Iron Maiden is one of the most successful heavy metal bands ever. They have sold more than 80 million albums and are renowned for their live shows - tickets for which they say sell faster now than at any point in their 30 years as a band. Sarah Montague speaks to the band's lead singer, Bruce Dickinson, the only member of the band who has lopped off the long, 'hard rocking' hair. And that is because of his dual life. For when he is not on stage performing in front of thousands he can often be found in a cockpit. He is a commercial pilot who has now set up his own aviation business. So how can you mix the hard rock lifestyle of a metal-head with the clean living required of a pilot and entrepreneur?