Daniel K. Inouye International Airport is a subordinate of the Oahu District officials. The airport has four major runways, which it operates in conjunction with the adjacent Hickam Air Force Base. The principal runway designated 8R/26L, also known as the Reef Runway, was the world's first major runway constructed entirely offshore. Completed in 1977, the Reef Runway was a designated alternate landing site for the Space Shuttle. In addition to the four paved runways, Daniel K. Inouye International Airport has two designated offshore runways designated 8W/26W and 4W/22W for use by seaplanes. The airport covers a total area of 4,220 acres (1,708 ha) of land. The entire terminal complex features 24-hour medical services, restaurants, shopping centers, and a business center with conference rooms for private use. Passengers have the option of using various short-term and long-term parking structures on the grounds of Daniel K. Inouye International Airport. For the 12-month period ending June 30, 2018, the airport had 310,179 aircraft operations, an average of 850 per day. Of these movements 52% were scheduled commercial, 31% air taxi, 12% general aviation and 4% military. There are 200 aircraft based at this airport: 53% single-engine, 17% multi-engine, 16% military, 11% helicopter, and 4% jet. All Nippon Airways has its Honolulu Office in Airport Building 47. When Mid-Pacific Airlines was in operations, its headquarters were on the airport property. Daniel K. Inouye International Airport has three terminals: Terminal 1, Terminal 2, and Terminal 3. The Wiki Wiki Shuttle provides inter-terminal transportation between the ticket lobbies of all three terminals and between the concourses in terminals 1 and 2. All gates in terminals 1 and 2 are connected post-security; however, passengers walking from Terminal 1 to gates in Terminal 2 must pass through a USDA agricultural inspection station for carry-on luggage. Effective June 1, 2018, the gate numbers at Daniel K. Inouye International Airport were renamed to an alphanumeric format, and the baggage claim numbers (formerly alphanumeric) were renumbered to numeric. These changes are intended to accommodate expansion with the new Mauka and Diamond Head concourses. Terminal 1, formerly known as the "Interisland Terminal," opened in 1993. The $130 million 8-gate terminal was the largest construction project undertaken at that time by the State Airports Division and replaced an earlier terminal built in 1961.