In 1998 Mountain Air added two Britten Norman Islanders and two Piper Aztec aircraft to its fleet and extended its services to provide New Zealand wide charter flights. Scheduled services were also developed to provide several flights a day between Auckland International Airport, Whangarei and Great Barrier Island in the Hauraki Gulf branded as Great Barrier Xpress. Whangarei was withdrawn in 2008. Services serve both Claris and Okiwi airports on Great Barrier. Special window kits have been put into the two Islander aircraft to provide more windows so passengers can have better views. Two more Britten-Norman Islander aircraft were added to the fleet in 2006 and 2007.
In June 2008, Mountain Air rebranded Great Barrier Xpress as Fly My Sky.
Fly My Sky also support parachute training for the Royal New Zealand Airforce at the RNZAF base Whenuapai.