The Midcoast St. Louis Downtown Airport facility is the company's largest and most diversified with more than 500,000 square feet in eight hangars. Located in Cahokia, Ill., only minutes from downtown St. Louis, the operation provides a full scope of services: scheduled inspection, unscheduled repair, avionics repair and upgrades, engine service, interior design and refurbishment, exterior design and paint, structural repair or modification, component and accessory service. . . or whatever combination a customer needs. St. Louis Downtown also is the primary location for Midcoast’s completion of Bombardier aircraft flown there "green" from the factory.

The facility is an FAA Class IV authorized service center (No. R03R822L), allowing it to work on all makes and models of business jets. Services are focused predominantly on supporting Challengers, Embraers, Globals and the newer, larger Falcons, Gulfstreams and Hawkers. The facility is manufacturer-authorized by Bombardier, Dassault Falcon Jet and others. The Midcoast team has strong experience with Gulfstreams, whose manufacturer does not authorize independent service centers.