Engineer turned comedian Tom Wrigglesworth and rising star of mechanical engineering Rob Bell climb on board Victor X-ray, a 200-ton, £200 million Boeing 747. This jumbo jet has flown over 36 million miles in its 14-year life with British Airways. Now it will be broken into tens of thousands of parts in the airline's maintenance hangar in Cardiff, before being painstakingly reassembled and certified fit to fly again. This is the first time this complex process has ever been filmed and it provides fascinating insights into just how a 747 works.Rob and Tom also visit the UK's largest plane salvage centre in the Cotswolds to discover what happens to a 747 when it reaches the end of its working life, and discover how valuable parts are stripped for resale before the carcass is torn apart to be recycled.