The Defense Department has activated a little-used program to order six U.S. commercial airlines to provide planes to help speed up the evacuations in Afghanistan. The airlines will provide 18 passenger jets to help ferry the evacuees. United Airlines is providing four jets; American Airlines, Atlas Air, Delta Air Lines and Omni Air are each providing three jets; Hawaiian Airlines is also contributing two of its jets for the operation. Many of the airlines are providing some of their largest planes for the operation. United, for instance, is using four Boeing 777-300 widebody jets.

The planes provided by the airlines would not be flying into or out of Kabul, a city where chaos and unrest has been building ever since the Taliban seized power last week. The military will instead use the commercial airline pilots and crews to transport thousands of Afghans who are arriving at staging points at U.S. bases in Bahrain, Qatar and the United Arab Emirates, and take them elsewhere. Military jets will continue to handle flying Afghan evacuees out of Kabul.

Secretary of State Antony Blinken talked about the situation on CBS’ “Face the Nation” Sunday. “The situation at the airport [in Afghanistan] is increasingly dire,” Secretary Blinken said, adding that the U.S. needed the additional planes to evacuate its American citizens and allies out of Afghanistan in a timely fashion.

Defense Secretary Lloyd Austin made the decision to call in the Civil Reserve Air Fleet, a program created in 1952 after the Berlin airlift, according to a statement released Sunday by the Pentagon. This allows for airlines to provide support in the case of a “major national defense emergency.” The CRAF has only been used twice before, during both the Iraq War of the early 1990s and the ensuing conflict that occurred after the Sept. 11th attacks.

The Pentagon said the enlistment of the 18 commercial airlines is not expected to have any type of significant impact on the flight schedules of any of the airlines taking part.