Ok, so to expand on the question slightly....
How about a student undergoing tail-dragger differences training. Can he go solo before he has his differences training signed off. (For example, instructor happy to send him solo to practice 3-pointers with 10kt wind down the runway, but he hasn't yet been taught wheel-landings?)
And if yes, what happens if we're talking about ratings other than SEP? Can an instructor send an MEP student solo? How about an IR student being sent solo in IMC???
My understanding on all these questions is No, and that includes 18greens' original question. I always considered that a pilot needs to either hold an appropriate qualification for the flight if he is captain, or else needs to be undergoing a course which has a solo element. But I've never put this to the test...
FFF
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