A POLICE van hit and damaged one of the engines of a Korean Air passenger jet hours before it was due to take off yesterday. The incident occurred shortly after 5am during a routine security exercise when the van backed up, hitting the engine with its siren. The impact dented the outer shield of engine No 1. The 29-year-old driver, a police officer, escaped injury. The 747-400 aircraft carrying 376 passengers eventually took off for Seoul at 9.25am, 10 minutes later than scheduled. The Airport Authority said it was working with the police to investigate why the accident happened. An airline spokesman said a maintenance crew carried out repairs on flight KE 606. 'The damage was minor and the flight was judged to be safe to travel,' he said.