Hi Pobjoy
Nice to get some more input,I think some of the problems with the T53 for the ATC were also that the normal winches and cables struggled with the weight of the a/c - and also I believe (bearing in mind how many years have passed) that it was flown (at Halton ?) the whole length of the runway with the airbrakes fully open ( they were that bad !!).
As I said previously - I think if they had managed to redesign the wing and reduce the weight then the ATC might have got them ,but I think they genuinely worried about letting 16 yr olds loose on them.
When we bought ours -my partner had asked me about the a/c characteristics...I just said ''they are heavy with cr@p airbrakes'' but he was told by the previous owner that the brakes were ''as good as a K13''...anyway he did his first approach 'K13 style' and actually had to 'go around' and try again 'libelle style'...I did not resist saying ITYS !!