Handheld GPS Reviews

I had wanted a GPS since my early days of flying. I delayed buying one until after getting my private license and building a decent amount of cross country time. I needed to learn the traditional methods of navigation before getting a gadget that would do the work for me. I also put off the purchase until I bought a plane, just in the unlikely case that the plane came with a GPS installed.

Once I had a year of flying experience, I started looking for a GPS to buy. First I ruled out all panel-mounted units. They're high-priced, and by the time I go to sell my plane, they'll probably seem primitive compared to what's on the market then. Handheld units have more features at much lower cost (although they can't be used for instrument approaches like some of the in-dash models). The price range of handhelds is roughly $150 to $1200. Some of the cheaper ones (under $300 or so) aren't designed for aviation use, although some pilots use them. (Any GPS is better than none, but before you get one, be aware that some cheaper units don't work when you go faster than a preset speed, like 99 knots. You will also need to enter the latitude and longitude of every waypoint you want to use.) Next higher on the price scale are models that contain limited aviation databases. (Airports are included, but things like runway lengths, radio frequencies, etc. usually aren't. The Garmin 89 is a nice unit in this category.) Once you get above about $500, most units have moving maps and more detailed airport, airspace, and navaid information. A few newer models have ground mapping (coastlines, rivers, major roads, etc.).

Update: There are now hundreds of GPS models on the market. Most of them are not designed for aviation use. Many of the more expensive models have extensive maps for boating or driving. Price is no longer an indication of whether a GPS is suitable for aviation. Make sure you get one with an airport database.

After comparing features and prices, I narrowed my search to a few models: the Garmin GPS 90 and GPSMap 195, Lowrance AirMap, and II Morrow's Precedus. It would have been nice to see these units personally to compare them before buying, but I don't know of any places where I could do so. Most dealers are mail-order companies, or sell only one brand. I also didn't know anyone who owned any of these models, so I read all the reviews, articles, and ads I could find. I really wanted the ground mapping feature; all of these units except the Garmin 90 have it. That model has won a lot of praise and provides a lot of features for a good price (currently under $600 discounted), but I ruled it out mainly because its display is smaller and harder to read than the other models. Then I ruled out the Precedus, which has a display that wasn't designed for ground mapping and looks like it. The Garmin 195 has by far the best display of any handheld currently on the market, and may well be the best model overall, but naturally it costs quite a bit more than the others. (It's also hard to find in stock, and I don't like the way Garmin puts the buttons on the top and the display on the bottom. No other brands do that, and it seems like an awkward design to me.)

That left me with the Lowrance AirMap, the GPS I ended up buying. It was one of the first models I seriously considered, and it has about everything I wanted. One of its major strengths is that its operating software can be updated by the user. Lowrance has revised the software several times already, fixing problems and adding more features. They send users a cartridge which goes in the back of the unit. Turn the GPS on, and the new software is automatically installed, then mail the cartridge back. From what I've read, the company has been providing these software updates free to registered users, so be sure to send in the warranty card if you buy an AirMap. (They'll probably start charging eventually, but at least the unit can be easily upgraded. Most models cannot be upgraded at all; the few that can generally require you to return the GPS to the factory or a dealer.)

The Jeppesen aviation database can be updated in the same way, but the cartridge stays in. These updates come out every four weeks and cost $75 each (or $795 for a year's worth), so I won't be updating mine very often. All of the models have a way of updating the database, but some require a return to the factory or dealer, or a separate-cost kit which connects to a PC. If I wanted to use my AirMap for boating or another nonflying use, I could remove the Jeppesen cartridge to automatically turn off all the aviation features. My GPS came with an Americas database that covers the whole Western Hemisphere, not just North and South America, but the Caribbean-area islands and Hawaii, too. The unit has a world map built-in, but if you move the cursor to Europe, you'll see political boundaries without the detail. I asked for the nearest airport with the cursor in France, and it came up with one in Canada. I assume AirMaps sold on the other side of the pond cover the other hemisphere equally well.

Unlike some units that only work when they're tracking enough satellites to determine your position, you can use the AirMap anywhere. (You just won't know where you are!) This makes it handy for several purposes:

• Learn to use it at home (easier than trying to read the manual and keep the plane right-side up at the same time).
• Find the nearest airport to your destination, determine the distance, estimate the flying time, and check the info against current charts to make sure the frequencies and so forth are correct.
• Plan flights in detail with the route editor. You can store 20 routes of 20 waypoints each; a waypoint can be an airport, navaid, intersection, latitude/longitude, a spot marked when the satellite tracking is on (great for finding your house from the air) or anywhere you move the cursor. The editor shows the distance and bearing for each leg. A route can be flown forward or backward (although you need a really strong headwind), and you can jump from, say, waypoint 2 to waypoint 6, handy for IFR pilots who get cleared direct to a distant fix.
• Use the built-in simulator. Enter your groundspeed (say 200 knots) and destination, and the AirMap will display the same things you'd see if you were really flying your planned course. (This is much cheaper than buying a new Bonanza if you want to get somewhere fast.) You can even steer with the arrow keys.

The AirMap has more pages (screens) than anyone would use. There are several map pages, with data fields on the top, bottom, or side of the map. Some pages have multiple maps, and the fields can be customized, so there are thousands of combinations possible. Maps can be zoomed in or out with a map width range of 4000 nautical miles down to 0.1 nm. There's an auto-zoom feature which changes the map scale as you travel; the closer you are to your destination, the smaller the map width. I prefer to zoom manually, though, because I'd rather see the next ten or fifty miles in greater detail than a hundred-mile-wide map. There are several other pages which display satellite info, battery status, a self-test, a crude HSI, and more.

The map pages have an automatic declutter feature which removes detail as you zoom out. Unlike some units, the AirMap doesn't let you customize this. You have to turn all items of a certain type on or off. Some of these types are VORs, NDBs, intersections, special use airspace (each subtype, such as warning area or class D airspace can be set on or off), highways, etc. The unit does a pretty good job of decluttering; I'm not sure if being able to customize the algorithm would be much more useful. If the map looks too cluttered, I zoom out a bit.

The AirMap's ground mapping is very nice, but not flawless. The location of some roads are off a bit, and I've found at least one interstate highway that was mislabeled. (These problems are blamed on the government surveys that are the source of the surface data; the positioning may be less accurate than the surveying that's done for airports.) To reduce the clutter, many roads aren't labeled; sometimes zooming in or out or scrolling the map will cause a highway number symbol to appear. It would be nice to have a way of pointing to a road or other item and asking "What's this?", but I haven't found a way to do this. I understand the Garmin 195 has this feature. To be fair, though, the purpose of the map is to display your current position within a reasonable margin of error. It's not meant to replace a chart.

Coastlines and bodies of water seem to be shown more precisely, maybe because the AirMap evolved from a GPS developed for boating use. There's a small kidney-shaped lake about five miles from our airport that's used as a practice area, and the AirMap draws it just right. Water is shown in gray to stand out easily from land. (There's an option to reverse the setting, but it seems more natural to shade the water.)

One annoying thing is that diagrams for some airports aren't included (like my home airport), even though the other airport info is there. It would seem like simple math to draw the diagrams knowing the runway numbers and lengths, but for some reason that's not done. This is true of other GPS models as well, so it seems to be an issue with the Jeppesen database. The manual doesn't say what determines whether an airport diagram is available, but it seems that if the airport has no instrument approach, there's no diagram either. I'm not sure that makes sense, though, since handhelds aren't certified for approaches anyway, and the AirMap has no info on approaches in its database.

The AirMap's yoke mount hasn't received much praise, but I like it. It clamps onto the yoke in under a minute with no tools. Velcro is used to attach the GPS. Since the mount is flat, it could be used to hold a clipboard, timer, or anything else backed with velcro instead of the GPS. Unless velcro loses its holding ability over time, I don't see a problem with it. At home I attached the unit to the mount, turned it upside down, and shook it to simulate turbulence; I couldn't make the AirMap fall off. (And if I'm ever flying inverted in rough air, the GPS won't be my first concern anyway.) The mount can be easily adjusted to set a comfortable viewing angle. When attached, the AirMap is positioned so its display is right below the instruments, making it easy to fit into your scan.

The antenna also gets its share of bad press. It doubles as a protective cover for the display, but in the plane it must be removed from the unit to track satellites unless the GPS is right next to a window. Removing the antenna involves rotating thumbscrews in opposite directions; it's not the most elegant design, but it's not a big deal. The antenna can be attached to a window with suction cups. The first time I flew with it, I couldn't get the AirMap to acquire its position, but through trial and error I found a good spot for the antenna. (The problem is more with my plane's high wings than the antenna; all that metal blocks a good chunk of the sky, and low wing pilots will have much less trouble getting a signal than I do.) The antenna seems to work well mounted right below the "orange juice can" air vent on the left side of the windshield, and that position doesn't block my view. The GPS usually gets a fix within a minute; I turn it on right after starting the engine and by the time I taxi to the runup area, it's ready to go. On the rare occasions when it lost its position in the air, it got it back in a minute or less.

I've found a few other handy uses for the AirMap other than its primary task of pointing me toward my destination:

• The displayed ground track is useful as a training aid- compare the desired course with the actual path flown.
• The ground track display also helps fly more accurate holding and traffic patterns.
• The distance-to-go number is great for making accurate position reports and deciding when to begin a descent.
• The airspace display helps alert me to call before entering controlled airspace.
• It's easy to mark a waypoint to go around airspace I want to avoid, and I can prevent accidentally straying in without having to go many miles out of the way.
• Keeping the track equal to the bearing to the destination automatically compensates for wind drift.
• Position and distance from a VOR, NDB, or intersection can be used to backup conventional navigation equipment. (Or maybe it's the other way around; the GPS is a lot more accurate than an ADF or VOR receiver, and those don't display distances.)
• The nearest airports feature is great for emergencies, low fuel situations, or full bladders.
• Take the AirMap to the mall, and find your car when you leave.

(The above article was originally written in 1998, but the basics are still relevant.)

January 2003 Update: The AirMap has been replaced by the AirMap 100. There are a number of handheld units suitable for aviation use. Note that a lot of GPS models are made for hiking, driving, boating, or general use. Be sure you spend enough to get one with an airport database, at the very least. You can always use an aviation GPS for other uses.

December 2003 Update: Lowrance has announced more AirMap models. Check back here in January for more reviews of current GPS models.

GPS Info on the Internet

• Garmin.
• Lowrance Avionics.
• Trimble Navigation.
• sci.geo.satellite-nav newsgroup.