B

bizjet

Member
I wonder why anyone installs VOR, or LOC receivers on their aircraft. GPS is a legal substitute for all but Localizer navigation. Even if an approach says "ADF required", it's not - if you have GPS and a data base. Same with VOR and airway navigation. I understand localizer if you need 200 1/2 landing minumums, but otherwise, why bother? Just curious.

I haven't flown a raw ADF bearing, or VOR radial in years. Still do lots of ILS's, but that's it. The equipment available for experimental aircraft is truly state of the art and I wonder why anyone would use old stuff.

Regards,

Bill
 
If the GPS fails, it's nice to have backups. If I'm putting a LOC, which is a requirement for me in an IFR airplane (I love ILS's), it gives me VOR capabilities
 
You make a good point and something that I've thought a lot about. I installed one because I want ILS capability and a backup to GPS. There are severals posts here on VAF where people tell the story of losing GPS signals on multiple GPS receivers due to DoD turning on selective availability of the signal -- especially out west when they are performing "war games".
 
not exactly

Check the AIM, but last time I did GPS was not named for VOR to VOR enroute. GPS is ok on an overlay for VOR approach. It is explicitly omited from the list for enroute on the airways. Reason, because they need error on the airways. GPS is just to accurate. Of course you can always go direct. But can you? Not around Class Bravo. If you transition Class B, chances are they will put you on an airway. Also to get your IFR ticket you need to shoot three approaches. GPS is one, ILS, and LOC I suppose would do. But a GPS gives you more fun. Another reason for a VOR is when you call 122.0 for weather, they like you to give your position realitive to a VOR. I suppose this is note written by a guy who learned on ADF and GPS. I'll bet I'm not convincing any GPS pilots. And maybe it doesn't matter because a Garmin 430 gives you legal IFR, plus a nav receiver. This one box gives you 5 approaches. wow 1) GPS, 2) ILS, 3) VOR, 4) Loc, 5) ADF (overlay)
 
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Paul Thomas said:
If the GPS fails, it's nice to have backups. If I'm putting a LOC, which is a requirement for me in an IFR airplane (I love ILS's), it gives me VOR capabilities
Click to expand...

I have this bad habit :), of asking a large number of pilots, including everyday commercial pilots............just how often their GPS has failed. In reality, it's very seldom and only of short duration. Of course, there will be always be a few who have suffered longer failures but it's few and far between. In regards to GA airplanes, I can safely say that it's antenna problems more than anything else. Out of five aviation GPS's I've owned since the early ninties when GPS came on line for civilian use, I've only suffered one major outage, and that was a long time ago.

A good friend who fly's 737-800's for Delta has only had one momentary outage in the eight years he's flown them. And that was close to a restricted military area.

There you have it from my point of view. I'm a GPS fanatic, and could care less when VOR stations for flying point A to B are decommissioned. My backup is a second GPS, and if I get that hard up, I have a hand-held nav-com in the flight bag. Needless to say, my airplane is not IFR equipped, but I would like it to be someday.

To me, setting up VOR's to fly from point to point, is only something to repel boredom. Unfortunately, it means your head has to be in the cockpit, rather than scanning. Same for whiz wheels and triangulating positions on a sectional.

L.Adamson --- RV6A/ Garmin 696
 
Jamie said:
You make a good point and something that I've thought a lot about. I installed one because I want ILS capability and a backup to GPS. There are severals posts here on VAF where people tell the story of losing GPS signals on multiple GPS receivers due to DoD turning on selective availability of the signal -- especially out west when they are performing "war games".
Click to expand...

I've heard that too. But then I fly out west, and am always around these military areas. It's been far too many years since my GPS has lost it's signal.

L.Adamson --- RV6A
 
Mainly because I want a 430W and it comes as part of the navigator. I could just get a 420 (This has been discussed before in the GPS forum), but the cost difference is minor so there's no reason not to spring for the full-up 430 and get VOR/LOC/GS capability.
 
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Well enjoy it if you got it

I don't have it, can't afford it and probably will not get it in the near future. VOR/LOC/GS work and I have them and use them - does that bother you an awfully lot? I'm sorry about that - NOT!

Bob Axsom
 
L.Adamson said:
I have this bad habit :), of asking a large number of pilots, including everyday commercial pilots............just how often their GPS has failed. In reality, it's very seldom and only of short duration. Of course, there will be always be a few who have suffered longer failures but it's few and far between. In regards to GA airplanes, I can safely say that it's antenna problems more than anything else. Out of five aviation GPS's I've owned since the early ninties when GPS came on line for civilian use, I've only suffered one major outage, and that was a long time ago.

A good friend who fly's 737-800's for Delta has only had one momentary outage in the eight years he's flown them. And that was close to a restricted military area.

There you have it from my point of view. I'm a GPS fanatic, and could care less when VOR stations for flying point A to B are decommissioned. My backup is a second GPS, and if I get that hard up, I have a hand-held nav-com in the flight bag. Needless to say, my airplane is not IFR equipped, but I would like it to be someday.

To me, setting up VOR's to fly from point to point, is only something to repel boredom. Unfortunately, it means your head has to be in the cockpit, rather than scanning. Same for whiz wheels and triangulating positions on a sectional.

L.Adamson --- RV6A/ Garmin 696
Click to expand...
I've had a GPS failure and it lasted over an hour. I was the only plane in the area affected and only during that flight. The GPS had good satellite reception but, if I blindly followed it, I would have been making circles over the everglades. The scary part is this is in a certified bird with a certified IFR install... I was a green pilot and the lesson has stuck with me. While I most often go GPS direct, I ready to navigate without it anytime.

I'm putting it down as an anomaly being in the bermuda triangle (I've seen other weirder stuff), and my failure would be thrown out by someone doing a statistical analysis but it taught me a valuable lesson.
 
Paul Thomas said:
but, if I blindly followed it, I would have been making circles over the everglades. The scary part is this is in a certified bird with a certified IFR install... I was a green pilot and the lesson has stuck with me. While I most often go GPS direct, I ready to navigate without it anytime.
Click to expand...

I wouldn't blindly follow a GPS either. In fact, since I fly in a very mountainous area, most of my GPS routing will follow VOR airway routes.
Since I use moving map GPS screens that show much of the big picture, I won't be blindly following a simple black line to a destination. As general rule, I pre-plan any long distance flight using a flight planner, then enter it in the GPS.........which is easily re-useable or reversable. I keep my sectionals out too. I always know where I'm at.

L.Adamson
 
I doubt that selective availability has been used in the last few years.

PS: Fly OVER Class B
 
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sglynn said:
Reason, because they need error on the airways. GPS is just to accurate. Of course you can always go direct. But can you? Not around Class Bravo.
Click to expand...

I have no idea what your source is for this statement but it clearly incorrect. How could GPS be too accurate on an airway? Centerline is centerline, and that is what airway navigation is predicated on.

If you have an IFR GPS installation you can use it to navigate VOR airways (AIM Chapter 1, Paragraph 1-2-3).
 
No ground based nav

I'm surely a minority, but my panel will be exclusively GPS. I don't plan to do more than file IFR for marginal VFR weather (I'm calling my panel VFR+). I'll have a GNC-300XL comm and a 696 - that's it. I'll have a hand held radio for backup comm duties. I'd love to have a 430, but I can't justify the expense and given the choice between an SL30 and a 300XL - I'll take the GPS.

Flame away!

Here's an early version of my panel mocked up. The transponder is now a GTX-327.
FP15012010A0001B.jpg
 
For me, there is not enough panel space in my -4 for a GPS navigator and not enough money in my bank account to buy one. When I had my -7 it had a GNS480 and the only time I did VOR approaches was for practice. ILS is a different ballgame though. At many airports you can still get lower on an ILS than an LPV approach. It is also good to have a backup navigation system built into the avionics of the plane so it couples to the autopilot, especially when in IMC.

The cost of entry into GPS only is still pretty high, especially for our spam can brethren. A 430W and a GPS/VOR//LOC/GS indicator plus installation in a spam can will be around $12,000 which is in today's market is a pretty high percentage of the aircraft's value.

From the DC area heading North up the Eastern seaboard, I have rarely been able to get any type of GPS direct routing, it's all airways, intersections, and VOR's. Granted the GPS can do that for you using the VOR's as waypoints but the point is the system in this area is still based on VOR's and will not be changing any time soon.
 
Why?

Redundancy. When I was tooling around in my old Mooney, I got a "signal lost" more than once. I'm just a VFR pilot but, I want to know where I am, and my gps alone wouldn't give me that comfort level.
 
aerovin said:
I have no idea what your source is for this statement but it clearly incorrect. How could GPS be too accurate on an airway? Centerline is centerline, and that is what airway navigation is predicated on.

If you have an IFR GPS installation you can use it to navigate VOR airways (AIM Chapter 1, Paragraph 1-2-3).
Click to expand...

While the statement about GPS being too accurate for safe airway navigation seems at first to be ridiculous, it actually has merit. The likelihood of being precisely on the centerline of an airway while navigating with VOR is quite low due to the coarse resolution of the VOR system. If the plane is several miles from the VOR, it most likely is not on the exact centerline of the airway.

However, GPS can hold an aircraft within one wingspan of the centerline. Imagine if every aircraft on the airway was within 50' of following the exact same track. Airway congestion would become a valid concern.

The designers of the Trio autopilot recognized this 'problem' and included a track "offset" feature so the pilot can have the system fly the plane a set distance from the centerline so as to avoid all those other aircraft that are glued precisely to the middle of the airway. :) Obviously this 'centerline congestion' situation didn't exist with VOR navigation so that was the intent of the original poster's statement about error being a part of the VOR system.
 
Redundancy

Interesting, ongoing, discussion. My problem with simply blowing off the VOR system is that it is there and it works. Most of us were taught to "use every available resource" while aviating. The GPS system seems to lull some people into a false sense of security. Part of this, I feel, is that the output is displayed in hard numbers and magenta lines, not a wiggling needle. The problem is that it is not perfect, and a backup is always a good idea. Here is another concern:

http://www.engadget.com/2010/02/10/solar-flares-set-to-wreak-havoc-with-gps-signals/

Be sure to click on "another reason" near the bottom of the text. :eek:

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
 
I have experienced three GPS outages of half an hour or more. All were in an airliner and the GPS receiver clearly indicated that the signal was lost. However, we weren't lost because we still had VOR receivers. All of these incidents were in the southwest, and there were notams available, but you had to do some digging to find them.

Pat
 
John Clark said:
Interesting, ongoing, discussion. My problem with simply blowing off the VOR system is that it is there and it works. Most of us were taught to "use every available resource" while aviating. The GPS system seems to lull some people into a false sense of security. Part of this, I feel, is that the output is displayed in hard numbers and magenta lines, not a wiggling needle. The problem is that it is not perfect, and a backup is always a good idea. Here is another concern:

http://www.engadget.com/2010/02/10/solar-flares-set-to-wreak-havoc-with-gps-signals/

Be sure to click on "another reason" near the bottom of the text. :eek:
Click to expand...

Getting to the nitty gritty...............

How many aircraft have been lost over the years with pilots using the antiquated VOR system? Far too many! I have loads of examples that would take much too long to list. Just check out Aspen, Colorado for instance. That "wiggling needle" is the problem, as it's always invited mass confusion. A magenta line overlay on a large & detailed moving map presents information and added situational awareness that only could be wished for, years ago. Just think of how many pilots, passengers, and aircraft would still be around, should those unlucky people just had today's technology.

At the present, we still even have airliners taking off on taxiways, as was demonstrated just last week. They made it successfully, and were much better off than the regional jet that took off on the wrong & shorter runway a few years ago. GPS, airport diagrams, and an overlay of our aircraft's position solves that whole problem. Applies to runway incursions in IMC conditions too.

I don't believe in this false sense of security for one minute. I'm not just young kid either being wowed by new technology, as I'm very near 60 years of age. It's just that I've kept track of every flight into terrain accident for many years, since our mountains around here seem to have a magnetic effect of pulling aircraft into the mountain sides. I know all the whys & wherefores of far too many accidents.

As a pilot or passenger, I consider GPS as the ultimate "b u t t" saver, when it comes to having a much better grasp of what's going on in IMC conditions. After all, would you rather have a full blown moving map, synthetic vision, and possible infra-red night vision as a backup, or simple "moving needles" when c r a p has hit the fan, and the pilots are confused, or have no idea they're confused until the last second. Even if the pilot of command has made the dumb mistake of scud running such as the pilots flying a twin engine firefighting aircraft did just miles from my home last year......... the passengers don't also have to share in the pilot's lack of judgement. This aircraft hit a mountain face at high speed. A simple Garmin GPS with terrain databases could have made all the difference.

You don't get terrain, obstacle warnings, TFR updates, XM satellite weather, airspace boundries, and much more with those "has been" VOR needles of the past. That's just a fact. Synthetic vision, thanks to the accuracy of GPS is the future, and I'll be truely thankful for it..

L.Adamson --- RV6A/ Garmin 696/ XM satellite weather
 
I don't think anyone is questioning the benefits of GPS, but explaining why having a VOR receiver for backup navigation is a good idea. As to the scud-running argument, remember the Bonanza video where they scud-runned into a canyon and hit the brush with their wing, even with the terrain display?
 
It depends on the GPS you have

GPS receivers are approved for IFR navigation under either TSO 129 for units that do not provide vertical approach guidance, or TSO 146A for WAAS units that include GPS vertical guidance and are approved for "sole means of navigation".

The following is excerpted from the FAA Advanced Avionics Handbook.
Alternate Airports​
​
​
​
It is very important to know what equipment is installed​
in the aircraft. GPS-based FMS/RNAV units certified to​
TSO-C145A or TSO-146A may be used when an alternate​
airport is required in the flight plan for the approaches at the​
destination and alternate airport if the WAAS is operational.
No other navigation avionics would be required. Units​
certified under TSO-C129 are not authorized for alternate​
approach requirements. The aircraft must have stand-alone
navigation equipment, such as VOR, and there must be an
approved instrument approach at the alternate airport based
on that equipment. (However, once diverted to the alternate​
airport, the pilot could fly a GPS-based approach there, as​
long as there is an operational, ground-based navaid and​
airborne receiver in the aircraft for use as a backup.)
​
For example, you could use a Garmin 430W GPS (TSO 146A) to fly GPS IFR without an alternate means of navigation, or you can use a Garmin 300XL (TSO 129A) and a Garmin SL30 VOR/LOC/GS to provide the same capability.

Ironically, the 430W receiver includes a VOR/LOC/GS receiver, so it appears that you can't avoid having one in either case.
 
Arrows

Flyfalcons said:
I don't think anyone is questioning the benefits of GPS, but explaining why having a VOR receiver for backup navigation is a good idea. As to the scud-running argument, remember the Bonanza video where they scud-runned into a canyon and hit the brush with their wing, even with the terrain display?
Click to expand...

Exactly my point, VOR is still a viable backup or "cross check." I'm not advocating ignoring new technology, just avoiding putting all your eggs in one basket. Dependence on any single source of navigation is foolish. Remember, all of the magic regarding terrain, moving maps and the like is relying on a single system, GPS, for position. I really like my 430, but there is paper chart handy too. In aviation, "It's not the arrow, it's the indian." No amount of technology will make up for poor decision making by the pilot.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
 
John Clark said:
Exactly my point, VOR is still a viable backup or "cross check." I'm not advocating ignoring new technology, just avoiding putting all your eggs in one basket. Dependence on any single source of navigation is foolish. Remember, all of the magic regarding terrain, moving maps and the like is relying on a single system, GPS, for position. I really like my 430, but there is paper chart handy too. In aviation, "It's not the arrow, it's the indian." No amount of technology will make up for poor decision making by the pilot.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
Click to expand...

I made a decision a long time ago not to fly these things IFR so there has never been a back up anything. It's a Garmin 295 and paper charts if it goes TU. (Recently I tried a cheap GPS from Wal-Mart as a back up and it will do the job if set up to navigate off road.)

The modus operation cross country is "VFR on Top" as long as the route is VFR departing and arriving and below. I can get down through anything to 1000-3 in an emergency with an auto pilot and the Dynon D10A.

Granted, it is a limited operation but I feel it matches the airplane. I've never not made it to SNF or OSH, fun places to visit once in a while.

Most of us fly less than 100 hours a year. A good airplane and a good engine is a big investment as is. Why have all this money tied up in all this equipment that far exceeds the capabilities of the airplane?
 
Flyfalcons said:
I don't think anyone is questioning the benefits of GPS, but explaining why having a VOR receiver for backup navigation is a good idea. As to the scud-running argument, remember the Bonanza video where they scud-runned into a canyon and hit the brush with their wing, even with the terrain display?
Click to expand...

Yes I do remember. The GPS was mounted on the right side of the cockpit & flashing terrain alerts. Too bad the pilot wasn't even paying attention to it, let alone the audio alerts that mine would be filling my headphones with. This GPS might as well not even been there, since the passengers seemed to have no clue of what it was doing either.

L.Adamson --- RV6A
 
Paying attention

L.Adamson said:
Too bad the pilot wasn't even paying attention to it, let alone the audio alerts that mine would be filling my headphones with. This GPS might as well not even been there, since the passengers seemed to have no clue of what it was doing either. L.Adamson --- RV6A
Click to expand...

OK, so if you are going to scud run up a narrow canyon in a fast airplane you need to mount the technology properly? Sorry, Larry, as a student of human factors, I'll bet that the lad couldn't have seen the GPS if it was dead center in front of him. Panic does interesting things to one's body. The trick is to avoid the situation, in this case, not entering the canyon in the first place.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
 
John Clark said:
OK, so if you are going to scud run up a narrow canyon in a fast airplane you need to mount the technology properly? Sorry, Larry, as a student of human factors, I'll bet that the lad couldn't have seen the GPS if it was dead center in front of him. Panic does interesting things to one's body. The trick is to avoid the situation, in this case, not entering the canyon in the first place.
Click to expand...

I agree....
 
John Clark said:
Exactly my point, VOR is still a viable backup or "cross check." I'm not advocating ignoring new technology, just avoiding putting all your eggs in one basket. Dependence on any single source of navigation is foolish. Remember, all of the magic regarding terrain, moving maps and the like is relying on a single system, GPS, for position.
Click to expand...

Actually, we're not relying on a "single system" when using a GPS in the cockpit. 24 separate GPS satellites are in operation at any one time. 31 to 32 operational units are in orbit, which is 7 or 8 as backups.

Our receivers require at least 4 satellites to compute position and altitude. In most cases, our receivers will usually pick up 8 (or more) satellites at any one time.

Put at least two separate GPS receivers in the cockpit, such as I do, and you have numerous forms of redundancy. With this many separate satellites in orbit, and the fact that you're probably picking up 4 "extra" satellites than ever needed at any one time, I'd say that the odds are much more in our favor.... than relying on 1 or 2 VOR's to find position, which can easily be 4 miles off laterally, and a DME system that severely degrades with altitude.

And, as mentioned previously, some have experienced loss of signal. But much depends on the age of the GPS, position of antenna, and a few military operations that should be accompanied with NOTAMS. I say age, because there is all the difference in the world between my older and newer GPS's in regards to acquisition time, and the number of satellites that they lock on to.

L.Adamson ---- RV6A/ Garmin 696

edit: And of course, a great advantage of GPS is the ability to fly more direct routes, than the sometimes criss-cross pattern of VORs. This could preclude the use of VOR as a backup, because you might just be out of range.
 
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L.Adamson said:
Actually, we're not relying on a "single system" when using a GPS in the cockpit. 24 separate GPS satellites are in operation at any one time. 31 to 32 operational units are in orbit, which is 7 or 8 as backups.

Our receivers require at least 4 satellites to compute position and altitude. In most cases, our receivers will usually pick up 8 (or more) satellites at any one time.

Put at least two separate GPS receivers in the cockpit, such as I do, and you have numerous forms of redundancy. With this many separate satellites in orbit, and the fact that you're probably picking up 4 "extra" satellites than ever needed at any one time, I'd say that the odds are much more in our favor.... than relying on 1 or 2 VOR's to find position, which can easily be 4 miles off laterally, and a DME system that severely degrades with altitude.

And, as mentioned previously, some have experienced loss of signal. But much depends on the age of the GPS, position of antenna, and a few military operations that should be accompanied with NOTAMS. I say age, because there is all the difference in the world between my older and newer GPS's in regards to acquisition time, and the number of satellites that they lock on to.

L.Adamson ---- RV6A/ Garmin 696

edit: And of course, a great advantage of GPS is the ability to fly more direct routes, than the sometimes criss-cross pattern of VORs. This could preclude the use of VOR as a backup, because you might just be out of range.
Click to expand...
The system may have multiple components and backup, but it's a single system IMO.
 
ridiculous

"It is very important to know what equipment is installed
in the aircraft. GPS-based FMS/RNAV units certified to
TSO-C145A or TSO-146A may be used when an alternate
airport is required in the flight plan for the approaches at the
destination and alternate airport if the WAAS is operational.
No other navigation avionics would be required. Units
certified under TSO-C129 are not authorized for alternate
approach requirements. The aircraft must have stand-alone
navigation equipment, such as VOR, and there must be an
approved instrument approach at the alternate airport based
on that equipment. (However, once diverted to the alternate
airport, the pilot could fly a GPS-based approach there, as
long as there is an operational, ground-based navaid and
airborne receiver in the aircraft for use as a backup.)"

This excerpt from the FAA cracks me up. How is a VOR anymore "standalone" than a GPS? They both require an external transmission and are both subject to equipment outages. Then it says you have to have a VOR to file to an alternate which by definition should have better weather than the original destination, yet it was ok to file GPS to the destination. Further, once you get to the alternate you are then authorized to use GPS. huh????

It appears to me the FAA is basing the requirement for a VOR as a means of redundancy but assumes the reason for the missed approach at the destination was what? A GPS failure and not weather? If this is the case then why is it then ok to only have a VOR and not a GPS? Does the redundancy argument work both ways?

I'm still goin with only GPS...maybe it will limit the days I can "FILE" IFR but obviously this reg will need to be updated in a few years when VORs are in fact put out of service.
 
Ken, one of the major issues is INTEGRITY of the navigation signal. VORs have that. Current standalone GPS signals do not.
 
RV8R999 said:
I'm still goin with only GPS...maybe it will limit the days I can "FILE" IFR but obviously this reg will need to be updated in a few years when VORs are in fact put out of service.
Click to expand...

Just when is that going to be? Around the same time they eliminate NDBs?
 
When I made the original post I wasn't thinking about the cost, which can be a real deal breaker, of course.

I've been flying GPS for 21 years and have yet to experience an outage. Not one. Just lucky, or is the system that good?

I'm really sold on it and I'm no computer savvy youngster. Just an old guy who likes doing things easily and accurately.

Too accurate? Well, could be. I'm thinking of oceanic operations where we used to sort of know where we were. With this stuff if it says that we're 55N, 35W, and at 35,000 - that's exactly where we are and if someone else thinks the same, he's exactly there, too. We are encouraged to offset from centerline and many do.

Interesting conversation, I think.

Regards,

Bill
 
RNAV GPS implementation

The IFR approach accident rate is significantly higher for the ?dive and drive? type of approaches (VOR, NDB, LOC) compared to the approaches with vertical guidance, such as ILS. General aviation seems to bear the brunt of most of the accidents. Installation of an ILS is about $1.5M per runway end plus ongoing maintenance.

The FAA GPS/RNAV initiative is to provide vertically guided IFR approaches to all qualifying runway ends in the US in order to help mitigate the accident rate. The most economical way to do it is by utilizing the GPS. The FAA has been mandated to develop and publish at least 500 new RNAV LPV WAAS approaches per year. The current number of RNAV LPV approaches is 1975, with about 250 of them having descent minima of 200? and ? mile visibility (same as ILS CAT I). There are just over 1200 ILSs in the US. By this time next year, there will be about twice as many runway ends with RNAV LPV approaches as ILS.

The reliability of ground base NAVAIDS can be debated. Outages for maintenance can sometimes be lengthy. Lighting strikes and other issues take a toll on the facilities. Some of the facilities taken out by Hurricane Katrina were out of service nearly a year and a half. The only IFR access to some of the airports on the Gulf Coast right after the hurricane was with GPS RNAV avionics.

WAAS has been determined to have the integrity and continuity to be used for primary navigation in IFR. We are now seeing lower minimum enroute altitudes published on IFR charts for aircraft equipped with GPS avionics. ?T? Routes and VFR waypoints are published in busy terminal areas for use in GPS avionics. The FAA published the new Instrument Pilot Standards, effective Jan 2010, which now allows the RNAV LPV approach to be flown to demonstrate the precision approach requirements. pg7--?Note: An LPV approach is technically a nonprecision approach, however, due to the precision of its glidepath and localizer-like lateral navigation characteristics, an LPV can be used to demonstrate precision approach proficiency (AOA VI TASK B).?

I see the handwriting on the wall and have invested in my avionics accordingly!
 
Well Jamie no one can predict exactly when but I can tell you the US Navy has budgeted over $2B (yes thats a B) toward ensuring our aircraft can navigate without VOR/TACANs within the next couple of years... we don't spend that kinda money on hunches. How do I know? I'm the guy that put the money in that pot. Take it for what its worth.

Regards,

Ken
 
Hmmm...
RAIM
Receiver Autonomous Integrity Monitoring (RAIM) provides integrity monitoring of GPS for aviation applications. In order for a GPS receiver to perform RAIM or Fault Detection (FD) function, a minimum of five visible satellites with satisfactory geometry must be visible to it. RAIM has various kind of implementations; one of them performs consistency checks between all position solutions obtained with various subsets of the visible satellites. The receiver provides an alert to the pilot if the consistency checks fail. RAIM availability is an important issue when using such kind of algorithm in safety-critical applications (as the aeronautical ones); in fact, because of geometry and satellite service maintenance, RAIM is not always available at all, meaning that the receiver's antenna could have sometimes less than five satellites in view. Availability is also a performance indicator of the RAIM algorithm, as it is, basically, a statistical method. Due to this it has a "power of test" which is a measure of the reliability of this test to detect a failure when it happens. This power of test is its availability and it is a function of the geometry of the constellation which is in view and of other environmental conditions. If availability is seen in this way it is clear that it is not an on?off feature meaning that the algorithm could be available but not with the required performance of detecting a failure when it happens. So availability is a performance factor of the algorithm and characterizes each one of the different kinds of RAIM algorithms and methodologies.
 
I've had multiple episodes of loss of a useable signal with GPS through the years, although fewer recently. Loran would often fail near CB - doesn't matter anymore. I agree with the pilot who said "I love ILS's."
 
I am an career avionics guy, and I agree that GPS is the greatest thing since sliced bread. However, in addition to GPS (WAAS) I will also have dual COM, Dual VOR, dual LOC and dual GS (in addition to dual EFIS AND a standby airspeed, standby altimeter, and standby ADI) in my RV-7. Actually, I have dual GPS too, if you count the stand-alone GPS receiver driving the APRS. Why? Because I can.
 
Not just a good idea...

It's the law.

I could be wrong on this but, it is my understanding that if you file GPS to your destination on an IFR flight plan and an alternate is required, then the alternate must have other than a GPS approach published and you and the aircraft must be able to perform it. This would imply an ILS, LOC or VOR. Also, I still see many more ILS approaches than precision WAAS approaches, although I fly mainly into large commercial airports.

Beer30?
 
Use everything available

I have read this and many other posts, seen a lot of talk about redundancy, many say they have a handheld radio as well. Just read an article a while back about the ridiculously small number of GA pilots who utilize PAR/ASR. Many of us are military aviators who grew up having PAR's as our ONLY form of precision approach. I think it would be a very useful tool for anyone (even VFR only pilots) to learn how and practice these ground controlled approaches. If your engine is designed to run without power (mags), and you plan to communicate without power (handheld radio) why not learn how to get out of weather that way? If you are unaware of how great this is, here it is in a nutshell: "N123SH, declaring an emergency, in the goo, no power, on handheld radio, can't see approach plates, request no gyro ASR 32"..."Turn left....Stop turn. Prepare to descend in one mile...Turn right....Stop turn, begin descent, recommended altitude 980 ft"....This is one of the easiest to perform, and you have a calm voice talking you down!
 
I can't add anything put my perspective.

I learned using paper maps and ground reference. But right after getting my certificate I went GPS. 15 years later I am learning to use a VOR. Why? Because I have lost the GPS signal twice on long x-countries. (I have two independent GPS antennas)

I had a VOR in the plane but it will do me no good unless I know how to use it. So I have learned.:)

I won't spend the money on a certified GPS like the 430. makes no since for my mission and knowledge level. I have the VOR already.
 
Just a fun bit of information...
Doing a project for school a few weeks ago I came across this data; every year the upkeep and maintenance of all the VOR's in the United States costs over $110,000,000. Although VOR's are proven and useful, I wonder how long it will be until VOR's are all phased out?
 
r0cknry said:
Just a fun bit of information...
Doing a project for school a few weeks ago I came across this data; every year the upkeep and maintenance of all the VOR's in the United States costs over $110,000,000. Although VOR's are proven and useful, I wonder how long it will be until VOR's are all phased out?
Click to expand...

Google and read the Federal Radionavigation Plan.
 
My choice: I did not want any single point failures to put me in what I'd call an emergency situation, so I went with an SL-30 (VOR/ILS) and a 420W (GPS, no VOR).

Is flying with nothing but a TSO C-145/146 (WAAS) gps legal ifr? In the FAA's opinion, as expressed in AIM 1-1-20, yes. Is it smart? That's a question for the PIC to decide. Sometimes avionics just die.

Is flying with just a TSO C-129 GPS (e.g., Garmin 300) legal ifr? In the FAA's opinion, as expressed in AIM 1-1-19 d.1. (b) and e.2., no. The AIM says not even enroute is allowed without other nav aids on-board and useable, for a 129 box. Now, I know some on this forum say the AIM is not regulatory. I believe FAR 91.205 and 1.1 give the FAA the authority here. Again, your choice, just be forewarned that an FAA inspector won't approve of IFR with only a TSO 129 box. You can fight them in court, if you chose. Good luck.

Can you legally use a GPS to fly a VOR or NDB approach? No, not unless it says "VOR or RNAV(GPS)" in the title, in which case it isn't a VOR, it's a GPS approach you're flying.

Can GPS substitute for an NDB or DME fix on an ILS? Yes, if it's in the GPS database.

Is a C145/146 box expensive? Yes. I personally would not have bought one except my home airport has an ILS with "ADF required", and I could not stomach the thought of an ADF antenna on my new plane !!

Why didn't the FAA impose all these rules on VORs and NDBs? I think it's because of the current culture there, where things are made "safe" by imposing rules. If we didn't have VORs, and they were invented tomorrow, I'd bet that there would be all sorts of rules about them imposed on part 91 operators. The FAA regrets that they "missed their chance" to force part 91 operators to use TSO'd VORs, DMEs, ADFs, etc. When GPS came along they saw their chance to "do it right". Sorry about the rant.
 
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Equipment

With more and more NDB and VOR stations being decommissioned we too have asked the question about GPS reliability on our corporate aircraft. Back in 2009 the FAA required flights made with GPS navigation to have a RAIM check to determine about outages along a route

Although we utilize foreflight we check with FLTPLAN.com to determine our RAIM for a trip. Our Hawker 800XP uses GPS-GPS DME-DME for navigation and eventually will occasionally throw in a VOR radial to enhance navigation however we will get a message that the GPS or DME is unreliable.

5 years ago this was very common for a message to be displayed but with the RAIM requirement we have not had a failure if we had the RAIM prediction for the flight. You can go to Fltplan.com and get a RAIM prediction for a route. This is a requirement if you expect to use GPS for your approach under IFR conditions.
I have included a statement from their web site. Hey it's free and cost you nothing to use.

FltPlan.com automatically provides a GPS RAIM PREDICTION report for your flights on aircraft with GPS equipment.You will find a simple message on the bottom left side of the NavLog:
Starting July 1st 2009, GPS RAIM availability must be confirmed for the intended route of flight, that relies on GPS for navigation (route and time), using current GPS satellite information .

I am planning on using dual GPS units with separate antenna's for my RV7
If you have a certified WAAS GPS receiver you can shoot GPS approaches to their lowest minimum usually rivals ILS approach.

If everything fails. You can still have a ASR approach given to you and approach controllers like to practice this too.
With dual Dynons or GRT or any other manufacture with backup batteries and an IPAD standing by you don't need any further backups.
You only have one motor, 1 alternator, and the facts of accidents tell us that this just does not happen where you will get a total failure. If you have a back up battery.. You only have one alternator belt so lets be real about this.

Only my Opinion,
Smilin Jack
 
It may have already been mentioned, but under current rules a GPS only (no VOR, etc) aircraft cannot be used for an instrument flight test.

For an IPC you'll need a work-around, too.
 
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