Original sentence: However, an F-104 went down during a sortie 100 nm SSW of DaNang on June 29.Initially, the new wing maintained tactical proficiency with the World War II-era F-51Ds inherited from the Air National Guard, then in February 1953 upgrading to the North American F-86H Sabre jet aircraft
Edited sentence: However, an F-104 went down during a sortie 100 nm SSW of DaNang on June 29.Initially, the new wing maintained tactical proficiency with the World War II–era F-51Ds inherited from the Air National Guard, then in February 1953 upgrading to the North American F-86H Sabre jet aircraft