U. S. Army Lt. Col. Ernest Irvin, 1-228th Aviation Regiment commander, salutes as a CH-47D Chinook prepares to take off from Soto Cano Air Base, Honduras for the last time, May 28, 2014. Two Chinooks are slated to be replaced with the newer CH-47F model. One of the helicopterss, affectionately known as "638", is the oldest active Chinook in the U. S. Army's inventory having flown in the Vietnam War. (Photo by U. S. Air National Guard Capt. Steven Stubbs)