S7 modifies 737-800 de-icing after engine contamination incidents

Russian carrier S7 Airlines has modified its de-icing procedures after a number of recent incidents involving Boeing 737-800s. The Moscow-based airline states that crews have observed “changes in the operating parameters” of engines on the type, resulting in decisions to return to the parking bay for technical inspection. “It was revealed that the unstable operation of the engine was caused by contamination of compressor blades, due to the ingestion of de-icing fluid particles,” says the carrier. S7 says this situation has a “cumulative” effect. Boeing 737-800s are fitted with CFM International CFM56 engines, which hang close to the ground, and the airline believes fluid on the apron during de-icing can be sucked into the powerplant. The airline stresses that the engines remained fully operational and were “not impaired” during the incidents, and the operating parameters did not exceed limits. S7 says Moscow and other regions of Russia are experiencing “more difficult” winter weather conditions than normal.<br/>