Kolkata: The instrument landing system (ILS) at Kazi Nazrul Islam Airport (RDP) that was installed nearly two years ago but could not be made operational due to lack of regulatory clearance was finally commissioned on Thursday following a nod from the Directorate General of Civil Aviation.

On Thursday morning, Air India flight AI 755 became the first aircraft to touch down at the airport at Andal near Durgapur at 7.40am using the ILS approach. The visibility at the time was 2,200 metre.

The Category-I ILS enables flights to land in low visibility of at least 800 metre. Without the aid, pilots required a visibility of nearly 3,000 metre. Kolkata airport has a more advanced CAT-IIIB ILS that allows pilots to touch down even when visibility is down to 50 metre.

Interference in signals due to the presence of a Coal India dumpsite in the vicinity had first delayed the commissioning of the ILS. Though the antenna was relocated and fresh trials were conducted prior to Bangladesh Prime Minister Sheikh Hasina’s visit this May, the ILS system comprising Localiser, Glide Scope and a distance measuring equipment worked perfectly. But the pilot of the trial flight reported a problem with the Precision Approach Path Indicator, a visual aid that provides guidance information to help a pilot acquire and maintain the correct approach path.

Kazi Nazrul Islam Airport is the third facility in the state after Kolkata and Bagdogra to be equipped with ILS.