Llanfairpg,
I think your pre-solo written test is a good idea, but can it really cover every single possibility of something which can go wrong? Of course not. No syllabus, test or experience can possibly cover everything. I'm sure any "reasonable person" would agree to that.
There is a recognised industry standard syllabus for flight training: the AOPA syllabus. I would suggest that showing that you've followed this syllabus (by means of a training record) would show that you have acted properly, in accordance with industry standards. Any additional testing is certainly a good idea, and won't harm either you students or yourself if the worst should happen, but an absence of additional testing beyond what is required by the syllabus should not in itself be considered negligent.
Documentary evidence of training isnt evidence of undersatnding and competence
True, but as TurboJ said earlier, a
lack of documentary evidence of training says a great deal; it shows that either the student has not been trained properly, or the instructor has not completed his duties in keeping a record of the training, neither of which is acceptable.
On the other hand, the comments written in the training record should provide written evidence that each exercise was not only completed, but completed to a satisfactory standard. Where this was not done on the first attempt, there should be evidence that the exercise was repeated until a satisfactory standard was achieved. Although this might not
prove that the student has achieved the required standard in the same way that a written test proves a level of knowledge (or at least proves that the student has learnt the answers to the questions, which is not the same thing as knowledge), it proves that the instructor has acted properly throughout the training.
And because there is a level of judgement involved, there are additional checks in place to ensure that new instructors, whose judgement of what is satisfactory may not yet be mature, are supervised by a more experienced instructor, and do not send students on their first solo (or first solo x-country, or first night solo).
FFF
---------------