Another nom de PPRuNe, eh?
The NPPL came in on 30 July 2002 because Industry said they wanted it. But the CAA cocked up the ANO at the time and we've been trying to unbugger it ever since. In fact I provided the latest clarification just yesterday....
If all you want to do is to fly light aeroplanes on nice days in the UK, then really there is no reason to go for a JAR-FCL PPL - the NPPL requires not less than 32 hours plus 2 x 1.5 hour tests, whereas the JAR-FCL PPL requires 45 hours including a single test of 2.5-3 hours. The NPPL is issued for life, the JAR-FCL PPL for only 5 years. Ratings, however, have also to maintained on both licences.
Medical requirements for the NPPL are simpler and cheaper.
The whole rationale was to make learning to fly and maintaining a licence simpler and cheaper. Hopefully the eventual ANO amendments currently being worked on will finally achieve this original aim.
NOTE - in this context:
'Light aeroplane' means a single piston engined aeroplane (not being a microlight or SLMG) with a maximum permitted weight of 2000 kg, in which not more than four people (including the pilot) are carried. This is termed a 'simple single engined aeroplane' (SSEA)
'Nice days' means day, VFR, not less than 5km in-flight visibility, clear of cloud and in sight of the surface.