Passengers of a Lucknow-bound Air India flight from Delhi had a narrow escape on Sunday after the windshield of the aircraft developed a crack after take-off. The aircraft had to make an emergency landing back at Indira Gandhi International Airport. According to sources at the airport, there were 160 passengers on board the flight, apart from crew members. The flight took off from the Delhi airport for Lucknow at 7.15 AM and after about one hour of being airborne, the pilot of the aircraft reportedly noticed cracks on the windshield, which could have proven dangerous at the high pressure zone at which an aircraft flies. The pilot informed the Delhi Air Traffic Control (ATC), following which full emergency conditions were declared at the airport. The Delhi ATC declared local stand-by for the flight AI 411 at 8.30 AM and the flight landed safely at the airport's runway 29 at 8.40 AM. After the aircraft landed and was safely parked, the stand-by for other aircraft was called off at 8.50 AM. Sources said that an alternate aircraft was arranged to fly the stranded passengers to Lucknow. The Air India spokesperson couldn't be contacted for comments despite repeated attempts.