States. During the Gulf War of 1990–91, the airline received a government contract to ferry U.S. military personnel between the key domestic bases of Dover AFB, Charleston AFB, Travis AFB, McChord AFB, and Kelly AFB. Sale Trump had personally guaranteed $135 million of the shuttle's debt. Following the default, Citibank made arrangements for Northwest Airlines to take control of the shuttle in exchange for relieving Trump's personal liability on its debt, and all sides were reportedly close to an agreement by April 1991. Delta Air Lines agreed to buy the competing Pan Am Shuttle in July, and Northwest announced that its acquisition of the Trump Shuttle was cancelled in August, reportedly due to the Trump Shuttle's unions demanding parity with Northwest employees and Trump refusing to discount the price to reflect this. USAir ultimately reached an agreement in December 1991 to take operational control of Trump Shuttle for up to ten years, with an option to buy it after five years. Bankers involved in the negotiations said that Trump would be relieved of at least $100 million of his guarantee, and possibly as much as $110 million, leaving him owing between $25 and $35 million in the closing out of his ownership of the company. On April 7, 1992, Trump Shuttle ceased to exist when it was merged into a new corporation, Shuttle, Inc., which began operating as the USAir Shuttle on April 12, 1992. US Airways subsequently purchased the remainder of Shuttle, Inc., on November 19, 1997, and the service subsequently operated under the name US Airways Shuttle. Shuttle, Inc., remained as a subsidiary of US Air Group until July 1, 2000, when it was merged into US Airways. In October 2015, US Airways merged with American Airlines, at which point the shuttle became the American Airlines Shuttle. Helicopter service Trump Air operated a scheduled helicopter service between LaGuardia Airport and Wall Street Heliport to provide connections with Trump Shuttle flights at LaGuardia. Trump Air also operated between New York City and East Hampton Airport from 1989 to 1992, and between West 30th Street Heliport and Steeplechase Pier in Atlantic City to serve Trump's casinos. It used a combination of Sikorsky S-61 and Boeing Chinook helicopters. It was established on March 22, 1988, with three Sikorsky S-61 helicopters, which could carry 24 passengers each, with service between the West 30th Street Heliport in Manhattan and Bader Field and the