St. John Hawke (Barry Van Dyke): Brother of Stringfellow, and raised by Santini after the death of his parents. Van Dyke took over the role from Christopher Connelly, who portrayed the character in early CBS episodes. Santini taught both Stringfellow and St. John how to fly, and both brothers showed particular talent as U.S. Army aviators during the Vietnam War. In 1969, St. John was separated from Stringfellow and the rest of his unit during a mission. He would remain missing in action for the next 18 years, until he was suddenly located in a deep-cover CIA mission in 1987. Returning to the United States, he reunited with Stringfellow and, due to his brother's injuries, took over as pilot of Airwolf.