Mechanical & Engine Failure · NTSB ERA12LA411
UNIVERSAL STINSON 108 — Portland, ME
| Date | June 24, 2012 |
| Location | Portland, ME |
| Aircraft | UNIVERSAL STINSON 108 |
| Purpose of flight | Personal |
| Conditions | Day · Visual Meteorological Cond |
| Phase / occurrence | Emergency descent Ditching |
| Pilot age | 60 |
| Pilot total time | 504 hrs · Building experience |
| Time in type | Unknown |
| Fatalities | 1 |
Probable cause
NTSB findings
- Aircraft-Aircraft power plant-Engine (reciprocating)-Recip eng cyl section-Fatigue/wear/corrosion - C
What happened
The airplane was flying over the ocean, along the coast at altitudes between 500 to 1,000 feet mean sea level, when the pilot reported a total loss of engine power and indicated that he was not going to be able to glide to the shore. The airplane subsequently impacted water about 100 yards from the shore and sank to a depth of about 70 feet. Postaccident examination of the airplane’s engine revealed that the No. 3 piston skirt fractured, and the resultant debris entered the engine and camshaft gear, affecting the magneto timing. Metallurgical examination of the piston skirt revealed fatigue originating near a machined through-hole. Although the No. 3 piston was overhauled about 5 years before the accident, it was an original piston on the accident engine, which was more than 65 years old.