Incident
at 3.50NM NW KINGFISHER LAKE ON (CNM5)
TSB Report #A22C0006: C-FDOD, a Bell Helicopter Textron 412 operated by Wisk Air Helicopters, was returning from a work site on a power line to the work camp at Kingfisher Lake, ON, with the pilot and 6 passengers on board. While enroute, the No. 1 "FUEL LOW" (quantity) caution annunciator illuminated. The pilot commenced a precautionary landing and planned for a possible single engine landing. During the descent, at approximately 200 feet above ground level, the No. 1 engine (Pratt and Whitney Canada PT6T-3B) lost power, accompanied by illumination of the associated caution/warning annunciators. While on short final, the No. 2 engine began to fluctuate and then lost power. A successful auto-rotative landing was conducted onto the frozen, snow covered surface of Kingfisher Lake with both engines inoperative. There were no injuries and the helicopter was undamaged. The helicopter was refueled the next day and flown to the Kingfisher Lake camp. After further inspection, the helicopter was ferried to the operators maintenance base under a flight permit. The operators maintenance personnel subsequently discovered several discrepancies. Loose B nuts in the No.1 fuel tank prevented the ejector pump from transferring fuel aft, over the baffle, to the boost pump side of the fuel tank. The examination also determined that the No. 2 engine was starved for fuel due to leaking flapper valve plates that, in a normal flight attitude, allowed fuel to move forward, through the baffle, at a rate that exceeded the recapture capacity of the ejector pump. The effect of these discrepancies was to trap unusable fuel forward of the baffle in each fuel tank. Further discrepancies were noted such as a damaged No. 2 low level float switch and inaccurate fuel quantity indication systems. The operator is conducting checks on the remaining aircraft in the fleet.