Brian
Administrator
Given the issues with GPS spoofing (and other issues related to military requirements), should the VOR MON program's VOR discontinuation program be halted? Should some of the already-decommissioned VORs be reinstated?
Should the VOR MON program be halted -- or somewhat reversed?
- Thread starter Brian
- Start date
I was opposed to the MON from the beginning for just this reason. As for recommissioning all the dead VOR's, I don't think the FAA has even a drop in the necessary money bucket to make that happen. They seem to have put all their navigational eggs in the GPS basket, and someone has dropped an anvil on top of them. And no, I don't have any ideas on how to fix what's broke here short of a few properly tuned AGM-88's.
Brian
Administrator
I had to look up AGM-88s. 
Brian
Administrator
There are a lot that are scheduled for decommissioning but haven't yet been decommissioned. The cost of maintaining those would seem to be a lot less than recommissioning dead VORs but perhaps that's not the case.
In any event, someone should be whispering "GPS spoofing" and "dead VORs" into the ears of a few senators.
In any event, someone should be whispering "GPS spoofing" and "dead VORs" into the ears of a few senators.
Aeromot
Superior Pilot
Practice your pilotage.
And then there are ones like SBY which is supposed to be staying in commission but has been OTS since about 2009 because they don't want to spend the money to fix it but it's an essential part of V1.
MRC01
In the Clouds
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I agree we should maintain a backup navigation network of some kind, and VOR/DME seems a good choice because it already exists and pilots already know how to use it. Why are they supposedly out of money to run it? They ran it for decades, and our fuel taxes and their budgets haven't shrunk. Seems they should be able to find the money with some disciplined re-prioritization.
Domenick
Instrument Training
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Bureaucracies become less efficient as they grow larger and larger.
chemgeek
Safe with Passengers
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I always thought the LORAN system (the latest version was eLORAN) would be a relatively affordable ground-based backup navigation system. Sure, it can be jammed, too, but hopefully military exercises wouldn't deliberately interfere with both GPS and LORAN at the same time. When LORAN-C became available for air navigation, it was a game-changer, and a lot more accurate than a VOR approach.
The MON pie is already in the oven. I don't see it being reversed. In the northeast, it is becoming difficult to find viable Victor airway routes to get to where you want to go, between decommissioned, permanently out-of-service, and temporarily out-of-service VORs. Many VORs that go down for the count simply become permanently disabled. (ULW has been out of service for years, but it's still charted and you can get cleared to it as a waypoint.)
The MON pie is already in the oven. I don't see it being reversed. In the northeast, it is becoming difficult to find viable Victor airway routes to get to where you want to go, between decommissioned, permanently out-of-service, and temporarily out-of-service VORs. Many VORs that go down for the count simply become permanently disabled. (ULW has been out of service for years, but it's still charted and you can get cleared to it as a waypoint.)
Troy Hamon
Private Pilot
I would like to see some effort to determine whether there is a way to prevent spoofing via checks from verified ground stations. If so, replacing VOR's with GPS ground stations would make more sense to me.
The problem with the idea of the second system (Loran, VOR, etc.) is the need for a second installation both in the plane and on the ground. At present, we still have lots of VOR equipment installed in legacy aircraft, but it feels like that is going to be rare in a few years. Much as the installation of Loran equipment was almost nonexistent when it was decommissioned.
And I know some people had it installed. Which is why I said almost. In my entire career I have never flown an aircraft with installed Loran equipment...and I have flown a lot of airplanes.
The problem with the idea of the second system (Loran, VOR, etc.) is the need for a second installation both in the plane and on the ground. At present, we still have lots of VOR equipment installed in legacy aircraft, but it feels like that is going to be rare in a few years. Much as the installation of Loran equipment was almost nonexistent when it was decommissioned.
And I know some people had it installed. Which is why I said almost. In my entire career I have never flown an aircraft with installed Loran equipment...and I have flown a lot of airplanes.
Brian
Administrator
I have!!!
My airplane had it installed when I bought it. I used to use it and the 430W AND my Garmin 435 when I was on long XCs. LOL
I had it pulled once the system was decommissioned and it became a brick.
My airplane had it installed when I bought it. I used to use it and the 430W AND my Garmin 435 when I was on long XCs. LOL
I had it pulled once the system was decommissioned and it became a brick.
Palmpilot
Superior Pilot
I remember flying one through southern Oregon and seeing a 60 nm position error at one point!
It would seem to me, not knowing much about the VOR system, that with computerized VOR receivers in planes, they could automagically search out three or four appropriate VOR's, and resolve your exact position, contain all the bells and whistles of the GPS panel mount and EFB's.
I've also wondered why they couldn't put GPS type/frequency broadcast stations on all the former VOR stations. Hard to believe that someone could spoof all the possible ground stations of either (VOR/GPS) type.
I've also wondered why they couldn't put GPS type/frequency broadcast stations on all the former VOR stations. Hard to believe that someone could spoof all the possible ground stations of either (VOR/GPS) type.
Group W
Long-Distance Cross Country
I don't think the VOR direction has resolution better than a degree or so. Also, many VORs can't be received at low altitudes, especially in mountainous terrain. So I can't see any way a purely VOR-based system could fully replace satellite-based GPS.
One of the features of GPS is that its accuracy allows relatively close spacing of aircraft in densely occupied airspace. Most proposed alternatives wouldn't be as accurate so wouldn't allow the present density of air traffic.
Roy
The way a VOR works was explained (simply) to me years ago. I can't say for sure the explanation, or my understanding was correct, but here it is.
Two signals are involved. One is steady and apparently omnidirectional, and the other is rotated (either electronically, or physically) around in a circle is only in phase with the first signal at 0 degrees. How far out of phase the second signal is from the first is the direction from the station. It may have been only in degrees when originally built, but it would seem, with modern technology they could split each degree into much smaller segments.
I wouldn't anticipate totally abandoning the GPS system, but if someone/something disabled a significant number of our GPS satellites, at least we'd have useful, widespread backup.
The only way that GPS will allow close spacing is if we do away with actual RADAR, and either let aircraft separate themselves based on shared GPS positions, or base our "RADAR" displays in ATC facilities purely on aircraft reported (ADS-B) position. Lucky thing all the bad guys (and gals) will equip their aircraft with ADS-B out so we can track them. I don't think it's a good idea to not use traditional RADAR to track aircraft, and whatever else is out there.
I also seem to remember reading that in places we CAN space aircraft closer, but flight crews don't want to be that close in trail to other aircraft. Wake turbulence is at least one concern.
Two signals are involved. One is steady and apparently omnidirectional, and the other is rotated (either electronically, or physically) around in a circle is only in phase with the first signal at 0 degrees. How far out of phase the second signal is from the first is the direction from the station. It may have been only in degrees when originally built, but it would seem, with modern technology they could split each degree into much smaller segments.
I wouldn't anticipate totally abandoning the GPS system, but if someone/something disabled a significant number of our GPS satellites, at least we'd have useful, widespread backup.
The only way that GPS will allow close spacing is if we do away with actual RADAR, and either let aircraft separate themselves based on shared GPS positions, or base our "RADAR" displays in ATC facilities purely on aircraft reported (ADS-B) position. Lucky thing all the bad guys (and gals) will equip their aircraft with ADS-B out so we can track them. I don't think it's a good idea to not use traditional RADAR to track aircraft, and whatever else is out there.
I also seem to remember reading that in places we CAN space aircraft closer, but flight crews don't want to be that close in trail to other aircraft. Wake turbulence is at least one concern.
Brian
Administrator
The reason I suggested halting the VOR MON system is that currently -- like right now -- tons of planes already have functioning avionics that work just fine with VORs. Simply not decommissioning any more right would at least leave a functional network (at least at 5000') that can be used in case of GPS spoofing or outages.
I've actually done that in real life. VORs don't need GPS accuracy. They need to get you home, unless you're in IMC.
We're spending tons of money to decommission a system that works when we are facing serious threats to the only remaining system. That just feels pretty damned stupid to me but I don't like to have a single point of failure.
I've actually done that in real life. VORs don't need GPS accuracy. They need to get you home, unless you're in IMC.
We're spending tons of money to decommission a system that works when we are facing serious threats to the only remaining system. That just feels pretty damned stupid to me but I don't like to have a single point of failure.
Domenick
Instrument Training
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Back in the old days, I used both my VOR NavComs over unfamiliar terrain. Get a bearing and 2 VORs and where the lines intersect is where you were a minute ago. Easy on a paper chart.
Could ground signals be boosted high enough to overwhelm the spoofing signals? Or would that simply create a broadcast power war?
This would be an elegant solution, except it requires all new equipment installed in existing aircraft. A non-starter.
IIRC, US GPS uses the same frequency(ies) for all satellites. This would presumably be true of ground stations. Any spoofing affecting your airborne receiver would overwhelm both satellite and ground stations.
Could ground signals be boosted high enough to overwhelm the spoofing signals? Or would that simply create a broadcast power war?
This would be an elegant solution, except it requires all new equipment installed in existing aircraft. A non-starter.
I wouldn't think it would require all new equipment. They're still VOR's on the VOR frequencies, so it would allow the installation of new fancy equipment that would provide moving maps and all the other bells and whistles of the GPS based equipment, but the old stuff would still work as it always has.
I wouldn't think it would require all new equipment. They're still VOR's on the VOR frequencies, so it would allow the installation of new fancy equipment that would provide moving maps and all the other bells and whistles of the GPS based equipment, but the old stuff would still work as it always has.