One way that some instructors whet the appetite of prospective flight students is to take them on a short cross-country flight for a “hamburger” during the introductory flight. It usually works pretty well. The budding aviator returns from the flight brimming with excitement and anxious to share the experience with ground-bound friends and family.
After that introductory flight, the hooked student is typically restricted to the airport traffic pattern and a local practice area designated for airwork. The frustration of not being able to make consistently smooth landings blurs the fond memory of actually going somewhere.
But eventually the student is kicked out of the local nest and begins putting into practice the navigation skills learned for the knowledge exam. Without electronic aids (VOR, ADF or GPS) there are two basic ways of navigating in VFR conditions: dead reckoning and pilotage. (Celestial navigation is a third way but shooting a sighting with a sextant from a general aviation cockpit is difficult.)
There’s an ongoing argument whether the proper spelling is “dead” or “ded” reckoning. (The “ded” proponents argue it’s for “deduced,” while the “dead” group thinks the reference is from a naval practice of throwing a buoyant object overboard to determine the ship’s speed relative to the object, which was assumed to be “dead” in the water.)
To navigate by dead reckoning you start with a fixed point (your departure airport, for example) and using your heading, groundspeed (corrected for the wind direction and speed) and the elapsed time calculate your position. If you’re over a sparsely settled area or over water where there are no visual checkpoints, dead reckoning is the best you can do. On a pre-GPS flight in a Piper Chieftain with Russ Hancock, chief test pilot with Colemill Enterprises, from Cozumel, Mexico, to New Orleans, an over-water distance of 753 nm, dead reckoning brought us within a couple miles of our calculated landfall on the Louisiana coast. I was impressed at how well dead reckoning worked.
Pilotage, the other VFR navigation method (that uses elements of dead reckoning), is done by marking a course line on a chart (typically a sectional) and selecting easily identified visual checkpoints on the ground along the course and noting the distance between them. The rule is that everything that appears on the chart is on the ground, but not everything on the ground is on the chart. Pilots quickly learn what makes a good checkpoint and what doesn’t. Good checkpoints include: drive-in movie theaters with their large reflective screens; lakes with dams; highway intersections; track ovals; fuel farms; grain elevators; small towns and airports. It’s also helpful to pick checkpoints that are half a mile or a mile off to the left side of the course line, which makes it easier to more accurately time how long it takes to go between the checkpoints. With the time and distance between points, the groundspeed can be calculated to confirm that there are sufficient fuel reserves. Pilots soon learn that if they draw their course line from the center of the departure airport but then don’t turn to their on-course heading until they’ve climbed out several miles from the airport, they’re already off course. At an uncontrolled field, circling back over the airport well above the traffic pattern altitude and waiting to start the timing to the first checkpoint will at least get them started on the right course.
For decades pilots navigating by pilotage have been aided by “air markings,” a tradition of visually marking navigation details on buildings and airports that started in 1934 and continues today. According to an article by Ellen Nobles-Harris that appeared in the 99 News magazine, Phoebe F. Omlie, who had been appointed Special Assistant for Air Intelligence of the National Advisory Committee for Aeronautics (NACA, which eventually became NASA) in 1933, convinced the chief of the Airport Marking and Mapping Section of the Bureau of Air Commerce to support an effort to get each state to identify its towns from the air.
Under the marking program, the states were divided into sections of 20 square miles and a marker was painted on the roof of a prominent building with the name of the nearest town at each 15-mile interval.
By 1936, with the approval for 16,000 markings, Omlie enlisted Louise Thaden, Helen Richey, Blanche Noyes, Nancy Harkness and Helen McCloskey, five of the most prominent women pilots, to act as field representatives for the marking program. Adopted by the Ninety-Nines, the National Air Marking Program was the first U.S. government program initiated, planned and directed by a woman with an all-women staff.
After Pearl Harbor was attacked, there was a concern that the markings, particularly on the east and west coasts, would aid enemy pilots in locating potential targets. As a result, Blanche Noyes, a charter member of the Ninety-Nines (and eventually its president), and her team members who had created a number of markings went back and blacked them out. Following the war, Noyes, in charge of the air marking division of the Civil Aeronautics Administration, headed up the effort to replace the markings that had been covered over and to add more.
Today, Ninety-Nines chapters around the country continue to organize marking “parties” to paint compass roses and names on airports. No doubt many student pilots on solo cross-country flights have been relieved to see the name painted on the airport confirming they were landing at their intended destination.
Unfortunately, today pilotage and dead reckoning are rarely used skills, relegated to the bottom of flight bags, first by VORs, then loran and now GPS. Today the techniques are most frequently dusted off to satisfy the requirements of the knowledge exam and the practical flight test.
Over the years the sectional charts published by the government have attempted to keep pace with the changes in navigation technology. In the 1930s the charts showed courses described by light beacons; in the 1940s, A-N ranges were depicted; and in the 1950s VORs began to appear on the charts. The sectionals evolved from those with maps on one side with charts and graphs such as mileage between airports and other information on the back, to sectionals with maps on both sides and a slightly confusing way of drawing a course line that continues to the opposite side of the chart.
| ** Air marking painted by the Michigan Ninety-Nines at the Houghton County Memorial Airport (CMX); Jeppesen’s new VFR+GPS Chart** |
But now a new series of charts has been introduced that acknowledges the widespread use of GPS navigators. At AirVenture in Oshkosh last summer, Jeppesen announced its own version of new sectional-type charts. Jeppesen’s VFR+GPS charts, as the name implies, are designed specifically for those pilots using GPS as their primary navigation tool.
According to Jeppesen, the charts were developed with feedback from pilots to build the charts around actual flight paths used most often by VFR pilots. By combining a “better use of color, contrast and intuitive symbols” with cultural data from NAVTEQ, which provides information on roads, cities and points of interest that can easily be identified from the air, and terrain data from Space Shuttle radar missions, Jeppesen has created the next generation of visual aeronautical charts.
Like the earlier government sectionals, the map detail on Jepp’s VFR+GPS charts is printed on only one side. The back side features JeppGuide airport maps, a local area listing of motels, restaurants and auto rental agencies, an airspace diagram, control frequencies, special use airspace, the phonetic alphabet, a VFR cruising altitude diagram and a knots to miles-per-hour conversion table.
By the end of 2009, Jepp expects to have issued charts that cover the entire United States. By late 2008, charts were available for Florida/Georgia (SE-4, SE-7, SE-8 and Miami, Tampa/Orlando and Atlanta Area charts); Illinois/Wisconsin (GL-3 and Chicago Area charts); and Colorado (NC-14 and Denver Area charts). Jepp’s launch plans are to first offer coverage in the busier areas of the country where there is Class B airspace and then add the rest of the country. Price of the charts is $9.99.
Over the years, advances in electronic technology have made it harder for VFR pilots to get lost. Now with Jeppesen’s VFR+GPS charts, the paperware has caught up with the hardware and, as the coverage is expanded, it’ll be that much easier for VFR pilots to get from here to there.
