WESTWIND AVIATION, INC.

THE PILOTS REPORTED THAT HE SET TAKEOFF POWER, ENGINE PARAMETERS READ NORMAL AND UPON REACHING 40 KNOTS HE SAW A ROLL BACK. HE EXECUTED AN ABORTED TAKEOFF AND HEARD SOME ENGINE SPUTTERING FOLLOWED BY THE ENGING SHUTTING OFF. MAINTENANCE FOUND NO ABNORMAL PROBLEMS ON THE FIRST FEW RUN UPS, BUT UPON FUTURE INSPECTION THEY DID FIND AN OIL LEAK APPEARING TO COME FROM THE TURBO CHARGER. HOWEVER, IT IS NOT CONFIRMED THAT THE TURBO CHARGER IS THE ISSUE. AT THIS TIME WE DO NOT KNOW THE CAUSE OF THIS ENGINE FAILURE.

ON 8/13/2008 AT APPROX 07:40 AM, AIRPLANE WHILE PERFORMING AERIAL APPLICATION EXPERIENCED A LOSS OF ENGINE POWER AND MADE AN EMERGENCY LANDING IN A FIELD. SUBSEQUENT INVESTIAGATION REVEALED THE IDLER GEAR BRG (PN 3103035-1) IN THE TORQUE SENSOR HAD FAILED ALLOWING THE LOSS OF DRIVE INPUT TO THE FUEL CONTROL RESULTING IN LOSS OF ENGINE POWER AND EMERGENCY LANDING. (K)

VIBRATION REPORTED BY PILOT. OPERATOR WAS UNABLE TO DYNAMIC BALANCE. OPERATOR NOTICED ONE BLADE HAS ROTATIONAL PLAY. UPON DISASSEMBLY NR 2 BLADE LINK BUSHING P/N A4564 WAS FOUND CRACKED WITH PIECES MISSING. THE LINK P/N B4743 AND BLADE ACTUATING PIN P/N B5072-1 WERE DAMAGED FROM METAL TO METAL CONTACT.

PILOT FOUND VERTICAL STABILIZER LOOSE ON PREFLIGHT. MAINTENANCE INSPECTED AND FOUND RT FWD ATTACHMENT FITTING BROKEN. REPLACED BOTH FWD FITTINGS WITH NEW PARTS. (K)

ON ROLL-OUT, AIRCRAFT WOULD NOT DEVELOP POWER. ONLY REACHED 24 MAP. APC WAS FOUND WITH CARBON AND METAL CONTAMINATION. AIRCRAFT HAD TURBOCHARGER CATASTROPHIC FAILURE 2 WEEKS PRIOR. POSSIBLE CAUSE WAS METAL PARTICLES FROM TURBO FAILURE CONTAMINATED SEAT VALVE IN CONTROLLER AND CAUSED APC TO FAIL.

PILOT REPORTED GOOD M.A.P. AT TAKEOFF. TWO MINUTES INTO FLIGHT, M.A.P. DROPPED TO 23 INCHES. THIRTY SECONDS LATER, M.A.P. DROPPED TO 20 INCHES. SUSPECT THIS IS WHEN TURBO FROZE UP AND RESTRICTED EXHAUST FLOW LIMITING ENGINE POWER. SUBMITTER STATED NO PASSENGERS ONBOARD OR THIS WOULD HAVE BEEN AN EMERGENCY LANDING.

PILOT REPORTED SLIGHT ENGINE VIBRATION AND PROPELLER SLOW TO RESPOND IN RETURN TO LOW PITCH. DISASSEMBLY REVEALED ONE BLADE WAS CRACKED 180 DEGREES NEAR BEARING SURFACE AT ROOT END. CAUSE UNKNOWN. CATASTROPHIC FAILURE IMMINENT. BLADE UNDER ANALYSIS AT MCCAULEY.

PENETRANT INSPECTION DURING NORMAL OVERHAUL INDICATED A FINE LINEAR CRACK OR SCRATCH. SUBSEQUENT EDDY CURRENT TESTING USING PHASE PLANE ANALYSIS INSTRUMENTATION REVEALED A CRACK APPROXIMATELY 1.5 INCHES LONG, ESTIMATED OVER .040 INCH DEEP ON THE EXTERIOR SURFACE OF NR 3 BLADE SOCKET ON THE LEADING EDGE SIDE SLIGHTLY ABOVE CENTERLINE OF THE HUB. THIS CONDITION IS NOT COMMONLY FOUND IN THE 'THREADLESS' STYLE OF MCAULY HUBS AND MAY BE OVERLOOKED WITHOUT EDDY CURRENT TEST.