Old Garmin GPS units

Nick Allen · Post by **Nick Allen** » Tue Feb 12, 2008 9:01 am

an equally old gizmo that just tells me on a two line display more or less where I am, using terms like "2 miles NW of Salisbury"

Ahh, that sounds like my old friend the Skyforce Locator. Wonderful object; and you're right that it's an fine enchancement to map-reading. Given how much they are fought over on eBay, seems like they should still be selling them new!

J.C. · Post by **J.C.** » Tue Feb 12, 2008 7:32 pm

Last year I bought an all singing and dancing job not in black and white (I can't spell colour),with terrain awarenes etc etc.
I just couldn't get on with it,it took ages to sort out,took up loads of room and I never trusted it because I knew I probably hadn't programmed it correctly!
Back to the trusty Garmin Pilot 111 for me!

Pete · Post by **Pete** » Wed Feb 13, 2008 5:53 pm

exactly my experience, some of them fail the KISS test.

The last thing that you want is to have to spend brain cycles on those things. I ponder the question - how many car crashes were caused by GPSitis.

That's not to say that they are not valuable, but anything much more than a heading indicator, and airspace markers are more confusion than help. What's the point of having green for land and blue for sea, you can see that out the window, if you can't, then you are flying illegally

I really don't get this biz of carrying an old model GPS as standby. If you haven't used it in a year or more, the chances are you won't remember how to use the thing !!

PB · Post by PB » Wed Feb 13, 2008 10:38 pm

Jeremy

You will be pleased to know that the Garmin 196C GPS has exactly the functionality you are looking for. In so far as I am aware it is also a function on the 296 and 496.

I use it all the time when giving position reports. If you are caught unawares by an ATC request for position I can usualy get the information up on the screen before I have my finger down on the PTT button.

At the bottom of the Position Page (one single button press away from the moving map) is a little legend that tells you how far away and on what radial you are from some local easily recognised feature.

In the above screen grab from the Garmin instruction manual the unit is 2.9 miles from Johnson County Executive airport on the 276 radial. In the UK it seems to give positions in relation to airfields and bigger towns. I'm really not sure how much simpler than that they can make it. (And yes, I know radials are normally true but there is nowhere in the UK it will make any significant difference.)

When you have purchased your unit, I will happily give you an hour of my time to run through some simple tricks on how to get the best from it.

Dave Hall · Post by **Dave Hall** » Thu Feb 14, 2008 1:01 pm

Pete, the idea was to have the GPS programmed with waypoints and capable of supporting a query if the pilot was getting a bit concerned that his nav was off, or the destination airfield was being a bit reluctant to show itself. A sort of confidence booster, really, for venturing further afield.
I'm in Jeremy's camp on what I would want from a GPS - looks like I can continue to use a chart and enjoy the view!

Pete · Post by **Pete** » Thu Feb 14, 2008 5:24 pm

Dave,

Don't get me wrong, I wasn't disparaging the use of an elderly GPS, just making the point that these folks who use a modern gee whizz *96 as their primary means of navigation and claim they have the old GPS as backup are kidding themselves.

Islander · Post by **Islander** » Thu Feb 14, 2008 10:12 pm

Jeremy Harris wrote:I sincerely hope that no one ever uses a GPS of any flavour as a primary means of navigation. As far as I'm aware this still unlawful, as GPS remains unapproved as a primary navigation system. Jeremy

Complete piffle, but don't let a lack of knowledge of a) aviation law, and b) current aviation practice stop you from spreading baseless nonsense!

As it happens:

1. The UK ANO stipulates no required means for primary navigation under VFR, nor does it disallow any particular means.

2. For compliance with European BRNAV requirements under IFR, GPS is the only approved primary navigation system that is likely to be found in a GA aeroplane!

3. How do you think it is possible to fly an RNAV (GNSS) instrument approach if GPS remains unapproved for primary navigation? With a map, compass and stopwatch?

4. How do you think it is possible to fly a PRNAV precision terminal procedure in a GA aeroplane if GPS remains unapproved for primary navigation. With a VOR/DME?

4. In support (!!!) of your contention that GPS is unreliable for aviation use, the USA currently has in excess of 6,500 instrument approach procedures based on sole-use of GPS. Over 1,000 of these are semi-precision approaches with minima similar to an ILS approach!

None of which is to say that the map, compass and stopwatch method isn't perfectly adequate for primary navigation under VFR. But it is quite wrong to suggest that the method is a) the only legally-available method, or b) even the safer or superior method!

Nick Allen · Post by **Nick Allen** » Thu Feb 14, 2008 11:51 pm

Well to be fair to Jeremy, GPS approaches were only approved in the UK very recently, and the CAA's publication on GPS (http://www.caa.co.uk/docs/33/SRG_GAD_SSL25.PDF) still says (in red): GPS must not be relied upon as a sole navigation reference in flight critical conditions. (Though it doesn't say what "flight critical" means!)
Out of interest, does anyone know if North America still has better GPS courtesy of the WAAS system, or has some technomagic brought the rest of the world up to this level?

Steve Brown · Post by **Steve Brown** » Fri Feb 15, 2008 4:09 pm

In full it says
The GPS system has generally shown
exceptional reliability, but it has been known to
suffer technical and human failure.
Consequently, GPS must not be relied upon
as a sole navigation reference in flight
critical applications.

That statement implies one should never use any system as a sole navigation reference in flight critical applications because all systems have been known to fail!!!!!

Yet the CAA allow ADF or VOR etc ( ie failure prone 'systems') as a previous poster points out - and for approaches too in mountainous terrrain !!!! - not just en route navigation.

How odd that GPS is singled out this way.

The ANO is the instrument that you will be proscecuted under - not loosely termed, abiguous and biased GA leaflets with undefined terms etc - good as they are for general advice!!!

Bill McCarthy · Post by **Bill McCarthy** » Fri Feb 15, 2008 4:30 pm

'Struth, I didn't know that all the world airlines are still using aeronautical charts and star navigational systems !!
It would appear that if the CAA were responsible for marine administration, ships would still be using sextants and such like.

I think my "Skyforce Locator" may be beyond repair. When I plugged in my Garmin to it, it went up in a puff of smoke with the screen going psychedelic.

Steve Brown · Post by **Steve Brown** » Fri Feb 15, 2008 5:36 pm

I looked at ( admittedly only ) one of these units :

quote

This GPS jammer simply plugs into your car charger and jams any signal broadcasting within 1450 to 1600Mhz range. It’s coverage is about 2 to 4 meters which is big enough to interrupt any GPS tracking device that may have been implemented in your vehicle. Pricing is not known yet but check out this site soon for it will be available very soon.

end quote

I don't think this particular unit will concern me too much at around 1000ft + altitude.

Must remember you can still get lost using a 'primary navigation aid' map ( ie a human system failure - or maybe it just blows away from your open cockpit) so should we be wary of not using maps too!!!!?

We are talking VFR in VMC here - having a map as backup / standby is okay isnt it?

(I gather there are no regulations about carrying any radio navigation equipment when IFR in IMC in uncontrolled airspace!)