[P7_TOM]

I must apologise for bringing in another UP post; but, there is a certain ring to the truth.  An implacable, irrefutable ring, like the doorbell to hell – unmistakable.   Without comment:-

NextGen heading for a $40B Failure with severely flawed ADS

FAA's NextGen is heading straight for a massive $40B failure. A big part of that problem is a severely distorted, misguided, ADS-B concept (far from the original ADS-B intent), that is now overspecified in key aspects (e.g., overspecified NIC and NAC), while failing in other critical areas... (all vehicles need to see each other directly, even UAVs - not via using ADS-R [ADS ridiculous] or UAT [Useless Aircraft Transponder]). ATC advocates claiming that ADS-B [in the US] needs WAAS level of accuracy and integrity are simply wrong. That's because FAA has NextGen's balance for C-N-S completely mis-designed and wrong, incorrectly assuming that ATS's future is based on and depends on essentially using PastGen's 1940s "pseudo radar" vector concept. FAA's ADS-B is simply not going to work, at any cost (which is still substantial, and well over $5K for any reasonable installation - don't believe one word of the commercialPR blitz now being put out by the ADS "junk dealers" and avionics shops for $1999 units, that aren't installed, and aren't even anywhere on the path to future [real] ATS modernization needs).

Instead, FAA should scrap 91.225/91.227, allow for the airline delay of ADS equipage to at least 2025 (which FAA has all but already agreed), and focus on design of a proper NextGen, based on RNP based trajectory [state vector] exchanges [with any data link], and use of a redefined ADS-A, ADS-B, and ADS-C criteria, that are more relevant, practical, affordable, and not massively overspecified, as the present absurd TSO and RTCA specs written by the avionics manufacturers, largely to cater to seriously misstated FAA (false) requirements, while unnecessarily driving up avionics equipment complexity, cost, and ultimately profit.

Caution is warranted for any Navaid shutdowns

"Is this jumping the gun?" Likely for most cases, YES - it is jumping the gun.

The human factors interfaces with most (if not all current) low end GA RNAV systems (and many RNAV systems even in BizJets) is still marginal, if not even awful, making them difficult and vulnerable for any serious IFR IMC use. Until and unless these RNAV systems (e.g., GPSs) have their HF user interfaces substantially improved in later generations for serious IFR flying, except for air carrier aviation that uses modern exceptionally good FMSs with RNP, and aids like ILS and GLS, ...it is a very risky proposition (safety wise) to shut down any significant number of classic Navaid facilities that are currently being used by low end GA.

That's why it is so critical that GA finally get access to low cost high quality RNP based FMS like navigators soon (driven by a GNSS + low cost inertial component engine), and be able to dump this current generation of very difficult to use GPS panel mount navigators (WAAS and LPV are virtually useless), that no amount of initial or recurrent training can ever adequately satisfy, ...short of a pilot staying current by having to fly with them for hours every, every single day.

Just about say’s it all, don’t it.