n468ac

n468ac

Well Known Member
I was thinking today ...

Why don't I see any GPS/Loran C moving mapping units for aircraft?

Since Loran C was approved for IFR (at lease in route) and many of us have had a GPS failure/lost of postion in flight. Why haven't we seen any nav units that have both GPS and Loran C receivers? For that matter why don't I see any new Loran C units? It would seam that Loran C would be a natural backup to GPS ... or ... am I missing something?

I've flown a 421 with a loran C unit a few years back ... it worked just as well as GPS ... it seams like the avonics people ran away from loran and I can't figure out why :confused: .
 
n468ac said:
I was thinking today ...

Why don't I see any GPS/Loran C moving mapping units for aircraft?

Since Loran C was approved for IFR (at lease in route) and many of us have had a GPS failure/lost of postion in flight. Why haven't we seen any nav units that have both GPS and Loran C receivers? For that matter why don't I see any new Loran C units? It would seam that Loran C would be a natural backup to GPS ... or ... am I missing something?

I've flown a 421 with a loran C unit a few years back ... it worked just as well as GPS ... it seams like the avonics people ran away from loran and I can't figure out why :confused: .
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The thing I think you are missing is that Loran has been phased out. Even though it is still operational, as failures occur in the system they are not being repaired. Eventually Loran will cease to exist completely.
 
RVbySDI said:
The thing I think you are missing is that Loran has been phased out. Even though it is still operational, as failures occur in the system they are not being repaired. Eventually Loran will cease to exist completely.
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http://www.navcen.uscg.gov/loran/default.htm

It would seam that part of your statement isn't true ... they are reviewing the loran system ... but they have upgraded loran C stations in Oct 2006 ... and I can't find any information about them not repairing off line stations or any stations that have been off line for a extended period of time. Since some stations are as new (equipment changed out) as Oct 2006, I don't think it's going away that quickly ... I also read on their site about Loran E testing in 2006.

Code: 
Recent Modernization Efforts
The LORAN Recapitalization Project (LRP) is an on-going effort to modernize the LORAN-C radio-navigation infrastructure in order to preserve operations well into the future. The LRP initiative will improve/update the system?s infrastructure allowing the U.S. LORAN System to meet present and future radio-navigation requirements. Advances in technology has allowed the Coast Guard to make significant improvements in the LORAN-C System such as: 

Synchronization of all Master Transmitting Stations to Universal Time Coordinated (UTC)

Improved timing stability with the installation of new Primary Frequency Standards at all of the Transmitting Stations.

Uninterruptible Power Supplies (UPS) have been installed at the transmitting stations to reduce the number of service interruptions caused by power anomalies.

The Transmitters have been upgraded with a new switching mechanism that reduces the time the station is off air for equipment switches down to 3 seconds. 
There are on-going modernization efforts to:

Replace the aging vacuum tube transmitters with a solid-state version. This work has already been accomplished at: 
LORAN Station George, WA
LORAN Station Dana, IN
LORAN Station Fallon, NV
LORAN Station Searchlight, NV 
LORAN Station Middletown, CA
LORAN Station Kodiak, AK


Replace the time and frequency equipment at the transmitting stations. This work has already been accomplished at:

LORAN Station George, WA
LORAN Station Dana, IN
LORAN Station Fallon, NV
LORAN Station Baudette, MN
LORAN Station Seneca, NY
LORAN Station Boise City, OK
LORAN Station Malone, FL 
LORAN Station Havre, MT
LORAN Station Searchlight, NV
LORAN Station Middletown, CA
LORAN Station Jupiter, FL
LORAN Station Carolina Beach, NC
LORAN Station Grangeville, LA
LORAN Station Raymondville, TX
LORAN Station Gillette, WY 
LORAN Station Las Cruces, NM
LORAN Station Nantucket, MA
LORAN Station Caribou, ME
LORAN Station Kodiak, AK
 
Allan has stock in Loran equip?

Allan Loran did work for its day. I remember it. Despite the new ground equip, it had and still does have its limitations. I have enough Loran experience in the 80's and early 90's to compare to GPS.

My first experience was renting a plane with a ARNAV Loran. A Piper Apache I owned had an early Apollo, where you entered stuff in lat/long and had to select the chain. I used it. I flew IFR off the needles but it was cool backup since I had no DME, I used it for distance, great for situational awareness. Since I flew between two Loran chains it was a pain because you had to enter the new chain. Of course later Loran units where automated and much better. I later had a late model II Morrow Apollo Loran in my RV-4. It worked better but still suffered loss of signal.

The Loran did not work well all over the USA. In the mountain down low, forget it. In parts of the Northwest there where LORAN GAPS.

GPS has more accuracy, better coverage (almost 100% and not effected by atmo or ground obstacles) and the antenna is small and low drag. With a hand held used Garmin or new Lowrance GPS for less than $500 GPS, I think this GPS "Fad" is going to catch on and here to stay. :D Also GPS has terrain and airspace data that I am not sure you could get in a vintage/reconditioned Loran unit.

My first GPS was a Garmin 195 "brick". I still have it and it still works great. Once I got that GPS for my RV, the panel mounted Loran was sold and never ever thought twice about Loran's again.
 
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Interesting

Paul Eastham said:
A few people are thinking about it, unclear how seriously: http://www.loran.org/library/2004ICNS2.pdf (PDF)
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To Gov would LOVE to not have VOR's because of the expense, but relying on GPS only has some pucker factor I suppose and Loran could be a cheap backup system. Now I would suppose it would be unlikely GPS would go out of service, especially if they put more in the sky. However I guess some meteorite storm could take them out. :eek:

As it is now I fly across oceans with no external nav with an Inertial Nav System. Of course GPS backs it up and updates it. After a few hours there is drift in the INS. Eventually INS's will be cheap and even GA planes can fly with their own internal nav! Right now they cost many 100's of thousand.

The money savings from not having VOR's could be huge in the US much less the world. There is something reassuring about having ground based NAV stations verses a satellite flying around in the sky at 11074.1141039 km/h! (6881.14 mph! )
 
I guess my question is ... why didn't garmin or bendix king just add a loran receiver to their GPS products (or add GPS to their loran products)?

We have a Garmin GPS III for backup now and it works great.

But I'm thinking about the future ... if the VOR system is completely shutdown (seams they are on that track) ... what is the backup system to GPS, especially if hard IFR where you can lose the GPS lock? I know WASS was designed to address this problem ? but some on this board have reported GPS outages when flying cross country, would WASS still give your GPS it position information? How would that affect your trip? What are you going to do in an area without ATC radar (happened to me a few times in the Midwest, radar was down for maintenance)?

I guess I like that we have VOR, NDB, GPS, Loran C all available right now, it gives us a lot of cross country options ? I hate to see us get locked into only having one option for navigation.
 
Let's not forget here that Uncle Sam has the ability to flip a switch and kill all civilian GPS signals instantly. In the event of a major terrorist attack or legitimate threat of one, if they had any thought whatsoever that civilian signals might be assisting or be used in some type of terrorist plot or event, just how long do you think those signals would remain online? My guess is about 32 milliseconds, as it takes just about that long for the signal to go from the ground to the satellite to tell the satellite to shut up. That's one of the issues being worked out now with the Europeans on their GPS constellation. Since these birds have worldwide coverage, any of the overlapping systems could be used for worldwide NAV, meaning now they have to flip their own switch, then make a phone call to the Brits to flip theirs, etc.
WAAS won't give any info if the main satellite constellation goes down. WAAS functions by receiving the constellation signal and finding it's GPS location according to that signal, comparing that computed location to it's known actual physical location, and then transmitting the "error" in that computed position to your receiver, so your unit can compute out the error and come up with a more accurate derived location. Without the primary constellation signal, WAAS goes down as well.
VOR's are likely to be around for a while, and it appears LORAN may have a new (possibly brief) lease on life, so we do have backup options for the time being. The odds of losing the entire constellation due to military shutdown are admittedly remote - they sure don't want to do that without very good reason - but the consequences are severe enough for an aircraft on a minimums approach to consider having a Plan B available, even if it costs a few pounds and a few square inches of panel space. You won't be able to tell the difference between a full constellation shutdown, a receiver death, or an antenna loss when it happens. I'll have ILS/GS receivers in my panel, right next to my GPS display. You could always put dual receivers in your panel for our GPS, and the European GPS, once it's fully online.
 
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gmcjetpilot said:
As it is now I fly across oceans with no external nav with an Inertial Nav System. Of course GPS backs it up and updates it. After a few hours there is drift in the INS. Eventually INS's will be cheap and even GA planes can fly with their own internal nav! Right now they cost many 100's of thousand.

The money savings from not having VOR's could be huge in the US much less the world. There is something reassuring about having ground based NAV stations verses a satellite flying around in the sky at 11074.1141039 km/h! (6881.14 mph! )
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George,

When you say INS, do you mean IRS? The 76's we had used IRS which I thought was far and away superior to INS. It certainly was more user friendly.

IRS stores previous drift errors and made corrections accordingly. The only update we had was a double DME fix when available, otherwise it was completely self contained and for the most part, very accurate. Some guys carried an hand held GPS because they did not trust it, buy 3 IRS are very good.

I can not image navigating with LORAN unless a ship at sea, for which it was developed a long, long time ago. The original airline nav equipment across the pound was a navigator. But the industry convinced the government they were not needed when double doppler, backed up by LORAN came on the scene. The navigator was replaced by added work load for the pilots in the form of taking a LORAN fix every xx minutes to confirm the doppler position. What a joke, clicking numbers to line up blips of "grass" on a green scope. If you were good at it, you could plot a position of where you were 20 minutes ago.

The track system was much more conservative then and for good reason as it wasn't unheard of for a flight to be 40 miles off an assigned track. :)

I thought LORAN had been retired to museums, but I guess that is not true.
 
David-aviator said:
I thought LORAN had been retired to museums, but I guess that is not true.
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Nope, I still use it, Apollo 602,(601?) find it preferable to my Garmin 195.
Depends on the type of flying you do----------in my -10, I will have modern GPS, and other fancy stuff, but in the old Stinson, the Loran is king.

Mike
 
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