	Although Large Commercial Airplanes Have Experienced Few Icing-Related Accidents since 1998, the Many Reported Icing Incidents Suggest that Icing Is an Ongoing Risk to Aviation Safety

According to NTSB’s aviation accident database, from 1998 to 2009 one  large commercial airplane was involved in a nonfatal accident after  encountering icing conditions during flight and five large commercial  airplanes were involved in nonfatal accidents related to snow or ice on  runways. Although there have been few accidents, FAA and others  recognize that incidents are potential precursors to accidents. During this same  time period, NASA’s Aviation Safety Reporting System (ASRS) received  over 600 icing and winter weather-related incident involving large  commercial airplanes. FAA and Other Aviation Stakeholders Have Undertaken a Variety of Efforts Aimed at Improving Safety in Icing/Winter Weather Conditions

		FAA Adopted a Plan to Increase Safety in Icing Conditions and Has Taken Other Actions to Improve Safety in Winter Weather

Following the 1994 fatal crash of American Eagle Flight 4184 in Roselawn,  Indiana, FAA issued a multiyear plan in 1997for improving the safety of  aircraft operating in icing conditions and created a steering committee to  monitor the progress of the planned activities. Over the last decade, FAA  made progress on the implementation of the objectives specified in its  multiyear plan by issuing or amending regulations, airworthiness  directives (ADs), and voluntary guidance to provide icing-related safety  oversight. For  example, FAA has supported NASA research related to severe icing  conditions and the National Center for Atmospheric Research (NCAR)  research related to weather and aircraft icing. For example, NTSB investigates and reports on civil aviation accidents  and issues safety recommendations to FAA and others, some of which it  deems most critical and places on a list of “Most Wanted”  recommendations. The private sector has also contributed to efforts to prevent accidents and  incidents related to icing and winter weather conditions. For example, as  shown in figure 2, aircraft manufacturers have deployed various  technologies such as wing deicers, anti-icing systems, and heated wings. In addition, airports operate ground deicing and runway clearing programs  that help ensure clean wings (see fig. 3) and runways. Continued Attention to Regulation, Training, and Coordination Issues Could Further Mitigate the Risks of Winter Weather Operations

While FAA and others are undertaking efforts to mitigate the risks of  aircraft icing and winter weather operations, through our interviews and  discussions with government and industry stakeholders, we have  identified challenges related to these risks that, if addressed by ongoing or  planned efforts, could improve aviation safety. These challenges include  (1) improving the timeliness of FAA’s winter weather rulemaking efforts,  (2) ensuring the availability of adequate resources for icing-related  research and development (R&D), (3) ensuring that pilot training is  thorough, relevant, and realistic, (4) ensuring the collection and  distribution of timely and accurate weather information, and (5)  developing a more integrated approach to effectively manage winter  operations.
Why GAO Did This Study

Ice formation on aircraft can disrupt the smooth flow of air over the wings and prevent the aircraft from taking off or decrease the pilot's ability to maintain control of the aircraft. Taxi and landing operations can also be risky in winter weather. Despite a variety of technologies designed to prevent ice from forming on planes, as well as persistent efforts by the Federal Aviation Administration (FAA) and other stakeholders to mitigate icing risks, icing remains a serious concern. As part of an ongoing review, this statement provides preliminary information on (1) the extent to which large commercial airplanes have experienced accidents and incidents related to icing and contaminated runways, (2) the efforts of FAA and aviation stakeholders to improve safety in icing and winter weather operating conditions, and (3) the challenges that continue to affect aviation safety in icing and winter weather operating conditions. GAO analyzed data obtained from FAA, the National Transportation Safety Board (NTSB), the National Aeronautics and Space Administration (NASA), and others. GAO conducted data reliability testing and determined that the data used in this report were sufficiently reliable for our purposes. Further, GAO obtained information from senior FAA and NTSB officials, representatives of the Flight Safety Foundation, and representatives of some key aviation industry stakeholder organizations. GAO provided a draft of this statement to FAA, NTSB, and NASA and incorporated their comments where appropriate.

What GAO Found

According to NTSB's aviation accident database, from 1998 to 2009 one large commercial airplane was involved in a nonfatal accident after encountering icing conditions during flight and five large commercial airplanes were involved in nonfatal accidents due to snow or ice on runways. However, FAA and others recognize that incidents are potential precursors to accidents and the many reported icing incidents suggest that these airplanes face ongoing risks from icing. For example, FAA and NASA databases contain information on over 600 icing-related incidents involving large commercial airplanes. FAA and other aviation stakeholders have undertaken many efforts to improve safety in icing conditions. For example, in 1997, FAA issued a multiyear plan for improving the safety of aircraft operating in icing conditions and has since made progress on the objectives specified in its plan by issuing regulations, airworthiness directives, and voluntary guidance, among other initiatives. Other government entities that have taken steps to increase aviation safety in icing conditions include NTSB, which has issued numerous recommendations as a result of its aviation accident investigations, and NASA, which has contributed to icing-related research. The private sector has deployed various technologies on aircraft, such as wing deicers, and operated ground deicing and runway clearing programs at airports. GAO identified challenges related to winter weather aviation operations that, if addressed by ongoing or planned efforts, could improve safety. These challenges include (1) improving the timeliness of FAA's winter weather rulemaking efforts; (2) ensuring the availability of adequate resources for icing-related research and development; (3) ensuring that pilot training is thorough and realistic; (4) ensuring the collection and distribution of accurate weather information; and (5) developing a more integrated approach to effectively manage winter operations.