The new Istanbul airport is expected to boost the Turkish aviation sector's growth by 27.5 percent in the next three years.

The number of passengers, including those on direct transit are expected to increase by 13 percent to reach around 219 million this year, compared with 193.6 million passengers last year, according to the General Directorate of State Airports Authority (DHMİ) updated data.

The authority forecasts over 230 million air passengers next year and a rise of 27.5 percent, year-on-year, to reach nearly 250 million in 2020. The largest increase will be seen in passengers on international flights - around 29 percent - to reach 107.7 million in 2020, compared with 83.5 million passengers last year. Domestic flight passengers were expected to rise to nearly 140 million - a 26.6-percent increase - compared with 110 million last year, DHMI said.

Air traffic, including transit overflights in Turkish airspace is projected to reach over 2.5 million this year compared with 1.91 million in 2017 - eventually rising to around 2.25 million by 2020.

Air cargo transportation across Turkey was around 3.5 million tons last year. It is expected to reach 3.8 million tons this year and 4.2 million tons in 2020.

The third airport in the city will be the world's biggest project built from scratch upon completion. The first phase of the new airport. 90 percent of which is already completed, is expected to formally open on Oct. 29.

In the first phase, the airport will welcome 90 million passengers annually. In the second phase, which is expected to complete in 2023, it is projected that the number would rise to 150-250 million.

A total of 1.38 billion people have passed through the country's airports during the last 10-year period. from 2008 to 2017, the DHMİ data shows.

The airport, which is being constructed using a build-operate-transfer (BOT) model by a consortium of Cengiz, Kolin, Limak, Mapa and Kalyon companies, has a total investment cost of 22.15 billion euros. The group was previously reported to invest in 10.25 billion euros. The consortium will operate the Istanbul's new airport for 25 years.

With an investment of 120 million euros, the airport will also harbor the world's largest duty-free shopping mall complex.