Out Of Service- Aircraft Engine Parts

My husband is always working on his plane, weather fixing the engine, or installing a new gadget, his plane is always out of service. The other day, one of his buddies wanted to take it out for a spin. He called and left a message, but didn't get a hold of my husband. He had it towed out to the runway, but the plane wouldn't start. My husbands friend tried back again, and finally got in contact with my husband. Little did my husbands' friend know that the plane wasn't in working order. The other day I found these handy aircraft engine parts service streamers. Now everyone knows when my husband's plane is out of service.