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DOT IG Finds Runway Status Lights a Viable Safety Technology
In a recent report the U.S. Department of Transportation's Inspector General (IG) found that the use of RWSL
(runway status lights) is a viable method for preventing runway incursions, but
more must be done before its full deployment can be achieved.
According to the IG, RWSL works well for this purpose because of these essential attributes:
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It gives timely warnings of potential conflicts.
It promptly and clearly indicates to pilots and vehicle
operators when it is unsafe for aircraft to enter or cross a runway or to
commence take-off.
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Its information is automated.
It provides this information at all times without human input.
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It doesn't interfere with air traffic operations. It acts as an independent safety enhancement. It
doesn't increase controller workload and doesn't interfere with the normal flow
of airport traffic or rhythm of controller movement of traffic.
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Its lights indicate status only.
RWSL doesn't convey any clearances; these are still only provided
by air traffic control.
During operational evaluations, and subsequent modifications, at Dallas-Fort Worth, the system met
or exceeded all performance criteria specified in the RWSL Research Management
Plan, the IG said. In addition, the IG said that all the system users it
conferred with at DFW agreed that the system works as intended and has no known
negative effects on capacity, communication, or safety.
According to the IG, runway incursions on the test runway at DFW (runway 18L/36R) decreased by 70 percent
after its introduction. During the 29 months before RWSL testing (October 1,
2002, through February 28, 2005), 10 runway incursions occurred, but during the
29 months after RWSL was installed (March 1, 2005, through July 31, 2007), only
three occurred.
Nevertheless, while RWSL has performed extremely well thus far, the IG believes the FAA must address several
issues to ensure its effective and timely implementation. For example:
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Since RWSL depends on ASDE-X (airport surface detection equipment - model x),
the interface between the two systems will need to be modified to address the
differences between the ASDE-X prototype system used at DFW for RWSL and the
version of ASDE-X being deployed nationally at other airports.
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Some of the airports
where FAA plans to deploy RWSL are undergoing or will
undergo airfield improvements. It will be important for the RWSL program office
to identify those airports and coordinate the deployment of RWSL in-ground
infrastructure concurrently with airfield construction.
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Part of the early success
of RWSL testing has been due to immediate input and
corrective actions taken when problems were identified. A key factor for
maintaining project momentum will be ensuring that similar "hands-on" knowledge
is retained during RWSL's transition from R&D to its acquisition phase.
Recommendations
To limit any potential risks
that could impact the successful and timely implementation of RWSL, the IG is
recommending that FAA:
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Modify the RWSL software design to address
the differences between the ASDE-X prototype system used at DFW for RWSL, and
the national ASDE-X system, being deployed at other airports.
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Ensure that the RWSL program office
coordinates with FAA's Airports line of business to identify locations that are
scheduled to receive RWSL and have ongoing or planned runway improvements and
(b) secures agreements with those airports to deploy RWSL in-ground
infrastructure concurrently with airfield construction to avoid duplicative
construction efforts and costs.
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Ensure that existing RWSL program expertise
is retained during the system's transition from R&D to the acquisition phase to
capitalize on lessons learned at DFW in addressing system and site-specific
anomalies.
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Expedite preparation of the acquisition package to
make the final investment decision earlier than the current July 2008
milestone to accelerate RWSL deployment as directed by Congress and the FAA's
Joint Resources Council.
The complete
IG report is available on the DOT Website. 01-23-2008. |
