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About the Companions:
The Plane & Pilot Review

By Bill Cox, Plane & Pilot Magazine
March 1998

A Practical GPS Guide

I was flying back from Oklahoma in a Riley 414, tracking west over Las Vegas and Death Valley on one of those CAVU chamber of commerce days. We'd stopped for fuel and lunch in Farmington, N.M.,then launched on the final over-mountain portion of our trip to Victor Aviation at Palo Alto Airport on the San Francisco Bay. We were just crossing the Panamint Range when my right-seat passenger asked me which of the mountains ahead was Mount Whitney.

Despite the excellent visibility, I'd filed IFR for the trip so I could use FL2OO where the airplane is most comfortable and does some of its best work. Looking down on the mountains, one peak looked pretty much like another. Trying not to sound too stupid, I picked out what I thought was the biggest and identified it as 14,491-foot Mount Whitney.

As we neared the Sierra Nevada, it became obvious I didn't know of what I spoke. I'd flown along the spine of those mountains dozens of times, and it was always a little confusing trying to pick out the exact promontory that resides as the tallest in the contiguous 48 states.

There are at least a half dozen peaks that top 14 000 feet in the general area of Whitney and choosing the right one as the highest can be a daunting task especially if you're navigating with only a high altitude en route chart in your lap. The high perspective doesn't allow any one mountain to stand out as the tallest.

Drawing on past experience flying air-to-air photo missions above the High Sierra, I told my passenger to look for a mountain with a relatively flat peak and an aluminum building on the top. We didn't spot it, so I knew I'd missed the right mountain. I had a GPS mounted on the panel of the 414, plus two handhelds in my flight bag, but I had no information on the exact location of Mount Whitney.

Less than a week later, my friend Clayton Wendt of Minneapolis, a regular contributor to Prodigy computer service's aviation bulletin board, dropped me an e-mail about his newest publication, the GPS Companion. Clayton is publishing perhaps the most comprehensive GPS guide I've ever seen, and it's only peripherally related to aviation.

The waypoints identified are so numerous, in fact, that it's not practical to publish one edition for the entire country. Instead, Clayton publishes one for each state. As this is written, Wendt has GPS Companion guides out for Minnesota, Wisconsin, Illinois, Florida and California, and he's working on the other states as quickly as he can.

Okay, you may be saying, what's so special about the GPS Companions? First, as mentioned above, they're not confined to aviation information. Wendt is an active pilot with a Cessna 170B, but he knew he needed to slant the new publications for a more general audience to have any chance of making a profit. For that reason, the publisher included all the airports in the respective states, but concentrated on listing virtually every other point of interest anyone could ask for, pilot or non-pilot.

Wendt knew that GPS is rapidly infiltrating the consumer market, especially on autos and motorcycles. Pep Boys, the huge auto parts and accessories company, currently is marketing a consumer version of the Garmin GPS-3, and I've recently seen ads for the same box in both Cycle World and Motor Trend magazines.

The California book is the largest so far, and the GPS Companion's list of waypoints for that state includes the locations of: 5338 cities and towns; 385 golf courses; 365 mountain peaks; 229 state and national parks; 221 public beaches; 181 colleges and universities; 144 water falls; 121 museums; 48 wineries; 32 piers and wharfs; 30 lighthouses; 20 racetracks; 13 observatories; and about 2000 other locations ranging from amusement parks, aquariums and stadiums to ski areas, dams and rock formations.

Wendt uses government survey data whenever possible to determine exact lat/lon coordinates and elevation. The position stated is accurate, right down to minute of angle. A minute of angle of latitude is exactly one nm and about 0.85 nm of longitude in the mid-United States, so a position stated to a second of arc places it within a box of roughly 100 square feet. (This assumes the coordinates calculated by the U.S. Geologic Survey are correct, and that's open to debate.) One hundred feet is the level of accuracy you can expect on most of the waypoints published in the compact GPS Companion series.

With Wendt's handy little 4x5 book in my flight bag, I'll now be able to fly directly to Mount Whitney at 36 34 45 N 118 70 30 W and point out the peak with confidence. Alternately, I'll be able to zero in on Hearst Castle at 35 41 07 N 121 10 00 W and fly directly over the huge, rectangular reflecting pool.

As usual, the standard proviso applies to any product not specifically approved by the FAA for navigation, and you'll find the obligatory warning in the front of every GPS Companion: "Airport location data isn't approved for aerial navigation." That doesn't mean you can't use the information in the Companion to help find airports, only that you need to have an approved navigation source on board. The various GPS Companions probably won't be updated-no reason since there's no certification involved, so Wendt is one of the first to admit the positions won't always be totally accurate.

If you're looking for something other than an airport such as Bridalveil Falls in Yosemite (37 43 00 N 119 38 45 W), you'll find Wendt's California GPS Companion an indispensable guide.

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