DL and the government do negotiate GSA City Pair pricing...along with every other airline.
Oh, they also fly to the CDC airport. Does that count?
http://www.cedarcity.org/76/Airport
Wait, I found another one:
Domestic Violence Prevention Enhancement and Leadership Through Alliances (DELTA)
http://www.cdc.gov/ViolencePrevention/DELTA/
"In 2010, the Family Violence Prevention and Services Act was reauthorized. The community demonstration projects were officially replaced with the DELTA name. The reauthorization continues to direct CDC to fund state domestic violence coalitions for the purpose of funding and supporting local efforts to prevent intimate partner violence."
And there is this:
"WASHINGTON: Although privacy experts worry about the government gathering personal information on airline travelers, Delta Airlines (DAL) is handing over electronic lists of passengers from some flights to help stop the spread of deadly infectious diseases.
The lists will allow health officials to notify more quickly those travelers who might have been exposed to illnesses such as dengue fever, flu, plague, SARS (search) and biological agents, the Centers for Disease Control and Prevention (search) told a congressional panel on Wednesday.
"The government is seeing that massive amounts of data can be useful for any number of purposes," said Marcia Hofmann, an attorney for the Electronic Privacy Information Center (search). "There need to be some regulations or restrictions on how airlines can share passenger information like this."
Passenger lists already are sent electronically to the Customs Bureau (search), which checks to see if any potential terrorists are aboard flights bound for the United States. The CDC wants access to the same lists, but only for flights coming from places with an outbreak of an infectious disease or for those that carried a passenger later found to be infected."
http://www.foxnews.com/story/2005/04/07/delta-handing-over-passenger-lists-to-cdc/