Using GPS

[RichieC43]

Hi Everyone,

Having never used a GPS and looking into the possibility of a USA flying holiday, I'm interested in what people make of flying with GPS.

Is it reliable enough to use as a primary nav aid, what's the accuracy like these days?

Are all GPS the same (or similar) or do I need specifically an aviation one?

How much information can be gleaned from it? Are we talking range and bearing to a nav aid/airfield in its basic form?

Thanks for any advice for a GPS Biff ;)

Thanks

Rich

[IO540]

GPS is very reliable and very accurate; just make sure you have an external aerial (or at least a suction-cup one attached to the inside top of the windscreen). Get an aircraft-powered (cigar lighter) one with internal batteries and carry spare batteries. Get one with a big moving map; anything less is a waste of time.

Regarding "primary nav", it is a bit of a misnomer because one should always use two methods concurrently; in VMC it could be GPS+map reading and in IMC GPS/VOR/DME. In practice the GPS will be entirely reliable and by far the most accurate 99.9% of the time but you need to be able to get about adequately using the other method if you have to.

[White Bear]

Heed IO540's advise, he is absolutely right.
Should you buy an aviation style GPS? In my opinion, yes. It'll have all the maps, airports, directories etc, already loaded, so turn it on, and go. It'll give you distance to destination, ETA (once airborne), your ground speed, what course your flying, what your tracking, how far off course you are, and what course to fly to get back on track, as well your altitude, and current position, and what ever else you set the screen up to display for you. If you can afford it, try a Garmin 295.

One very important caveat, LEARN HOW TO USE IT BEFORE FLYING WITH IT. The last thing you need should things go wrong, is to wrestle with the GPS unit because your not sure how program the next waypoint, or how to find the 'nearest' airport.

Secondly, I don't know about the UK, but in the U.S. you are required to carry current maps for any area you are flying over. My advise: Make a flight plan everytime, draw it out on your maps, and keep them handy. Pay attention to what the GPS is telling you, compare the ground your flying over to your map, and update your position every 15 min or so. Some terrain you might fly over might be quite featureless, no rivers, no roads, no towns for great distances. Pay attention. Maps by the way, are relatively cheap and easily available from any FBO.
Enjoy the friendly skies,
W.B.

[IO540]

Forgot to add: if buying a GPS in the UK, make sure it comes with a U.S. database! Some certainly don't.

Current charts, planning the whole flight (MSAs, planned altitudes, loading it all into the GPS) on the ground are all essential.

The Americans are also fond of PDA-based solutions and they've got some good ones over there; unfortunately they tend to come with poor European databases.

[flyingfemme]

If you're travelling small is good - Garmin Pilot III or GPS92 (no moving map) is good. The Pilot eats batteries faster than the 92.

You can download the database of your choice online for $35 from Garmin and swap between areas at will. Software updates are free.

If the unit has a basemap, that will not be changeable - so buy the area you fly most often and live with the downgrade when travelling.