CEN14LA226 · Flight Design Gmbh CTLS
Flight Design Gmbh CTLS · Accident: loss of engine power (total) en route
From Fox Stephens Field Gilmer Municipal Airport (JXI) to Denton Enterprise Airport (DTO)
Event
- NTSB case
- CEN14LA226
- 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
- Unknown
- 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
Flight Design Gmbh CTLS
- Aircraft type
- Flight Design CTLS
- 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
- N106SF
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Fox Stephens Field Gilmer Municipal Airport (JXI), Gilmer, TXTo Denton Enterprise Airport (DTO), Denton, TX
- Aircraft age
- About 5 years (built 2009)
- 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
- Defining eventThe 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
- Loss of engine power (total)
- 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
- Aircraft › Aircraft power plant
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The private pilot reported that a routine maintenance inspection had been completed earlier on the day of the accident. During the initial personal flight after the inspection, the engine exhaust gas temperatures (EGT) differed by up to 150 degrees, although they remained within the specified operating limitations. The pilot chose to divert to an intermediate airport to investigate any mechanical issue with the engine. The pilot reported that a mechanic informed him that the EGT difference was not unusual for that particular engine. No significant engine issues were identified, and two subsequent run-ups were normal. A third run-up and subsequent takeoff were also normal. As the flight progressed, the EGT indications were within limitations, and, after 25 minutes, they had equalized. About 5 minutes later, the engine and propeller "stopped abruptly." The pilot's attempts to restore engine power were unsuccessful. He subsequently executed a forced landing to an athletic field. During the landing, the nose landing gear separated, and the airplane nosed over.
A postaccident engine examination revealed that the No. 4 cylinder exhaust valve had failed near the valve head due to bending fatigue. The No. 4 cylinder, piston, and exhaust valve head exhibited extensive gouging, scraping, and deformation consistent with secondary damage due to the failed exhaust valve. Further examination revealed that the No. 4 cylinder exhaust train tappet exhibited severe wear, which had significantly reduced the height of the exhaust tappet compared to the height of the intake tappet. The resulting gap in the exhaust valve train due to the shortened tappet likely caused excessive impact loads between the exhaust valve and the cylinder valve seat during engine operation, which resulted in the valve's failure. The subsequent secondary damage due to the separated valve head ultimately caused the catastrophic engine failure.
Probable cause
The fatigue failure of the No. 4 cylinder exhaust valve due to excessive wear of the corresponding train tappet, which resulted in a total loss of engine power.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN14LA226
- Event ID
- 20140501X11854
- Case number
- CEN14LA226
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 74b876263ce8746be91672d593e0b738c63646cb44bb7bc4516cac59cc7fa489; retrieved 2026-09-15T23:34:07.153Z.