Canada’s Transportation Safety Board (TSB) released a final report early this month on the June 2010 accident at Ottawa’s MacDonald-Cartier International Airport (CYOW) in which the pilots of a Trans States Airlines Embraer ERJ 145LR were unable to stop the aircraft on the airport’s 8,000-foot Runway 7 during landing.
With 33 passengers and a crew of three–none of whom was injured–the aircraft made a smooth touchdown 1,740 feet beyond the threshold of a wet runway approximately eight knots too fast. The crew’s speed calculations for the runway conditions were found to be in error. The crew also chose a “flaps 22” setting rather than full (45 degrees) flaps, in violation of company policy. The smooth touchdown set the stage for the viscous hydroplaning that followed. The aircraft floated just enough on touchdown to remove pressure on the weight-on-wheels switch needed to establish braking. Two seconds later the aircraft touched down again, approximately 2,300 feet from the landing threshold, at which point the first officer–the flying pilot–depressed the brakes and lowered the nosewheel to the surface. The spoilers deployed automatically, but the aircraft did not slow down. It held to the runway centerline until about 200 feet before the end of the hard surface, at which time it veered left, departing the hard surface at 62 knots. The aircraft was substantially damaged as it continued skidding and, after the nose gear collapsed, it came to rest 550 feet past the departure end of the runway. The investigation found that all systems, including the anti-skid, were fully operational before touchdown.Source: AIN, Robert P. Mark
Gravity always wins!