Runway Safety: Progress on Reducing Runway Incursions Impeded by Leadership, Technology, and Other Challenges
Published: 2008-02-13T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: While aviation accidents in the United States are relatively infrequent, recent incidents have heightened concerns about safety on airport runways. As the nation's aviation system becomes more crowded every day, increased congestion at airports may exacerbate ground safety concerns. This statement discusses (1) the trends in runway incursions, (2) what FAA has done to improve runway safety, and (3) what more could be done. This statement is based on GAO's November 2007 report issued to this committee on runway safety. GAO's work on that report included surveying experts on the causes of runway incidents and accidents and the effectiveness of measures to address them, reviewing safety data, and interviewing agency and industry officials. This statement also contains information from FAA on recent incursions and actions taken since November 2007.
section_title: What GAO Found
paragraphs: Recent data indicate that runway incursions, which are precursors to aviation accidents, are growing. Although the number and rate of incursions declined after reaching a peak in fiscal year 2001 and remained relatively constant for the next 5 years, they show a recent upward trend. From fiscal year 2006 through fiscal year 2007, the number and rate of incursions increased by 12 percent and both were nearly as high as their 2001 peak. Furthermore, the number of serious incursions--where collisions are narrowly or barely avoided--increased from 2 during the first quarter of fiscal year 2007 to 10 during the same quarter in fiscal year 2008. FAA has taken steps to address runway safety, but further progress has been impeded by the lack of leadership and coordination, technology challenges, lack of data, and human factors-related issues. FAA's actions have included deploying and testing technology designed to prevent runway collisions and promoting changes in airport layout, markings, signage, and lighting. However, until recently, FAA's Office of Runway Safety did not have a permanent director. Also, FAA has not updated its national runway safety plan since 2002, despite agency policy that such a plan be prepared every 2 to 3 years, resulting in uncoordinated efforts within the agency. Moreover, runway safety technology currently being installed, which is designed to provide air traffic controllers with the position and identification of aircraft on the ground and alerts of potential collisions, is behind schedule and experiencing cost increases and operational difficulties with its alerting function. FAA also lacks reliable runway safety data and the mechanisms to ensure that the data are complete. Furthermore, air traffic controller fatigue, which may result from regularly working overtime, continues to be a matter of concern for the National Transportation Safety Board (NTSB) and others. FAA could take additional measures to improve runway safety. These measures include implementing GAO's recommendations to prepare a new national runway safety plan, address controller overtime and fatigue, and start a nonpunitive, confidential, voluntary program for air traffic controllers to report safety risks in the national airspace system, which would be similar to a program that FAA has already established for pilots and others in the aviation community. Such a program could help the agency to understand the causes and circumstances regarding runway safety incidents. Additional improvements, suggested by experts and NTSB, include developing and deploying technology to provide alerts directly to pilots.

section_title: Letter
paragraphs: Thank you for the opportunity to testify today on runway safety. While  aviation accidents in the United States are relatively infrequent, recent  incidents have heightened concerns about safety on airport runways. On  August 16, 2007, for example, at Los Angeles International Airport—one of  the nation’s busiest airports—two commercial aircraft carrying 296 people  came within 37 feet of colliding, resulting in an incident that is called a  runway incursion. As the nation’s aviation system becomes more crowded  every day, increased congestion at airports may exacerbate ground safety  concerns. At airports, the Federal Aviation Administration (FAA) focuses  its safety oversight on the movement areas—runways and taxiways— where the chances of catastrophic accidents are greater than other areas.
My testimony today is focused on (1) the trends in runway incursions, (2)  what steps FAA has taken to improve runway safety, and (3) what more  could be done. This statement is based on our November 2007 report on  runway safety and work that we conducted between January 2008 and  February 2008 to obtain updated information on recent incursions and  actions taken by FAA since our report was issued. Our work on the  November 2007 report included surveying experts on the causes of runway  incidents and accidents, the effectiveness of measures that are being taken  to address them, and what additional measures could be taken. We  conducted this work in accordance with generally accepted government  auditing standards. Those standards require that we plan and perform the  audit to obtain sufficient, appropriate evidence to provide a reasonable  basis for our findings and conclusions based on our audit objectives.
Recent data indicate that runway incursions, which are precursors to  aviation accidents, are growing. Although the number and rate of  incursions declined after reaching a peak in fiscal year 2001 and remained  relatively constant for the next 5 years, they show a recent upward trend.  From fiscal years 2006 through 2007, the number and rate of incursions  increased by 12 percent and were nearly as high as when they reached  their 2001 peak. Furthermore, the number of serious incursions—where  collisions were narrowly or barely avoided—increased substantially  during the first quarter of fiscal year 2008, compared to the same quarter in  fiscal year 2007.
FAA has taken steps to address runway safety, but the lack of leadership  and coordination, technology challenges, lack of data, and human factors- related issues impede further progress. To improve runway safety, FAA  has deployed and tested technology designed to prevent runway collisions;  promoted changes in airport layout, markings, signage, and lighting; and  provided training for pilots and air traffic controllers.  However, until  recently, FAA’s Office of Runway Safety did not have a permanent  director.  Also, FAA has not updated its national runway safety plan since  2002, despite agency policy that such a plan be prepared every 2 to 3 years,  which resulted in uncoordinated runway safety efforts by individual FAA  offices. Moreover, the runway safety technology that FAA is currently  installing, which is designed to provide air traffic controllers with the  position and identification of aircraft on the ground and alerts of potential  collisions, is behind schedule and experiencing cost increases and having  operational difficulties with its alerting function. Additional technology to  prevent runway incursions is years away from deployment. FAA also lacks  reliable runway safety data and the mechanisms to ensure that the data are  complete. Furthermore, air traffic controller fatigue, a human factors issue  that may result from regularly working overtime, continues to be a matter  of concern for the National Transportation Safety Board (NTSB) and other  aviation stakeholders.
FAA could take additional measures to improve runway safety. In our  November 2007 report, we recommended that FAA prepare a new national  runway safety plan; address controller overtime and fatigue; and start a  nonpunitive, confidential, voluntary program for air traffic controllers to  report safety risks in the national airspace system, similar to a program  that FAA has already established for pilots and others in the aviation  community. Such a program could help the agency to understand the  causes and circumstances regarding runway safety incidents.  The agency  agreed to consider our recommendations.  Additional improvements,  suggested by experts we surveyed and NTSB, include developing and  deploying technology that provided alerts of potential incursions directly  to pilots.
subsections: section_title: Number and Rate of Incursions Show Upward Trend
paragraphs: Runway safety is a longstanding major aviation safety concern; prevention  of runway incursions, which are precursors to aviation accidents, has been  on NTSB’s list of most wanted transportation improvements since 1990  because runway collisions can be catastrophic. Recent data indicate that  runway incursions are growing and may become even more numerous as  the volume of air traffic increases. The number and rate of incursions  declined from a peak in fiscal year 2001 and remained relatively constant  for the next 5 years. However, from fiscal years 2006 through 2007, the  number and rate of incursions increased by 12 percent and nearly regained  the 2001 peak (see fig. 1).
Additionally, data for the first quarter of fiscal year 2008 show that the  number of incursions increased substantially after FAA began using a  definition of incursions developed by the International Civil Aviation  Organization (ICAO), a United Nations specialized agency.  Using the  ICAO definition, FAA is now counting some incidents as incursions that  had been formerly classified as surface incidents. During the first quarter  of fiscal year 2008, using the ICAO definition, FAA counted 230 incursions.  If FAA had continued to use its previous definition, it would have counted  94 incursions. According to an FAA official, by adopting the ICAO  definition, FAA expects to report about 900 to 1,000 incursions this year.  Fig. 2 shows the number and rate of incursions, by quarter, during fiscal  year 2007 and during the first quarter of fiscal year 2008.
Moreover, the number and rate of serious incursions—where collisions  were narrowly or barely avoided—increased substantially during the first  quarter of fiscal year 2008, compared to the same quarter in fiscal year  2007. During the first quarter of fiscal year 2008, 10 serious incursions  occurred, compared to 2 serious incursions during the first quarter of  fiscal year 2007.  (See fig. 3.)
Most runway incursions involve general aviation aircraft. According to  FAA, 72 percent of incursions from fiscal years 2003 through 2006 involved  at least one general aviation aircraft. However, about one-third of the most  serious incursions from fiscal years 2002 through 2007—about 9 per  year—involved at least one commercial aircraft that can carry many  passengers.  That number includes two serious incursions that occurred  just two months ago, in December 2007.  (See table 3 in the appendix for  additional information on recent serious incursions.)  Figure 4 shows the  number of serious incursions involving commercial aircraft from fiscal  years 2001 through 2007.
In the United States, most incursions have occurred at major commercial  airports, where the volume of traffic is greater. Los Angeles International  Airport and Chicago O’Hare International Airport had the greatest number  of runway incursions from fiscal years 2001 through 2007, as shown in fig.  5.
The primary causes of incursions, as cited by experts we surveyed and  some airport officials, include human factors issues, such as  miscommunication between air traffic controllers and pilots, a lack of  situational awareness on the airfield by pilots, and performance and  judgment errors by air traffic controllers and pilots. According to FAA, 57  percent of incursions during fiscal year 2007 were caused by pilot errors,  28 percent were caused by air traffic controller errors, and 15 percent  were caused by vehicle operator or pedestrian errors (see fig. 6).
section_title: Challenges Remain Despite Numerous Efforts to Address Runway Safety
paragraphs: FAA, airports, and airlines have taken steps to address runway safety, but  the lack of leadership and coordination, technology challenges, lack of  data, and human factors-related issues impede further progress. To  improve runway safety, FAA has deployed and tested technology designed  to prevent runway collisions; promoted changes in airport layout,  markings, signage, and lighting; and provided training for pilots and air  traffic controllers. In addition, in August 2007, following several serious  incursions, FAA met with aviation community stakeholders and agreed on  a short-term plan to improve runway safety. In January 2008, FAA reported  on the status of those actions, which included    accelerating the upgrading of airport markings, which were originally  required to be completed by June 30, 2008, at medium and large  airports,    upgrading markings at smaller commercial airports, which had not    completing a runway safety review of 20 airports that were selected on  the basis of runway incident data, and  requiring that nonairport employees, such as airline mechanics, receive  recurrent driver training at 385 airports.
According to FAA, since the August 2007 meeting, all 112 active air  carriers have reported that they are (1) providing pilots with similar or  other training that incorporates scenarios from aircraft pushback through  taxi, and (2) reviewing procedures to identify and develop a plan to  address elements that contribute to pilot distraction while taxiing. FAA  also indicated that it had completed an analysis of air traffic control  procedures pertaining to taxi clearances and found that more explicit taxi  instructions are needed, and that it had signed a partnership agreement  with the National Air Traffic Controllers Association to create a voluntary  safety reporting system for air traffic controllers.
In our November 2007 report, we found that FAA’s Office of Runway  Safety had not carried out its leadership role to coordinate and monitor  the agency’s runway safety efforts.  Until recently, the office did not have a  permanent director for the previous 2 years and staffing levels declined.   FAA took a positive step by hiring a permanent director at the Senior  Executive Service level for the office in August 2007.  The new director  has indicated he is considering several initiatives, including establishing a  joint FAA-industry working group to analyze the causes of incursions and  track runway safety improvements.  In our November 2007 report, we also  found that FAA had not updated its national runway safety plan since  2002, despite agency policy that such a plan be prepared every 2 to 3 years.  The lack of an updated plan resulted in uncoordinated runway safety  efforts by individual FAA offices. For example, in the absence of an  updated national runway plan, each FAA office is expected to separately  include its runway safety initiatives in its own business plan.  However,  this practice does not provide the same national focus and emphasis on  runway safety that a national plan provides.  Furthermore, not all offices  with runway safety responsibilities included efforts to reduce incursions in  their business plans. Until the national runway safety plan is updated, the  agency lacks a comprehensive, coordinated strategy to provide a sustained  level of attention to improving runway safety.
The deployment of surface surveillance technology to airports is a major  part of FAA’s strategy to improve runway safety, but it has presented  challenges. To provide ground surveillance, FAA has deployed the Airport  Movement Area Safety System (AMASS), which uses the Airport Surface  Detection Equipment-3 (ASDE-3) radar, at 34 of the nation’s busiest  airports and is deploying an updated system, ASDE-X, at 35 major airports.   The current deployment schedule will result in a total of 44 airports having  AMASS and/or ASDE-X (see table 5 in the appendix). Both systems are  designed to provide controllers with alerts when they detect a possible  collision on the ground. As of January 2008, ASDE-X was commissioned  at 11 of the 35 airports scheduled to receive it. FAA is also testing runway  status lights, which are a series of lights embedded in the runways that  give pilots a visible warning when runways are not clear to enter, cross, or  depart on, at the Dallas-Ft. Worth International Airport and the San Diego  International Airport. The agency made an initial investment decision last  year to deploy the system at 19 airports, starting in November 2009, and is  planning to make a final investment decision in June 2008. In addition,  FAA is testing the Final Approach Runway Occupancy Signal at the Long  Beach-Daugherty Field airport in California, which activates a flashing  light visible to aircraft on approach as a warning to pilots when a runway  is occupied and hazardous for landing.
However, FAA risks not meeting its current ASDE-X cost and schedule  plans, which have been revised twice since 2001, and the system is  experiencing operational difficulties with its alerting function. Although it  took about 4 years for ASDE-X to be commissioned at 11 airports, FAA  plans to deploy the system at the remaining 24 additional airports by 2010.  In addition, not all 11 ASDE-X airports have key safety features of the  system. For example, as of January 2008, two ASDE-X airports did not  have safety logic, which generates a visible and audible alert to an air  traffic controller regarding a potential runway collision. Furthermore, the  ASDE-X airports are experiencing problems with false alerts, which occur  when the system incorrectly predicts an impending collision, and false  targets, which occur when the system incorrectly identifies something on  the airfield as an aircraft or vehicle and could generate a false alert.  Moreover, most airports in the United States have no runway safety  technology to supplement a controller’s vision of the airfield and will not  have such technology even after FAA completes its plan to deploy ASDE-X  at 35 major airports. While FAA is testing additional technology to prevent  runway collisions, such as the Final Approach Runway Occupancy Signal,  the systems are years away from deployment.  Another technology,  runway status lights, have had positive preliminary test evaluations, but  need a surface surveillance system such as ASDE-3/AMASS or ASDE-X to  operate. In addition, FAA is still testing a low cost surface surveillance  system that already is being used at 44 airports outside of the United  States. Furthermore, systems that provide direct collision warnings to  flight crews, which NTSB and experts have recommended, are still being  developed.
FAA lacks reliable runway safety data and the mechanisms to ensure that  the data are complete. Although FAA collects information about runway  incursions and classifies their severity, its tabulation of the number of  incursions does not reflect the actual number of incidents that occur. FAA  only counts incursions that occur at airports with air traffic control  towers, so the actual number of incursions, which includes those that  occurred at airports without air traffic control towers, is higher than FAA  reports.  While the change in definition of incursions that FAA adopted at  the beginning of fiscal year 2008 will increase the number of incursions  counted, it will not address this problem.  In addition, an internal agency  audit of 2006 incursion data questioned the accuracy of some of the  incursion severity classifications. FAA plans to start a nonpunitive,  confidential, voluntary program for air traffic controllers similar to a  program that FAA has already established for pilots and others in the  aviation community.  The new program will enable air traffic controllers to  report anything that they perceive could contribute to safety risks in the  national airspace system. The benefit of such program is that the  information obtained might not be reported otherwise, and could increase  the amount of data collected on the causes and circumstances of runway  incursions. However, FAA has not indicated when such a program would  be implemented.
FAA has also taken some steps to address human factors issues through  educational initiatives, such as developing simulated recreations of actual  incursions to enhance air traffic controller training. However, air traffic  controller fatigue, which may result from regularly working overtime,  continues to be a human factors issue affecting runway safety. NTSB,  which investigates transportation accidents, has identified four instances  from 2001 through 2006 when tired controllers made errors that resulted in  serious incursions. We found that, as of May 2007, at least 20 percent of  the controllers at 25 air traffic control facilities, including towers at several  of the country’s busiest airports, were regularly working 6-day weeks. (See  table 7 in the appendix for additional information.)
Experts we surveyed indicated that the actions that FAA could take with  the greatest potential to prevent runway incursions, considering costs,  technological feasibility, and operational changes, were measures to  provide information or alerts directly to pilots. Experts believed that  lighting systems that guide pilots as they taxi at the airport, and  technology that provides enhanced situational awareness on the airfield  and alerts of potential incursions, would be of particular importance.
section_title: Recommendations
paragraphs: In our November 2007 report, we recommended that FAA (1) prepare a  new national runway safety plan, (2) develop an implementation schedule  for establishing a nonpunitive voluntary safety reporting program for air  traffic controllers, and (3) develop a mitigation plan for addressing  controller overtime.  The agency agreed to consider our recommendations.
In closing, although FAA has taken many actions to improve runway  safety, the number of serious incursions that are continuing to occur— many of which involved aircraft carrying hundreds of passengers— suggests that this country continues to face a high risk of a catastrophic  runway collision. FAA must provide sustained attention to improving  runway safety through leadership, technology, and other means. As the  volume of air traffic continues to increase, providing sustained attention to  runway safety will become even more critical.
Mr. Chairman, this concludes my prepared statement. I would be pleased  to respond to any questions from you or other members of the  Subcommittee.
section_title: GAO Contact and Staff Acknowledgments
paragraphs: For further information on this testimony, please contact Dr. Gerald L.  Dillingham at (202) 512-2834 or dillinghamg@gao.gov.  Individuals making  key contributions to this testimony include Teresa Spisak, Bob Homan,  and David Goldstein.