 The first two were conversions of standard Model 300s, while the remaining 17 were purpose-built; since they were delivered the FAA has used the fleet to check the extensive network of navaids in the United States.200 and 300 Series King Airs have been used for similar duties in several other countries, including Australia, Germany, Hong Kong (a B200C used for navaid calibration was the first aircraft to land at the then-new Chek Lap Kok Airport in 1996), Norway, Sweden and Taiwan.The King Air 350 is based on the King Air 300 with a span increase and winglets, a fuselage stretch for an over main cabin, long enough for double club seating.