1st solo
Everything that Fireflybob has said I wholeheartedly agree with. However, I frequently wonder whether a student being in command of an aircraft at the very early stage of a lengthy and comprehensive syllabus makes sense.
Having taught a large number of students who for medical reasons could not go solo until almost at the end, I have not observed any dissadvantage to them, owing to this, nor to their eventual successful completion.
We no longer emphasise solo at the say 10-15 hour stage and therefore have commonly covered at least some Nav. before solo. Covering a much greater content of the course removes a lot of pressure from some students and gives them a more enjoyable and varied progress. I'm sure we can all think back to the time when week after week we trolled round and round the circuit in frustration, waiting for the penny to drop. Then the thrill of going x/country and no longer staring at the same lump of concrete ad nauseum.