Future of VOR and Instrument?

WDD

WDD

Final Approach
PoA Supporter
Joined
Oct 16, 2019
Messages
6,165
Location
Atlanta / Marietta
Display Name
Display name:
Vintage Snazzy (so my adult children say)
This thread is just for discussion. Nothing will be changing next month.

From a new to flying person's perspective, why not do away with VORs, DME's, etc. and just go all in with WAAS GPS? Essentially you're using electronic aids to tell you where to fly, land, etc. GPS system offers more advantages. Why not just transition?

I know I've heard the argument about "what if GPS goes down"? To be honest I can't see how all the GPS satellites and WAAS ground stations would go out at the same time. I can see VOR towers going off line. It seems to be more of "you need to do it the old way because the new way isn't proven".
 
VORs will be around for the foreseeable future as the "Minimum Operating Network: https://www.faa.gov/about/office_or...chops/navservices/transition_programs/vormon/

Is you surmise, the MON is intended to be a backup for the GPS, which is as prone to Murphey's Law ("If anything can go wrong, it will go wrong") as anything else in this world. The last thing the FAA would want to do is place 100% reliance on space-based systems and then weather the s--t storm that would follow if no backup had been provided. When land-based Enhanced Loran comes to fruition it will be the backup.
 
I asked the SAME question to my CFI and he said it's redundancy.
Guess it's like money; you never can have too much of it. :p
 
Watch the NOTAMs. The military regularly jams GPS signals in specified areas. GPS, as it's coming from satellites, is a very weak signal and can be jammed relatively easily.

On transport aircraft, the flight management systems, which these days are using GPS most of the time as their most accurate position updating source, can fall back to DME/DME and VOR/DME updating from ground stations when GPS is not available or inadequate geometry exists for a more accurate position solution.
 
Your phone/airplane/tablet GPS is more fragile than 99.999% of the people think/understand. It can easily be spoofed and altered. There are 2 versions of GPS - the consumer and the military versions. The miltary version is much more hardened & robust and the on-ground receivers are much more robust. Yes, I know Clinton turned on the 3m signal years ago, but that's not the military version, just a more accurate version of both categories of GPS.
 
murphey said:
Your phone/airplane/tablet GPS is more fragile than 99.999% of the people think/understand. It can easily be spoofed and altered. There are 2 versions of GPS - the consumer and the military versions. The military version is much more hardened & robust and the on-ground receivers are much more robust. Yes, I know Clinton turned on the 3m signal years ago, but that's not the military version, just a more accurate version of both categories of GPS.
Click to expand...

I'll have to look up getting unjammable, Military Grade GPS units. I'm sure searching around with those terms wouldn't trigger any attention.............
 
It's just normal evolution. New tech supplants old tech, but it is a slow process. Part is that people don't move on completely. Part is we want to be sure of the new tech. There are probably other reasons.

Look at all the folks who jumped on the LORAN bandwagon. Latest, greatest thing. And it is gone.

it's normal and there is no real reason to rush it.
 
Belt and suspenders; if you think of GPS as the "belt", picture it as decorated nicely, very ornamental, reversible, and made of cheap elastic and T-shirt material. It wont' stand-up to much stress. The suspenders are the ground-based systems; definitely not invulnerable, but definitely more robust (and accessible if it came to that.) Some military systems supplement GPS guidance with other systems, in case of jamming or signal loss.
 
Larry in TN said:
Watch the NOTAMs. The military regularly jams GPS signals in specified areas. GPS, as it's coming from satellites, is a very weak signal and can be jammed relatively easily.

On transport aircraft, the flight management systems, which these days are using GPS most of the time as their most accurate position updating source, can fall back to DME/DME and VOR/DME updating from ground stations when GPS is not available or inadequate geometry exists for a more accurate position solution.
Click to expand...

I thought the primary nav on commercial transports was still INS?
 
GRG55 said:
I thought the primary nav on commercial transports was still INS?
Click to expand...

The current latest and greatest are "hybrid IRS" which are highly accurate IRUs which are constantly updated with GPS inputs. This also provides enhanced AIM (Align in Motion) ability in case reinitialization is necessary. In the event GPS is lost, the IRUs' drift rate is quite minimal.

Count me in the "GPS is demonstrably fragile" category with regards to GA use as we know it. Solar activity, intentional military degradation or jamming, and equipment failure are all very real, not far-fetched at all possibilities. I would always want some form of ground-based nav available to me in a GA aircraft.
 
GRG55 said:
I thought the primary nav on commercial transports was still INS?
Click to expand...
INS alone won't hold a sufficiently-accurate position for long. It drifts, and the FMS must have position updating to keep ANP under 1.0, and most definitely under 0.30 for approaches.

The original 757/767, in the 1980s, had three IRUs feeding two FMSs. The IRUs were aligned prior to pushback, and could be quick-aligned just before takeoff, then used VOR/DME and DME/DME updating throughout the flight to (generally) keep ANP below 0.30 (assuming sufficient geometry to available stations). When you flew out of your onboard database, or away from ground-based navaids, the IRS would give enough input to the FMSs to keep your position accurate enough for oceanic airspace (ANP 10) for out six hours. As you approached the other coastline the DME/DME updating would resume and your ANP would drop to within enroute limits.

GPS updating was added later and is almost always the most accurate position source for the FMS updating but the DME/DME and VOR/DME updating is still there in the background when GPS becomes unreliable or had poor geometry.

The IRS is never realigned in-flight. The IRU positions keep drifting throughout the flight. It is only the FMS positions that are updated.
 
Walboy said:
Meh...I'm in an area where I'm almost constantly affected by one of these NOTAMs. I have never lost a GPS signal, ever.
Click to expand...
I have. Many times.

Had an extended outage in the area northeast of Las Vegas once. Probably ten or fifteen minutes until we flew out of it.

Every arrival into MEX (Mexico City) produces momentary drop-outs of both GPSs. I've been told it is RF jammers at a prison the arrival flies over but can't confirm.

GPS has a very weak RF signal which can be rendered unusable by stronger signals, either intentional or not. A failure in an unreleated aircraft system could produce such interference. The military also has the ability to degrade or eliminate the GPS signal. There could also be problems with the satellites themselves. Potentially, an enemy could be able to take out enough GPS satellites to degrade performance. The VOR/DME network has no such common point that can fail or be attacked and current FMS installations already are using that network as a backup.
 
Walboy said:
Meh...I'm in an area where I'm almost constantly affected by one of these NOTAMs. I have never lost a GPS signal, ever.
Click to expand...

Come to the southwest. The White Sands area will do practice jamming. It works, I can confirm that. Then all the high altitude jockeys start complaining about the signal loss... :lol:

But.... I learned to fly below the tops of the mountain range west of White Sands and I get the signal back.
 
WDD said:
This thread is just for discussion. Nothing will be changing next month.

From a new to flying person's perspective, why not do away with VORs, DME's, etc. and just go all in with WAAS GPS? Essentially you're using electronic aids to tell you where to fly, land, etc. GPS system offers more advantages. Why not just transition?

I know I've heard the argument about "what if GPS goes down"? To be honest I can't see how all the GPS satellites and WAAS ground stations would go out at the same time. I can see VOR towers going off line. It seems to be more of "you need to do it the old way because the new way isn't proven".
Click to expand...

GPS needs Satellites. They are in Geostationary orbits. Space Junk exists. What if.......

 
I think that all of my flying during GPS NOTAMs has been below the altitude specified for my area, so it's no surprise that I have not been personally affected. It probably also helps that the centers of the affected areas have generally been on the other side of the Sierras.
 
luvflyin said:
GPS needs Satellites. They are in Geostationary orbits.
Click to expand...
Right, I agree with your point.

GPS satellites are not in geostationary orbits, though. They are well below it in medium earth orbit at about 12,550 mi. Geostationary orbits are about 22,236 mi.

The point remains, they are vulnerable to both space junk and intentional attacks.
 
Larry in TN said:
Right, I agree with your point.

GPS satellites are not in geostationary orbits, though. They are well below it in medium earth orbit at about 12,550 mi. Geostationary orbits are about 22,236 mi.

The point remains, they are vulnerable to both space junk and intentional attacks.
Click to expand...

Oh. I just assumed geostationary. Seemed to make sense it would be easier to ‘crunch the numbers’ if they were just ‘parked’ at a fixed point.
 
The only thing resembling a GPS failure I've had is a WAAS failure on an approach, which was indicated by a reversion of my GPS to LNAV. I reported it, as we are supposed to, and the tower almost seemed to have no idea what I was talking about. I was visual anyway.

Anyway, there is certainly value to maintaining radio navigation capability. There's a reason the MON is being maintained, especially in the mountainous regions. Also, there are a few important airports that still rely on radio signal approaches exclusively or for the best minimums, for various reasons.
 
luvflyin said:
Oh. I just assumed geostationary. Seemed to make sense it would be easier to ‘crunch the numbers’ if they were just ‘parked’ at a fixed point.
Click to expand...
Geostationary orbit is over the equator. You wouldn't have coverage at high latitudes. You also need satellites at multiple latitudes to proceduce the geometry necessary for accurate fixes in virtually any location.
 
WDD said:
This thread is just for discussion. Nothing will be changing next month.

From a new to flying person's perspective, why not do away with VORs, DME's, etc. and just go all in with WAAS GPS? Essentially you're using electronic aids to tell you where to fly, land, etc. GPS system offers more advantages. Why not just transition?

I know I've heard the argument about "what if GPS goes down"? To be honest I can't see how all the GPS satellites and WAAS ground stations would go out at the same time. I can see VOR towers going off line. It seems to be more of "you need to do it the old way because the new way isn't proven".
Click to expand...
I've flown through one vacuum-pump failure and two wide-area GPS outages in 17 years and 1,200 hours. They're both rare events, but not so rare that we don't need backup available.
 
Bill Greenwood said:
What is a "vor tower"? I ve never seen of heard of one, is there a photo?
Click to expand...
VORTAC.jpg


Nauga,
who saved 1000 words
 
I wouldn't call that a tower, and never has hear that prhrase used for it before.?
 
I have a Loran unit that works fine, and it was working fine the day they turned the Loran signal off. I recall exactly Pres Obama when asked about it said, "Everybody has gps anyway." No i dont and I even knew how to work that Loran unit.
 
luvflyin said:
GPS needs Satellites. They are in Geostationary orbits. Space Junk exists. What if.......
Click to expand...
Are you sure about that?

Geostationary orbit altitude is approximately 35,786 km (22,236 miles). The GPS constellation satellites are at a altitude of approx. 20,000 km and have an orbital period of roughly 12 hours.

EDIT - Larry beat me to it.
 
Bill, what brand/model LORAN did you have?
 
Larry in TN said:
The point remains, they are vulnerable to both space junk and intentional attacks.
Click to expand...
If you've got enough space junk or jamming power to take out the whole constellation or even a large portion of it, GA's loss of GPS nav is probably not the worst problem you're facing. Both tend to have pretty localized effects, despite NOTAM notices of potentially affected areas.

Nauga,
burning through
 
Ryan F. said:
The current latest and greatest are "hybrid IRS" which are highly accurate IRUs which are constantly updated with GPS inputs. This also provides enhanced AIM (Align in Motion) ability in case reinitialization is necessary. In the event GPS is lost, the IRUs' drift rate is quite minimal.

Count me in the "GPS is demonstrably fragile" category with regards to GA use as we know it. Solar activity, intentional military degradation or jamming, and equipment failure are all very real, not far-fetched at all possibilities. I would always want some form of ground-based nav available to me in a GA aircraft.
Click to expand...

A paper chart and a window work pretty well, and are nearly impossible to jam.
 
Ryan F. said:
I would always want some form of ground-based nav available to me in a GA aircraft.
Click to expand...


The most reliable ground-based nav is the ground.

Pilotage with a paper chart makes a pretty good alternate nav, and a compass ain't such a bad idea, either.
 
Half Fast said:
The most reliable ground-based nav is the ground.

Pilotage with a paper chart makes a pretty good alternate nav, and a compass ain't such a bad idea, either.
Click to expand...
Doesn't work so well in IMC, unfortunately. Agreed that compass and a map are a great VFR backup.
 
David Megginson said:
Doesn't work so well in IMC, unfortunately. Agreed that compass and a map are a great VFR backup.
Click to expand...


I'm a VFR pilot. Pretty unlikely GPS would go kaput at the same instant I commit a major act of stupidity by blundering into IMC. Besides, at that point my navigational needs will be reduced to making a 180 turn to get back to clear skies.
 
Ryan F. said:
The current latest and greatest are "hybrid IRS" which are highly accurate IRUs which are constantly updated with GPS inputs. This also provides enhanced AIM (Align in Motion) ability in case reinitialization is necessary. In the event GPS is lost, the IRUs' drift rate is quite minimal.

Count me in the "GPS is demonstrably fragile" category with regards to GA use as we know it. Solar activity, intentional military degradation or jamming, and equipment failure are all very real, not far-fetched at all possibilities. I would always want some form of ground-based nav available to me in a GA aircraft.
Click to expand...

yeah, I can’t think it is only here in Norway that we have had incidents of other jamming too of GPS. It’s been reported more than a few times, most recently an air ambulance helicopter that had minutes where they couldn’t read GPS it was jammed. Report on it says GPS jamming devices though illegal are bought online. Thieves worried about trackers in stolen items, truckers and others that may have monitoring GPS from their company. Whatever other reasons folk think they have. They triangulated to find the one in the last incident, the police did, and found the device, which is small (it amazed me how little it takes) plugged into a cars cigarette lighter plug.
 
Krusn, I think the Loran is a King like my other avionics. I should be certain but havent turned it on really since the turned the system off. In other planes I have had a couple of Apollo ones which worked well.
 
nauga said:
If you've got enough space junk or jamming power to take out the whole constellation or even a large portion of it, GA's loss of GPS nav is probably not the worst problem you're facing.
Click to expand...
I really haven't been talking about GA. The backup VOR/DME network is needed by transport jets to continue updating their FMS positions when GPS isn't available. There are still some 767s flying around without GPS updating at all. They rely completely on VOR and DME updating for the FMS position.
 
If you are IFR, there will be plenty of times when you have to do an ILS. Can't do that if you don't have a nav radio.
 
Half Fast said:
I'm a VFR pilot. Pretty unlikely GPS would go kaput at the same instant I commit a major act of stupidity by blundering into IMC. Besides, at that point my navigational needs will be reduced to making a 180 turn to get back to clear skies.
Click to expand...
Absolutely right. When we talk about a "backup to GPS", we always mean "an IFR backup to GPS". Pilots navigated VFR long before we had GPS, VORs, NDBs, or even A-N ranges.
 
Jamming exercises are usually NOTAM'd in advance. The challenge will come when we're facing the real thing.

For example, imagine some terror group launching a 20-drone attack on US public targets. We're already seeing extensive use of cheap, Chinese-built attack drones in Libya and elsewhere (including the refinery attack in Saudi Arabia). If the US government believes 20+ drones are heading for major public targets, they'll just shut down the GPS satellite transmitters with no warning, probably for a week or more, and also turn on widespread jamming for GLONOST.
 
You must log in or register to reply here.
Back
Top