20030124001099A

(.19) On January 24, 2003, about 1626 pacific standard time, a Beech 95, N2733Y, experienced the loss of a propeller blade and the subsequent separation of the right engine from its firewall attachment mounts. The event occurred in rancho cucamonga, California, during an undetermined phase of flight. Thereafter, witnesses reported observing the right engine suspended below the right wing, and the airplane entered a steep right bank turn until rolling upside down. It then descended until impacting a private residence in a near vertical nose down attitude. The sole occupant in the house was not injured. The airplane was destroyed, and its private pilot, the sole occupant, was fatally injured. The airplane was co-owned by the pilot, and he possessed an aircraft repairman certificate. The post maintenance evaluation (test) flight was performed under 14 CFR part 91. Visual meteorological conditions prevailed. The flight was initiated from the cable airport, upland, California, about 1615 (estimated time). The airplane was recovered from the accident site along with right engine-associated wreckage that was found about 1 mile away. A preliminary metallurgical examination and complete teardown inspection was performed on the separated hartzell propeller blade. A local laboratory reported that its "fracture surface had a flat section that revealed 'beach marks,' indicative of a fatigue fracture." Also, several corrosion pits were present on the inner bore of the propeller in proximity to the fatigue cracks. The blade was found fractured inches outboard of its hub attachment clamps. The blade has been sent to the national transportation safety board's materials laboratory in Washington, d.c. for a complete examination. The airplane's maintenance record logbook indicates that the airplane's last annual inspection was completed on January 24, 2003. The listed total airframe time was 9,679 hours. The time since its last engine and propeller overhaul was listed as 0.0 hours. The propellers had been overhauled by t & w propellers, inc., chino, California. (-23) the aircraft departed cable airport for a test flight after the installation of the recently overhauled right propeller. Shortly after departing the traffic pattern, one of the propellers on the right engine departed the propeller hub, causing loss of control of the aircraft. The aircraft cras hed into a house in a near vertical attitude. There was extensive damage to the house and the aircraft was destroyed. The pilot, who was the only occupant, sustained fatal injuries. There were no injuries on the ground. Initial examination of the failed propeller indicated a fatigue crack and subsequent failure and separation of the prop near the hub assembly.