Safety of emergency medical services flights  The safety of emergency medical services flights has become a topic of public interest in the United States, with the expansion of emergency medical services aviation operations, such as air ambulance and MEDEVAC, and the increasing frequency of related accidents. Emergency medical services (EMS) aviation operations (conducted with either helicopters or fixed-wing aircraft) provide an important service to the public by transporting seriously ill patients or donor organs to emergency care facilities. The pressure to quickly conduct these operations in various environmental conditions (for example, inclement weather, at night, and unfamiliar landing sites for helicopter operations) makes EMS operations inherently dangerous, and the hazards associated with EMS operations are resulting in an increasing number of accidents. The U.S. National Transportation Safety Board (NTSB) conducted a special investigation and issued a report on January 25, 2006 titled: "Special Investigation Report on Emergency Medical Services Operations". The report was not intended to burden operators with undue requirements or to handicap this vital function in any way; rather the purpose of the report was to identify and recommend operational strategies and technologies that will help ensure that these vital EMS flights arrive safely and continue to provide a valuable service to the public. Between January 2002 and January 2005, 55 EMS aircraft accidents occurred in the United States (this number of EMS accidents had not been seen since the 1980s) these accidents resulted in 54 fatalities and 18 serious injuries (see appendix B of the report for more information). Although the number of flight hours flown by EMS helicopter operations in the United States has increased from about 162,000 in 1991 to an estimated 300,000 in 2005, the average accident rate has also increased from 3.53 accidents per 100,000 flight hours between 1992 and 2001 to 4.56 accidents per 100,000 flight hours between 1997 and 2001. As a result, the National Transportation Safety Board initiated a special investigation of these 55 accidents and identified the following recurring safety issues:   Of the 55 accidents that occurred between January 2002 and January 2005, the following seven were considered by the NTSB to provide the best examples of the safety issues involved:  These seven accidents were specifically cited, where applicable, in the report's discussion of each safety issue. More detailed flight histories, as well as probable cause statements for these accidents, were provided in appendix A of the report. In 2008, midair collisions of emergency flights caused the deaths of 28 crew members and patients. The Safety Board examined similar safety issues after the occurrence of 59 EMS accidents between May 1978 and December 1986 and concluded in a 1988 safety study that many areas of EMS operations needed improvement, including weather forecasting, operations during instrument meteorological conditions (IMC), personnel training requirements, design standards, crashworthiness, and EMS operations management.