Complex sentence: Its main base is at Yellowknife Airport (CYZF) with two other bases at Hay River/Merlyn Carter Airport (CYHY) and Red Deer Regional Airport (CYQF).
Split into simpler sentences: Its main base is at Yellowknife Airport (CYZF). It has two other bases at Hay River/Merlyn Carter Airport (CYHY) and Red Deer Regional Airport (CYQF).