During refueling, Cooper outlined his flight plan to the cockpit crew: a southeast course toward Mexico City at the minimum airspeed possible without stalling the aircraft—approximately —at a maximum altitude. He further specified that the landing gear remain deployed in the takeoff/landing position, the wing flaps be lowered 15 degrees, and the cabin remain unpressurized. Copilot William J. Rataczak informed Cooper that the aircraft's range was limited to approximately under the specified flight configuration, which meant that a second refueling would be necessary before entering Mexico. Cooper and the crew discussed options and agreed on Reno, Nevada, as the refueling Cooper further directed that the aircraft take off with the rear exit door open and its staircase extended. Northwest's home office objected, on grounds that it was unsafe to take off with the aft staircase deployed. Cooper countered that it was indeed safe, but he would not argue the point; he would lower it once they were airborne.