The 737-300 was brought into service in 1981. It was used by both US Airways and Southwest Airlines. The 737-300 is the first model of the 737 Classic series. The -300 can usually hold 128 passengers. The 737-300 series was made until 1999. The last -300 was delivered to Air New Zealand on 17 December 1999. This was the 1,113th 737-300 made.