What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Aircraft crashed en route. (.4) the pilot boarded the 4 passengers and cargo (unsecured) for a chartered flight to a fishing lodge. The floatplane departed uneventfully. About 45 min. Later, while cruising about 1,700 ft. above rugged terrain and a river, the engine began to lose power and the floatplane descended. The pilot attempted a forced landing in a small lake that was 1,200 ft. in length and located about 1 mile west of the river. During the approach to landing, the airplane stalled and impacted swampy terrain at the lake's edge in a steep nose down attitude. An examination of the wreckage revealed that the no. 1 engine exhaust pushrod had failed in fatigue just below the top (valve) ball end. Examination of the pushrod revealed that material had been pushed away from the rod during installation of the ball end. The fatigue crack may have initiated from a score mark produced by the installation. Pushrod life is reduced due to surface scratches. The life of the failed pushrod could not be determined. Insufficient information exists in the overhaul manual regarding pushrod life/inspection.
As the FAA filed it
AIRCRAFT CRASHED EN ROUTE. (.4) THE PILOT BOARDED THE 4 PASSENGERS AND CARGO (UNSECURED) FOR A CHARTERED FLIGHT TO A FISHING LODGE. THE FLOATPLANE DEPARTED UNEVENTFULLY. ABOUT 45 MIN. LATER, WHILE CRUISING ABOUT 1,700 FT. ABOVE RUGGED TERRAIN AND A RIVER, THE ENGINE BEGAN TO LOSE POWER AND THE FLOATPLANE DESCENDED. THE PILOT ATTEMPTED A FORCED LANDING IN A SMALL LAKE THAT WAS 1,200 FT. IN LENGTH AND LOCATED ABOUT 1 MILE WEST OF THE RIVER. DURING THE APPROACH TO LANDING, THE AIRPLANE STALLED AND IMPACTED SWAMPY TERRAIN AT THE LAKE'S EDGE IN A STEEP NOSE DOWN ATTITUDE. AN EXAMINATION OF THE WRECKAGE REVEALED THAT THE NO. 1 ENGINE EXHAUST PUSHROD HAD FAILED IN FATIGUE JUST BELOW THE TOP (VALVE) BALL END. EXAMINATION OF THE PUSHROD REVEALED THAT MATERIAL HAD BEEN PUSHED AWAY FROM THE ROD DURING INSTALLATION OF THE BALL END. THE FATIGUE CRACK MAY HAVE INITIATED FROM A SCORE MARK PRODUCED BY THE INSTALLATION. PUSHROD LIFE IS REDUCED DUE TO SURFACE SCRATCHES. THE LIFE OF THE FAILED PUSHROD COULD NOT BE DETERMINED. INSUFFICIENT INFORMATION EXISTS IN THE OVERHAUL MANUAL REGARDING PUSHROD LIFE/INSPECTION.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.