# NTSB CEN25LA077: Piper PA-28-181, N504AF, Addison, TX, January 15, 2025 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: January 14, 2025, 18:30 local (Jan 15, 2025, 00:30 UTC) - Place: Addison, TX - Coordinates: 32.968556, -96.836444 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.9686&lon=-96.8364&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Fuel related](https://openairdocs.org/ntsb-events/190) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 23, 2026 - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA FSDO - NTSB case key (mKey): 199551 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN25LA077 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/199551/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=199551 - Page: https://openairdocs.org/ntsb/CEN25LA077 ## Probable cause A partial loss of engine power during takeoff due to the partial blockage of the fuel diaphragm metering stem and the No. 1 cylinder fuel injector nozzle. Contributing to the accident was maintenance that allowed the introduction of debris that resulted in the blocked fuel system. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fuel system: fuel distribution](https://openairdocs.org/ntsb-findings/01022820): Aircraft › Aircraft systems · Damaged/degraded (probable cause); cases with it: [Piper PA-28-181, 3 cases](https://openairdocs.org/ntsb-findings/01022820/cases.md?model=7102807), [All aircraft, 141 cases](https://openairdocs.org/ntsb-findings/01022820/cases.md) - [Maintenance: replacement](https://openairdocs.org/ntsb-findings/02062020): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Piper PA-28-181, 2 cases](https://openairdocs.org/ntsb-findings/02062020/cases.md?model=7102807), [All aircraft, 70 cases](https://openairdocs.org/ntsb-findings/02062020/cases.md) - [Engine fuel and control: fuel flow sensor](https://openairdocs.org/ntsb-findings/01057333): Aircraft › Aircraft power plant · Related maintenance info; cases with it: [Piper PA-28-181, 1 case](https://openairdocs.org/ntsb-findings/01057333/cases.md?model=7102807), [All aircraft, 3 cases](https://openairdocs.org/ntsb-findings/01057333/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-28-181, 2 cases](https://openairdocs.org/ntsb-events/040/sequence.md?model=7102807), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Initial climb: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340); cases with it: [Piper PA-28-181, 4 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=7102807), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Initial climb: Fuel related](https://openairdocs.org/ntsb-events/190) (defining event); cases with it: [Piper PA-28-181, 6 cases](https://openairdocs.org/ntsb-events/190/sequence.md?model=7102807), [All aircraft, 361 cases](https://openairdocs.org/ntsb-events/190/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Piper PA-28-181, 23 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=7102807), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Piper PA-28-181, 10 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=7102807), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) - [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094); cases with it: [Piper PA-28-181, 11 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=7102807), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The pilot reported that, about 150 ft above ground level during the initial climb, the engine lost partial power. Unable to continue the climb, the pilot declared an emergency and attempted to land on the remaining usable runway. The airplane landed hard and the right main landing gear collapsed, which resulted in substantial damage to the right wing. Postaccident examination of recorded engine data showed evidence that the engine’s No. 1 cylinder had reduced fuel flow at the time of the accident. Further examination revealed grayish white foreign object debris in the fuel diaphragm metering stem and in the No. 1 cylinder fuel injector nozzle. The debris was consistent with the sealant found on the male threads of the attachment fittings for the fuel flow transducer. Based on the available information, the sealant was likely inadvertently introduced into the fuel line when the fuel flow transducer was replaced the week before the accident. According to the mechanic who performed the maintenance, he removed the sealant following the maintenance instructions provided by the manufacturer. The post maintenance test run was completed without issue. The sealant debris likely migrated to the diaphragm metering stem and fuel injector nozzle, which resulted in a partial blockage, and subsequent restricted fuel flow to the engine during the initial climb and the partial loss of engine power. ## Factual narrative On January 14, 2025, about 1830 central standard time, a Piper PA-28-181 airplane, N504AF, was substantially damaged when it was involved in an accident near Addison, Texas. 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 during the initial climb, about 150 ft above ground level, the engine lost partial power. Unable to continue the climb, the pilot declared an emergency and attempted to land on the remaining usable runway. The airplane landed hard, the right main landing gear collapsed, and the airplane came to a stop upright. The right wing sustained substantial damage. Recorded engine data for the accident flight indicated a sudden increase in the exhaust gas temperature (EGT) for cylinder No. 1, followed by a drop, during the takeoff. Postaccident examination of the engine revealed that it appeared to be undamaged and remained attached to the airframe. Several engine functional test runs were conducted during the examination. The engine started, idled, and operated without hesitation at full throttle, both with and without the electric fuel pump activated. The engine stabilized at 1,800 rpm and a magneto check was performed. When the left magneto was selected off, there was a decrease in power of about 70 rpm rpm. When the right magneto was selected off, there was a drop of about 50 rpm. With both magnetos selected on, the engine produced about 2,350 rpm at full power. During subsequent test runs, high EGT was observed on cylinder No. 1. The EGT probes from cylinder Nos. 1 and 3 were swapped; however, the high EGT indication remained with cylinder No. 1. The fuel injector nozzle lines were then disconnected from the fuel injectors, and fuel flowed through each line using the electric fuel pump. Fuel captured from each nozzle was observed to be of about equal quantity. The fuel injector nozzle for cylinder No. 1 was removed and inspected; grayish white foreign object debris (FOD) was found. The contaminant was removed, and the engine was test run again; however, high EGT on cylinder No. 1 was observed. During subsequent testing, operation lean of peak resulted in elevated EGT indications on all four cylinders. When the mixture was enriched to rich of peak, EGT values decreased on all cylinders except cylinder No. 1, which remained elevated. The fuel flow divider cap and metering stem were then removed and inspected. A larger piece of grayish white FOD was found partially obstructing the port corresponding to cylinder No. 1. The fuel flow transducer was examined and the sealant found on the attachment fittings was consistent with the FOD found in both the fuel injector nozzle and the flow divider metering stem. The FOD was removed from the fuel flow divider metering stem and the fittings at the fuel flow transducer were removed and cleaned until no sealant residue remained. During subsequent test runs, the engine was operated across a range of powersettings from idle (about 750 rpm) to full power (about 2,350 rpm). No anomalies were noted, and EGT indications were approximately equal across all cylinders at various throttle and mixture settings. A review of the maintenance records revealed that the fuel flow transducer was removed and replaced a week before the accident, on January 8, 2025. The tachometer time listed in the maintenance record entry was 4,880.1. The tachometer, as observed at the start of the examination, was 4,899.8. The mechanic who completed the maintenance reported that he performed all maintenance in accordance with the approved maintenance manual for the Piper PA-28-181, including the most recent revision. He stated that the maintenance was performed because a pilot reported that the fuel flow gauge was indicating erroneous readings at idle and full throttle. The mechanic reported that he cleaned the attachment fittings and removed the old sealant before installing the new fuel flow transducer in accordance with the maintenance manual. After completing the maintenance, he performed an engine ground run and all operational tests were satisfactory. ## Aircraft - Registration: [N504AF](https://openairdocs.org/aircraft/N504AF), registered now, S/N 28020004, built 2020 (OpenAirDocs) - Reported make and model: PIPER AIRCRAFT INC PA-28-181 - Registry model: [Piper PA-28-181](https://openairdocs.org/model/piper-pa-28-181) (registry code 7102832) (OpenAirDocs) - Registry engine: [Lycoming IO-360-B4A](https://openairdocs.org/engine/lycoming-io-360-b4a) (registry code 41867, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 28020004 - Year built: 2020 - Airframe hours: 4898.8 - Engines: LYCOMING IO-360-B4A 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Ameriflyers Of Texas Inc - Registered owner: Ameriflyers Of Texas Inc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, December 25, 2024 - Departed: ADS, Dallas, TX - Destination: ADS, Dallas, TX - Airport: ADS, Addison Airport, runway 16/34, 7,203 × 100 ft, asphalt - Equipment: Electronic multifunction display, Auto-pilot, ADS-B, Stall warning system, Electronic primary flight display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 19; injuries: none; private; airplane ratings: single-engine land; medical: class 1, with waivers/limitations; seat: left; restraint: 3-point; flight hours: 131 total, 131 in this make and model, 69 as pilot in command, 73 in the last 90 days, 33 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night - Wind: 120° at 5 knots - Visibility: 13 statute miles - Lowest ceiling: none - Temperature: 48 °F, dew point 28 °F - Altimeter: 30.37 inHg - Icing: Unknown - Observed at: KADS - METAR: KADS 150047Z 12005KT 13SM SKC 09/M02 A3037 ## 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 20250114012979A](https://openairdocs.org/incident/20250114012979A), Jan 14, 2025: Piper Aircraft Inc PA-28-181, Addison Airport, TX, Substantial damage. The pilot expressed he performed all the ground takeoff checks and everything was perfect. All the instruments were in the green before departure. He then… ## Docket (9 files) The files NTSB released with the investigation on September 23, 2026, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=199551. 130 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 10 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20268738&FileExtension=pdf&FileName=NTSB%20Form%206120.1_Redacted-Rel.pdf - Pilot's statement (item 2, PDF, 1 page, 75 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20253004&FileExtension=pdf&FileName=Pilot%20Statement_Redacted-Rel.pdf - Examination summary (item 3, PDF, 8 pages, 176 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20277486&FileExtension=pdf&FileName=CEN25LA077%20Examination%20Summary-Rel.pdf - Photos (item 4, PDF, 2 pages, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20267824&FileExtension=pdf&FileName=Investigation%20Photographs-Rel.pdf - Maintenance records (item 5, PDF, 1 page, 459 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20253726&FileExtension=pdf&FileName=Maintanence%20Excerpt_Redacted-Rel.pdf - Maintenance mor (item 6, PDF, 1 page, 64 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20264921&FileExtension=pdf&FileName=MOR%20Maintanence-Rel.pdf - Engine datalog (item 7, XLSX, 126 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20264778&FileExtension=xlsx&FileName=N504AF%20Datalog-Rel.xlsx - Release of aircraft wreckage, NTSB form 6120.15 (item 8, PDF, 1 page, 101 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20264796&FileExtension=pdf&FileName=Wreckage%20Release%20Redacted-Rel.pdf - NTSB party forms (item 9, PDF, 3 pages, 193 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20328420&FileExtension=pdf&FileName=Party%20Representative%20Forms_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.