Convair CV-240

The trip from Boston was routine and at 2112 the flight contacted the Portland tower and received landing instructions as follows "Northeast 812 Able cleared to enter traffic pattern Runway 20. Wind east variable southeast 5. The altimeter 2998. Check on base leg." At 2116 the flight reported turning into final approach and was cleared to land on Runway 20. As the aircraft passed over the approach end of the runway, at an estimated altitude of 20 to 25 feet and an indicated airspeed of 120 mph, the throttles were brought back to what was expected to be the closed position, preparatory to landing. However, due to malfunctioning of the propeller reverse lock mechanism, the throttles were actually brought back beyond the closed position and into the propeller reverse pitch position instead. This unexpected reversal of propeller pitch in flight resulted in an extremely hard landing 237 feet past the approach end of the runway with serious damage to the aircraft structure. The airplane, however, continued along the runway a distance of 1,065 feet from the point of initial impact before it came to rest. Fuel which had been spilled along the runway was ignited by sparks from the damaged aircraft and propellers scraping along the runway surface. The fire became concentrated for a period on the right side adjacent to the right engine and right wing root, but subsequently enveloped the major portion of the aircraft. All passengers were evacuated in an orderly manner through the rear cabin exit door. The captain and first officer made their escape through the left cockpit window after all effective action possible had been taken to control the fire. The airport fire equipment arrived shortly thereafter but was unable to extinguish the fire before the aircraft had been damaged beyond economical repair. Five people were slightly injured while all other occupants were unhurt.

After 2.700 feet of takeoff roll the aircraft became airborne with an estimated air speed of 120 miles per hour, but at an altitude from 20 to 50 feet the right engine failed and the right propeller automatically feathered. Retraction of the landing gear was accomplished after momentary hesitation as the flight continued straight ahead, gaining altitude very slowly. It passed over the end of the runway at about 50 feet. A power transmission line, 11,700 feet from the start of the takeoff roll. was located across the flight's course. Two towers of this transmission line between which the aircraft was flown extended to an elevation of 371 feet, or a height of 111 feet above the southwest end of Runway 2 from where the takeoff was started. Elevation of the lowest point of the top series of wires as they hung between the two towers was 335 feet or 75 feet above the southwest end of Runway 2. The flight cleared these wires at this lowest point by 10 to 20 feet. Just before flying over the power lines at an air speed of 110 miles per hour, a slow retraction of the flaps was started. After crossing the power lines, the air speed fell to 105 miles per hour even though the left engine continued to develop full takeoff power. Not being able to hold altitude, a shallow right turn was made to relatively clear terrain where the aircraft was crash landed 18,713 feet northeast from the starting point of the takeoff. The aircraft slid over the ground for a distance of 217 feet, skidded over an embankment and a highway, then came to rest. Control tower personnel had observed the feathering of the right propeller and the slow rate of climb. Feeling that the aircraft would not remain airborne, the airport controller instructed another air carrier flight, then on a landing approach to Memphis, to circle the Convair so as to keep the tower advised of its position. Instructions were immediately transmitted to the field's fire and crash personnel following which the city fire and police departments and hospitals were notified. Since fire and crash equipment had actually been dispatched while the aircraft was still in flight, it arrived only two or three minutes after the crash. Fire which started in the left engine nacelle after landing was quickly extinguished, and prompt medical attention was available for all occupants. Although the stewardess had received minor injuries, she, with the aid of one of the passengers, had opened two emergency exits. She had then deplaned all passengers. Thirteen passengers and one crew member received serious injuries, and 18 passengers and two crew members received minor injuries.