Bengaluru airport's new runway is fog-proof, but not the old one

Fog-related visibility issues had disrupted hundreds of flights at the Kempegowda International Airport, playing havoc with the plans of thousands of passengers for years. The new runway with its Cat-III B Instrument Landing System (ILS) will address this problem this winter, but not the first runway.

Now closed for rehabilitation, the first runway (North Runway) will not get an ILS upgrade. But the runway will have its entire top layer resurfaced and strengthened and center lights installed. The ILS will continue to be Category-I.

“Upgrading the ILS is a very expensive process. We will have to increase the user fees for that. The user consultation panel has said there is no requirement for Cat-III now,” BIAL Chief Executive Officer (CEO) told DH.

Revenue hit hard

The Covid-19 lockdown and the months-long disruption of flights had hit BIAL revenues hard. The airport operator had declared that its revenues were down by over 75%. By December, when the fog disruptions are expected, the passenger traffic is unlikely to be anywhere close to pre-Covid levels.

ILS Category-I would mean any pilot approaching the North Runway in foggy conditions will have to decide whether to land or not at a ‘Decision Height’ of over 200 ft (60m). Under Cat-I, the pilot is also required to see the runway center line from a distance of 2,600 ft to land safely. This is the Runway Visual Range (RVR).

The new runway’s Cat-IIIB capability allows pilots to decide even at a Decision Height of less than 50ft (10m). The RVR requirement is a much lower 150-700 ft (50-200m). BIAL had earlier announced that once the runway rehabilitation is complete, the airport will have the flexibility to operate both runways in low visibility and adverse weather conditions.

The new runway is equipped with an indigenous Aviation Weather Monitoring System (AWMS) at both ends and four Drishti Transmissometers to measure RVR. In all, KIA has a total of six Indian-made RVRs at both runways, all equipped to measure RVR down to 25m.

Visibility often drops to near-zero in the entire area covering the airport in Devanahalli. The ATC has had to halt landings and take-offs for long hours in the early mornings. This period often starts late November or early December, extending till February.