How accurate is the Argus?
No more, no less, than the long range navigation system supplying the data to the Argus. For example, Loran C accuracy is determined by the quality of reception (signal propagation), and the geometry between the receiver (you) and the transmitters. A full description of these factors can usually be found in a Loran C user’s manual. Under normally favorable circumstances, Loran C can give accuracy to 600 feet, and repeatability to 60 feet. Under less than favorable circumstances, it can degrade to a mile or so. GPS is typically much more accurate, but government-imposed “selective availability” can reduce its accuracy to 300 feet on a random basis. With typical navigation system accuracies the Argus can not only help you find the airport, it can even be useful for directional guidance while on the ground. Far more important, however, is what it can not do. Because of the error potential of the Loran C or GPS, you can not simply fly an approach using the Argus as a reference. Although th