In this photo taken on Tuesday, March 11, 2014, Master Sgt. Doug Keller, avionics technician of Des Moines and currently working Speedline with the 132nd Fighter Wing, Iowa Air National Guard, talks during a tour of operations in Des Moines, Iowa. They are upgrading and providing maintenance for National Guard units around the country, Alabama f-16's shown here. He is showing the analog instruments that is being swapped out for the electronic display, left. (AP Photo/The Des Moines Register, Rodney White) MAGS OUT, TV OUT, NO SALES, MANDATORY CREDIT