After the King Air 250, the 300 series was introduced providing some key upgrades including: more powerful engines reaching speeds of 310 kts, an 1250 nm, room for 13 people and interior dimensions of 4.9W x 4.8H x 16.7L (feet). The next step up is the King Air 350. The 350 includes a nearly three foot longer fuselage, winglets, and increased range of up to 2,182 miles.