GAO: Rate of U.S. Runway Incursions Isn't Decreasing

In a new report on runway safety, the U.S. Government Accounting Office (GAO) states the rate of runway incursions hasn't decreased over the last five years, in spite of the FAA's efforts.

While the number and rate of incursions declined after reaching a peak in fiscal year 2001 and remained relatively constant for the next five years, preliminary data for fiscal year 2007 indicate that the overall incursion rate increased again, and is nearly as high as the fiscal year 2001 peak.

The GAO blames the poor progress on the FAA's lack of coordination and leadership, technology challenges, the lack of pertinent data, and human-factor issues.  To improve the situation, the congressional investigative arm recommends that the FAA prepare a new plan for runway safety, improve data collection on runway overruns and ramp accidents, and address air traffic controller concerns regarding overtime and fatigue.

To reach its conclusions, the GAO relied heavily on interviews of aviation experts, which interestingly, indicated that the most effective actions in preventing runway incursions were lower-cost ones, such as enhancing airport markings, lighting, and signage, notwithstanding the substantial interest in more expensive anti-incursion runway technologies.

The following is a summary of the report's discussion as it pertains to technology solutions.

Runway Incursions

The use of surface surveillance technology is a major part of FAA's strategy to improve runway safety.  The agency has deployed AMASS (airport movement area safety system), which uses ASDE-3 (airport surface detection equipment, model 3) radar, and is deploying ASDE-X (airport surface detection equipment, model X) to give ground controllers better situational awareness of the airport surface activity.  The planned deployment of ASDE-3/AMASS was completed in 2003 at 34 of America's busiest airports.

ASDE-X, which integrates data from a variety of sources including radars and aircraft and vehicle transponders, is now being deployed at 35 major airports.  In a new "Fact Sheet" posted on its Website, the FAA reports that 11 U.S. airports of the 35 airports which are slated to get ASDE-X, now have operational systems. The FAA recently accelerated the ASDE-X schedule and now projects that all systems will be deployed by fall 2010 - one year earlier than originally anticipated.

The GAO noted that ASDE-X has faced cost increases and schedule delays from its original baselines and is experiencing operational difficulties with its alerting function.  At the same time, additional technology to prevent runway collisions is years away from deployment.

Runway Status Lights
The GAO said its survey of experts indicated that the use of lighted guidance systems that define airport taxi routes offer the greatest potential for preventing runway incursions.

The FAA is currently testing a series of embedded runway status and entry lights at Dallas-Ft. Worth and the San Diego that visibly warn pilots when a runway is not clear. They are a fully automatic, require no controller input. Ten of 17 experts the GAO surveyed indicated that these were very or extremely effective in addressing runway incursions.  Surface surveillance systems, such as ASDE-3/AMASS and ASDE-X, provide the data needed to operate runway status lights, and the systems' safety logic assesses any possible conflicts on the airfield and provides alerts of potential collisions.

The FAA believes future additions to these status light systems could include runway intersection lights and lights to warn pilots exiting at high speeds about traffic on closely-spaced parallel runways, which has been problematic for the northern parallel runway complex at Los Angeles International, for example.

FAROS and Other Low-Cost Technologies
The GAO also noted that the FAA is testing FAROS (final approach runway occupancy signal) at Long Beach, California, which activates a flashing light visible to aircraft on approach as a warning to pilots when a runway is occupied.  And at Spokane, Washington, the agency is testing another low- cost surface surveillance system, similar to ones being used at 44 airports outside of the U.S.

Perimeter Taxiways
Some airports are constructing new perimeter taxiways (also called end-around taxiways), with the help of FAA funds, that allow aircraft to taxi to gates without crossing active runways. Atlanta's Hartsfield-Jackson opened a perimeter taxiway in April 2007 at a cost of $48 million, and the Dallas-Ft. Worth plans to open one in October 2008, that will cost about $63.8 million.

Eleven of 16 experts the GAO surveyed indicated that FAA's approval of perimeter taxiways was very or extremely effective in addressing runway incursions.

Signage and Marking Changes
The FAA also has standardized airport signage and markings, including issuing new standards for surface markings that require the use of glass beads for better reflectivity, requiring new taxiway markings that alert pilots that they are approaching runway entrances, and doubling the size of markings indicating where aircraft should hold before proceeding onto the runway.

A majority of its surveyed experts indicated that these measures were very or extremely effective, the GAO said.

Runway Overruns

The GAO's survey of experts indicated that addressing the causes and circumstances of overruns, such as pilot's lack of information about runway slickness could provide the greatest potential for reducing runway overruns.

Nevertheless, when an overrun occurs, runway safety areas reduce the chance of the aircraft being damaged, and the GAO acknowledged that the FAA has made progress in improving them. As of May 2007, 70 percent of the runways at U.S. commercial airports substantially complied with runway safety area standards (1000 feet beyond the payment end), up from 55 percent in 2000.

EMAS
Recognizing some airports don't have enough space to establish normal runway safety areas, the FAA developed a system called EMAS (engineered materials arresting system), which uses a bed of crushable concrete to stop overrunning aircraft.

The entire report: "Aviation Runway and Ramp Safety: Sustained Efforts to Address Leadership, Technology, and Other Challenges Needed to Reduce Accidents and Incidents (GAO-08-29), November 20, 2007, can viewed by: Summary (HTML), Highlights Page (PDF) or Full Report (PDF, 86 pages).  12-10-2007.

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