Surprised no one has brought up the (unconfirmed) story of the 25 yr old 747 CA @ UPS, don't know what era; I've heard a lot of talk about very young flight crews- including the CA- at SAA in the '70's, and I'd be surprised if it wasn't true.
There are probably hundreds of people who've made captain on the 74 before the age of 30; plane's been around a long time.
