I think that it should also be pointed out that if you are flying on US Govt money (whether you work for them directly or not) they have very strict rules about Business. And, further, that they do not pay attention to these rules and will rarely approve business-class travel even if the regulations say that it is called for. Further, contractors will very rarely push back. The result is 26-hour trips to Africa in Economy because some desk officer posted out there doesn't see why this is a problem.