Accident Overview
On December 3, 2012, about 1050 Alaska standard time, a Cessna 208B airplane, registration N169LJ, operated by Hageland Aviation Services, Inc. (doing business as ERA Alaska) as Flight 140, sustained substantial damage during a forced landing shortly after takeoff from Mekoryuk Airport, Mekoryuk, Alaska. The flight, a scheduled commuter service under 14 CFR Part 135, was conducted under visual flight rules (VFR) with visual meteorological conditions. Company flight following procedures were in effect. The flight originated about 1045 and was destined for Bethel, Alaska.
Injuries and Damage
The airplane carried nine occupants: two pilots and seven passengers. The two pilots and six passengers were not injured; one passenger sustained minor injuries. During the forced landing, the fuselage and right wing received substantial damage.
Sequence of Events
According to the pilot-in-command (PIC), the second-in-command (SIC) was flying. The takeoff and initial climb were normal. Shortly after passing 1,000 feet, the engine "coughed," began vibrating, and lost power. An attempted restart was unsuccessful. The PIC assumed control and executed a forced landing on a frozen bay approximately 5 miles northeast of Mekoryuk Airport. Witnesses at the airport observed the airplane descending and responded with snow machines and all-terrain vehicles to transport the occupants back to Mekoryuk.
Engine Examination
The airplane was equipped with a Pratt & Whitney PT6A-114A turbine engine. A postaccident examination at Pratt & Whitney Canada facilities, overseen by an NTSB powerplants investigator, revealed that a blade on the first stage compressor rotor failed due to a fatigue fracture. The fatigue crack initiated from the leading edge area and propagated toward the trailing edge; at mid-chord, the blade released by tensile overload. The initiation point of the fracture could not be determined due to secondary damage to the fracture surface. During the last engine overhaul, five first stage compressor blades had been replaced with new blades. The failed blade was one of those five, based on recorded batch numbers.