UK legislation has always required the validation of foreign licences to fly UK

registered aircraft for commercial purposes. The EU regulations differ in that the

validation of foreign licences is required to fly foreign registered aircraft if the operator

is based in the EU. For example, if a UK AOC holder is to use pilots with FAA licences

to fly a US registered aircraft for commercial purposes, those pilots must have their

licences validated by the CAA in accordance with the Part-FCL Regulation.