Justin Christopher Graff

I think a major downsizing of the VOR system is a poor short and long term decision. I understand the need to reduce costs as a US taxpayer, but markedly reducing the VOR system is short sighted. Frankly, elimination of the relatively low cost LORAN system was also short sighted. The costs of maintenance for the VOR system I am sure are significant, but their installation and their commissioning had to have been quite high. What is not being taken into consideration here is the vulnerability of the GPS satellite system to solar flare activity, or less likely, but equally damaging, an EMP (electromagnetic pulse) which can be used as a weapon on the GPS system. A major electrical storm could knock out the majority or all of the GPS satellites. If this occurs, the US domestic air carrier navigation infrastructure would be decimated. Keeping a few 100 VORs active would not be adequate to guide and separate the 1000s of air carrier jets flying daily and guide them into airports. There would be pandemonium. It would take years to build, launch, and commission new GPS satellites if a major electrical storm took out our GPS system. It will be a tough several years even if we have our full VOR network, and without it, I think we will have a catastrophe. Before making a decision on this, please speak to the fine government employees at the national space weather program (http://www.nswp.gov/) and the national space weather prediction center (http://www.swpc.noaa.gov/). From lectures I have attended, they are concerned about the tenuous nature of our GPS satellite system. This is the first time I have felt a need to write to the FAA regarding a NPRM. There have been many things that have come up, but this issue got me to look into how to comment.