In a study to measure the effectiveness of FAA's initiatives to curb terminal area incursions, GAO found that the rate of incidents increased from 11 per million operations in fiscal 2004 to 18 per million in fiscal 2010. Within this statistic, however, the total number of incidents related to foreign objects on a runway, called "runway incursions," has dropped since fiscal 2008.
Additionally, both the rate and total number of errors caused by air traffic controllers have increased considerably during the past few years, from around 200 mistakes in the first quarter of fiscal 2008 to nearly 400 in the second quarter of fiscal 2011. GAO reported that FAA has not met its related performance goals, and has not made comprehensive data available for some of the reported incidents.
FAA oversight in the terminal area applies only to certain categories of incidents, such as runway incursions. For instance, the agency does not oversee runway overruns, when a plane remains on the runway too long.
Among the safety initiatives FAA has undertaken is the Air Traffic Safety Action Program, which allows air traffic controllers to escape punishment for their mistakes if they voluntarily disclose them. GAO noted that this program had the potential to make data less comprehensive, as some serious incidents were reported only through the initiative and did not get entered into the official database for logging errors. FAA also is implementing new technology that will automatically detect errors in the terminal system instead of relying on controllers and their supervisors.
In the report, GAO recommended FAA extend oversight of terminal area safety to include runway overruns and ramp areas, develop risk-based measures for runway safety incidents and improve the methods for sharing information on incidents. The Transportation Department, which houses FAA, agreed to consider the recommendations.