GAO casts doubt on FAA satellite program
- By Paula Shaki Trimble
- Jun 14, 2000
It is unclear whether the benefits make up for the cost of a new space-
and ground-based navigation system being developed by the Federal Aviation
Administration, according to a General Accounting Office review of the FAA's
Wide Area Augmentation System released Tuesday.
WAAS will be a network of reference stations and communications satellites.
It will verify and correct the signal received from the Defense Department's
Global Positioning System satellites before sending the navigation information
Initial capability was planned for September 2000 but software problems
and the agency's failure to prove that WAAS would not fail to warn pilots
information more than once in 10 million approaches caused further delays,
cost growth and a scaling back of the early capabilities of the system.
The ability of WAAS to warn pilots of incorrect data is called the integrity
of the system.
The FAA now plans to provide limited precision guidance capability with
WAAS by 2002 and an independent team is evaluating any changes that will
be needed to provide a more enhanced system in the future.
GAO estimates the FAA may need three or more years to demonstrate the requirement
that WAAS will virtually never fail to warn pilots of an erroneous GPS signal.
That could cost an additional $200 to $240 million.
"The difficulties in proving the integrity requirement have occurred
largely because FAA management and the integrated product team underestimated
the complexity of resolving the integrity issue and, as a result, failed
to recognize the seriousness of the problem," according to the GAO report,
"National Airspace System: Persistent Problems in FAA's New Navigation System
Highlight Need for Periodic Evaluation." GAO did the review for Sen. Richard
Shelby, chairman of the Senate Appropriations Committee's Subcommittee on
"Software development - the most critical component of key FAA modernization
programs - has been the Achilles' heel of FAA's efforts to deliver programs
on time and within budget," the report said.
The FAA did not closely monitor the contractor's effort to demonstrate
integrity, and members of the team did not have a clear understanding of
their roles, the GAO report said. GAO pointed out that lack of monitoring
and poor communications have been recurring problems in FAA's air traffic
control modernization program.
GAO said the FAA took an acknowledged high risk approach: It agreed on a
design for the system and established milestones for system deployment before
completing the research and development needed to demonstrate the system's
capability. If the FAA continues along this path, GAO said, it could incur
significant costs for other system components, such as satellites, to make
the design fully operational - without knowing whether the system will meet
its performance requirements.
GAO is pleased with the FAA's new approach, which allows time for collecting
and evaluating data on system performance, the extent to which users have
purchased equipment and the availability of emerging new technologies for
the new navigation system. However, GAO recommended the FAA devise a specific
plan for reevaluating WAAS at critical points in development and having
the progress of the system independently validated at the checkpoints before
Congress approves additional funding.
In response to the report, the FAA told GAO that users would receive major
benefits from any level of precision approach into airports and airports
would not necessarily need to invest in upgrades of their facilities to
take advantage of the approaches. The FAA also stressed some cost growth
was due to other factors, such as changes in the way Department of Transportation
calculates project costs.
* Develop a comprehensive plan that would provide the framework for
the agency's future investments in its new navigation system. This plan
should establish future checkpoints at which the FAA would determine whether
the contractor's approach for meeting performance requirements conforms
to the agency's guidelines, if users' needs have changed and whether other
technologies have matured and could meet users' needs and the agency's requirements.
* Have an external organization evaluate the agency's progress at these
checkpoints and include the results of this evaluation in the agency's request
for future funding of the navigation system.