?lat=35.9638&lon=-83.8737&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: 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: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 192929 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA23LA347 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192929/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192929 - Page: https://openairdocs.org/ntsb/ERA23LA347 ## Probable cause An in-flight fire that resulted from an inadequate 100-hr inspection, which failed to detect and correct improper electrical cable routing in the engine compartment. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Electrical power system: electrical pwr sys wiring](https://openairdocs.org/ntsb-findings/01022497): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [Piper PA-28-180, 1 case](https://openairdocs.org/ntsb-findings/01022497/cases.md?model=7102808), [All aircraft, 44 cases](https://openairdocs.org/ntsb-findings/01022497/cases.md) - [Maintenance: scheduled/routine maintenance](https://openairdocs.org/ntsb-findings/02062010): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Piper PA-28-180, 6 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md?model=7102808), [All aircraft, 320 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft maintenance event](https://openairdocs.org/ntsb-events/040); cases with it: [Piper PA-28-180, 3 cases](https://openairdocs.org/ntsb-events/040/sequence.md?model=7102808), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Takeoff: Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150) (defining event); cases with it: [Piper PA-28-180, 4 cases](https://openairdocs.org/ntsb-events/150/sequence.md?model=7102808), [All aircraft, 504 cases](https://openairdocs.org/ntsb-events/150/sequence.md) ## Analysis When the flight instructor initiated a takeoff roll, the engine rpm initially increased to 2,200, then decreased to 800, followed by flames emanating from the engine cowling. The flight instructor rejected the takeoff, secured the engine, and exited the airplane on the runway; however, the fire continued in the engine compartment until airport personnel were able to extinguish it. Postaccident examination of the engine compartment revealed that about a 25 to 30-in length of starter motor electrical lead was not clamped and had drooped down on top of the fuel primer line. Metal beads on top of the fuel primer line were consistent with chaffing and welding due to contact from the electrical lead. It is likely that arcing from the lead ignited fuel in the fuel primer line. The airplane had been operated for 73 hours during a 1-month period following its most recent 100-hr inspection. The electrical lead drooping down and resting on top of the fuel primer line was contrary to Federal Aviation Administration (FAA) and aircraft manufacturer maintenance instructions regarding proper routing and should have been identified and corrected during the most recent 100-hr inspection. ## Factual narrative On July 27, 2023, about 1441 eastern daylight time, a Piper PA-28-180, N15417, was substantially damaged when it was involved in an accident near Knoxville, Tennessee. 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. The flight instructor reported that the accident flight was the student pilot’s first flight (discovery flight). The flight instructor added that the preflight inspection, engine start, taxi, and run-up were normal. He initiated a takeoff roll on runway 26 by letting the student pilot advance the throttle. The engine rpm initially increased to 2,200, then decreased to 800, followed by flames emanating from the engine cowling. The flight instructor rejected the takeoff, advanced the throttle lever, retracted the mixture level, and turned off all electrical equipment, including the master switch. He also instructed the student pilot to turn the magnetos and fuel selector to off, which he did. They then exited the airplane on the runway and called the fixed based operator for assistance. Examination of the engine compartment by a Federal Aviation Administration inspector revealed substantial damage to an engine mount tube. The inspector also noted that about a 25 to 30-in length of starter motor electrical lead was not clamped and had drooped down on top of the fuel primer line. He also observed metal “beads” on top of the fuel primer line, consistent with chaffing and welding due to contact from the electrical lead. Review of maintenance records revealed that the airplane had been operated for 73 hours during a 1-month period following its most recent 100-hr inspection. FAA Advisory Circular AC 43-13-1, Section 2 Fuel Systems, revealed: “…b Routing. Make sure that the line does not chafe against control cables, airframe structure etc., or come in contact with electrical wiring or conduit…In no case should wiring be supported by the fuel line…” Review of Piper Cherokee Service Manual, Table III-I Inspection Report, B. Engine Group, revealed: “…39. Inspect engine compartment wiring for condition (chafing, cracked insulation, general deterioration), security, proper routing, and correct installation…” ## Aircraft - Registration: [N15417](https://openairdocs.org/aircraft/N15417), registered now, S/N 28-7305073, built 1972 (OpenAirDocs) - Reported make and model: PIPER PA28 (180) - Registry model: [Piper PA-28-180](https://openairdocs.org/model/piper-pa-28-180) (registry code 7102808) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 28-7305073 - Year built: 1972 - Airframe hours: 8449 - Engines: Lycoming O-360-A4A 180 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Instructional, Part 91 - Operator: Knoxville Flight Training Academy - Registered owner: Bremfour Aviation Group Inc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, June 27, 2023, 73 hours before - Airport: DKX, Knoxville Downtown Island Airport, runway 26, 3,499 × 75 ft, asphalt - Equipment: ADS-B, Electronic primary flight display, Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 25; injuries: none; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review July 21, 2023; seat: right; restraint: 3-point; flight hours: 912 total, 300 in this make and model, 848 as pilot in command, 201 in the last 90 days, 78 in the last 30 days, 0 in the last 24 hours - Student pilot; injuries: minor; seat: left; restraint: 3-point; flight hours: 0 total, 0 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 90 °F, dew point 70 °F - Altimeter: 30.11 inHg - Observed at: DKX - METAR: METAR KDKX 271835Z AUTO 27004KT 10SM CLR 32/21 A3011 RMK A01= ## 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 20230727012959A](https://openairdocs.org/incident/20230727012959A), Jul 27, 2023: Piper PA-28-180, Knoxville, TN, Substantial damage. On July 27, 2023 a part 61 flight school had a discovery flight scheduled in a Piper PA-28-180, and during the take off roll a fire was noted in the engine… ## Docket (5 files) The files NTSB released with the investigation on June 20, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192929. 7.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 13 pages, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16151173&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Memorandum for the record (item 2, PDF, 1 page, 67 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16150881&FileExtension=pdf&FileName=MFR-Rel.pdf - Excerpts from maintenance records (item 3, PDF, 4 pages, 5.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16150643&FileExtension=pdf&FileName=Mx%20Excerpts_Redacted-Rel.pdf - Excerpts from maintenance instructions (ac 43.13-1B) (item 4, PDF, 2 pages, 180 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16147939&FileExtension=pdf&FileName=Maintenance%20Instruction%20Excerpts-Rel.pdf - Photo array (item 5, PDF, 4 pages, 3 photos, 473 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16152093&FileExtension=pdf&FileName=MFR-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.