Basic Professional Navigation Techniques

"To err is human, to forgive, divine." Let's take a look at how this oft-quoted phrase applies to the art and science of aviation. Certainly we as aviators, being mere mortal beings in a very complex world, are vulnerable to the most likely of fault-producing hazards: human error. Even the science fiction icon of artificial intelligence, HAL from Sir Arthur C. Clarke's novel 2001: A Space Odyssey, was convinced that the crew's problems stemmed from human error. Human error seems inevitable, and I myself am still pursuing the perfect flight. However, the goal should be to reduce the risk as much as possible in every conceivable way, so as to come nearer to that divine plateau of perfection.

Aviation, by its very nature, is for the most part unforgiving of mistakes. A famous photo of a World War I fighter aircraft suspended in a tree illustrates this point. The hapless pilot may or may not have lived to tell about it. If you have made your share of mistakes as I have, and are still here to talk about them and learn from them, then indeed aviation has granted you forgiveness so that you can tell others, and others can learn from your tales. One tale I am sure we all share is getting lost. The truth of the matter is that there are those who have and those who will. This insidious error has even crept into airline cockpits, obviously aviators in the "those who will" category.

In my particular incident, there I was, a fresh, young 18-year-old student pilot with a huge amount of flight time totaling 35 hours, on my way from Dubuque, Iowa, to Wausau, Wisconsin. I had just completed leg one of this triangular odyssey from Milwaukee without a hitch, noting that I had just flown an airplane by myself a longer distance than I had ever driven a car! Feeling somewhere between apprehensive and confident, I set out on the second leg. Coincidentally, but very relevant to this story, a very strong cold front had also started its trek along my intended flight path, moving west to east as I departed Dubuque.

Weather forecasting being how it is, my weather briefer indicated that cold front passage would take place sometime after the completion of my third leg, with a major wind shift taking place in conjunction with its passage across my flight path. As I sped toward Wausau, things began to get bumpy. Visibility also seemed to improve, which was a welcome change. But the most peculiar thing was that my calculated headings using dead reckoning just didn't seem to coincide with what I was seeing on the ground. The terrain and checkpoints below didn't look anything like what was beneath that thick pencil line on my sectional chart.

Deciding to cross-check this discrepancy by tuning in a VOR station on the pencil line, centering the CDI, and trying that heading, I found that I was almost 25 degrees off course. Convinced that the electronic navigation was not telling the truth after mustering up all of the experience that I could draw upon, I proceeded to fly my flight-planned headings as previously calculated, which were based on much different winds, and predictably missed Wausau by 50 miles.

Luckily, I found an airport that looked just like Wausau on the chart and landed there, still scratching my head over the navigation discrepancies. I finally learned that this was not Wausau upon opening the phone book in the booth adjacent to the FBO parking area. I entered early into the group of "those who have," and I learned an important lesson about trusting instrument indications - especially after searching and finding no reason not to trust what my instruments were indicating. Skepticism is actually healthy for aviators, but you should not vehemently argue with the facts.

Amazingly, every so often an airline crew stumbles into the "those who have" club by landing at the wrong airport, much to the dismay of the passengers who paid to get from "A" to "B" but somehow landed at "C." You have probably read about these incidents, and the setup is usually the same: nighttime, VFR conditions, two airports closely spaced with similar runway configurations, followed by the crew being "cleared for the visual approach" after stating that they have the intended runway (and airport) in sight.

I witnessed this exact scenario recently in the daytime, as a Boeing 727 airline crew called the runway in sight approaching over water toward the two shoreline airports only 13 miles apart. As they got closer, having called the field 30 miles away, an alert controller realized that they were lined up for the "right runway at the wrong airport" and queried them. The embarrassed crew turned the airplane away and landed at their intended destination without incident as scheduled, and no doubt they ate humble pie for dessert that night at the hotel restaurant. But isn't this the nature of aviation, never letting you get too confident over things? The moment you come to the erroneous conclusion that you have mastered aviation, you are promptly put in your place with the rest of us mortals who are striving to become perfect aviators every day.

Now let's take a look at how we can avoid these navigation errors which present themselves as opportunities on a daily basis for all aviators, from student to airline captains. Basically, with the exception of global positioning system (GPS) navigation, all civil aircraft en-route radio navigation is accomplished by linking aircraft radios with ground-based navigation installations. These ground installations include the nondirectional radio beacon or NDB, the VHF omni-directional range or VOR, the VHF omni-directional range/tactical air navigation or vortac (the tac, coming from the military need for tactical air navigation or TACAN, a transmitting unit which is integrated with VORs), and loran, which uses a network of 27 land-based radio transmitters to provide an accurate system for long-range navigation. (See the Aeronautical Information Manual for more about loran.)

You should determine the status of any navigation aid before even stepping into your airplane. This is accomplished by the Notices to Airmen (notam) system, time-critical aeronautical information which is of either a temporary nature or is not known far enough in advance to permit publication on charts or in other operational publications. If a VOR, vortac, or NDB is inoperative along your route of flight, you will hear about it through the notam system during your weather briefing from the flight service station. These navigation facility status changes are noted in the category called Notam (D) or distant. Other categories not related to navigation include Notam (L) or local, and Flight Data Center (FDC) notams, which include changes on aeronautical charts.

By obtaining a proper and thorough preflight briefing, you can eliminate one of the reasons why you "cannot seem to pick up anything from the 'Alpha VOR.'" This is part of being a professional in the cockpit. Your fellow aviators feel it is bad form if you notify ATC that a certain VOR is off the air, when indeed it was notamed off the air two days ago.

The next important check is making sure all of your navigation instruments in the cockpit are turned on before taxiing, even if you do not plan to use all of them. Get in the habit of doing things the way professional aviators do them. You may end up being paid to fly some day, and even if not, it pays to fly the same professional way. Identify navigation stations before takeoff if possible, making sure that the Morse code identification for that particular VOR or NDB matches the ident code on your navigation chart. This is critical, because that radios are just electronic/mechanical devices subject to failure or performing improperly on a whim.

If you don't hear the proper ident - or anything, for that matter - your aircraft radio and the ground station are not in agreement for some reason, and now the troubleshooting must continue. On certain radios, the mechanical frequency digit selection knob may slip, causing a different frequency to be selected other than the one that is displayed. The only way you would know this is by checking the ident feature before relying on this radio for navigation. A red flag or similar warning (depending on the radio) would not necessarily appear to tell you of this problem. If you are using the type of ADF receiver commonly found in most airplanes (including the airliner I fly), there are no flags or indications of malfunction when using this radio. The only way you know that it is working properly is by the continuous ident heard on your speaker or headset.

Airline crews routinely fly NDB approaches in simulators and sometimes in actual flight. Woe to the airman who does not have the ident feature squawking in the background, as the NDB will mysteriously fail every time, leading to a very interesting arrival to the international airport. NDB range is limited to about 35 nautical miles, so beware when attempting to navigate precisely using them. You might as well be flying in the Bermuda Triangle, relying on NDBs beyond this range.

VORs and vortacs come in three classes with varying range and altitude parameters for navigation. Class T (terminal) is good out to 25 nm from 1,000 feet to 12,000 feet above ground level (agl), Class L (low altitude) is reliable out to 40 nm between 1,000 and 18,000 feet agl, and Class H (high altitude) works well to 40 nm from 1,000 to 14,500 feet agl. Above 14,500 feet agl, they are reliable out to 100 nm and beyond at jet altitudes. So again, plan your flights accordingly, using navigation facilities that are within range of your aircraft.

But none of this equipment will be helpful if the pilot doesn't make use of it. Even when flying primarily via pilotage, keep your VOR receiver tuned to a nearby navaid. With two VOR receivers, you can easily track a course between two VORs - and if your route is off the airways, you can use two nav receivers to quickly triangulate your position. By continually checking your pilotage against radio navigation aids, or vice versa, you'll avoid the embarrassment that I faced years ago when I landed at what I thought was Wausau.

Speaking of ground installations for navigation, there is also another oft-forgotten system worth mentioning. The VHF direction finder (or DF steer) is one of the common systems that help pilots without their being aware of its operation. It is a radio receiver used by the operator of a ground station listed in the Airport/Facility Directory, which indicates the magnetic direction of the aircraft from the ground station each time the aircraft transmits. FSS personnel have assisted many lost VFR pilots using this equipment, giving them a steer home.

Sometimes it is the basics in aviation that seem routine and automatic, but if not understood or used properly can lead to situations adding one more link to the "PJ Chain" (poor judgment chain). This in turn can add so much additional weight to a flight that the end result is an emergency. A good common-sense, professional approach to your flying will take you a long way � safely - and allow you to break that chain before you even get off the ground. A professional aviator would not have it any other way.

Joel Stoller is a Douglas DC-9 captain for Midwest Express Airlines. He is also a part-time flight instructor who has more than 16,000 flying hours, including more than 600 hours of dual instruction.