This B-737 aircraft is cn #21640/536, a 737-291. It was built in October 1978 and delivered to Frontier that same month. It was leased to Air Florida in December 1979 and returned to Frontier in June 1980. It was sold to United Airlines in October 1985. It was sold to Sky King Inc. January 2004 and then Aviation Technologies in May 2004. It was leased to Nova Air in December 2004 and then to BSAT in May 2010.