AFDW Airmen celebrate AF birthday at Nationals baseball game Published Sept. 21, 2018 By Master Sgt. Michael B. Keller Air Force District of Washington WASHINGTON, D.C. -- The Washington Nationals dedicated their game against the New York Mets to honor the Air Force's 71st birthday on "U.S. Air Force Day" at Nationals Park in Washington D.C., Sept. 20, 2018.