Learjet C-21A

The crew was completing a positioning flight to Talil AFB (Imam Ali), Iraq. On approach, the aircraft was too high and descended with an excessive speed and a tailwind component of 10 knots. The crew failed to initiate a go-around and the aircraft landed about two-third down the runway. Unable to stop within the remaining distance, the aircraft overran, lost its undercarriage and came to rest in a sandy area about 60 metres past the runway end. Both pilots escaped uninjured while the aircraft was damaged beyond repair and later destroyed by soldiers from the 68th Transportation Company.

The crew was performing a local training flight at Decatur Airport, consisting of touch-and-go maneuvers. On final approach to runway 24, the instructor elected to simulate a failure of the right engine. Anticipating the touch-and-go procedure, the instructor deactivated the yaw damper system while the aircraft was about 10-20 feet above the runway. As the speed increased, the instructor called out 'speed' twice when the copilot reduced the power on the left engine. The aircraft rolled to the right, causing the right wingtip to struck the ground. The aircraft went out of control, veered off runway and came to rest, bursting into flames. Both pilots escaped with minor injuries while the aircraft was destroyed.

The mishap aircraft, call sign Pacer 43, was conducting pattern work operations during an off-station training mission at Ellsworth AFB, SD (RCA). Shortly before impact, the mishap crew was conducting a simulated single-engine approach to runway 31 at Ellsworth AFB. Subsequent analysis showed that there was a significantly greater amount of fuel in the left wing and left wing tip tank than the right. The gross fuel imbalance resulted from an unmonitored transfer of fuel from the right wing and right wing tip tank to the left that was initiated by the crew approximately nine and one-half minutes before impact. As the aircraft approached the point when it would normally transition to a flare, it leveled off and began a climbing turn to the west, toward the tower. It did not touch down prior to the turn, but veered left immediately during the flare, and then rolled back to wings level momentarily as it climbed. The heavier left wing, and application of power to the right engine for the go-around, caused the aircraft to roll back into a steeper left turn, stayed in a climbing left turn with the bank continuing to increase until il rolled through more than 90 degrees of bank. As the aircraft reached the highest point of the climb (approximately 450 feet), the bank angle was more than 90 degrees, and perhaps slightly inverted as the nose dropped and the aircraft began to descend. The aircraft impacted the ground in a grassy field.

The C-21A, a USAF designation of the Learjet 35A was assigned to the 332nd Airlift Flight at Randolph AFB, Texas. The aircraft would depart Randolph AFB as flight Kiowa 71 to Wright-Patterson AFB, Andrews AFB and then back to Randolph. The aircraft was landed at Andrews AFB at 10:57. The crew requested a full load of fuel and told Serv-Air maintenance technicians that they had been unable to transfer fuel from the wing tanks to the fuselage tank. A Serv-Air maintenance technician removed the fuel-control panel from the aircraft and replaced the fuselage-tank transfer/fill switch. The maintenance technician told the crew that replacement of the fuselage-tank switch had not corrected the problem and that he was going to try to correct the problem by replacing the fuel-control relay panel. This was a time consuming job. The crew decided to continue back to Randolph without the repairs. The fuselage fuel tank was full and they had not had trouble earlier in the day getting fuel out of the fuselage tank. The aircraft departed from Andrews AFB at 16:38. The aircraft was in cruise flight at FL390 at 17:53 when the crew began to transfer fuel from the fuselage tank to the wing tanks. The crew did not know that the right standby fuel pump was operating and was preventing fuel from being transferred from the fuselage tank to the right wing. Bearings in the right standby pump were in a deteriorated condition and the pump had required higher-than-normal electrical current for rotation. The higher-than-normal electrical current had caused progressive damage to two contacts in the fuel control relay panel and eventually had caused the contacts to bond together. This caused the pump to run continuously throughout the flight and to prevent fuel transfer from the fuselage tank to the right wing. The aircrew noticed that the left wing-tip tank had become 800 pounds [363 kilograms] heavier than the right wing-tip tank during the transfer, and they attempted to analyse the malfunction and correct the imbalance. A fuel-imbalance during-fuel-transfer malfunction however was not included in the Air Force training syllabus, nor was the procedure contained in the C-21A checklist. At 17:56, the copilot told the Atlanta Air Route Traffic Control Center (Atlanta Center) controller, "Sir, we need to revise our flight plan. We’re having a problem getting some fuel out of one of our wings. Can we get vectors to Maxwell Air Force Base? And we’re going to need to dump fuel for about five minutes." The crew at 18:00 began to dump fuel from the left wing-tip tank. However, they still had an imbalance in the wing tanks themselves of about 200 pounds (91 kilograms). At 18:03 the flight was cleared to descend from FL350. The crew then observed that fuel quantity was decreasing rapidly in the right wing tank, that the left wing tank was full and that the left wing-tip tank had begun to fill with fuel. At 18:07, the copilot told the Atlanta Center controller, "Sir, we’d like to declare an emergency at this time for a fuel problem and, ah, get to Maxwell quick as we can." They were cleared direct to Maxwell AFB and cleared to descend to 17,000 feet, and later to 11,000 feet. At 18:15, the copilot told Atlanta Center, "We need to change the airfield, to get to the closest piece of pavement we can land on." The controller said, "Kiowa 71, we got an airport at 12 o’clock and 12 miles. It’s Alexander City." The crew accepted this and began their emergency descent into Alexander City airport. At 18:16 the copilot took over control since the captain did not have the airfield in sight and the copilot did. The aircraft was northeast of the airport at 8,800 feet and was descending at 5,600 feet per minute with the wing-lift spoilers extended when the copilot told Atlanta Center that they were on a left base for the runway. The crew attempted to fly a visual traffic pattern to runway 18 but were in a poor position to complete the approach and landing. They subsequently elected to enter a left downwind leg for runway 36. As airspeed was reduced, aileron authority diminished and, because of the fuel imbalance, the aircraft became difficult to control. The copilot, flying from the right seat, did not have a good view of the runway and asked the aircraft commander for help in positioning the aircraft on downwind and in beginning the turn toward the runway. The captain wanted to get the gear down but the copilot had difficult controlling the plane already: "Don’t put anything down," the copilot said. "Nothing down, nothing down." The aircraft was at 2,030 feet when the gear-warning horn sounded. The captain said, "Gear down. Gear down." The copilot said, "No. Stand by. Stand by." "Gear down," the captain said. "Gear down, man." "No, not yet, not yet," the copilot said. The copilot then asked the aircraft commander to "push the power up a little bit for me." Power was increased and the gear was extended. The aircraft was at about 1,500 feet and was one mile southwest of the runway at 18:19 when the copilot began a left turn. Approximately halfway through the final turn and one mile due south of runway 36, the aircraft abruptly rolled out, flew through the extended runway centerline and continued in an east, northeasterly direction approximately 800 feet above the ground. The copilot had rolled out of the turn to regain lateral control of the aircraft. At this time the right engine was operating at a reduced thrust setting in an attempt to counteract the effects of the fuel imbalance. The captain, to center the ball in the slip indicator, applied pressure on the left rudder, against pressure that was being applied on the right rudder by the copilot. The captain said, "Step on the rudder. Step on the rudder." The copilot said, "Paul, no. Paul, don’t." The application of left rudder caused the aircraft to roll left rapidly. It rolled inverted entered the trees and struck the ground.

The aircraft was engaged in a local training flight at Maxwell AFB, carrying three pilots. At liftoff, it went out of control and crashed near the runway. Two occupants were killed and a third pilot was injured.