Mercury Air Services added a new hangar, shop space and tenant office structure last month to its FBO at Charleston International Airport, S.C. The new 23,000-sq-ft hangar bay with 28-foot-high doors can accommodate business jets as large as the Global Express. There is also a 15,000-sq-ft maintenance area and 7,000 sq ft of office and shop space. Meanwhile, under a new 10-year contract, Mercury Air Services at Charleston Executive Airport on Johns Island will make improvements, including installing an above-ground fuel farm.