TIA and congestion: Ways to deal with it

Tribhuvan International Airport is currently operating for 21 hours a day. Its operational capacity can be expanded by another three hours. This means TIA, theoretically speaking, still has to offer 12.5 per cent more capacity

As we are debating the need of a full-fledged Second International Airport (SIA) vis-à-vis its location, modality of construction, and environmental impacts of the construction among others in Nijgadh of Bara, we must not forget we have already spent over two and a half decades doing nothing but talking.

In the meantime we have come with Gautam Buddha Regional International Airport (GBIA) and Pokhara Regional International Airport (PRIA). Construction of these two projects is under way. We do not know when the construction of SIA will start. Around 60 per cent of hardware works of GBIA has been completed, and it is expected to be completed by June next year. But much of software or operational readiness works—airspace negotiation, airspace design, procedures design, manpower planning and testing and training of designed procedures among others—is still pending. PRIA construction started in April 2016. It is expected to be completed at best by the end of April 2021. Lately, a debate arose on “PRIA Infrastructure Investment Justification” after an expert committee formed by the concerned ministry gave its “expert opinion” to the minister of civil aviation. This debate is likely to surface again in near future

Be that as it may, the reality is Tribhuvan International Airport (TIA) is the only international airport in the country today. It is currently operating 21 hours a day. Its operational capacity can be expanded by another three hours to make it a round-the-clock airport. This means TIA, theoretically speaking, still has to offer 12.5 per cent more capacity. However, the fact is the recently extended time of 2.5 hours is not actually being fully utilized yet in practical terms. Furthermore, when the Runway and Taxiways at TIA are improved with the end-to-end parallel taxiways and with easy (if not rapid) exit taxiways, it can save up to 160 minutes.

Suppose, at present 40 international flights—80 international movements—are being operated, each consuming additional two minutes of runway occupancy time, while in lining-up for departure and or after landing runway vacation process, we can add at least 12.5 per cent more capacity, resulting in 25 per cent more capacity on the ground side (combined by time extension and taxiway extension/modification alone). Thus, there would be a significant capacity surplus to ease the present congestion. Similarly, by redesigning the Standard Instrument Departure Routes (SIDs) and Standard Arrival Routes (STARs), we can increase the air capacity significantly.  For example, instead of SIDs those have the compulsion for aircraft to make one orbit of Kathmandu valley; they can fly by just making an arc departure—which saves at least 1.5 minutes per SID departure.

Although it may not be suitable for all types of aircraft, it will be just appropriate for certain types and size of aircraft.  In this manner, we can save a lot of extra operational time at our disposal. For example, there are roughly 30 SIDs, making orbits in international, and 15 domestic SIDs plus, say, five overhead checking mountain flights per day, totalling 50. If we save 1.5 minutes, we will save 75 (1.5x50) minutes per day on SIDs only.  Likewise we have nine international parking stands. If each aircraft consumes, say, 1.5 hours of ground time, we can handle 126 (21x9/1.5) international flights in terms of parking bay in 21 hours of operation. But we have to properly slot the aircraft schedules. Furthermore, if we add two more bays and run airport for 24 hours, we can accommodate 176 (24x11/1.5) international flights per day which would be enough to bring more than double of the tourists than what we have today.

Looking at this, of course one will be surprised at the current bay congestion when we have only around 50 international flights per day. This results in aircraft holding in the air. A dirty little secret is at least four to five medium or heavy aircraft occupy the bay for 24 hours continuously because they don’t have any operation or simply because of some technical reasons (refer to Himalaya and Nepal Airlines idle aircraft parked at TIA). Furthermore sometimes traffic is delayed because of operational restriction as TIA has no standard separation of “runway and taxiway for heavy category aircraft” for simultaneous operation in taxiway and runway.

The air holds by aircraft severely reduce the air capacity and create a situation of air congestion. For example, if there is the capacity to hold 10 aircraft within Kathmandu terminal control area and suppose one aircraft is holding there now, in fact, it is occupying 10 per cent of available air capacity. It is always true that congestion in ground creates congestion on air and vice-versa.

Looking at these calculations, both air and ground capacity at TIA are not saturated and can be easily increased by more than 30 per cent. Besides unavailability of many other facilities, TIA is operating for airlines with load restrictions. It is because of narrow steep terrain (aircraft performance). Possibilities of an extended hour of air or ground hold, traffic condition in the air, bay congestion on the ground and weather changes are also severely affecting airlines’ optimum payload capacity.

Currently, TIA is not only an international airport, it is also a major national infrastructure and the backbone of national economy.

Panthi is president of Nepal Air Traffic Controllers Association