A Hasty Decision

On May 10, 1979, at Sochi Airport, a passenger aircraft was preparing for departure to Chelyabinsk. It was an Il-18D operated by Aeroflot. On board were 72 passengers and 7 crew members.

The flight was scheduled for the daytime. Weather conditions were generally favorable: hot, with a temperature of +24°C, and a light wind of 5 m/s that posed no hindrance to takeoff. The crew completed all standard pre-flight procedures, lined up the aircraft on the runway, and began the takeoff roll.

Before every takeoff, a decision speed (V1) is calculated. This is the speed at which the crew must decide to either continuing or aborting the takeoff. It is determined such that if a failure occurs below V1, the aircraft can be safely stopped within the remaining runway. If the failure occurs above V1, the only safe option is to continue the takeoff and deal with the issue in the air.

During the takeoff roll, the Il-18 accelerated to 220 km/h - slightly above V1. At that moment, the navigator noticed that the airspeed had stopped increasing and reported it to the captain. The captain decided to abort the takeoff. There were still 1,100 meters of runway remaining. The flight engineer reduced engine power, but the aircraft continued accelerating, reaching 250 km/h. Despite maximum braking, the aircraft overran the runway and collided with trees. Five crew members and ten passengers were injured.

It was later determined that the brief stagnation in indicated airspeed was caused by a sudden gust of wind. The effect lasted only three seconds. All other takeoff parameters were within normal limits, and there was nothing preventing a safe departure. The investigation commission noted that the Il-18’s flight manual contained no guidance for situations where indicated airspeed stops increasing after V1. Additionally, a long break from flying, combined with high ambient temperatures and the specific environment of Sochi Airport, contributed to the crew’s psychological unpreparedness in that moment.

The accident was caused by the captain’s hasty decision to abort the takeoff due to a brief pause in airspeed increase, despite the aircraft's performance matching calculated takeoff parameters.