DFC,
Thanks for the JAR FCL stuff. Although it is still a grey area because of the local (ie National!) definitions, such as old single seaters allowed in the UK up to 390kgs and the Germans allowing extra weight for ballistic parachutes.
Regards medicals:
You wrote:
An NPPL medical declaration can only be used with an NPPL licence.
Not quite true, the NPPL medical - because the old "pink chit" was abolished - is how I keep my UK PPL (microlights) valid.
Thus if one adds a National Microlight Rating to a valid JAR-PPL which also has an SEP Rating, if you want to start using the NPPL medical declarations you gave to get an NPPL issued on the basis of the JAR-PPL first.
Maybe true for a JAR licence, but not true for a UK PPL(A) who only flies microlights. One panel examiner for microlights flies on a UK PPL (A) with a NPPL medical, but also flies light aircraft on a NPPL (SSEA) to save on the PPL medical!
This is done by a "dispensation" from the CAA that is in the files at BMAA HQ, so not in any of the ANO, JAR or CAA docs!
Back to your "can I fly" with JAR, my three-axis microlight instructor has a JAR SEP, a Canadian light aircraft licence and a Microlight Instructor rating. But no microlight rating! (he does a test every two years to keep his light aircraft licence valid and has a Class 2 medical).
In this not all really too complex?
Very best,
XA