Originally Posted by view-with-a-room

There are multiple matches for CM airline code, including Copa Airlines and CM Airlines:
Copa Airlines
The IATA airline code for Copa Airlines is CM. Copa Airlines is the flag carrier of Panama and a leading airline in Latin America. It serves destinations in North, Central, and South America, as well as the Caribbean. Copa Airlines is headquartered in Panama City and its main hub is at Tocumen International Airport. It is also a member of the Star Alliance, the largest global airline partnership.
CM Airlines
The IATA airline code for CM Airlines is H5. CM Airlines is a regional carrier based in Tegucigalpa, Honduras and operates out of Toncontín International Airport. It serves destinations in two countries, including Guatemala City, and has a fleet of 14 aircraft. According to the airline, "CM" stands for "Cielo Maya" (Mayan sky).