United States of America

The crew (one instructor and two pilots under training) was completing a local training at Glenview Airport. On approach to runway 27, the instructor decided to initiate a go-around procedure then started an approach to runway 35. He cancelled his IFR flight plan when control was lost. The airplane crashed onto several houses located near the airport. All three crew members were killed while there were no casualties on ground.

On March 3, 1991, a United Airlines Boeing 737, registration number N999UA, operating as flight 585, was on a scheduled passenger flight from Denver, Colorado, to Colorado Springs, Colorado. Visual meteorological conditions prevailed at the time, and the flight was on an instrument flight rules flight plan. Numerous witnesses reported that shortly after completing its turn onto the final approach course to runway 35 at Colorado Springs Municipal Airport, about 0944 mountain standard time, the airplane rolled steadily to the right and pitched nose down until it reached a nearly vertical attitude before hitting the ground in an area known as Widefield Park. The airplane was destroyed, and the 2 flight crewmembers, 3 flight attendants, and 20 passengers aboard were fatally injured.

The pilot of the multi-engine aircraft reported that his right engine was losing oil as he was climbing to cruise altitude. He secured the engine, feathered the propeller, and maneuvered to return to the airport. The pilot trimmed the aircraft for single engine operation and extended the main landing gear. During the approach, the operating left engine would not develop full power and the pilot reported to atc that he could not make the airport. The aircraft continued its emergency descent, impacted trees, and descended uncontrolled through a densely wooded area. A fuel tank ruptured during the uncontrolled descent through the trees and a fire/explosion occurred. The aircraft continued to burn after ground impact. Both engines were disassembled and numerous mechanical anomalies were found. They had been recently overhauled. This was the first flight of the aircraft since the engine overhauls. The pilot/owner was en route to sell the aircraft when the accident occurred. The pilot, sole on board, was killed.

Upon touchdown at Avon Park Airport, tyre(s) burst. The crew lost control of the airplane that veered off runway, lost its undercarriage and came to rest. Both pilots escaped uninjured and the aircraft was damaged beyond repair.

Airplane was departing on a required maintenance test flight following replacement of both engines. Witnesses stated that the takeoff roll and initial climb appeared normal, but that at about 500 feet agl, the airplane entered a right bank which continued until the wings were vertical and the nose fell through. Airplane impacted in an inverted steep nose down attitude. Examination of wreckage revealed that the right engine had been secured and feathered. Subsequent investigation did not reveal any evidence of pre-impact failure or malfunction of either engine or any of the airframe systems. Engine mounting/rigging continuity could not be established due to impact damage. The pilot was a principal in the operator's organization and not one of the regular line pilots. Evidence indicated that the gear was up and that the left spoiler was deployed at impact. Emerg procedure taught in transition training is to use rudder trim as soon as possible after engine failure to preclude deployment of spoilers. Rudder trim found in neutral position. All three occupants were killed.

The flight had flown through weather conducive to airframe ice about 40 minutes prior to the accident during descent into Cleveland. During the 35-minute turnaround at Cleveland the crew did not exit the airplane to conduct an exterior preflight inspection to verify that the wings were free of ice contamination. It was snowing while they were on the ground. The airplane stalled and rolled into the ground immediately after takeoff. There was no operator requirement for the preflight. The flight had not been given training regarding the effects of wing contamination on the airplane. The FAA and the manufacturer have been aware for several years of the propensity of the DC-9 series 10 to the loss of control caused by wing contamination, but neither of them took positive action to include related information in the approved airplane flight manual. Both pilots were killed.

The flight crew reported to the tower controller that they were over the airport and requested a right downwind circling approach to runway 15. The tower controller and other witnesses observed the airplane in a steep right bank on base leg. The airplane overshot the extended runway centerline. The tower controller observed the airplane entering a steeper right bank to correct back to the runway centerline. The controller stated that he observed the airplane "flutter" and then crash right-wing first, about one mile north of the runway threshold. Other witnesses reported a variety of indications consistent with a loss of control. The last recorded transmission was "Oh no you're (stall…)." The ( ) indicates that the word was questionable text. Both engines were producing about 1,700 pounds of thrust (2,561 pounds available). A snow squall had just passed over the airport and was obscuring mountains to the east. The terrain was snow covered. The accident occurred about eight minutes before official sunset. The approach procedure is not authorized at night or for category D airplanes. Minimums for the approach were three miles visibility with an MDA of 10,840 feet. Airport elevation is 7,815 feet. Both pilots were rated in the airplane. It could not be determined which pilot was at the controls at the time of the accident.

During an updated 0528 est weather briefing, the pilot was advised of flight precautions for IFR weather conditions in the Georgia and Alabama areas. At 0841 est he departed Macon, GA on an IFR flight plan to Anniston, AL. At 0821 cst, approximately 22 miles southeast from the Anniston Airport, the pilot contacted Atlanta center and cancelled his IFR flight plan. He was advised that the minimum safe altitude in his area was 2,900 feet msl. Two minutes later he contacted Anniston radio and requested local weather conditions. He was given the latest reported (0756 cst) weather as ceiling 1,500 broken, 3,100 overcast, 5 miles with fog. The Anniston airport field elevation is 526 feet. The aircraft subsequently impacted a mountain top 10 miles southwest of the airport at an elevation of approximately 2,300 feet. The 0850 cst Anniston weather was 800 feet overcast, 4 miles in fog. All four occupants were killed.

SKW5569, N683AV, had been cleared to runway 24L, at intersection 45, to position and hold. The local controller, because of her preoccupation with another airplane, forgot she had placed SKW5569 on the runway and subsequently cleared US1493, N388US, for landing. After the collision, the two airplanes slid off the runway into an unoccupied fire station. The tower operating procedures did not require flight progress strips to be processed through the local ground control position. Because this strip was not present, the local controller misidentified an airplane and issued a landing clearance. The technical appraisal program for air traffic controllers is not being fully utilized because of a lack of understanding by supervisors and the unavailability of appraisal histories.

SKW5569, N683AV, had been cleared to runway 24L, at intersection 45, to position and hold. The local controller, because of her preoccupation with another airplane, forgot she had placed SKW5569 on the runway and subsequently cleared US1493, N388US, for landing. After the collision, the two airplanes slid off the runway into an unoccupied fire station. The tower operating procedures did not require flight progress strips to be processed through the local ground control position. Because this strip was not present, the local controller misidentified an airplane and issued a landing clearance. The technical appraisal program for air traffic controllers is not being fully utilized because of a lack of understanding by supervisors and the unavailability of appraisal histories.