Civil aviation safety in the UK is regulated by independent aviation safety regulators: the European Aviation Safety Agency (EASA) and the UK Civil Aviation Authority (CAA). As such the Department for Transport does not itself issue guidance. In July 2001, the Federal Aviation Administration issued an Airworthiness Directive (AD) related to a potential unsafe condition associated with unreliable airspeed indication. The AD was issued in order to mandate action for Airbus A330 aircraft registered in the US, which had already been taken in Europe by France as the State of Design for that aircraft. The French Directorate General of Civil Aviation recognised a potential safety problem and issued two ADs on the Airbus A330 in February 2001 The UK Civil Aviation Authority (CAA) made the ADs mandatory in the UK at that time.