Thanks all
I am a B2 and C with 20+ years experinence, of which 10+ is certifying and I have accumulated a fair amount of cover in this time. Could I talk about the socio-economic impact of a TCAS mod? No. Is this the sort of subject matter that I would have to research before applying for an I Eng? I will have another look at the web site and any further advice would be greatly appreciated.