Don became interested in flying while working as a Police Officer in Tempe, AZ in the late 1970's. He was able to use his piloting skills with the Police Department as a surveillance pilot and as a personal pilot for the Mayor's assembly.

While earning his Airline Transport Pilot Certificate, he worked as a flight instructor and charter pilot with Arizona Piper Inc. He then flew charters and an air ambulance for the U.S. Public Health Service in Gallup, New Mexico.

In 1981, Don went to work for the Federal Aviation Administration. He was in the second class hired after President Ronald Regan fired all the striking Air Traffic Controllers. He started his career as an Air Traffic Controller at the Los Angeles ARTCC, Air Route Traffic Control Center, in Palmdale, CA. In 1985, he was selected to take part in a program to foster a better understanding of Military Operations. He spent a week on the US Navy Aircraft Carrier, USS Kitty Hawk, observing day to day operations.

Don worked in the System Requirements Branch in the Los Angeles Regional Office. He was responsible for the staff study that led to the creation of the Southern California TRACON, Terminal Radar Approach Control, which consolidated all the area TRACON's into a single facility.

In 1991, he moved to Westbury, NY to become the Assistant Air Traffic Manager at the New York TRACON. He continued up the FAA career ladder becoming the Branch Manager of Systems Requirements at the Eastern Regional Office located in Jamaica, NY.

In 1994, Don accepted a position as the Assistant Manager of the Portland Combined, ATCT, Air Traffic Control Tower and TRACON. He was very proud of his achievement of becoming a Full Performance Level Controller at the Portland TRACON.

In 2005, he took over as the Air Traffic Manager at the HIO ATCT in Hillsboro, OR where he finished out his career with the FAA. Over the years, he received many awards for his hard work and dedication. He retired in July 2007.

Don was a true American Patriot. He loved God, his family and friends, and his Country. He left behind his wife of 16 years, Toni Watkins-Cline and his daughters, Lindsay Suzanne Hager and Emily Rose Cline. He also has 3 beautiful granddaughters to date (2014) that he never got to meet. Hannah Dawn Hager (2008), McKenzie Grace Rodriguez (2009) and Mariela Noemi Rodriguez (2011).