There is a popular misconception about the requirements for the holder of an ICAO instructor rating to obtain a JAA instructor rating. The statement by SD that "The course is reduced to 15 hours flight training and 30 on the ground." is not, strictly speaking, correct. The actual requirement is that holders of a non-JAA instructor rating shall:
"Have completed in accordance with JAR–FCL the approved relevant course(s) of theoretical instruction and flight training. The course may be modified, as approved by the Authority, taking into account the previous training and the experience of the applicant, but shall comprise at least 30 hours of ground instruction and 15 hours of dual flight instruction performed by a flight instructor holding a JAR–FCL licence and rating in accordance with JAR–FCL 1.330(f);"
It is clear, therefore, that the intention of the JAA is that most non-JAA rating holders will complete all or most of the full FI course of 125 ground and 30 hours flight training and that it is only the most experienced and accomplished that can expect to have the training reduced to 30 and 15 hours respectively.