Matthew Waugh

May 2002

Updated June 2002

As many people have pointed out, very few pilot’s are making full use of their GPS, and frankly it’s unlikely that many pilot’s are ever going to make the full use of their GPS. Perhaps if you own your own airplane and you’re an electronic and gadget freak you might know and use everything after a number of months, but for most of us it’s just not going to happen. We need to decide WHAT we’re going to learn, and we should make a thoughtful decision on how we’re going to invest our learning time and bran cells. So as you start educating yourself on GPS what should you learn first, second and so on to make the best use of your GPS.

This article is mostly targeted at pilot’s who rent or at least who fly different aircraft with different GPS equipment. When you step into the plane you don’t know how the last pilot may have configured the unit or what they may have been doing with it. The only thing we can be sure of, your preferences aren’t the same as the last pilot’s preferences.

This is just one person’s opinion, so if you have comments or feedback please send them along to me via e-mail at mat@mwaugh.com.

Turn it On and Off

So first things first, learn how to turn the GPS on and off. You want to know how to turn it on so you can use it (well duh!) but the startup sequence of any GPS I’ve seen involved more than just one knob turn or button push. You need to acknowledge database updates, acknowledge flight plans being cleared and help the unit figure out where it is. You also need to learn what the unit is telling you as it powers up. If your database is not up to date you may, at a minimum, be unable to legally fly approaches, and some units may decline to even allow you to select an approach to fly.

You also need to know how to turn your unit off. First off all you need to be able to turn off any piece of equipment in the cockpit off because it may be confusing you, and GPS has an infinite number of ways of doing that, and turning the unit off will concentrate your mind on the simpler navigation tools at your disposal. Secondly, turning the unit off will almost always return the unit to some reasonable state when it’s powered back on. Sometimes that’s your best option when you’re fifteen layers deep in a menu you don’t understand.

Initial Setup

You’ll also want to learn how to check and set some basic configuration options. For example on many systems there are options for how the map is displayed, common options include “track up” and “north up.” This is generally a preference item, and you’ll need to know both your preference and how to set that preference. Other things to check for are “CDI Scaling”, “flight plan clearing” and “track history” and any number of other options that can be tweaked. The manual will probably give you hints on the options that are most changed and over time you’ll figure it out. Ask other pilots and flight instructors for common configuration items they’ve encountered.

One pilot found the GPS wasn’t working and eventually it was determined that “somebody” had dived deep into the menus and found an option to turn off satellite reception in the unit. Why, who knows, and hopefully not a common “preference” you’ll run into.

You’ll also want to determine how to access the various information screens. At a minimum, on most units, you’ll want to know how to bring up the CDI display and the moving map, and in the case of the moving map how to change the scale. There are probably a number of other screens that will give you a variety of heading and track information as well as speeds and times. There are probably also options for determining what is displayed on the map, VORs, NDBs, intersections, airports etc. You’ll want to be familiar with how some of these options can be configured because it’s going to be disappointing to find that the display of airports has been suppressed on the moving map if it’s a feature you find useful (and who doesn’t?).

Go Direct

This is the level of expertise that many pilots reach and are perfectly happy with. This is the ability to go directly from the present position to a specific point which maybe a VOR, airport, NDB or any other kind of waypoint the GPS unit has in it’s database.

Know how your unit differentiates between types of fix. Some units want the leading ‘K’ (in the US) before an airport’s 3 unit id, some units have a separate item to choose between airports and VORs.

Also know how the NEAREST button works because you’ll often be able to use this button to choose from a list of waypoints and bypass the whole process of selecting individual letters.

If all you use is GPS Direct you’ve got a very functional navigation unit and, in my opinion, you can walk tall among your fellow pilots. You’re a safer pilot and, truth be known, most of the other pilots of your acquaintance are “direct” pilots as well.

Setting the OBS

In most GPS units you can set a course line from a waypoint so that you can navigate to that course using the CDI and you can see the course line displayed on the moving map. This is sort of one step above “go direct”, it lets you intercept a course and then go direct.

Flight Plans

The next step in your education should be flight plans. This allows you to enter a pre-determined set of points and you’ll be able to have the GPS unit lead you from one point to another. If you’re a “direct” pilot then you’ve been used to just plugging in the next waypoint as you pass the last waypoint, the wonder of a flight plan is you load all the points once.

Most units have stored flight plans and the concept of an active flight plan. When you load an active flight plan you can often choose to load it in reverse, so if you enter a flight plan for your outbound trip you don’t have to re-enter it to come back, just load it in reverse.

Earlier we noted in the configuration stage that you need to know how your unit clears flight plans. In one mode, as soon as you enter a “direct to” waypoint the entire flight plan is discarded, in another mode the direct to waypoint is put in front of the next waypoint to allow you to navigate to the direct waypoint and then to the original point on your flight plan. It can be disappointing to load a 16 point flight plan, have ATC give you a quick detour, and find you’ve blown all the active waypoints out of the system.

You’ll also need to know how to delete items from your flight plan and how to skip forward over segments. ATC may give you, or if you’re VFR you may decide, to bypass that dogleg and go direct to the next VOR down the line. You’ll need to know how to skip forward a segment in the active flight plan.

Approaches

For IFR pilots (rated or in training) the next thing to know is how to load approaches at your destination airport. The rules for what approaches can be loaded (often the destination must be the last point in your active flight plan) and the difference between loading an approach and activating it are all crucial.

Know how to handle vectors to final approach and how to skip segments of an approach (much like editing a flight plan).

Where am I?

It’s all very well using the GPS to know you’re on course and where you’re going, but do you actually know where you are, right now, and especially can you present the information in a format ATC can understand? ATC would prefer that you provide your position as Fix, Radial, Distance (FRD) and not as longitude and latitude. Most aviation GPS’s can provide a position as an FRD, although it may not be an obvious function but subsidary information as part of some other function. For example, the GX60 series of GPS provide the FRD as part of the “Arc Assist” page. So you can find out where you are based on the nearest navigational device (normally a VOR).

You also want to know how to change the fix that the FRD is based on, partly because ATC may want to know your position relative to a specific fix, but mainly because it’ll be useful in the next function we’ll describe.

On Course Heading

One of the advantages of a GPS is the ability and ATC’s willingness to allow you to go direct. You’ll often find that if you flight plan indicates you can go GPS direct that ATC will offer direct. However, in order to take advantage of this service ATC will often want to know “what’s your on course heading to XX”. This is where knowing your position as a FRD against a fix you can define will help you. By setting “XX” as the fix you’ll get the RADIAL  from the fix, reverse it to get the on course heading (and remember to reverse it, it’ll confuse ATC if you don’t).

Next!

We’ve exhausted my skills – what do you think should be next? Send me e-mail at mat@mwaugh.com and tell me.

Getting GPS Instruction

If you’re going to pay an instructor for GPS instruction understand first of all if the instructor has any experience with the GPS in order to be able to provide instruction. There is absolutely nothing wrong with working with your instructor as you both discover how the units works, and your instructor has to eat, so paying them for their time well may be appropriate. Just understand if they’re teaching or learning along with you so you’ll know how the session is going to go.

Don’t learn the GPS in the air. Sure, in the end you’ve got to fly some time with the GPS so you can put it all together, but running the engine, and for most of us more importantly running the Hobbs, is not necessary to learn 95% of what you want to learn about the GPS.

Most GPS manufacturers make available a simulator to run on a PC. Get a copy. Most GPS interfaces are a bit clunky anyway, and adding the limitations of a mouse can making it even weirder, but you can get the concepts down and you’ll actually find using the real unit easier than the simulator.

Read the manual, it can be hard work, and you may not want to read the whole thing, but dig into the parts of the manual that describe the things you want to achieve on the GPS, it’ll be worth the time and “no-doze” you have to eat to stay awake.

Sit in the plane and power-up the unit (make sure your plane isn’t one of those where the Hobbs runs off the master) and practice setting up configurations, entering some flight plans and approaches and dealing with changed clearances.

Finally – go out and fly the plane. Practice controlling the plane while configuring the GPS (unusual attitude recovery, it’s not just for flight reviews anymore) both VFR and under the hood. Practice using the GPS to drive the various navigations heads (CDI, HSI etc.) and make sure you know how to determine if the GPS  or the steam driven VOR is driving the needle.

Make sure SOMEBODY is looking out of the window. It’s all too easy for all the occupants of the plane to get heads down trying to figure out what the GPS is up to and end up with nobody performing the important function of “see and avoid”.