FAA/Ohio University United Parcel Service DGPS Autoland Flight Test Demonstration

Test results are presented from a feasibility determination of Differential Global Positioning System (DGPS) Category (CAT) IIIb precision approach and landings. A code-based DGPS architecture with integrity monitoring was used. In addition, the feasibility of a combined DGPS/Instrument Landing System (ILS) architecture was evaluated. A total of 50 approaches were flown: thirty-two approaches used DGPS for both lateral and vertical guidance, 14 used DGPS for lateral and ILS for vertical guidance, and 4 approaches used ILS only. A United Parcel Service Boeing 757 was the test aircraft for all flight tests. The results of the tests show that code-based DGPS as well as combined DGPS/ILS, when used as the input to an autopilot, can attain vertical and lateral accuracies consistent with Required Navigation Performance for CAT IIIb.