The FAA recently released a list of more than 700 VOR and NDB instrument approach procedures that it proposes to cancel as the move towards the NextGen satellite-based air traffic system continues. The FAA has set targets to reduce the number of operating VORs from 967 to 500 by the year 2020 according to the VOR MON Implementation Program dated October 24, 2012.
While there are certainly obvious cost considerations for maintaining both ground and satellite based navigation simultaneously, it remains to be seen if this movement towards only satellite based navigation will be detrimental in the future. Redundancy and back-up systems are an essential part of aviation safety and aircraft operation. All technologies are subject to interruption from natural disasters or sabotage, however satellite technology is also subject to other factors as well such as solar flares. The FAA contends that this NextGen transition should be relatively seamless since it believes that most aircraft will have WAAS GPS receivers as part of ADS-B compliance. However, several ADS-B products being offered today are incorporating GPS receivers for aircraft that do not have a dedicated WAAS GPS navigation radio on board. Therefore, general aviation owners who can meet the ADS-B mandate with a UAT or transponder with built-in GPS will lose their ability for ILS approaches at the locations on the FAA closure list.
Alternatively, the FAA and USA as a country cannot afford to fund and account for every “what if” scenario. Some of this responsibility will have to be taken on by owners and operators who are hesitant or cannot afford to upgrade their legacy avionics to NextGen type systems in the aircraft. It seems to be a unified opinion that the National Airspace system is old and needs to be updated. Safety and reliability cannot be assured with 50+ year old technology. For example, many owner/operators were not pleased when they were forced to discontinue using LORAN in place of GPS. However, no one can dispute the benefits of GPS technology in aircraft. If planned properly and in a timely manner, most avionics upgrades can be painless, unobtrusive, and fundable. It appears that the movement towards the Next Generation (NextGen) of aircraft technology is very strong and will not discontinue until all older technologies have been addressed. Part of that is just simply human nature and progress. Unfortunately, as with all things in life, that comes with a price most of the time. That is not what many General Aviation operators want to hear, but it is the truth.