KOLKATA: A hijack threat note found in the washroom of a Mumbai-bound Air India flight before take-off on Wednesday morning prompted security officials to move the aircraft to an isolation bay at the airport, an official said.The flight was scheduled to depart at 10.20am, news agency PTI reported.The note, which threatened that the plane would be hijacked at 11.10am, was found in the washroom shortly before the flight’s departure, Kolkata airport director Vikram Singh said.All passengers who had boarded the aircraft were deboarded, and the plane was moved to the isolation bay, PTI reported.Security protocols were immediately activated, and the aircraft was taken to the isolation bay for a thorough inspection and necessary precautionary measures, Singh said.(With agency inputs)