Poor co-ordination between air traffic controllers and meteorological support personnel, and the crew’s failure to execute a go-around, led the fatal UTAir Tupolev Tu-134 crash at Samara Airport earlier this year.
Six passengers were killed when the jet, arriving from Surgut on 17 March, struck the ground and broke up while attempting to land in low-visibility conditions. It crashed 300m short of runway 23 and 100m to the right of its centreline.
Russia’s Interstate Aviation Committee (MAK) says the aircraft was landing in heavy fog, conditions which were “substantially worse” than established weather minima. It says the crash resulted from “organisational and procedural deficiencies” in the interaction between meteorological services and air traffic control, as well as errors by the Tu-134’s crew.
These deficiencies meant that crucial information from the KRAMS-4 automatic weather station at Samara Kurumoch Airport, relating to the deterioration of conditions below the established minima, was not transmitted in time to air traffic control services or the aircraft’s crew. Nor, says MAK, did the approach controller use radar surveillance capabilities effectively.
But it states that, at the decision height of the approach, despite the absence of firm visual contact with approach lights and other ground markings, the crew did not make a “timely” decision to abandon the landing and execute a go-around.
Flight P2 471 had departed Surgut, about 1,630km northeast of Samara, with 57 occupants. The crew was aware that weather conditions at Samara were poor, with visibility down to 200m, and three alternate airports – Kazan, Ulyanovsk and Ufa – were selected.
Forecasts had predicted an improvement, including visibility of 3,000m, by around 10:00, when the flight would be nearing its destination.
During the last few minutes of the flight, however, as the aircraft descended towards Samara around 10:30, fog enveloped parts of the airport and visibility became rapidly worse.
Information from the automated weather station had been indicating visibility of 1,200m but this figure diminished quickly, dropping to 800m and then to around 600m while the jet was still 20km from Samara.
The aircraft continued with the approach and, despite the worsening weather, was given clearance to land. As the jet descended the approach controller informed the crew that it was on the glide slope.
But analysis of the flight data shows that, at the time the controller relayed this information, the aircraft was actually deviating to the right of the approach path. The jet was at least 40m off the axis at the time it passed one of the airport boundary market beacons, and was drifting further to the right, but the crew was not warned by the controller about the error.
MAK says visibility at the time of the accident “did not exceed” around 400-500m, and was far below the levels required to land at Samara. It says: “Weather was considerably worse than the forecast and did not correspond to the minima at Samara. But this information was not relayed to air traffic control and, as a result, to the air crew.”