3rd of July 2013
At 14.00 lt (local time) a Canadair CL-215-6B11 (CL-415) was being crew prepared by its crew at Wabush Airport (Newfoundland, Canda) for a firefighting mission on a forest fire, northeast of Wabush, Newfoundland and Labrador (Canada). The captain would be the pilot flying (PF) and the copilot would be the pilot monitoring (PM).
The PM completed the exterior checks and cockpit preflight checks.
The aircraft being recovered from the lake, not the missing float on the left wing. (Source; baaa-arco.com © TSB Canada)
The aircraft was loaded with 7000 pounds of fuel and 1000 pounds of firefighting foam. Based on this information the water-drop control computer determined how much water could be scooped during the water pick-up from Moosehead lake (as they had done during a mission on the 2nd of July, dropping water on the same fire as today's mission).
After take-off, the PM completed the "After Take-off" checklist, followed by the necessary checklists in preparation for the water scooping run on Moosehead lake. Four minutes after take off the aircraft touched down on Moosehead Lake on a heading of 250º for its first scoping run of the day. As per procedure, the PF applied take-off power while the PM adjusted the torque during the scooping run. At one point the PM noticed that the water tanks were completely full, and that the probes (used to scoop water from the lake) were stil down. He advised the PF about this and noticed that the "PROBE AUTO/MANUAL" switch was in the manual position. He then proceeded to manually select the probes up. 3490 feet after touch down the probes were retracted.
Although the indications in the flight deck indicated that the water quantity in the tanks was in excess of that allowed for this take-off, the crew continued to take off. The PF at that time initiated a turn to the left to make sure the take-off distance available would be sufficiant. 2 seconds later the aircraft started to lift out The aircraft in the lake of the water, as the left-wing float contacted (Source & © TSB Canada) the water. With the aircraft hull 7 feet (2,1 meters) above water, the left float was still in contact with the water`, a shortwhile later the float seperated from its pylon, which caused a sudden pitch-down moment. As the foward section of the hull hit the water causing the fuselage to tear open. As the right float hit the water it also was torn of ithe wing, including its pylon.
The aircraft came to a rest with the forward section of the aircraft underwater. The crew climbed on the wing as the aircraft slowy sunk, without activating the ELT (Emergency Locator Transmitter, shutting down the engines or selecting electrical power off. They contacted the company by cellular phone and were picked up by a boat ~30 minutes after the accident.
The aircraft fuselage in use as a shed (Source baaa-acro.com © Barry Ambrose)
The aircraft was damaged beyond repair
The accident was investigated by the Transportation Safety Board, after completing their investigation they published the final report, stating the following findings as to the cause and contributing factors;
It is likely that the PROBES AUTO/MANUAL switch was inadvertently moved from the AUTO to the MANUAL selection when the centre pedestal cover was removed.
The PROBES AUTO/MANUAL switch position check was not included on the Newfoundland and Labrador Government Air Services CL-415 checklist.
The flight crew was occupied with other flight activities during the scooping run and did not notice that the water quantity exceeded the predetermined limit until after the tanks had filled to capacity.
The flight crew decided to continue the take-off with the aircraft in an overweight condition.
The extended period with the probes deployed on the water resulted in a longer take-off run, and the pilot flying decided to alter the departure path to the left.
The left float contacted the surface of the lake during ithe nitiation of the left turn. Aircraft control was lost and resulted in ca ollision with the water.
The full TSB Canada report is available by clicking here, the animation below was made by the TSB Canada, based on the FDR data;