St. Louis Downtown (CPS) is a medium sized, primarily general and corporate aviation airport, located on the southeast edge of the city of St. Louis in Illinois. It is about fourteen miles southeast of the St Louis Lambert International (STL) and almost fifteen miles west of the Scott AFB/Mid America St. Louis airports. It has Class Delta airspace that underlies the St. Louis Class Bravo. Pilots headed to St. Louis Downtown for the first time need to ensure they are familiar with the requirements to operate in this airspace environment.