His appeal will likely be based on his denial of the right to take any discovery or admit any evidence at trial to establish that his disobediance of orders was justified, i.e. that Obama is not a natural born citizen.
He pleaded guilty to the disobeying orders charges. In doing so, he said, under oath, that his orders were legal and he knew they were legal when he disobeyed them. The only charge on which he went to trial was the missing movement charge, and the only defense he put up to that charge was the claim that he hadn't been ordered to be on a specific flight.