Greenfield Airport in Pakyong as seen from above Pakyong town

GANGTOK: Greenfield Airport in Pakyong, which has been stalled from operations since end of 2019, has been declared open for operations from January 23. SpiceJet, so far, is the only airline that has been onboard in Pakyong and for the future as well, it seems like it will the only airline catering to Delhi and Kolkata as declared earlier by the airline.

There is a specific technical reason for the same. With its high-altitude, table-top runway, Pakyong has for long struggled with visibility concern, resulting in air operations being stalled after a year-long operation since October 4, 2018. Now, to ease the visibility concern, Airport Authority of India has reached a consensus with Directorate General of Civil Aviation to introduce Required Navigation Performance System, specific to Pakyong Airport only in the country.

Required navigation performance (RNP) is a type of performance-based navigation (PBN) that allows an aircraft to fly a specific path between two 3D-defined points in space. A navigation specification that includes a requirement for on-board navigation performance monitoring and alerting is referred to as an RNP specification. Therefore, if ATC radar monitoring is not provided, safe navigation in respect to terrain shall be self-monitored by the pilot and RNP shall be used. RNP also refers to the level of performance required for a specific procedure or a specific block of airspace. An RNP of 10 means that a navigation system must be able to calculate its position to within a circle with a radius of 10 nautical miles.

According to Airport Authority of India, RNP is a metric of system navigational capability. “The Airports Authority of India is moving towards a performance-based national airspace system. In the future, your ability to fly in certain areas may be governed by ability to achieve precise navigational performance within specific tolerances. RNP 0.1 will be used for approaches, and it refers to 0.1 nautical mile accuracy. This accuracy may be achieved through various means (GPS, GAGAN, flight management system using automatic DME updates), but aircraft will be certified to a particular RNP. There are other requirements beyond accuracy that will be defined for each RNP operation before it is implemented”.

“The same to be implemented for Pakyong Airport, requires 5 km of air region”, informed AAI Director for Pakyong Airport Ramtanu Saha following a meeting with Indian Air Force Officials, AAI officials and officials from DGCA at Bagdogra Airport on Tuesday. “Pakyong is a dangerous place to have an airport, undoubtedly. It is a hilly area that is border sensitive. We have not been given the air region. We have approached for 5 km of the area with navigation through our own Air Traffic Control. Concerning the same the Limit of Authority agreement had to be signed. There were officials who had come from Eastern Region along with officials from Guwahati, Airport Authority of India. There are 2-3 air regions that will come in concern, with all their consent it was finally approved for RNP”.

There will be no aircraft or no pilot coming to Pakyong airport without the approval from AAI and DGCA. ” DGCA had initially mentioned 2400 meters altitude, so the same has been cleared now. It is also a combination with the SpiceJet Airline and its pilot as 5-6 pilots under the airline have been trained for RNP so far. A Hill in the southern side enroute towards Pakyong is an obstruction, from our reference point. We had asked for 25 kms of air region to be cleared. But it is not happening, hence the gap between two hills has 5 km width, so the flight will cross over that 5 km of air region. The RNP has been approved for the very first time in Sikkim”, informed the Director Saha.

Noticeably, the RNP was first used in Alaska for Raegan Airport since 2005 with validation for their own RNP from the Federal Aviation Administration taking place in April, 2009. “RNP is not accepted across the country and neither are airlines and its pilot trained for the same. It is being implemented for the first time in a hilly region in India. So, this particular will be aircraft specific and pilot specific. Only 4-6 pilots have been trained for RNP and only they will be brought to Pakyong. Any other airline willing to come, will have to undergo the same training. In 2 years, there have been no other airline other than SpiceJet. All airlines need to come forth for better visibility approach training. Otherwise, they need to follow the 5 km RNP. This is an extraordinary effort for our airport built at a cost of Rs. 560 Crores”, stated Saha.

Pakyong Airport has a landing strip of 1700 meters with the proposed Q400 Bombardier needing only 1500 meters of landing strip, But, Pakyong being a table top runaway, more space is needed for its safety. “1700 meters are made of concrete, after which there will be a safety area which requires a minimum of 90 meters, ours is 120 meters. On the other end as well, it should have a safety area of 100 meters. It is called as Runway Safety Area. To get the extra area for Runway Safety, we are taking more land from the State government which is 4.83 acres on the Southern Side of the airport”.

The Western Side of the airport towards the Damlakha Hill has been prone to landslides, hence it is being controlled with round bolting, and various other technology. It will also have a wall to avoid landslide from the side. It is part of Basic Strip expansion with 40 meters expansion in the Western Side.

The Southern Side towards Dikling-Maney Dara area has always been a gorge kind of an area, so to counter the same. All the debris from the expansion on the Western Side, will dumped in the cliff area on the Southern Side. “It is part of having the 75 meters space from central line for expansion. The hill being cut on the Western Side, all the debris will be added to the Southern Side, as though it were terrace farming being practiced, it will be step by step. It will reach as high as the runway, resulting in addition of 150 meters in length towards the Southern Side. It will also have approached light for better visibility. Approach Light needed for an airport is a minimum of 1 km but Pakyong Airport is happy to have 300 meters of approach light area, which will be standard. The basic strip is 40 meters wide from the central line, hence it fell under 2C category of airport. When it becomes 75 meters plus 5 meters of road, it will be 3C. It has to be 75 meters on either side from the central line”, Saha.

The proposal for the Delhi flight was initiated by Director Ramatanu Saha, who had requested many other airlines to take flight operations in Pakyong. “When SpiceJet came for a trial flight on November 17, I had given the proposal for the Delhi connecting flight. But there were concern of whether the flight would cover such a long flight. We were even considerate about making a landing at Patna Airport for fuel. Q400 Bombarier is a 70-seater passenger flight. The same used to fly from Kolkata, it used to reach full capacity. But,when it used to return from Pakyong, the passenger count would come down to as less as 56. Also, Guwahati flight used to have a meagre 30-32 passengers, they were in a loss. The Delhi flight has been considered taking in mind the passengers ranging from the Chief Minister to a common citizen having to rely on Bagdogra airport for all air connectivity. But the road connecting Bagdogra is very bad, the National Highway is troubled, hence this does seem to be a solution”.

There are only 5 table top runways in the country with Pakyong being one of them. Infrastructure development increases the factor for safety.

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