GPS Question?

[JetMouse]

I'm currently looking at a GPS as a back up to the PLOG. One question I have is about the maps built into the GPS. It seems people like Garmin expect you to pay about £30-£40 a month to download a new map.

For those of you who have a GPS do you actually do this? Is it that necessary? Your thoughts please...

Thanks
JM

[Mike Cross]

I have a Garmin 196 and find it excellent apart from one annoying fault. It seems the natural frequency of vibration of the mighty C85 on the Luscombe concides with that of the batteries and they vibrate. A momentary loss of connection is the result which makes the thing power down. Others have had the same problem. The remedy I use is some strips of foam draught excluder stuck on the inside of the battery cover to help stop them vibrating.

The onboard database has a lot of information in it, some of it, like frequencies and airspace, is subject to change, other parts like the location of airfields and towns is not.

Needless to say I don't use it to the exclusion of the chart so I rely on keeping the chart up to date and watching NOTAM. It's backed up by NavBox Pro, for which I do subscribe to the update service so my frequency lists and airspace are up to date when I am planning.

The 196 comes with one free update and I haven't felt the need to update since. I have however updated the system software a couple of times from the Garmin website. Watch out though because the update process is likely to wipe out all of your personal waypoints and stored routes.

CAA Chart Updates available here. (http://www.caa.co.uk/application.aspx?categoryid=64&pagetype=65&applicationid=8&mode=500map)

Mike

[DRJAD]

I have a GPS IIIP at present, and have had the unit for about two years.

In that time, I've updated the software once, and the database 4 times.

Always cross check with CAA VFR and Aerad IFR charts, and NOTAMS, after setting a route to fly. Seems to work.

[Three Blades]

If you are looking for simply a back up to your PLOG rather than a more complex system then even the simplest GPS will work well.
A Garmin Geko or eTrex can easily be loaded with waypoint and route dtat from a PC and can be used to keep you on track. Whilst it will not show you airspace and lots of pretty pictures, it only costs £100.
Now if you want to have GPS as an (unofficial) primary navigation aid then that is totally another question and another price.

[GroundBound]

The Garmins (and I suspect other manufacturers) are supplied with a Jeppeson database of aeronautical information, which is more or less current at the time of production (with 1 free update on purchase). This provides airports, runways, frequencies, navigation aids, airspace volumes etc. for a given area (e.g. Atlantic area = Europe and Africa).

However, the aeronautical data is subject to change every month according to the AIRAC cycle, so after one month some of the aeonautical data in your GPS is out of date, and you are probably missing some new data.

You can buy monthly updates from Jeppeson, through the Garmin site for around $40 a month, or a 13 month susbscription for +/- $300.

Whether you need to do this or not is a matter of choice - how much money do you have, what do you want the GPS aeronautical data for, and what has changed in your most-likely flying areas that you need to be updated in your GPS? Getting updates because of changes to ILS frequencies in Angola is maybe not the best of reasons. However, if the Birmingham TMA and CTRs have changed significiantly that might justify an update.

The "VFR GPS" aeronautical data, especially if not updated, should not be your first port of call for aeronautical information such as nav. aids, frequencies and controlled airspace. You can cross check your PLOG and the GPS to see if the aeronautical data corresponds.

If your current database properly reflects the area you are planning to fly in, then there should be no problem.

I took out a 13 month subscription but then decided it was too expensive. Now I update about 2 or 3 times a year (= 1 hour of flying).

(edited to add that nav. aid locations don't usually change much from month to month :) - however, airport frequencies can be more variable).

GB

[IO540]

This is one of the daft conflicts which presumably we have to live with.

From our training, we are supposed to use PRINTED charts for flight planning.

(Legally this isn't the case; the requirements tend to be phrased as "suitable" rather than "printed".)

Not because they are up to date (they hardly can be, being published once a year, or less often for many areas) but because they are "official". Why are they official? Perhaps it's tradition, but also there are not a few fingers in the map copyright gravy train!

On the other hand, one can buy software charts like e.g. Jeppesen FliteStar/FliteMap (some £500 for all of Europe, plus as much again every year for the 2-weekly update service - a comparable cost to buying the equivalent printed charts) and these will be a lot more up to date than anything that's printed.

Same goes for the databases in physical GPS units. Because there are no GPS approaches around here, there is no legal requirement to update the database. But if someone does, say every 6 months, they SHOULD have a more up to date database than anything one can buy.

The trouble is that anything other than printed charts (and SIA ones in France) is not going to count for much if one busts some airspace.

The other thing is that with a "VFR" GPS (basically any handheld unit) the vendor has no incentive to fix errors because they can always wash their hands of a problem, on the grounds that it is for supplementary nav only.

Even more strangely, the GPS Jepp database has things missing, which aren't missing from the GPS Jepp printed data (or the electronic data in FliteStar). E.g. airways are shown as just a line in the GPS databases whereas they are properly shown in the latter data. THAT is the main argument for having either the printed charts or the FliteStar electronic ones. (One can also print chart sections from the latter and this is how a lot of people completely avoid purchasing printed charts).

[Onan the Clumsy]

I updated my 295 once - about three years ago. I got the disk of ebay - a real one, not a knock off which made it a little cheaper.

It's a great unit but I don't use it for the info (that's a PITA to get to anyway) I just use it for speed, heading etc and the maps to see if I'm busting Bravo airspace. If they ever change, then I'll update the database.

It's a backup really. If I was in IFR, I'd have it updated regularly. (ok, and it'd be a 430 anyway)

[Johnm]

My wee pilot III has always had its software up to date and a dtatbase update spring and autumn. Seems to work OK, but I don't rely on frequencies etc. just the geography.