West Bengal Chief Minister Mamata Banerjee's helicopter made an emergency landing at Sevoke Airbase near Siliguri due to low visibility, Trinamool Congress leader Rajib Banerjee said on Tuesday. She was going to Bagdogra after addressing a public gathering in Jalpaiguri, he added. Rajib Banerjee informed that the TMC supremo is safe. The low visibility was reportedly triggered by heavy rains.