The formal application meeting for ARJ21 supplementary operation certification was held in Chengdu Airlines on December 7th, 2015. Immediately following the meeting, Chengdu Airlines organized on-the-post training activity, on-the-job training, and verified the aircraft maintenance manuals one by one, etc. During the half month after ARJ21 AC106 was officially delivered on November 29th, Chengdu Airlines had made preparations for the demonstration operation of ARJ21 actively.