Have to say I'm strongly on MJ's side in this discussion.
Ask yourself, what's the purpose of solo flying in the basic PPL training course? If it is just to satisfy the regulators requirement for 10 hours P1 then there would seem to be no justification for sending a lapsed licence holder on solo flights prior to renewal by skill test. However, the requirement for pre-licence solo is clearly not just a box ticking exercise but rather an opportunity for the tyro pilot to develop his confidence, hone his judgement end decision making skills.
A pilot who holds a licence, possibly expired many years ago, needs to develop these skills just the same as the new pilot does hence solo flying is perfectly justifiable in appropriate cases.
This, as I see it, is one of the great benefits of Part FCL. As Head of Training it is entirely within my gift to assess that a particular individual would benefit from solo practice and to send him off on his own just as I would for a ab-initio student.
Bose,
Consider a pilot who did his PPL 25 years ago, flew a total of 100 hours over the next two years and has not flown since. His licence (old CAA lifetime variety) is still valid but his SEP rating is long expired. Can you see that this (albeit extreme) case is just like a basic PPL student and therefore needs solo as part of his training? Indeed, the AMC suggests that for a rating renewal after just three years then entire training should be repeated - surely this would include solo flying??
I have sent renewal students on solo flights before and would certainly do so again if I felt it would be of benefit.
As far as using these solos towards de-restricting an inexperienced instructor; I don't see why not. The process of sending a student off on a solo is essentially the same. I don't work with restricted FIs in my school so not something I've ever considered.
Happy landings
3 Point