ASN Wikibase Occurrence # 165781
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information.
If you feel this information is incomplete or incorrect, you can submit corrected information.
| Date: | Friday 25 April 2014 |
| Time: | 17:42 |
| Type: |  Flight Design CTLS |
| Owner/operator: | Private |
| Registration: | N106SF |
| MSN: | F-09-10-13 |
| Year of manufacture: | 2009 |
| Total airframe hrs: | 1613 hours |
| Engine model: | Rotax 912ULS |
| Fatalities: | Fatalities: 0 / Occupants: 2 |
| Aircraft damage: | Substantial |
| Category: | Accident |
| Location: | SportsPark, NW of Majors Airport (KGVT), Greenville, Texas -
 United States of America
|
| Phase: | Landing |
| Nature: | Private |
| Departure airport: | Gilmer, TX (JXI) |
| Denton, TX (DTO) | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
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.
Accident investigation:
 |
|
Sources:
NTSB
FAA register: http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?NNumbertxt=106SF
Location
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 26-Apr-2014 05:26 | Geno | Added |
| 02-May-2014 22:07 | Geno | Updated [Nature, Departure airport, Source, Narrative] |
| 21-Dec-2016 19:28 | ASN Update Bot | Updated [Time, Damage, Category, Investigating agency] |
| 29-Nov-2017 14:03 | ASN Update Bot | Updated [Other fatalities, Departure airport, Destination airport, Source, Narrative] |
Corrections or additions? ... Edit this accident description
The Aviation Safety Network is an exclusive service provided by:
Quick Links:
| ASN Home | Send Correction / Feedback |
| FSF Home | Disclaimer | Copyright |
| Contact Us | Privacy Policy |
| Press / Media |
CONNECT WITH US:
©2024 Flight Safety Foundation