Aeroflot Flight E-46

The aircraft was operating flight E-46 on the route Volgograd — Nalchik — Leninakan, piloted by a crew with Captain (PIC) R.G. Bagdasaryan. At 17:07, the Yak-40 took off from Nalchik Airport and, after climbing, reached an altitude of 6,600 meters. On board were 4 crew members and 17 passengers.^[1]

After passing Kislovodsk, the aircraft veered to the right, for which the crew was warned by the dispatcher of the Minvody regional center. However, the response to commands to return to the designated flight path (DFP) was slow, and the aircraft followed parallel to it, 10 kilometers from the route. By the time the aircraft passed Gori, it was brought back onto the DFP and at 17:53 contacted the dispatcher of the Tbilisi regional center (RC Tbilisi), reporting passing Gori at an altitude of 6,600 meters. The Tbilisi dispatcher confirmed the passage of Gori and instructed to descend to 5,700 meters. Subsequently, en route to Leninakan, the crew periodically changed the flight course, which reduced from 185° to 130°, without actively navigating the aircraft, resulting in a left deviation from the route by 28 kilometers. At 18:02, the pilots reported to the RC Tbilisi dispatcher about leaving the zone as calculated at an altitude of 5,700 meters. However, in reality, the aircraft was not at the 100 km calculated exit point but 57 kilometers from Tbilisi, 28 kilometers left of the route, with 39 kilometers remaining to the Air Traffic Control (ATC) transfer boundary.^[1]

At 18:03, the crew contacted the Leninakan Airport approach dispatcher, reporting entry into the zone, although they were actually still 87 kilometers away and 29 kilometers left of the route. A minute and a half later, the aircraft requested its position. The dispatcher reported an azimuth of 30° and stated that the aircraft was not visible on the radar screen. This could have indicated a significant left deviation from the flight path, but the dispatcher took no action to correct it. Not knowing their actual position, the pilots soon reported passing the control boundary at 21 kilometers and that conditions were suitable for visual flight. The approach dispatcher then allowed them to descend to 3,300 meters at the Radio Navigation Point (RNP). While descending to the specified altitude, the crew did not navigate the aircraft to the airport beacon and did not use onboard or ground radio navigation systems (RNS).^[1]

The sky was covered with cumulus clouds at an altitude of 600—1000 meters, with a top edge of 7—8 kilometers, visibility more than 10 kilometers, and the mountain peaks were partially obscured by clouds. During descent, the crew reported passing through 3,600 meters, and the approach controller instructed them to contact the circle controller, whose duties he was performing. Despite not seeing the aircraft on the radar screen, he allowed the crew to descend to 900 meters for the third turn. The airliner was actually 40 kilometers from the airport, but the crew was unaware of this and at 18:08, after receiving clearance to descend, reported passing the airport RNP, although they were off course, and began maneuvering for landing.^[1]

At 18:09, while performing a right turn with a 13° bank at a course of 178°, the Yak-40 crashed into the slope of Mount Shishtepe at an altitude of 2,523 meters at a speed of 330 km/h, 41 kilometers northeast of Leninakan Airport (between Spitak and Stepanavan, Lori Province). The aircraft was completely destroyed on impact, and all 21 people on board — 4 crew members and 17 passengers — were killed.^[1]

According to the commission's findings, the following reasons led to the disaster:^[1]

1. The crew did not conduct active aircraft navigation on the Gori — Leninakan route segment, did not comprehensively use the RNS, and as a result, deviated from the route and did not know their actual location. In the final flight segment, not knowing their location and not reaching the RNP, the crew began descent and landing maneuvers outside the aerodrome scheme, grossly violating the requirements of NPP GA-78 and the Flight Operation Manual at Leninakan Airport.
2. The RC Tbilisi dispatcher managed the aircraft's flight unsatisfactorily: did not maintain control via radar, did not prevent deviation from the route, did not take measures to guide the aircraft back to the route, and when transferring flight control to the Leninakan Airport approach zone, in violation of NPP GA-78, NSD GA-81, and the RC dispatcher work technology, did not establish the actual aircraft location and did not inform the crew.
3. The Leninakan Airport approach controller, upon the crew's report of entering the zone, did not identify the aircraft, did not provide its position to the crew, did not assess the reported azimuth of 30°, did not give instructions to return to the route, and did not ensure the aircraft was guided to the RNP using the direction finder. Without continuous radar control over the aircraft's flight, after receiving the crew's report of passing the 21-kilometer control boundary and not knowing the actual aircraft location, he allowed descent from a safe altitude of 4,200 meters to 3,300 meters. Then, while continuing the duties of the circle controller, without continuous radar control over the aircraft's movement in both the approach zone and circle zone, did not guide the aircraft to the RNP, did not require a safe altitude control circle for identification, did not transmit information on landing approach conditions, and allowed descent to 900 meters and landing approach outside the aerodrome scheme without knowing the aircraft's location, violating the requirements of NPP GA-78, NSD GA-81, the Flight Operation Manual at Leninakan Airport, and the approach and circle controller work technology. In the absence of radar control over the aircraft, he did not seek assistance from the Air Defense, nor did he use their means to determine the aircraft's location.
4. The senior controller abstained from managing and directing the Yak-40 flight, showed complete inaction in controlling the approach and circle controller's work, and did not take proper measures to prevent the aircraft's disaster.

The Yak-40 aircraft disaster occurred due to gross violations of the Air Traffic Control service dispatchers and the aircraft crew of the NPP GA-78 and the Flight Operation Manual at Leninakan Airport, which led to the premature descent of the aircraft outside the aerodrome scheme and its collision with a mountainside.^[1]