Plot: Michael Portillo experiences a terrifying ‘victory roll’ in a World War II Spitfire, high above the most famous aerodrome of the Battle of Britain, Biggin Hill. The 80-year-old aircraft, in which so many young men risked their lives for the nation, is one of a fleet intensively maintained by a dedicated team of technicians, and Michael is privileged to be flown by an ex-Royal Navy pilot