I don't get it. This is an American plane. The Americans fought the Nazis. The flags are "kill flags" which celebrate the killing of Nazis. It's not obvious to me what is offensive here. Is it that an image of a swastika would appear anywhere in public even in the context of celebrating Nazi destruction?
12 Iraqi troops, militiamen killed in multiple ISIS suicide attacks (AP)
from the article: Nazi swastika adorns Sports Illustrated Swimsuit Issue