I have been reading this post with some interest as a friend and former work mate has gone to a big Commercial School as an Instructor teaching CPL’s on approved courses, he is going out to the US to work for them for a little while just to get started. He tells me that they say it is ok for UK CPL licensed instructors to work in the US on a validation of their licences by the FAA. He can do anything as far as instructing is required out there, but I think there is something about them having to get sign off for their students flights by a US instructor before they can send them solo. Seems that the FAA take a much more reasonable line about this than the CAA, no wonder that the FAA system works so well it is much more practical.