Although the Required Navigation Performance–Authorization Required (RNP-AR) system has been introduced at Gautam Buddha International Airport in Bhairahawa, its implementation remains pending.

Previously, the airport had installed the Instrument Landing System (ILS) for instrument-based flight operations. However, due to a lack of approval from India, ILS has not been operational. As a result, heavy fog and mist during winter have continued to disrupt flight operations at the airport.

Reduced visibility caused by fog has led to frequent diversions of international flights. In response, the Civil Aviation Authority of Nepal (CAAN) has introduced the satellite-based RNP-AR system. This technology is already in use at many airports and airlines worldwide.

According to Bhairahawa Airport General Manager Pratap Babu Tiwari, the RNP-AR system was implemented on January 24, but it has not yet been used.

"CAAN has completed all necessary procedures on its part. Now, airlines must show interest, seek approval from regulatory bodies, and train their pilots. Airlines wishing to use this system must bring aircraft equipped with RNP-AR and obtain necessary permits. However, no airline has yet come forward to do so," Tiwari stated.

Currently, flights operate using mechanical navigation, requiring a minimum visibility of 1,800 meters. In contrast, the RNP-AR system enables flights to take off and land with visibility as low as 900 meters.

"This technology allows pilots to determine their exact position, direction, and angle in relation to the runway using cockpit displays," Tiwari explained. "The aircraft must align precisely with the runway’s centerline during landing. If the aircraft deviates, the system immediately issues an alert, enhancing safety."

The satellite-based RNP-AR system is expected to eliminate visibility-related flight disruptions. However, for its implementation, aircraft, pilots, and air traffic control (ATC) personnel must meet specific standards and undergo training. Certified pilots must conduct test flights to validate the system. International airlines must first secure approval from their respective regulatory authorities before obtaining certification from CAAN.

Unlike other navigation systems, RNP-AR does not require additional ground-based infrastructure. Instead, aircraft must be equipped with the necessary satellite-based technology. Most large international aircraft already have this system installed, whereas smaller domestic aircraft may need modifications.

So far, interest in adopting this technology has been minimal. However, some airlines that previously operated at Bhairahawa or are planning to resume flights already have RNP-AR-equipped aircraft, making implementation easier.

"Flydubai has expressed interest and has initiated the approval process. Air Jazeera has also shown interest, likely because their aircraft already have the system installed," Tiwari added.

CAAN has already developed the required route charts for RNP-AR, and now it is up to the airlines to take the next step.

Previously, airlines suspended flights to Bhairahawa due to low winter visibility and the non-operational ILS system. However, as fog and mist have reduced in the mornings and evenings, airlines have resumed operations, according to airport spokesperson Vinod Singh Rawat.

Currently, Jazeera Airways, Thai AirAsia, Flydubai, and Nepal Airlines operate regular flights from Bhairahawa.

• Thai AirAsia operates Bangkok-Bhairahawa flights on Mondays and Thursdays.
• Jazeera Airways flies the Kuwait-Bhairahawa route on Tuesdays, Thursdays, and Saturdays.
• Flydubai operates daily flights on the Dubai-Bhairahawa-Kathmandu-Dubai route.
• Nepal Airlines conducts flights on Sundays, Mondays, Wednesdays, and Fridays on the Kathmandu-Bhairahawa-Dubai-Kathmandu route.

In total, these four airlines currently operate 16 weekly flights from Gautam Buddha International Airport.

Meanwhile, Qatar Airways, which previously operated the Doha-Bhairahawa-Kathmandu-Doha route, has not resumed its flights.