Set in the South Pacific during World War Two, the series dealt with a squadron of US pilots known as the Black Sheep (called such due to the fact most were misfits and disciplinary cases before joining the outfit). The best part of the series were the aerial combat sequences; using a mix of archived material from the war, newly filmed sequences, and superbly edited tapings of radio transmissions, the producers made it seem like you were up there in the sky with the squadron in the encounters with the Japanese. On the ground, the dramatic scenes were often done just as well; you got to realize that even though the squadron was made up of screwballs they behaved as a unit and worked as a team to make it through whatever came up.
Later episodes in the series tend to be rather lacking in entertainment value. The addition of "Pappy's Lambs" - a group of nurses assigned to the island - was probably meant to help ratings, but at the same time the focus started to swing towards them and away from the war against the Japanese, which had been the backbone of the more successful earlier episodes. The overall writing of the series seems to have deteriorated as the show got towards the end of its run as well.
While mixed in quality through its run, the show is definitely worth watching, if nothing else for the Corsairs that were restored to be used on the show - great aircraft!