Aviation Safety: FAA Has Increased Efforts to Address Runway Incursions
Released: 2008-09-25T00:00:00

Letter

The Overall Number and Rate of Incursions Increased This Fiscal Year

Runway safety is a long-standing major aviation safety concern. The prevention of runway incursions, which are precursors to aviation accidents, has been on the National Transportation Safety Board’s (NTSB) list of most wanted transportation improvements since 1990 because runway collisions can be catastrophic. The number and rate of incursions reached a peak in fiscal year 2001 and remained relatively constant for the next 5 years. However, from fiscal year 2006 through fiscal year 2007, the overall number and rate of incursions increased by 12 percent and nearly regained the 2001 peak (see fig. 1).

Data for the first three quarters of fiscal year 2008 show that the number of incursions counted increased substantially after FAA adopted 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 the agency formerly classified as surface incidents. Using its new definition, FAA had counted 957 incursions during fiscal year 2008 as of September 16, 2008, 712 of which occurred during the first three quarters.

If FAA had continued using its previous definition, that data would have shown an increase in the number and rate of incursions, with the rate exceeding the earlier peak in 2001. Using the previous definition, FAA would have counted 293 incursions during the first three quarters of fiscal year 2008, compared with 275 for the first three quarters of fiscal year 2007, an increase of 7 percent. Under FAA’s previous incursion definition, the overall rate of incursions for the first three quarters of fiscal year 2008 was 6.72 per 1 million air traffic control tower operations, compared with 6.11 for the first three quarters of fiscal year 2007 and 6.1 for fiscal year 2001. Thus, the first three quarters of fiscal year 2008 represent a 10 percent increase in the rate over both the first three quarters of fiscal year 2007 and fiscal year 2001, an earlier peak year for the number and rate of incursions. Figure 2 shows the number and rate of incursions, by quarter, during fiscal year 2007 and during the first three quarters of fiscal year 2008.

From fiscal year 2001 through fiscal year 2007, the number of serious incursions—incidents in which collisions are narrowly or barely avoided— decreased from 53 to 24, or by about 55 percent. The number of serious incursions, which is not affected by FAA’s adoption of a new incursion definition, has decreased from 24 in fiscal year 2007 to 23 in fiscal year 2008 as of September 16, 2008, but the rate has increased. The rate of serious incursions for fiscal year 2008 through September 16, 2008 was 0.41 per 1 million tower operations, compared with 0.39 for fiscal year 2007, an increase of 5 percent. The number and rate of serious incursions, by quarter, during fiscal year 2007 and fiscal year 2008 are shown in figure 3.

Most runway incursions involve general aviation aircraft. According to FAA, about 67 percent of incursions from fiscal year 2005 through August 2008 involved at least one general aviation aircraft. However, about one- third of the most serious incursions during fiscal year 2002 through August 2008—about 9 per year—involved at least one commercial aircraft. The involvement of commercial aircraft in incursions is of particular concern because they can carry many passengers. For example, on April 6, 2008, a Boeing 777, which was being towed from a maintenance facility at the Dallas-Fort Worth International Airport, entered a runway where an American Airlines MD-80 had just landed, and the two aircraft missed each other by about 25 feet. As of September 16, 2008, there have been 7 serious incursions involving commercial aircraft in fiscal year 2008, compared with 8 in fiscal year 2007. (See table 3 in app. I for additional information about serious incursions involving commercial aircraft during fiscal years 2007 and 2008.) Figure 4 shows the number of serious incursions involving commercial aircraft from fiscal year 2001 through fiscal year 2008.

In the United States, most incursions have occurred at major commercial airports, where the volume of air traffic is greater. Chicago O’Hare International and Los Angeles International Airports had the most runway incursions from fiscal year 2001 through August 18, 2008, as shown in figure 5.

The primary causes of incursions, according to experts we surveyed and some airport officials, are human factors issues, which can include 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, in fiscal year 2007, 57 percent of incursions were caused by pilot errors, 28 percent by air traffic controller errors, and 15 percent by vehicle operator or pedestrian errors (see fig.6). Air traffic controller errors are a particular concern because, as we noted in our June 2008 testimony before this Subcommittee, FAA is hiring large numbers of new air traffic controllers to replace those who are retiring and the proportion of new hires is increasing over time. Our analysis of FAA’s hiring and retirement projections indicates that by 2011, up to 59 percent of the controller workforce will have less than 5 years of experience. Newly certified controllers may be less efficient than experienced controllers in handling the high volumes of traffic that occur at large and congested airports, and any loss in efficiency could affect runway safety.

FAA Has Increased Efforts to Oversee Runway Safety, but Collision Risk Remains

During fiscal year 2008, FAA has given higher priority to improving runway safety than it did during the previous 2 years, when the agency did not have a permanent director for its Office of Runway Safety. FAA’s recent actions to improve runway safety include continuing to deploy and test new technology designed to prevent runway collisions; promoting changes in airport layout, markings, signage, and lighting; and issuing new air traffic procedures. However, NTSB officials and some aviation safety experts said that the risk of a runway collision is still high.

Efforts to develop and deploy technology have been among FAA’s major actions to improve runway safety. To provide ground surveillance on the airfield, FAA has deployed the Airport Movement Area Safety System (AMASS), which uses the Airport Surface Detection Equipment (ASDE-3) radar, at 34 of the nation’s busiest airports and is deploying an updated system, the Airport Surface Detection Equipment, Model X (ASDE-X), at 35 major airports. According to its current plans, FAA will complete the deployment of ASDE-X by 2010, and a total of 44 airports will then have AMASS, ASDE-X, or both (see table 6 in app. I). FAA is also testing low- cost surface surveillance systems in Spokane, Washington, and has solicited industry proposals to acquire and install low-cost ground surveillance systems at 6 additional airports that are not scheduled to receive ASDE-3 or ASDE-X. Both ASDE-3 and ASDE-X are designed to alert controllers when they detect a potential collision on the ground. As of August 29, 2008, FAA had commissioned ASDE-X at 13 airports, up from 11 in August 2007. According to FAA, all ASDE-X-commissioned airports now have safety logic, which generates visible and audible signals to air traffic controllers of potential runway collisions. In our February 2008 testimony, we indicated that 2 ASDE-X-commissioned airports did not yet have safety logic. According to FAA, for all future systems, safety logic will be implemented when ASDE-X system is installed.

Despite ongoing efforts, FAA risks not meeting its current plans to complete the deployment of ASDE-X by 2010. FAA plans to finish installing ASDE-X at New York LaGuardia, Memphis International, and Las Vegas McCarran International Airports, where the agency is coordinating the implementation of ASDE-X with the completion of new air traffic control towers, after the fall of 2010. In addition, although it took about 4 years for ASDE-X to be installed at the first 11 airports and ASDE-X was commissioned at 2 airports during the first 11 months of fiscal year 2008, FAA plans to install the system at 19 additional airports by the end of fiscal year 2010. In commenting on whether the 19 remaining installations can be completed on schedule, FAA’s ASDE-X program manager said that the installations at all 19 airports have already begun, that the system installations are not done one airport at a time, and that the agency is working hard to push local governments and airports to obtain the needed approvals and leases.

In November 2007, we reported operational difficulties with ASDE-X’s alerting functions. For example, some ASDE-X-commissioned airports were experiencing 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, such as an aircraft or vehicle, that could generate a false alert. We reported that the control tower at Hartsfield-Jackson Atlanta International Airport reported the most problems with false alerts and that the control tower at Seattle- Tacoma International Airport reported the most problems with false targets. However, FAA recently provided documentation indicating that the number of false alerts at Hartsfield-Jackson Atlanta International Airport had declined by 84 percent during 2008 and that the number of false alerts at Seattle-Tacoma International Airport had declined by 90 percent after the airport received a software upgrade in March 2008.

Another technology for improving runway safety that FAA recently decided to install at 22 airports is a runway status lights system. This technology, which gives pilots a visible warning when runways are not safe to enter, cross, or depart on, has already been tested and has received positive evaluations at Dallas-Fort Worth International and San Diego International Airports (see table 7 in app. I for a list of airports to receive runway status lights). Proposed legislation to reauthorize FAA would authorize $74 million to acquire and install runway status lights. In November 2007, we reported that 10 of 17 experts we surveyed indicated that FAA’s testing of runway status lights was very or extremely effective in addressing runway incursions. In addition, the Department of Transportation’s Inspector General reported in January 2008 that runway incursions on the test runway at Dallas-Fort Worth International Airport decreased by 70 percent during the 29 months of testing, compared with the 29 months before testing. In addition, FAA and NTSB officials said that runway status lights prevented a serious incursion from occurring at Dallas-Fort Worth International Airport on May 15, 2008, involving an MD- 80 aircraft and a regional jet. According to FAA, the MD-80 aborted its takeoff after seeing the status lights turn red when the regional jet was crossing that runway farther ahead. However, runway status lights need a surface surveillance system such as ASDE-3/AMASS or ASDE-X to operate, making the timely deployment of ASDE-X at the remaining 19 airports even more important.

Still another runway safety technology that FAA is testing is the Final Approach Occupancy Signal (FAROS) at Long Beach-Daugherty Field airport in California. FAROS activates a flashing light visible to aircraft on approach as a warning to pilots when a runway is occupied and hazardous for landing. FAA is also planning to install and evaluate an enhanced version of FAROS at Dallas-Fort Worth International Airport. According to FAA, the additional information on runway traffic provided by FAROS can improve the pilot’s situational awareness and help reduce the severity of an incursion. However, nationwide deployment of FAROS is years away. Furthermore, FAA is still testing a low-cost surface surveillance system that already is being used at 44 airports outside the United States. FAA has also offered to provide up to $5 million to test in-cockpit displays that inform pilots where they are located on runways or electronic flight bags, which are electronic display systems that provide pilots with a variety of aviation data. In addition, in the longer term, deployment of the Automatic Dependent Surveillance-Broadcast (ADS-B) system, a satellite-based technology that broadcasts aircraft identification, position, and speed with once-per-second updates, will provide pilots with greater situational awareness and help to keep aircraft at safe distances from each other on the runways.

Besides deploying and testing technology, FAA has taken other actions to improve runway safety, including issuing new air traffic procedures requiring controllers to give explicit instructions to pilots on precise routes to take from the gate to the runway; conducting safety reviews at 42 airports based on incursion and wrong- runway-departure data, the findings from which were used to improve signage and markings, as well as implement training programs for airport personnel (see table 8 in app. I for a list of the airports reviewed); establishing the Runway Safety Council, consisting of FAA and aviation industry representatives, to analyze the root causes of serious incursions and recommend runway safety improvements; and testing a voluntary safety reporting program for air traffic controllers at facilities in the Chicago area—a program we had recommended in our November 2007 report that FAA implement.

In June 2008, FAA also completed an internal review of runway incursions at Boston Logan International Airport with a team of experts from FAA, the airport, and a major airline to identify best practices to prevent incursions. FAA is currently reviewing runway incursions at Hartsfield- Jackson Atlanta International Airport and is planning reviews at 8 additional airports based on the frequency of runway incursions. In addition, FAA plans to work with a contractor to validate the alerting perimeters of AMASS and ASDE-X to ensure that controllers receive warnings in time to act on them and relay the warnings to pilots. Furthermore, according to an FAA official, the agency is drafting a new national runway safety plan, which we recommended in our November 2007 report. In addition, in July 2008, FAA submitted, as requested by this Subcommittee, its first quarterly progress report on how it was handling serious incursions.

Several aviation safety stakeholders, including officials from associations representing airlines and pilots, said that FAA has increased its attention to runway safety during the past year. For example, an official from the Air Transport Association (ATA), which represents the airline industry, said that FAA’s level of attention to runway safety is noticeably better than last year, there is more communication, and FAA leadership at the highest levels is focused on the issue. In addition, an official from the Air Line Pilots Association (ALPA) said that the new air traffic procedures requiring controllers to give explicit instructions to pilots on precise routes to take from the gate to the runway were a substantial improvement, resulting in less confusion. However, an official from the National Air Traffic Controllers Association (NATCA) said that FAA had not made progress in addressing air traffic controller overtime and fatigue issues over the last year. In November 2007, we reported that, as of May 2007, at least 20 percent of the controllers at 25 air traffic control facilities, including towers at several major airports, were regularly working 6-day weeks, which could cause fatigue. We also recommended that FAA develop a mitigation plan for addressing controller overtime. FAA officials said that this year, the agency had offered relocation and retention incentives for controllers, targeting major facilities experiencing high rates of overtime. The officials said that 80 controllers had been selected to receive the relocation bonuses and that 100 controllers had accepted retention bonuses in exchange for 2 more years of service. An FAA official said that it was too early to tell what impact those actions would have on the frequency of overtime. To address controller fatigue issues, FAA officials said that the agency held a summit on the subject in June 2008 and is considering shift scheduling changes for controllers.

In commenting on the voluntary safety reporting program for air traffic controllers being tested in the Chicago area, FAA officials said that since the test program began last month, controllers have submitted about 40 reports, 4 of which involved runway incidents. Senior NATCA officials said that although controllers are participating, some are concerned that FAA will take disciplinary actions against them for reporting safety incidents. However, FAA officials said that it is not agency policy to discipline controllers for reporting incidents through the program except under the circumstances specified in the memorandum of understanding with NATCA involving criminal activity, substance abuse, controlled substances, alcohol, or intentional falsification.

According to FAA, airlines have also taken actions to improve runway safety. For example, FAA indicated that all 112 active air carriers have reported that they (1) provide pilots with simulator or other training that incorporates scenarios from aircraft pushback through taxi and (2) have reviewed cockpit procedures to identify and develop a plan to address elements that contribute to pilot distraction while taxiing. Verification of these actions during FAA’s inspections will ensure that these activities are fully implemented.

With the help of FAA funding, several airports have made recent changes to their runways and taxiways to reduce the risk of collisions. In June 2008, Los Angeles International Airport opened a new center taxiway that requires aircraft to reduce speed before exiting. Previously, aircraft used high-speed taxiways in that area of the airfield, resulting in runway incursions when aircraft did not stop in time before approaching active runways. In our February 2008 testimony, we reported that Los Angeles International Airport had experienced the most runway incursions in fiscal years 2001 through 2007. However, the new taxiway may have been a contributing factor in reducing the number of incursions at Los Angeles International Airport this fiscal year, compared with last year. Using FAA’s previous definition of incursions to compare both years, the Los Angeles International Airport had 3 incursions during fiscal year 2008 through September 16, 2008, and none were serious, compared with 8 during fiscal year 2007, including 2 serious ones. When data through August 2008 are included, Chicago O’Hare International Airport has experienced the most runway incursions since fiscal year 2001. In October 2008, Dallas-Fort Worth International Airport plans to open a perimeter taxiway (also called an end-around taxiway) that gives aircraft access to gates without crossing active runways. Crossing active runways is one of the many causes of incursions. In April 2007, Hartsfield-Jackson Atlanta International Airport also opened a perimeter taxiway. According to an airport official, the perimeter taxiway eliminates about 560 runway crossings per day, or about one-third of the airport’s total daily runway crossings.

In November 2007, we reported 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 FAA hired a permanent director at the senior executive service (SES) level for the Office of Runway Safety in August 2007, that office had been without a permanent director for the previous 2 years. Since a permanent director was hired, the number of full-time staff in the Office of Runway Safety has increased, up to 41 as of August 2008 from about 37, including contractors, led by a non-SES-level acting director in May 2007. Although we did not determine what the appropriate level of staffing for the Office of Runway Safety would be, we note that before 2004, when FAA provided a high level of attention to runway safety, the office had 66 full-time staff, including contractors.

NTSB officials and some aviation safety experts said that, despite the numerous actions taken by FAA to improve runway safety, the risk of a runway collision is still high. NTSB officials, for example, cited two nonfatal runway collisions that occurred this year—one at an untowered airport in Pawtucket, Rhode Island, where two general aviation aircraft collided on a runway, substantially damaging both aircraft, and another accident at the airport in Reading, Pennsylvania, where a landing general aviation aircraft collided with a tractor that was at the intersection of a runway and a taxiway, breaking off part of the aircraft’s left wing. In addition, an official from the Flight Safety Foundation said that although the probability of a runway collision is very low, the severity of such an accident means that the risk is high. The low probability of a runway collision is supported by the fact that FAA controls the takeoff, landing, and flights of about 50,000 aircraft every day, but the most recent fatal runway collision at a towered airport involving commercial aircraft occurred 14 years ago, in 1994, when a Trans World Airlines MD-82 collided with a general aviation aircraft on a runway at Lambert-St. Louis International Airport, killing 2 people. However, the worst accident in aviation history involved a runway collision, in 1977, when two Boeing 747s collided on a runway in Tenerife, the Canary Islands, killing 583 passengers and crew. Moreover, despite recent reductions in air traffic, by 2025, air traffic is projected to increase two- to threefold, equating to about 100,000 to 150,000 flights a day, making airports even more congested than they are today.

To address runway overruns, FAA and airports have increased the percentage of runways that are in compliance with FAA standards for runway safety areas—unobstructed areas that surround runways to enhance safety in the event that an aircraft overruns, overshoots, or veers off a runway. As of August 2008, 76 percent of 1,015 runways at 561 commercial service airports were in substantial compliance with runway safety area standards, up from 70 percent in May 2007. FAA considers runway safety areas that meet 90 percent of the standards to be in substantial compliance. Increased compliance with runway safety area standards reduces the chances of aviation accidents resulting from overruns. In addition, as of August 2008, the Engineered Materials Arresting System (EMAS), a bed of crushable concrete designed to stop overrunning aircraft, was installed at 35 runway ends at 24 U.S. airports, up from 24 runway ends at 19 U.S. airports during June 2007. Furthermore, as of August 2008, there were plans to install 15 additional EMAS systems at 11 additional airports. (Table 9 in app. I lists the airports with EMAS installations.) In our November 2007 report, we recommended that FAA develop and implement a plan to collect data on runway overruns that do not result in damage or injury for analyses of trends and causes of overruns. In response, FAA indicated that a working group will be established to assess what additional runway overrun data could be collected and to make recommendations by the end of this year.

Addressing Human Factors Issues Could Help Improve Runway Safety

FAA could further improve runway safety by addressing human factors issues, which aviation safety experts identified as the primary cause of incursions. To address these issues, FAA could encourage the development of new technology, revise additional procedures, and adopt best practices. Proposed legislation to reauthorize FAA would support additional efforts to improve runway safety by authorizing $114 million to develop runway incursion reduction programs and to deploy technology.

In November 2007, we reported that, according to experts we surveyed, encouraging the development of a runway incursion warning system in the cockpit would be among the most effective actions that FAA could take to improve runway safety. In addition, in 2000, NTSB recommended, among other things, that FAA require airports to deploy a ground movement safety system to prevent runway incursions and develop a direct incursion warning capability for flight crews. A system that provides a direct warning to the cockpit being developed by Honeywell and the Sensis Corporation, called the Runway Incursion Cockpit Alerting System, is designed to work at airports equipped with ASDE-X and functioning safety logic. A demonstration of the system was conducted with FAA and NTSB officials at Syracuse Hancock International Airport in August 2007. NTSB officials said that FAA could move faster to approve technology that provides runway incursion warnings directly to the cockpit. However, FAA officials said the cockpit warning system would need to be thoroughly reviewed before being approved for use, a process they said could take at least 2 years.

Also to improve runway safety, ATA and ALPA officials suggested FAA could standardize air traffic control phraseology. Future FAA air traffic procedures will cover clearances for runway crossings, takeoffs, and multiple landings and will include the adoption of international phraseology such as “line up and wait” instead of “position and hold.” A senior ALPA official said that adopting international standards for air traffic control phraseology could be particularly useful at airports that handle a large volume of foreign airline traffic, such as Los Angeles International Airport. However, senior NATCA officials said they are concerned about FAA’s adoption of international taxiing phraseology because of the complexity of handling the high volume of air traffic in the United States. These officials also said that FAA could do more to reduce air traffic controller overtime and take additional actions to address controller fatigue. In the meantime, NATCA plans to start its own fatigue management initiative, according to senior NATCA officials. In addition, a NATCA official said that FAA’s focus on reporting the number of serious incursions should not distract attention from less serious incursions, which the official said are also important. A human factors expert we contacted agreed, saying that serious incursions are only the “tip of the iceberg,” that less serious incursions can lead to more serious ones, and that the entire scope of incidents should be examined.

Adopting best practices for runway safety, such as ones that FAA has compiled, also could help address human factors issues. These include practices such as conducting runway safety training for controllers, pilots, and airport personnel; checking the accuracy of airport diagrams and updating them as needed; encouraging pilots to turn aircraft lights on during landing and departure; and eliminating distractions in the control tower.

In closing, although FAA has increased its efforts to improve runway safety through a multilayered approach, the current high level of attention must be sustained to reduce the risk of potentially catastrophic runway accidents. Although the number of serious incursions has declined since 2001, the continuing incidence of near collisions involving commercial aircraft and the continuing increase in the overall number and rate of incursions suggest that a significant risk of catastrophic runway collisions still exists. A significant reduction in the number and rate of incursions may not be realized until the development and installation of runway safety technology is complete. Therefore, FAA must continue to provide a high level of attention to further reduce the number of serious incursions and reverse the upward trend in the overall number of runway incursions through the timely deployment of technology, sustained leadership, and other means.

Mr. Chairman, this concludes my prepared statement. I would be pleased to respond to any questions from you or other Members of the Subcommittee.

GAO Contact and Staff Acknowledgments

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 Pamela Vines.

Appendix I: Data on Runway Incursions and Deployment of Related Safety Technology

Not yet available.

Information not contained in the NTSB incident reports.

Serious incursions involving at least one commercial 2008 (through Sept. 16, 2008)

John Wayne-Orange County, Santa Ana, CA Long Beach-Daugherty Field, CA General Mitchell International, Milwaukee, WI des 30 incrsions that FAA had not yet classified as of Ast 18, 2008. The above nmbers combine data sing FAA’s previos definition of incrsions from fiscal year 2001 throgh fiscal year 2007 and the ICAO definition of incrsions dring fiscal year 2008. The nmber of serios incrsions is not affected by FAA’s adoption of the ICAO definition.

William P. Hobby, Houston, TX led deployment dates are as of Ag. 25, 2008, and represent when the facility first declares the system ready for conditional se. Once the system is formally accepted by the facility, the system is commissioned. FAA’s draft accelerated schedle, shown in this table, targets completing ASDE-X deployment by the fall of 2010, except at New York LaGardia, Memphis International, and Las Vegas McCarran International Airports, where the agency is coordinating ASDE-X implementation with the completion of new air traffic control towers.

Chicago O’Hare International Fort Lauderdale-Hollywood International, FL George Bush Intercontinental, Houston, TX rrently being tested at these locations.

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