FTW01LA026 · Piper PA-46-310P
Piper PA-46-310P · Accident: total loss of engine power (mechanical failure) en route
From Wiley Post Airport (PWA) to Addison Airport (ADS)
Event
- NTSB case
- FTW01LA026
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Piper PA-46-310P
- Aircraft type
- Piper PA-46
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N9298Y
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Wiley Post Airport (PWA), Oklahoma City, OKTo Addison Airport (ADS), Addison, TX
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Total loss of engine power (mechanical failure)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Engine instruments, tit gage › Inaccurate
- Miscellaneous, engine › Overtemperature
- Unknown › Maintenance, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While in cruise on a night cross-country flight, the airplane's engine lost power. The pilot attempted a forced landing to a nearby airport, however, the airplane touched down in a field short of the runway. The engine had accumulated 265.5 hours since factory remanufacture. During examination of the engine, the number 3 connecting rod was found separated from the crankshaft. The number 4 piston exhibited a hole burned through the crown structure of the piston. The hole was located along a crack that extended across the top of the piston, in-line with the piston pin. Metallurgical examination determined that fatigue cracking of the piston initiated from a stamp mark "4" on the top surface of the piston. The stamp mark, which was made by the manufacturer during engine buildup, acted as a stress raiser and was responsible for initiation of the crack. Once the crack extended to the interior surface of the piston, hot combustion gasses created the burn through hole and escaped into the crankcase, leading to engine failure. The accident airplane had experienced a previous in-flight engine failure in which an engine teardown revealed a piston with a burned through hole in the crown structure of the piston. This engine had accumulated 640 hours since factory remanufacture; however, this piston did not have any stamp marks on its top surface. The Turbine Inlet Temperature (TIT) gauge, thermocouple, and probes were removed from the accident airplane, and the thermocouple leads were found spliced in two locations. According to the aircraft's maintenance manual, faulty thermocouple leads should be replaced. They should never be spliced, as this will change the resistance of the leads, which is critical for the proper operation of the TIT gauge. The pilot stated that he followed the leaning procedure in the airplane's operating handbook and leaned the engine by referencing the TIT gauge.
Probable cause
the loss of engine power due to improper splicing of the TIT thermocouple leads by unknown persons, which led to over temperature operation of the engine due to inaccurate TIT gauge readings. Contributing factors were the manufacturer's stamp on the top of the piston, which created a stress riser leading to fatigue cracking of the piston, and the lack of suitable terrain for the forced landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW01LA026
- Event ID
- 20001212X22291
- Case number
- FTW01LA026
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2000-11-27.
- API snapshot SHA-256: 37743ecfa7d7dca0fc25474c53d44c19f350e92c75a745ee39e4e88ea9b34e9a; retrieved 2026-09-21T20:02:29.415Z.