THE US GENERAL Accounting Office (GAO) is raising doubts over the Federal Aviation Administration's ability to meet its global-positioning-system (GPS) implementation schedule.

The investigative arm of the US Congress has recommended that Transportation Secretary Federico Pena direct the FAA to come up with a comprehensive plan for augmenting the GPS. The plan should lay out schedule and cost estimates for developing and implementing wide- and local-area augmentation systems (W/LAAS), it says.

Although the FAA has met GPS milestones to date, "the agency will face more complex and difficult tasks in achieving future milestones," the GAO says. It expresses particular concern over the FAA's schedule for developing and fielding the WAAS.

The GAO questions whether the WAAS can be implemented by 1997 as planned, because software development alone may take 24-28 months, and could be slowed by "difficulties" beyond FAA control. It says that GPS planning is not comprehensive since it lacks detailed schedule and cost estimates. The FAA insists that its WAAS schedule is achievable.

Source: Flight International