sentences:  With the exception of the single C-5 (which had Pratt & Whitney R-2800 engines, as fitted to the Douglas DC-6), these variants were all powered by Rolls-Royce Merlin engines and 51 of the production examples were pressurised.On 8 April 1954, a Royal Canadian Air Force Canadian Car and Foundry Harvard Mk.II "3309" collided with Trans-Canada Airlines North Star "CF-TFW" over Moose Jaw, Saskatchewan, killing 36 people aboard the aircraft and one person on the ground.As a result of this crash, training flights are restricted south of the Trans Canada Highway and civil aviation transit north of the highway.