Tiger Transit is a US shipping corporation in Delta Green canon, described in Delta Green: Countdown. It began as a CIA front in 1965 and has survived, with varying levels of government influence and leverage, at least into the late 1990s.
In Countdown, Tiger Transit has offices in Miami, Memphis, Seattle, Washington D.C. and San Francisco, with its headquarters in New York and its airplane maintenance hub at Midway Airport in Chicago. As long as Tiger Transit maintains its unique support from the government, it may well be flying with illegal cargo to and from Midway or Chicago O'Hare International Airport.
There are several smaller fields near Chicago for special jobs: Palwaukee Airport a.k.a. Chicago Executive (lots of "discrete" charter and private freight), Lake-in-the-Hills Airport (reliever for O'Hare, notable for taking small freight overflow), Chicago Rockford International (UPS does freight through there, with ground logistics hub nearby) and Waukegan Regional. All of these have a reasonably-sized Vietnamese, Cambodian, Laotian or Hmong population within 20 minutes driving as of 2012.1