An inline baggage scanning system is finally being installed in the domestic section of the airport, ending a wait of more than five years for a passenger amenity that is meant to be a basic feature of any modern terminal.

Work started on Monday in check-in portal C of the integrated terminal’s domestic area and will be extended to the remaining ones over the next couple of months. Airport officials said it would take about 15 days on an average to complete the installation in each portal.

Of the eight check-in portals within the terminal, five are assigned for domestic operations.

A separate inline baggage scanning system would be set up for out-of-gauge luggage, according to officials. The international section of the terminal, which already offers inline baggage scanning, will be upgraded to the new system.

“Since this is a functional airport, it will take us more time to install the inline baggage scanning system. In a newly constructed one, the process of installation would be much faster,” an official said.

The installation was to be completed by June but a delay in the arrival of equipment imported from the US forced a change in schedule. Domestic airlines operating to and from Calcutta requested the airport authorities to start the process after Diwali to avoid chaos during the peak of holiday traffic.

Airport officials said work started in the domestic section first because the number of passengers it handles is far more compared to the international traffic. On Monday, the airport had 30,279 domestic passengers checking in. The departure count in the international section was 4,223.

Airlines have been told that they could face problems in handling registered baggage at that particular check-in portal where work is in progress. “Bags deposited by passengers at that portal are being diverted to the baggage make-up area of another portal in the basement of the building. This is creating some congestion,” an official said.

Once the inline baggage screening system becomes operational, passengers using the domestic section need not queue up separately at X-ray kiosks to get their bags scanned before check-in.

In an automated system, a bag deposited at the check-in counter goes through X-ray machines on a conveyor belt. The belts are fitted with cameras and sensors that create images of the luggage with a barcode. The luggage is screened in a control room manned by trained personnel.

The out-of-gauge belt will ease the check-in hassles of passengers carrying golf clubs or other cargo that does not fit in the conveyor belt. Currently, any such item carried by a passenger has to be scanned and then carried to the baggage make-up area before it is sent to the aircraft.