In the frozen pre-dawn hours of February 9, 1976, a routine domestic flight in the Soviet Union became the site of a catastrophic crash that killed twenty-four of the 114 people on board. Aeroflot Flight 3739 was scheduled to carry passengers from Irkutsk, in eastern Siberia, to Pulkovo Airport in what was then Leningrad — today's Saint Petersburg — with a stopover at Tolmachevo Airport in Novosibirsk. The aircraft was a Tupolev Tu-104A, a Soviet jet that had been one of the world's first commercial jet airliners when it entered service in 1956. This particular machine had made its maiden flight on November 26, 1956, and had been delivered to Irkutsk in December 1957 following test flights. Originally configured to seat seventy passengers, it had subsequently been reconfigured to accommodate eighty-five. By the morning of the crash, it had accumulated 22,069 flight hours and 10,308 pressurization cycles.
The crew assembled for the flight was experienced. Ivan Nikolaevich Svistunov served as pilot in command. Anatoly Fedorovich Grafenkov was the copilot. Yuri Mikhailovich Krasnoyarsk occupied the navigator's position, while Vladimir Nikolaevich Dubrovsky was aboard as a navigator in training. Nikolai Yefimovich Konshin served as flight engineer, and German Vladimirovich Firstov was the radio operator. Ariada Leonidova Shabalina was aboard as a flight attendant-instructor, overseeing a cabin crew of three.
Even before the aircraft lifted off the ground, a serious procedural failure had already taken hold. Ninety-nine passengers boarded at Irkutsk through official channels. Then five additional passengers were permitted to board without proper documentation. Four of them carried tickets but had not been listed on the flight manifest. The fifth was the adult son of the radio operator, traveling without any ticket at all. Two of the unauthorized passengers were placed in the aircraft's restrooms. Two others stood at the front of the cabin. The radio operator's son was allowed to sit in the cockpit. None of the five were listed in the flight documents. The precise positions of all the unofficial passengers remain unclear from the surviving record.
At 8:15 in the morning local time, Flight 3739 began its takeoff run from Irkutsk International Airport on a bearing of 116 degrees. Almost immediately, the aircraft began rolling to the right. The pilots responded forcefully, pushing the ailerons to roll the plane some twenty degrees to the left in an effort to level it out. The plane broke free of the runway at approximately 300 kilometers per hour, or 160 knots. For a brief moment the crew appeared to have the situation in hand, achieving something close to level flight. But at thirty meters above the ground — barely one hundred feet — the aircraft began rolling to the right once more. Losing altitude rapidly and now banking at seventy degrees, the plane crashed just eight seconds after lifting off, coming down only 180 meters past the southeast end of the runway. In the wreckage, a Chosonminhang Tupolev Tu-154, registered P-551 — an aircraft that would later become part of the Air Koryo fleet — was struck and damaged.
The investigation that followed probed the physical condition of the aircraft first. Suspicion initially fell on the right wing, with engineers hypothesizing that some modification during maintenance had created an aerodynamic imbalance. The remains of the wing were sent to the Central Aerohydrodynamic Institute for analysis, and the findings were definitive: the wing itself had been fully functional right up to the moment of impact.
Attention shifted to the circumstances of the takeoff. Flight testing on another Tu-104 revealed an important characteristic of the type: under crosswind conditions at low altitude, the aircraft was prone to banking, and the standard corrective response of adjusting the ailerons was inadequate. The proper recovery in such a situation required sharply pulling back on the throttles — a counterintuitive action in a low-altitude takeoff emergency.
The investigating commission concluded that the crash resulted from a combination of factors. Most critically, the aircraft had been refueled asymmetrically. Calculations showed that the right fuel tanks held an estimated 1,300 to 1,500 kilograms more fuel than the left tanks — a significant imbalance that predisposed the aircraft to roll toward the heavier side. Combined with a crosswind that pushed against the right wing at the moment of takeoff, the aircraft was placed in an extremely difficult situation from the instant it left the runway. The pilots, faced with an unexpected and rapidly developing emergency, responded with aileron inputs that were insufficient for the conditions. They did not execute the sharp throttle reduction that the situation demanded.
The accident offered grim lessons about weight distribution, pre-flight verification, and emergency procedure training. The unauthorized passengers further complicated the picture, adding unknown weight factors to a plane already compromised by asymmetric fuel loading. The crash remained one of the more thoroughly documented Soviet aviation accidents of its era, a case study in how multiple small failures can accumulate into irreversible catastrophe.
