Russian investigators have detailed an incident involving an ATR 42, which was found to have not been properly de-iced after it experienced control problems during take-off.
The incident occurred on 25 October, the day after Russia's Interstate Aviation Committee announced the completion of a seminar dedicated to de-icing procedures, which ATR and Airbus had participated in.
In a flight safety notification, federal air transport service Rosaviatsia states that the ATR 42-500 was operated by the carrier Taimyr, under the NordStar brand.
The aircraft (VQ-BKO) departed Krasnoyarsk's Yemelyanovo airport, but during the climb, the crew noticed that the turboprop was exhibiting "uncharacteristic behaviour".
Rosaviatsia says the aircraft's fuselage was vibrating and the pilots decided to return to the airport.
Post-flight inspection revealed the presence of ice deposits on the upper surface of the wing and on parts of the starboard propeller. Meteorological data for Krasnoyarsk showed that temperatures were several degrees below zero throughout the day.
Rosaviatsia says these findings indicate that the de-icing of the aircraft was not carried out fully.
De-icing procedures became a high-profile issue in Russia after the fatal crash of a UTair ATR during take-off from Tyumen six months earlier on 2 April.
Several carriers participated in the de-icing seminar, including Aeroflot, Transaero and S7 Airlines as well as the operators of Moscow Vnukovo, Novosibirsk and Arkhangelsk airports.