after a development process that cost us$5.4 billion to december 2015, including a us$3.2 billion writeoff, the smallest model in the series, the 110-125 seat cs100 received initial type certification from transport canada on 18 december 2015. at the time, the company had 250 firm orders and letters of intent, plus commitments for another 360; but most of these were for the cs300 model, which was expected to be certified by the summer of 2016. the first cs100 was expected to be in service with lufthansa's subsidiary swiss by mid-2016.