Hong Kong International Airport is a major international airport and the primary airport serving the Hong Kong. It is built on reclaimed land on the island of Chek Lap Kok, Hong Kong. The airport is also referred to as Chek Lap Kok International Airport or Chek Lap Kok Airport, to distinguish it from its predecessor, the former Kai Tak International Airport. Having been in commercial operation since 1998, Hong Kong International Airport is one of the largest trans-shipment centres, passenger hubs and gateways for destinations in greater China, Asia and the world. The airport is the world's busiest cargo gateway and one of the world's busiest passenger airports. It is also home to one of the world's largest passenger terminal buildings (the largest when opened in 1998). The airport is operated by the Airport Authority Hong Kong (AAHH), which was established on 1 December 1995, 24 hours a day and is the primary hub for Cathay Pacific (the flag carrier of Hong Kong), Greater Bay Airlines, Hong Kong Airlines, HK Express and Air Hong Kong (cargo carrier). The airport is one of the hubs of Oneworld alliance, and also one of the Asia-Pacific cargo hubs for UPS Airlines. It is a focus city for China Airlines and China Eastern Airlines. Ethiopian Airlines utilise Hong Kong as a stopover point for their flights. HKIA is an important contributor to Hong Kong's economy, with approximately 65,000 employees. More than 100 airlines operate flights from the airport to over 180 cities across the globe. In 2015, HKIA handled 68.5 million passengers, making it the 8th busiest airport worldwide by passenger traffic and the 4th busiest airport worldwide by international passenger traffic. Since 2010, it has also surpassed Memphis International Airport to become the world's busiest airport by cargo traffic (except in 2020 due to the COVID-19 pandemic). To facilitate the increased traffic due to the third runway, Terminal 2 has been undergoing redevelopment since 2019 and will not reopen until at least 2024. The Center Runway has also been closed for upgrades and also will not reopen until at least the end of 2023. History Chek Lap Kok Airport was designed as a replacement for the former Hong Kong International Airport (commonly known as Kai Tak Airport) built in 1925. Located in the densely built-up Kowloon City District with a single runway extending into Kowloon Bay, Hong Kong airport had turned on the