According to the following website:
https://www.angelfire.com/dc/jinxx1/...111FSwwII.html
"When the 111th TRS moved from the 12th Air Force to the 9th AF, a couple of changes in markings came about. Squadrons now had two place designators, in this case "N5" for the 111th and a letter for the individual aircraft. N5 Y is F-6C 42-103196. The second change is the adoption of red tail stripes."
Danny