The pilot allegedly got into in a verbal duel with the ground engineer while boarding the flight after all 122 passengers were seated, delaying its departure by around three hours.
"The commander (pilot) of the flight has been taken off the roster. The incident is being investigated by the management," an Air India Spokesperson said.
Airline sources said the engineer, who suffered 'minor' injury on his chin, was being administered medical aid.
The flight to US via Delhi was initially scheduled to take off at 8.45 AM but left for its destination at around 11.45 AM.