Originally Posted by
PPRuNe Radar
The real fact of the matter is that an infringement of CAS has the potential to result in a mid air collision. .... One collision may have been seen as unlucky, but two will place the authorities in the realms of negligence if they have not taken measures such as mandatory surveillance equipment and other technologies to prevent it reoccurring. So they will use a very large sledgehammer to crack the nut ... and GA.
While not disagreeing that a mid-air would precipitate action, it is useful to note that, where mid-airs with CAT have occurred (and over the decades there are a number), the authorities have generally reacted in a reasonably sensible and proportionate way (IMHO). Specifically Mode C veils were introduced decades ago in the US following the collision above Cerritos. HOWEVER, unlike the current CAA proposals, there was recognition of what could and could not be achieved at reasonable cost. Hence, the ability for gliders and non-electric aircraft to get exemptions.
The CAA proposal (back to the start of the thread) is to fit a very expensive and, to-date technically unproven (unless someone can post the CAA approval for 'portable' battery powered Mode-S for gliders and microlights), solutions. In addition, the proposed solutions do nothing much for the roughly annual GA/GA or GA/MIL mid-air in the UK. It feels like another case of a disproportionate effort to address one rather remote (but very bad) risk while ignoring the rather more common but less bad risk.
not in range of any books at the mo, can anyone answer this v.quick question with certainty - at the mo', is a transponder mandatory for class D airspace transit?
No - But if you are technically capable of carrying one go and get one with altitude encoding, it makes everyone else's life easier and makes the case less robust for forcing those people who can't down a blind alley - and possibly it will save your life as more people carry ACAS and NATS does actually start to help like providing a much expanded EGLF LARS)