GPS -v- MAP

[old man emu]

Recent experience has convinced me that I will NEVER use a GPS as my primary source of information for navigation.

 

I've been driving here and there in England in overcast and rainy weather. So far I have not been able to determine satisfactorily from sun sightings where the Cardinal Points are. Also I haven't got the mental picture of the location of towns and cities on a map that I have of places in Australia. I have, however, been using a Tom-Tom for getting from place to place.

 

Although roads in England are very well signposted with their number A1, B146, etc, and there are signs which tell the distance to the next town, if you are going 50-60 kilometres from point to point, the signage is not much help because it doesn't give the distance to distant points.

 

I have found the GPS to be very accurate over the short distance, but have had to purchase a book of road maps so I can have an idea of the route of my whole trip. Now I can plan a trip using the GPS, preview it by running a simulation while cross-referencing it to the map. Being able to do this has increased my confidence in the GPS, but has not convinced me that I should ever abandon the printed map. The GPS is great for navigating round-a-bouts, which proliferate here, and for time estimates, but if it ever fails, the piece of paper with squiggly lines on it will bring me back to hearth and home.

 

Old Man Emu

 

 

[nathan_c]

not that you should ever not use maps, but to play the devils advocate (bare in mind my very limited experience) surely there is a huge difference between using a car gps and an aviation gps?

 

 

[Guest nunans]

Alot of the gps units rec flyers use are not particularly more tested or certified than your average automotive gps. Just different softwareand maps as far as i understand. There are tso'd aviation gps units that are used for RNAV approaches etc but not many raaus registered aircraft would be fitted with one.

 

 

[dazza 38]

My Car GPS Garmin 1390T or something like that. It is pretty accurate, even down to the speed limit sign on the GPS screen changing from one speed zone to the next with in a couple of meters of the speed limit road sign. Not bad when doing a 100 KPH

 

 

[old man emu]

I'm not bagging GPS units. I'm just saying that despite all their whizz-bangery, I wouldn't use them as my primary navigation tool.

 

OME

 

 

[Sapphire]

Navigation courses never have you use gps as primary source. Though there are times when dead reconing can be luck. Try fly much east of Victoria River Downs

 

 

[Guest SAJabiruflyer]

I'm not bagging GPS units. I'm just saying that despite all their whizz-bangery, I wouldn't use them as my primary navigation tool.OME

I hate to say it, but as someone who fixes computer equipment, I dont have a lot of faith in technology. At work we've only just gone to an electronic diary, after me resisting it for years. I know my paper diary never crashed, never rebooted, never lost data. So, when flying, how about MAPS front and centre, then plane's GPS, your iPhone's GPS with OzRunways, and your iPad with OzRunways. Surely 3 devices cant all fail....

 

 

[Sapphire]

I am Borg-I never get lost

 

 

[facthunter]

If they all rely on the same satellites the system is not fail safe. They can be de-activated..Nev

 

 

[turboplanner]

The way George Bush senior has been acting, he could organize Obama to turn them off Nev.

 

 

[Sapphire]

If they all rely on the same satellites the system is not fail safe. They can be de-activated..Nev

When they get turned off, that will separate educated from the uneducated.

 

 

[kaz3g]

Hey guys... Every time you step into an aeroplane you are placing your trust in technology.

 

Navigation systems have been around since the 30's when pilots followed the "beam". Then came ADF and VOR. Then we got Loran C which was only good for shorter distances and primarily land-based ops until Omega gave blue water coverage. Now we have GPS and sextants are a collectors item.

 

Every one of these was and remains an aid to navigation. Remember the Italian liner captain a year or so back who ran aground while doing a sail past for the masses? He didn't look at his charts. He didn't need paper charts because he had the electronic version right there on the screen in front of him but he did have to look at it.

 

Most of the time when I'm flying I don't need to look at my paper charts, either. I have used the AirNav moving map system with Air Services charts and approvals for the last 5 years or so and found it extremely accurate. I now use Ozrunways as well and I still have my panel mounted Garmin. there is even a RecFlying unit in my flight bag so I can find my way on the ground when I arrive. They give me great confidence and reduce the workload when flying over long distances and in remote areas.

 

But my paper charts are there beside me together with my flight plan as required by law so I can revert to them if WWIII breaks out or if I have a total electronic failure. And, if that happens, I will be starting on paper with a very clear fix of my current position, clock and compass to help me.

 

Kaz

 

 

[Sapphire]

I've seen pilots come out of a/c looking like lit christmas trees. When the lights go out, so do you unless you have your map "as required by law". [or you already know the route] Who needs a law when all you need is common sense.

 

 

[facthunter]

The essence of navigating is to never rely on a single source of data. There has to be something to verify it by. The DC 10 Erebus catastrophe relied on One set of Data to put the plane where it went, and that had been altered and not picked up. The plane flew on a different track.

 

It's like applying the variation or wind in the wrong sense or loading the fuel in kilo's instead of pounds/ litres /us gallons imperial gallons etc. Never trust just one thing. Have someone else check your figures Does the figure you have got fit the standard range of possibilities for that operation. ie 3 hour flight @ 25 lit/hour and Fuel carried total 70? What!! That's not a seven it's a 9. we should have 90 not 70.. Nev

 

 

[dodo]

I think OME's basic point is that using GPS alone, you lose orientation. It is way too easy to just follow directions. If for somereason you then have to change your plan, youdon't have a mental picture of where you are relative to the main features or locations you need.

 

As along time map user in a car, I still find it slightly disturbing to navigate by GPS. the reason I use GPS is because I can't reasonably read a map in one hand and drive in traffic, but it leaves me unsure of where I am. Perhaps a bigger, more comprehensive GPS - but if I don't have the time/concentration to spare to look at a map, I won't have it for a large format GPS map either.

 

As an example, using GPS for navigation in a strange country, needing to divert would leave you unsure of the relationship between possible diversions.

 

Of course, proper pre-trip planning obviates most of this, but in an unfamiliar area, it isn't practical to get a comprehensive idea of locations in a few hours.

 

My guess is GPS will become all-pervasive, and a few unwary pilots will die because they trusted in one device, without a wider or more comprehensive awareness of their surroundings. Or maybe I am getting old.

 

dodo

 

 

[poteroo]

I guess that reliance on any single reference is risky. Cross-referencing is the go. WW2 pilots in PNG relied on their altimeters to cross the Finisterre and Owen Stanley ranges, and although the instruments were reading accurately - the tops of many peaks were inaccurate, and in the wrong sense. There is still a lot of aluminium up in the mists of PNG's peaks, and it was a mapping problem.

 

GPS is actually an excellent 'teaching' aid for pilots doing their initial navs. It can be used to graphically show drift from heading to track, and to reveal the changing wind directions and speeds at different altitudes. It can be used to confirm abeam positions calculated off the map, and it's also a good 'tool' to confirm intercepting an outbound track when this is done by 'eye' under VFR. Then - it gets turned off and the student is back with maps again.

 

happy days,

 

 

[turboplanner]

If anyone wants a deep understanding of navigation, from a natural viewpoint that has never appeared in any Australian aviation training, I'd recommend "We, the Navigators" by David Lewis.

 

The first thirty or so pages are hard work because he is setting the scene, but then he goes on location with the living descendents of the old Polynesian navigators - the guys who could navigate from Tahiti to Hawaii and back again, to an accuracy of around 30 miles in 500 without ever using a compass or clock.

 

It shows how they navigate from stars , starting with a recognised star on the horizon and accurately placing the canoe, then as the star sets, picking up the next star approaching the horizon. It covers navigating by wave pattern, winds, and using land birds to widen the footprint of an island from 60 to 100 miles (watching the birds fishing during the day, and making a bee line for land at the end of the day), and it shows how the navigators would engage a long string of islands obliquely so they couldn't miss engaging bird life etc.

 

We orientate to our own position when we navigate, but some of the Polynesians orientate to a datum island, te advantage being that the know the island will always be in a particular star location, or wind pattern.

 

On trips of 50 or so miles, it was not unusual for the navigators to sail straight to the channel into the lagoon, without any instruments.

 

I'll certainly be lookig at Navigation from a different point of view in the future.

 

 

[fly_tornado]

Could just be the English weather. I wouldn't want to be flying around the UK in December.

 

 

[Jabiru Phil]

Do all the merchant and cruise ships in the oceans have road maps?

 

Just a thought.

 

I was leaving a USA city some years ago before gps time. I did about 70 miles circling the city in smog before my wife mentioned that the same sky scraper seems to be not moving. I had a map too

 

Having spent many years in the bush has made me more aware of the natural landcrape for navigation on cloudy days, for instance, wind direction and sand hill direction for that area.

 

Must admit that I carry 2 X gps and all maps for the areas plus Ozrunways. Keeps me occupied on longer trips and I enjoy the excercise.

 

Phil

 

 

[old man emu]

Could just be the English weather. I wouldn't want to be flying around the UK in December.

Sounds like to weather in eastern Australia hasn't been too bright either.

 

Until I find an airfield, I'm going to be travelling like an emu. The only birds moving in England at the moment are the ducks and swans.

 

OME

 

 

[Herm]

And make sure your compass was not made in China. Most Compass in LSA aircraft are as reliable as the one I had in my Bata Scout shoe. This IMHO is the weak point in most cases. Not the electronics.

 

Mardy

 

 

[Thalass]

As an avionics AME i'm all for shiny technology. But i still check the route my gps has picked for me, and memorise the street latouts so i have sone situational awareness. I don't like just blindly following instructions from a machine. The same would apply in the air. Note that a particular hill should appear at a particular time or distance, etc, so i have some idea what to expect. The same that you would do with a dead tree format map. Of course my flying experience is minimal so i can't talk much.

 

 

[68volksy]

When I was six years old i learnt to use a map. Never had to be re-trained in how to use it or had to upgrade my hardware. Never had to replace the batteries. Never tried to bore anyone to death pointing at all the cool little blue dots and pink lines. It's always moved the way I want - even when I have greasy fingers. In the same vein it's always zoomed to exactly the right ratio through a little flex of the elbow and wrist. Never been concerned about dropping it or leaving it in the sun or dribbling my coffee on it. It has the greatest little moving cursor that shows exactly where I am at any time and is shaped just like my finger although it has the option to change the shape to look like the tip of my pencil.

 

 

[Yenn]

"I am Borg-I never get lost" Sapphire, I don't understand this quotation, maybe you can enlighten me. My name is Borg and I can't say that I have never been lost, but I have always worked out where I was eventually.

 

As far as I am concerned tha GPS is a good aid, but watch it with a jaundiced eye. I had an aerial come off one day while on a cross country flight. No problems, but the gPS does make it easy togive an ETA or distance and bearing from a known point to another plane. I don't trust it after seeing it point off 45 degrees from my destination which was in sight. It did that 3 times on a there and back trip.

 

 

[Ryanm]

"I am Borg-I never get lost" Sapphire, I don't understand this quotation, maybe you can enlighten me. My name is Borg and I can't say that I have never been lost, but I have always worked out where I was eventually.As far as I am concerned tha GPS is a good aid, but watch it with a jaundiced eye. I had an aerial come off one day while on a cross country flight. No problems, but the gPS does make it easy togive an ETA or distance and bearing from a known point to another plane. I don't trust it after seeing it point off 45 degrees from my destination which was in sight. It did that 3 times on a there and back trip.

Was the arrival airfield programmed into the GPS correctly? It may have had a slightly off lat/long position.