National Airspace System: Questions Concerning FAA's Wide Area Augmentation System

Pursuant to a congressional request, GAO responded to questions concerning the Federal Aviation Administration's (FAA) Wide Area Augmentation System's (WAAS) development costs and the FAA's decision to replace the contractor, focusing on the: (1) history of WAAS cost estimates and major factors in cost changes; (2) history of WAAS program requirement changes and sources for these changes; (3) factors in FAA's decision to terminate the Wilcox contract; and (4) implications of ending WAAS' development at the completion of Phase I.