Calcutta, Nov. 5: An Air India plane with 59 passengers on board hit a stepladder vehicle while entering the taxiway at Calcutta airport today, raising questions about aircraft safety in the apron area.

The Calcutta-Guwahati flight, AI-729, was scheduled to take off at 9.45am but passengers were stranded for nearly six hours after the plane’swing suffered damage and it had to be grounded.

The directorate-general of civil aviation (DGCA) has ordered an inquiry into the incident while Air India is also conducting an internal probe.

“The stepladder vehicle overturned under the impact and oil spilled from it,” said an airport official, adding that there was very little chance of the aircraft catching fire because of the spill.

“The wing tip clearance required for safe movement of a flight on the ground was not there,” he added.

The Airbus 319 was parked at bay No. 22 of the airport. It was scheduled to enter taxiway “A” before taking off from the airport’s main runway.

As the aircraft was about to enter the taxiway, the tip of its right wing hit the stepladder, which was parked in the apron area. The pilot immediately brought the aircraft to a halt as ground staff rushed to the spot.

“Apparently, this ladder was not used for the Guwahati flight. May be its driver had parked it there to drive it across the taxiway,” said an Air India official.

Airport sources said the ground staff were unaware that the vehicle was in the aircraft’s path.

“The aircraft had to be grounded for repairs. Some passengers were accommodated in other flights while others were sent by another aircraft,” an airline spokesperson said. The flight finally took off at around 4pm.

Airport officials said lack of proper vehicle management in the apron area has often led to small accidents.

“There are frequent incidents of drivers violating driving rules in the apron area which can lead to mishaps,” said an official.

Inspection jeeps, tow bars, luggage carriers, passenger buses, stepladder and catering vehicles ply in the apron area.