Incident Overview
During the initial takeoff climb, the right engine lost power due to an uncontained failure. The aircraft was unable to climb, compelling the pilot to execute a forced landing. The pilot selected a street as the landing area and performed a gear-up landing while maneuvering to avoid street light poles and automobiles. After touchdown, the aircraft slid into a block wall. A fire erupted following impact, caused by a fuel leak in the left wing.
Engine Examination
The engines were examined at the manufacturer's facilities. The right engine showed evidence of an uncontained separation of the second stage turbine rotor disk. Examination of the disk fragments revealed a low cycle fatigue fracture mode. The fatigue initiated from multiple areas at and adjacent to the inside diameter bore surface near the aft side of the disk. According to the engine manufacturer, the multiple indication areas were associated with uninspectable size porosity and primary carbides in the cast material. No material or casting defects were detected on any of the fractures through the wheel.
Probable Cause
The official probable cause was an uncontained failure of the second stage turbine wheel due to fatigue. Contributing factors included obstructions in the forced landing area and the inability of the aircraft to climb after the turbine wheel failure.