1977 Tavda mid-air collision

On the day of the accident, the An-2 aircraft tail number 44992 was operating flight Щ-801 on a route from Sverdlovsk to Turinskaya Slobod, Turinsk, Tabory, Tavda, and Tyumen. It departed Uktus Airport in Sverdlovsk at 11:14 and landed at Turinskaya Sloboda. At 11:22, it took off toward Turinsk but encountered poor weather, with visibility below the minimum required. The crew returned to Turinskaya Sloboda. After conditions improved, the flight plan was changed to bypass Turinsk and Tabory, heading directly to Tavda. Flight 801 departed again at 12:35 and landed at Tavda Airport at 13:02.^{[citation needed]}

Meanwhile, at 11:33 Moscow time (13:33 local), An-2 tail number 15925 departed Plekhanovo Airport in Tyumen on an additional flight 397 to Tavda, carrying 2 crew members and 13 passengers, including 2 children. The crew had a weather forecast indicating moderate continuous clouds, broken clouds at 150-200 meters, rain, 2–4 km visibility, and light winds—conditions above the meteorological minimum. However, Tavda Airport was not informed of the flight plan or departure.^{[citation needed]}

At 11:56 Moscow time, the crew of aircraft 15925 contacted Tavda's Local Air Lines Command and Control Point, reporting they were flying at 200 meters and expected to land at 12:07. At the same time, two other An-2s from Tyumen, also lacking submitted flight plans or departure information, entered Tavda's airspace within three minutes of each other despite the required separation of 10 minutes in visibility under 4 km.^[1]

At 13:53, aircraft 44992 took off from Tavda Airport bound for Tyumen, carrying 2 crew members and 12 passengers, including 2 children. According to the weather forecast received by the crew, the route was expected to have continuous medium cloud cover and variable stratocumulus clouds at 400–600 meters, rain, mist, visibility of 6 to 10 km, and moderate turbulence. The dispatcher cleared aircraft 44992 to exit the airport zone at an altitude of 150 meters, following Visual Flight Rules (VFR). Unaware of the approaching aircraft, the Tavda airport dispatcher left his post for 20 minutes. The approaching aircraft crews received approach conditions, weather at Tavda Airport, and the departure time of aircraft 44992 from the ground channel radio operator.^[1]

The aircraft, flying towards each other, most likely entered a zone where rain mixed with snow was falling, with cloud cover at 150-200 meters and visibility around 2 km.^{[citation needed]} At 14:02 (12:02 MSK), 200–300 meters south of the village of Novoselovka (Sverdlovsk Oblast) (Tavda District) and 18 km south of Tavda Airport (azimuth 186°), aircraft 15925 and 44992 collided at an altitude of 175 meters. The left wing sections of both aircraft impacted each other, resulting in a loss of control and subsequent crashes 392 meters apart in a field. All 29 people on both aircraft perished.^[1]

According to the commission's conclusions, the accident was caused by inadequate flight safety measures on local air routes in the Tyumen and Ural Civil Aviation Directorates, the absence of the Tavda airport dispatcher from his post, and the sudden encounter with adverse weather conditions that complicated visual flight operations. The commission members were divided on which cause (the absence of the air traffic controller or the adverse weather conditions) was the primary cause and which was secondary.^[1]