NTSB Identification: ERA11LA224
14 CFR Part 91: General Aviation
Accident occurred Friday, April 01, 2011 in Greenwood, MS
Probable Cause Approval Date: 02/23/2012
Aircraft: PIPER PA 46-350P, registration: N146DG
Injuries: 2 Uninjured.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The airplane was climbing through 13,000 feet when the pilot heard a loud "pop" and observed a large reduction in manifold pressure. He declared an emergency to an air traffic controller and initiated a slow descent to the nearest airport recommended by the controller. The pilot asked the controller if there was a mechanic at that airport and the controller stated that there was not but that a mechanic was available at another airport. The pilot elected to go to the other airport, which was farther away.
The pilot acquired the airport visually but was initially a little high and planned to enter the traffic pattern on a downwind leg for the opposite runway; the pilot lowered the landing gear to assist in losing altitude. However, the airplane was then low and the airspeed was decreasing. The pilot subsequently decided to abandon the downwind approach and land straight-in to the runway. The oil pressure gauge indicated zero and the oil warning light illuminated. The pilot continued to run the engine until he thought he could reach the runway, and then he shut down the engine. He subsequently raised the landing gear as the airplane became low, but the airspeed also decreased. He realized that he was not going to reach the runway and lined up with a grassy area short of the runway to avoid colliding with the instrument landing system. He extended the landing gear and flaps and the airplane touched down and collided with a ditch.
A postaccident examination of the engine assembly revealed that the right turbocharger would not rotate when actuated by hand. The turbocharger was removed and oil was noted in the compressor outlet tubing. Several of the blades were broken and some were bent near the tip in the direction opposite of rotation. Metallurgical examination of the right turbocharger revealed that the turbine wheel assembly failed due to a fatigue fracture of one of the turbine wheel blades, which led to an imbalance of the turbine wheel.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The pilot did not obtain the proper touchdown point as a result of his decision to shut down the engine and to deploy the landing gear and flaps before the landing was assured. Contributing to the accident was his decision to overfly a closer suitable airport and the fatigue fracture of a turbine blade in the right turbocharger, which led to an imbalance of the turbine wheel and the subsequent failure of the turbocharger. Full narrative available
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