If you want a Decepticon well-versed in the arts of combat and, well, deception, you should probably call Starscream. Or Soundwave, or someone like that. If, however, you want a Decepticon eager to prove his worth, Nacelle is the guy you should call. Sure, he may not be as good at flying as most of those other guys, and his not-inconsiderable knowledge of Cybertron's history may cause him to get a bit muddled-up once in a while, but at heart, Nacelle just wants to prove he's just as good as some of those more famous Decepticons.
His alt-mode is a Modified F-15 Eagle