The Thiruvananthapuram-Kochi-Delhi flight had taken off with 120 passengers at 7.40 am when the pilot noticed some snag in the aircraft. It was immediately sent back to Kochi, airport sources said.
The passengers and crew were offloaded and fuel discharged.
A Bangalore bound flight was diverted to Delhi for the stranded passengers. The Bangalore passengers were accommodated in a jet airlines flight, the sources said.
AI had commenced the much awaited non-stop flight service to Delhi only from Saturday.