Needed: Source for the air force's chicken gun

Hi, I need to find out if the air force's chicken gun (frozen chicken is shot at engines to test the engine's ability to meet little flying birdies) is for real, and if it is, a source (paper, article, etc) that says that it exists. I've seen this a couple of times in news, but I've never seen a source quoted. I know this is not the usual cypherpunkish themes, but I've found that the people on this list are some of the best informed ones, and I am hoping you all can help. Please reply to me and not the list. Thanx very very much. Ciao. -Tai ps: btw, I need the source quite urgently... thanx again!