Retired passenger jets are landed at Cotswold Airport, where they are methodically taken apart over the course of several weeks and months. First the engines are taken off, drained of fuel and sent off to be reused on other aircraft. Other valuable parts include the landing gear, avionics, auxillary power unit, the escape chutes. The remaining air frame is stripped of other parts that are sold off, including doors, seats. The cockpits are often used for training. Entire fuselages are sold to air crew training colleges, while film crews also buy them for use on set. Parts have appeared in films like Star Wars, World War Z, Doctor Who, Red Dwarf. Mark Gregory founded Air Salvage International 20 years ago using his severance pay from the now defunct airline Dan-Air.