Great words of wisdom VX. You and I are clearly like minded. ADUX was indeed low cost one shot. but a new one cost almost as much as an SC15 You are completely wrong about the project teams aspirations for multiple use. these things were costing us more to store and repack than they were worth. never got properly cleared on the J. unused ones were disposed of some time ago when we found we had more SC15s than you could shake a stick at. Never could find any good stats to quantify reliability for any UK AD system. All down to hearsay and uninformed opinion. Just like PPRuNe really!