Passengers had boarded the aircraft by midnight last night but the plane left only at around 6.35 AM with no information being shared with passengers for the delay, one of the passengers said.
The flight AI-101 was scheduled to depart at 1:00 AM.
As passengers were not allowed to deplane, they became restless with flight attendants stonewalling all information, the passenger claimed.
Air India's spokesman said the flight was delayed because one of the pilots was found to be sick during the last medical examination before taking off the 16-hour flight and as per rules he could not fly the plane.
According to norms, passengers travelling on all US-bound planes have to undergo a thorough security check and therefore, a decision was taken not to allow deplaning of passengers from the aircraft.