Contrary to several other reviews, I found the CGI in this film to be better than expected. OK, it is a B movie and the effects are not particularly good, but I have seen many, many movies with far worse effects than this. The acting is acceptable in the main, and the storyline, albeit slow, is far from rubbish. However, without the CGI there'd be no action/aerial scenes at all; rendering the movie title a misnomer.
Most of the film centres around the ground time of the Fortress crew and their boyish antics and could probably do with more time given to action and in flight scenes, but I stuck with this till the end (which was actually ok) and certainly didn't consider the 90 minutes of my life wasted.
Maybe a poor mans 'Memphis Belle' but if picked up cheap you could certainly do far worse....just don't expect too much in the way of aerial action.
NB - the film does contain an abundance of expletives, and as such may not appeal to anyone looking for family friendly.