Safe NPAs in 2015?...perhaps an oxymoron?
For air transport, there is no reason to be doing anything but RNP and moving expeditiously toward use of GLS based approaches any more, globally. They are vastly better than any other approach options, including even ILS, they can be much less expensive, and vastly more reliable, especially if properly designed and produced. GBAS and especially RNP can be cost effective for any airport, even rarely used locations like ETOPS alternates. The installation costs for GBAS can be vastly lower than any other navaid type, and in the long run, we don't even need off runway approach lighting any more, if the airplanes are using their autoflight systems properly (including options like HUD AIII if desired, for pilots to still use manual control through rollout). The very same refrain that "All that we need are good pilots with good training" was heard at the sunset of the bi-plane, tailwheel, radio operators, navigators, 4-course range, DR, star shots, ADF, VOR, VORTAC, Tacan, MLS, Talar, State, A-Scan, C-Scan, Co-Scan, Microvision, VAM, Consolan, Loran, Decca, mag-checks, ILM, PAFAM, BCRS, circling approaches,....and now finally MDA(H)s and LOC approaches. But who now would go back to any of those bygone eras, except for perhaps some historic DC-3 nostalgia? Instead, there is a vastly better, safer, less expensive way, ....even for good well trained professional pilots. So let's not stay on this present course of losing perfectly good jets, and passengers, and thoughtful pilots not otherwise trying to crash, for no good reason whatsoever. It is time to move on, to 100% RNP and GLS, globally. Then we'll finally see these unnecessarily hull losses abate.