FAA can also issue airworthiness directives. 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. FAA Largely Met Its Own Inspection Requirements Related to Icing

As part of its Air Transportation Oversight System (ATOS), FAA assesses  large carriers’ ground deicing programs to ensure that they meet relevant  safety regulations. In fiscal years 2005  through 2009, FAA initiated enforcement actions against large commercial  carriers in 274 cases following one or more violations of icing-related  regulations. 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 research  related to icing. In addition, the private sector has deployed various FAA- required technologies on aircraft, such as wing deicers and ice detectors,  and operated ground deicing and runway clearing programs at airports. 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, and voluntary guidance to provide  icing-related safety oversight. Improving the timeliness of FAA’s winter weather rulemaking efforts. FAA said that, in conjunction with the aviation industry, it  needs to begin focusing on winter operations holistically because there are  many vital elements to safe operations in winter weather conditions,  including airport surface conditions, aircraft ground deicing, aircraft in- flight icing and icing certification, dissemination of airport condition  information, air traffic handling of aircraft in icing conditions, and air  traffic arrival and departure sequencing. Further,  aviation stakeholders have identified challenges that if addressed, could  improve safety. Among others, these challenges include improving the  timeliness of FAA’s winter weather rulemaking efforts, ensuring the  availability of adequate resources for icing-related R&D, and developing a  more integrated approach to effectively manage winter operations. FAA has not formally updated its 1997 Inflight Aircraft Icing  Plan, meaning the stakeholders do not have a consolidated and readily  accessible source of information on the key in-flight icing actions FAA has  under way or planned. A plan that addresses both in-flight and ground icing issues, as  well as the challenges stakeholders identified for this report, would help  FAA measure its ongoing and planned efforts against its goals for  improving safety. Furthermore, a comprehensive plan could help identify  gaps or other areas for improvement and assist FAA in developing an  integrated approach to winter operations. Recommendation for Executive Action

To help facilitate FAA’s and other stakeholders’ efforts to address  challenges to improving safety in icing and winter weather conditions, we  recommend that the Secretary of Transportation direct the Administrator,  FAA, to develop a comprehensive plan, in consultation with public and  private stakeholders, to guide these efforts. In response, the  Department of Transportation agreed to consider our recommendation  and provided technical comments which we incorporated as appropriate. Appendix I: Objectives, Scope, and Methodology

We reviewed (1) the extent to which large commercial airplanes have  experienced accidents and incidents related to icing and contaminated  runways, (2) the Federal Aviation Administration’s (FAA) inspection and  enforcement activities related to icing, (3) the efforts of FAA and other  aviation stakeholders to improve safety in icing and winter weather  operating conditions, and (4) the challenges that continue to affect  aviation safety in icing and winter weather operating conditions. To review the extent to which large commercial airplanes have  experienced accidents and incidents related to icing and contaminated  runways, we analyzed data obtained from FAA, the National  Transportation Safety Board (NTSB), and the National Aeronautics and  Space Administration (NASA).
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. Takeoff and landing operations can also be risky in winter weather. Despite persistent efforts by the Federal Aviation Administration (FAA) and others to mitigate icing risks, icing remains a serious concern. GAO reviewed (1) the extent to which commercial airplanes have experienced accidents and incidents related to icing, (2) FAA's inspection and enforcement activities related to icing, (3) the efforts of FAA and others to improve safety in winter weather, and (4) the challenges that continue to affect aviation safety in winter weather. GAO analyzed data obtained from FAA, the National Transportation Safety Board (NTSB), the National Aeronautics and Space Administration (NASA), and others. Further, GAO obtained information from FAA and NTSB officials and representatives of key aviation industry stakeholders.

What GAO Found

According to NTSB's aviation accident database, from 1998 to 2009 large commercial airplanes were involved in six nonfatal accidents related to icing (including in-flight and runway). However, FAA and others recognize that incidents are potential precursors to accidents. Although large commercial airplanes have experienced few icing-related accidents in the last decade, the several hundred icing-related incidents involving these airplanes contained in FAA and NASA databases suggest that they face ongoing risks from icing. Based on multiple inspections, FAA assesses each large carrier's ground deicing program to ensure that it meets relevant safety regulations. For fiscal years 2005 to 2009, FAA largely met its own requirements for inspecting carriers' ground deicing programs. When a carrier violates a safety regulation, FAA can take enforcement action against the carrier. For fiscal years 2005 to 2009, FAA initiated enforcement actions against large commercial carriers in 274 cases for violations of icing-related regulations. 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. However, FAA has not formally updated its 1997 in-flight icing plan, meaning the stakeholders do not have a consolidated and readily accessible source of information on the key in-flight icing actions FAA has under way or planned. NTSB has issued numerous recommendations as a result of its aviation accident investigations, and NASA has contributed to research related to icing. In addition, the private sector has deployed various FAA-required technologies on aircraft, such as wing deicers, and operated ground deicing and runway clearing programs at airports. GAO's interviews with government and industry stakeholders identified challenges related to winter weather operations that, if addressed, could improve safety. Among others, these challenges include improving the timeliness of FAA's winter weather rulemaking efforts, ensuring the availability of resources for icing-related research, and developing a more integrated approach to effectively manage winter operations. With respect to an integrated approach, FAA said it needs to begin focusing on winter operations holistically because there are many vital elements to safe operations in winter weather, such as airport surface conditions, aircraft ground deicing, aircraft in-flight icing and icing certification, and air traffic handling of aircraft in icing conditions. A plan that addresses both in-flight and ground icing issues, as well as the challenges stakeholders identified for this report, would help FAA measure its ongoing and planned efforts against its goals for improving safety. Furthermore, a comprehensive plan could help identify gaps or other areas for improvement and assist FAA in developing an integrated approach to winter operations.

What GAO Recommends

To help facilitate FAA's efforts to address challenges to improving safety in winter weather conditions, GAO recommends that FAA develop a plan focused on winter operations holistically that includes detailed goals and milestones. In response, the Department of Transportation agreed to consider GAO's recommendation and provided technical comments, which were incorporated as appropriate.