According to what's painted on the side of this Stearman, it is a PT-17. However, according to its cn it was built as a PT-18 Kaydet with a Jacobs engine to a 1940 USAAC order and allocated the military serial 40-1971. It was first registered in Australia on 25 May 1998 and is currently operated by Nigel Arnot out of Brisbane. Seen here at the Wide Bay International Airshow.