Crashondeck,
Quote: It seems crazy to me that the MOD still wont put money into some form of TCAS
The MOD are investing in exactly that. It's called the Collision Warning System, and is a high priority project. The technical challenges of such a system are enormous, though: aircraft in formation, lumpy terrain & OLF, non-squawkers, microlights etc etc. In the interim, 'See and Avoid' remains the safest bet.