The local homeland security office is clear in as much that any student completing training towards a licence certificate or rating requires an M1 visa. ie if you have a FAA PPL and want to get a JAA PPL, then this is not considered training as you are licenced and rated in the aircraft that you are flying. If however you do not have any licence you would need a visa. In another manner, if you hold an SEP PPL and want to add a MEP, you would need a visa. It has been rumoured that the FAA Examiners will soon need to take copied of the visas as well as their ID's when giving check rides.
A visa waiver form is not and does not give you a B visa; you have to apply for a B visa. A visa waiver (green form) is a programme offered through the Airlines to avoid some approved countries the requirement to attain a visa to visit those Countries.......not train, study or work.
Generally there are two B visa, B1 and B2. One is primarily for people who own a house etc and want to be in the US for up to 6 months at a time. The other is attained when you are visiting the US on business and allows you to work on behalf of the Company that sent you to the US.
The process for the B visa is very similar to that of the M visa but they are harder to come by these days as people were abusing the system.......shock horror
Engine Noise
It is really simple to get a M2 visa for your wife/significant other......we just add her details onto the form and you take it along with yours to the US Embassy appointment.