The C-141 departed Athens for a night-time flight to Madrid, the first leg of a flight back to McGuire AFB. The crew were cleared for an ILS approach to Torrejon’s runway 23. Weather was reported as 20,000 foot overcast, with 10 NM visibility. During the descent the crew forgot to use the Descent Checklist. Thus, the crew had failed to set their altimeters from 29.92″ to the local altimeter setting of 30.17″. Additionally, they did not turn on the radar altimeter. While at FL60 the crew was given a clearance to a lower altitude. Because of heavy radio traffic, the clearance was garbled. They were not sure if the controller had cleared them down to 5000 or 3000 feet. They agreed that it must have been 3000 feet. They read back “three thousand feet”, but the controller failed to notice the error. When reporting “passing 5000 for 3000” to another controller, the error again was not noticed. Nearing 3000 feet, the navigator noticed a hill ahead and above their altitude, but the pilot reassured him that “everything looks clear ahead”, with the lights of the air base visible in the valley below. At an altitude of 3050 feet, at a speed of 250 kts, the airplane impacted terrain near the edge of a plateau, 40 km east of the Torrej¢n Air Force Base. It became airborne again, rolled over and crashed into a ravine in an inverted attitude. At the time of the accident, the crew had spent only eight of the last 60 hours in bed. Investigators determined that several switches had been left in an incorrect position, indicating the fatigue of the crew.