Aircraft manufacturer Bombardier told airlines to ground their Q400 aircraft after landing gear collapsed in two separate incidents in the past week. Bombardier told airlines that aircraft with more than 10,000 landing gear cycles should be grounded, but several airlines are taking a more conservative approaching, pulling most or all Q400s from service. In the US, this has caused Horizon Airlines (part of Alaska) to cancel about 25% of its schedule.
The Q400 is a turbo prop that has seen far more usage outside of the US, where propeller-based airplanes don’t have the stigma they do here. Airlines that fly it say it’s a quiet airplane with low costs.