Tribhuvan International Airport (TIA) is at the final stage of awarding a $28-million contract for the rehabilitation of its battered runway.

Four Chinese firms have been prequalified following the completion of their technical evaluation—China National Aero Technology International Engineering Corporation, China Harbor Engineering, Beijing Changdao Municipal Engineering Group and a Nepali-Chinese JV of China Railway No 5 Engineering Group and Swachchhanda Nirman Sewa.

“We will be asking the prequalified bidders to submit financial proposals, and one of them will be picked to implement the project,” said Murari Bhandari, chief of the runway rehabilitation project. “We have targeted awarding the project contract before the Dashain festival in September.”

Milling machines will be used to remove the pavement to rehabilitate the runway. The design of the project was originally prepared in 2014. However, after the earthquake of April 2015, the project decided to review it. The review is in the final stage, Bhandari said.

“When an airport is improved, it has to be done quickly; so we have to work according to a carefully planned schedule,” he added. According to TIA, the airport will have to be shut down from 12 midnight to 6am daily to carry out the runway rehabilitation works.

The project contractor will be given a year’s time to make preparations, Bhandari said. The company should have all its logistics in place before it is allowed on to the runway.

“Extensive planning is needed since there are so many reasons that can lead to delays. The contractor should have twice the amount of materials and equipment required. Considering all these requirements and preparations, on-ground work will begin after the monsoons in 2018,”

he said.

For the last five years, TIA has been forbidding aircraft weighing more than 196 tonnes to land on the tattered runway to prevent further damage. The old runway has been affecting smooth operation of aircraft due to repeated occurrences of cracks in the pavement.

The Civil Aviation Authority of Nepal (Caan) has allocated $28 million for the improvement of the 3,050-metre runway and taxiways. It will dip into the Airport Development Fund (ADF) to finance the project.

Since July 2014, Caan has been collecting an extra Rs1,000 in airport development tax from each passenger departing on international flights from TIA. The money thus accumulated in the ADF will be spent on projects to improve facilities at TIA.

According to Caan officials, the net construction time which is six hours in the night time for runway construction is four months. For the construction of the taxiway, it will take at least eight months.

A study conducted by Caan in 2014 had concluded that the runway at TIA was not strong enough to handle wide body jets due to its ageing asphalt foundation, and distress is caused to the upper surface instantly when heavy planes land.

The damage to the lower asphalt layers is reflected quickly in the upper surface, resulting in cracks and other damage to the runway.

Repeated occurrences of cracks on the runway at the country’s sole international aerial gateway have been affecting smooth operation of aircraft since 2011. The report said that when compared to the core part of the runway between 2006 and 2013, damage to the intermediate layers was caused by the operation of large jets like the Airbus A330 and Boeing 777.

In 2013, there were 1,000 operations of A330-300 aircraft, 955 of Boeing 777 and 452 of A330-200, and the numbers are expected to double in the next 20 years. Cracks first appeared on the runway in June 2011, and they have become a recurrent problem since then.

Cracks were reported occasionally in 2012. However, the problem worsened in 2013, forcing Caan to take a harsh decision to bar aircraft weighing more than 196 tonnes from landing at TIA. In 1964, Tribhuvan Airport was named as Tribhuvan International Airport.