An aircraft has landed at a busy UK airport and taxied away from the runway. A tower controller asks the flight crew to hold position and the pilot reads the instruction back to confirm. The runway is clear and the controller is about to issue a landing clearance when they see that the aircraft is no longer holding its position.  It is now infringing the runway and continuing to roll forward.This is the first episode of a two-part series looking at runway safety and specifically incursions at commercial airports. We speak with aviation experts including the UK CAA’s Principal Aerodrome Inspector, a commercial airline pilot and an air traffic controller about the risks relating to runway incursions and how to mitigate them.Guidance and resources mentioned in this episode:CAP 168 –Licensing of aerodromesUK (EU) No 139/2014 - The UK Aerodrome Regulation, UK Acceptable Means of Compliance and Guidance Material, and UK Certification Specification and Guidance Material for Aerodrome DesignCAP 790 –Requirement for an Airside Driving Permit (ADP) schemeEuropean Action Plan for the Prevention of Runway Incursions (EAPPRI)