By Simon Hradecky, via The Aviation Herald
A Horizon de Havilland Dash 8-400 on behalf of Alaska Airlines, registration N408QX performing flight QX-2118/AS-2118 from Seattle,WA (USA) to Calgary,AB (Canada) with 74 people on board, was on final approach to Calgary’s runway 10 when the crew selected the gear down, the left main gear however did not extend. The crew went around and entered a hold to run the relevant checklists, a manual gear extension was able to extend and lock all gear. The aircraft landed on runway 16 about 35 minutes after going around.
The Canadian TSB reported the aircraft vacated the runway onto taxiway C1 from where it was towed to the apron. A worn left main gear up lock had failed to release the gear.
Original source, here.