Eclipse

On 30 June 1973, an Aeroflot Tu-134A was preparing to depart from Amman, the capital of Jordan. It was scheduled to fly to Moscow with intermediate stops in Beirut and Yerevan. There were 78 passengers and 7 crew members on board. On the day of departure, a partial solar eclipse was observed over the city.

The crew began the takeoff roll. The aircraft was being flown from the captain’s seat by a check pilot - the deputy commander of the flight unit. When the airliner reached 265 km/h, the check pilot started to lift the nosewheel off the runway. At that moment, however, he suddenly noticed that the indicated airspeed had rapidly dropped from 265 to 240 km/h. He exclaimed, “What is this?”, and a few seconds later, “Engine failure!” He then decided to reject the takeoff. With about 500 meters of runway remaining, the crew deployed reverse thrust. The emergency braking system was not used.

There was not enough runway left to stop, and the Tu-134 overran the runway. It bounced at the edge of a ravine, dropped onto the slope, and continued on, knocking down trees and utility poles. About 290 meters beyond the runway end, the aircraft struck a single-story reinforced-concrete building and came to a stop. The airliner broke into three sections, and the navigator’s cockpit was crushed. The building was completely destroyed. A small post-crash fire broke out, but rescuers extinguished it quickly. The accident killed two crew members (the navigator and the radio operator) and seven residents of the building.

During the investigation, the check pilot stated that he rejected the takeoff because the speed dropped to 240 km/h. The captain also confirmed a decrease in speed, but could not recall exactly when it occurred - before or after the check pilot changed the engine power setting. The flight engineer, for his part, insisted that both engines were operating normally and that no engine-failure warnings had been received. He added that even with one engine failed, indicated airspeed would not decrease; only the rate of acceleration would be reduced. The flight recorders also showed normal operation of both engines. No failures of other aircraft systems were found.

The commission ultimately concluded that the airspeed did not decrease during the takeoff run. The check pilot intended to lift off at 270-275 km/h. Therefore, when the navigator called out at 260 km/h that the nosewheel-lift speed had been reached, the pilot continued the takeoff roll. After the navigator repeated the call, the check pilot lifted the nose gear off the runway. Subconsciously, he had “set” himself to expect this action at a speed above 270 km/h. When he glanced at the airspeed indicator and saw 265 km/h, he formed the false impression that the speed had begun to drop. That is why he decided to reject the takeoff. The figure “240 km/h” likely imprinted in his memory because he saw it only after deceleration had already begun.

In addition, the Institute of Biomedical Problems issued an opinion that the solar eclipse could also have contributed to disruptions in the pilots’ actions. Changes in illumination can increase overall physiological stress and interfere with ongoing activity. Moreover, they can affect the body’s general tone, including the muscular system. Changes in lighting are accompanied by changes in muscle tone, shifting a person’s activity to a slightly different level. In such conditions, well-rehearsed actions may become less well matched to the demands of the situation.