IndiGo flight 6E-451 had departed Bengaluru for Lucknow when the threatening message was found. Following standard safety protocols, the pilots immediately turned the aircraft around and returned to Bengaluru to allow security procedures to begin. Bengaluru: A full emergency was declared at Kempegowda International Airport’s Terminal 1 on Saturday after crew members discovered a suspected hijack threat note inside the lavatory of an IndiGo flight bound for Lucknow.