Air ambulances are an integral part of U.S. emergency medical systems, primarily transporting patients between hospitals, but also providing transport from accident scenes or for organs, medical supplies, and specialty medical teams. Air ambulances may be helicopters or fixed-wing aircraft. Helicopter air ambulances provide on-scene responses and much of the shorter-distance hospital-to-hospital transport, while fixed-wing aircraft are used mainly for longer facility-to-facility transport. (See fig. 1.) Helicopter air ambulances make up about 74 percent of the air ambulance fleet and, unlike fixed-wing aircraft, do not always operate under the direction of air traffic controllers. They also often operate in challenging conditions, flying, for example, at night during inclement weather and using makeshift landing zones at remote sites. My testimony today focuses on the safety of helicopter air ambulance operations. Air ambulance operations can take many different forms but are generally one of two business models—hospital-based or stand-alone. In a hospital- based model, a hospital typically provides the medical services and staff and contracts with an aviation services provider for pilots, mechanics, and aircraft. The aviation services provider also holds the FAA operating certificate. The hospital pays the operator for services supplied. In a stand-alone (independent or community-based) model, an independent operator sets up a base in a community and serves various facilities and localities. Typically, the operator holds the FAA operating certificate and either employs both the medical and flight crews or contracts with an aviation services provider for them. This stand-alone model carries more financial risk for the operator because revenues depend solely on payments for transporting patients. Some operators provide both hospital- based and stand-alone services and may have bases located over wide geographic areas. Regardless of the business model employed, most air ambulances—except government and military aircraft—must operate under rules specified in Part 135 of Title 14 of the Code of Federal Regulations when patients are on board and may operate under rules specified in Part 91 when patients are not present. As a result, different legs of air ambulance missions may be flown under different rules. However, some operators fly under part 135 regardless of whether patients are on board the aircraft. (See fig. 2.) Flight rules under Parts 91 and 135 differ in two key areas—(1) minimum requirements for weather and visibility and (2) rest requirements for pilots. The Part 135 requirements are more stringent. According to industry experts and observers, the air ambulance industry has grown, but data limitations make it difficult to determine by how much. Data for several years on the number of aircraft and number of operating locations are available in a database maintained by the Calspan- University of Buffalo Research Center (CUBRC) in alliance with the Association of Air Medical Services (AAMS). For 2003, the first year for which data are available, AAMS members reported a total of 545 helicopters stationed at 472 bases (airports, hospitals, and helipads). By 2008, the number of helicopters listed in the database had grown to 840, an increase of 54 percent, and the number of bases had grown to 699, an increase of 48 percent (see fig. 3). While a database official said that the data partly reflect the use of a revised criterion that allowed for the inclusion of more helicopters and for improved reporting since the database was established, the increase also reflects actual growth. Data are less readily available on whether this increase number of aircraft translates into an increased number of operating hours. FAA does not collect flight-hour data from air ambulance operators. Unlike scheduled air carriers, which are required to report flight hours, air ambulance operators and other types of on-demand operators regulated under Part 135 are not required to report flight activity data to FAA or the Department of Transportation. Historically, FAA estimated the number of flight hours, using responses to its annual General Aviation and Air Taxi and Avionics (GAATAA) survey. These estimates may not be reliable, however, because the survey is based on a sample of aircraft owners and response rates have historically been low. According to the government and industry officials we interviewed and the literature we reviewed, most of the air ambulance industry’s growth has been in the stand-alone (independent) provider business model. Testimony from industry stakeholders recently submitted to NTSB further identifies the stand-alone provider business model as the current area of industry growth. The growth in the stand-alone provider business model has led to increased competition in some locales. According to the officials we interviewed and others who have studied the industry, the increase in the stand-alone provider business model is linked to the development, mandated in 1997, of a Medicare fee schedule for ambulance transports, which has increased the potential for profit making. This fee schedule was implemented gradually starting in 2002, and since January 2006, 100 percent of payments for air ambulance services have been made under the fee schedule. Because the fee schedule has created the potential for higher and more certain revenues, competition has increased in certain areas, according to many of our sources. Increased competition can lead to potentially unsafe practices, industry experts said. Although we were unable to determine how widespread these activities are, experts cited the potential for such practices, including helicopter shopping and call jumping. Helicopter shopping refers to calling a series of operators until an operator agrees to take a flight assignment, without telling the subsequently called operators why the previously called operators declined the flight. This practice can be unsafe if the operator that accepts the flight assignment is not aware of all of the facts surrounding the assignment. Call jumping occurs when an air ambulance operator responds to a scene without being dispatched to it or when multiple operators are summoned to an accident scene. This situation is potentially dangerous because the aircraft are all operating in the same uncontrolled airspace—often at night or in marginal weather conditions—increasing the risk of a midair collision or other accident. From 1998 through 2008, the air ambulance industry averaged 13 accidents per year, according to NTSB data. The annual number of air ambulance accidents increased from 8 in 1998 to a high of 19 in 2003. Since 2003, the number of accidents has slightly declined, fluctuating between 11 and 15 accidents per year. While the total number of air ambulance accidents peaked in 2003, the number of fatal accidents peaked in 2008, when 9 fatal accidents occurred (see fig. 4). Of 141 accidents that occurred from 1998 to 2008, 48 accidents resulted in the deaths of 128 people. From 1998 through 2007, the air ambulance industry averaged 10 fatalities per year. The number of overall fatalities increased sharply in 2008, however, to 29. Both the spike in the number of fatal accidents in 2008 and the overall number of accidents are a cause for concern. However, given the apparent growth in the industry, the increase in the number of accidents may not indicate that the industry has experienced, on the whole, the industry’s safety record has worsened. More specifically, without actual data on the number of hours flown, no accident rate can be accurately calculated. Because an accurate accident rate is important to a complete understanding of the industry’s safety, we recommended in 2007 that FAA collect data on flight activity, including flight hours. In response, FAA has surveyed all helicopter air ambulance operators to collect flight activity data. However, to date, FAA’s survey response rate is low, raising questions about whether this information can serve as an accurate measure or indicator of flight activity. In the absence of actual flight activity data, others have attempted to estimate flight hours and accident rates for the industry. For example, an Air Medical Physician Association (AMPA) study estimated annual flight hours for the air medical industry through an operator survey, determining that the overall air medical helicopter accident rate has dropped slightly in recent years to approximately 3 accidents per 100,000 flight hours. However, the study’s preliminary estimates for 2008 indicate that the fatal accident rate tripled over the 2007 rate, increasing from 0.54 fatal accidents per 100,000 flight hours in 2007 to 1.8 fatal accidents per 100,000 flight hours in 2008. Data on the causes and factors underlying air ambulance accidents indicate that while the majority of accidents are caused by pilot error, a number of risks, including nighttime operations, adverse weather conditions, and flights to remote sites, also contribute to accidents. NTSB data on helicopter accidents occurring from 1998 through 2008 show that pilot error was deemed the probable cause in more than 70 percent of air ambulance accidents, while factors related to flight environment (such as light, weather, and terrain) contributed to 54 percent of all accidents. Nighttime accidents for air ambulance helicopters were prevalent, and air ambulance accidents tended to be more severe when they occurred at night than during the day. Similarly, air ambulance accidents were often associated with adverse weather conditions (e.g., wind gust and fog). Finally, flying to remote sites may further expose the crew to other risks associated with unfamiliar topography and makeshift landing sites. In 2007, we reported that the air ambulance industry’s response to the higher number of accidents has taken a variety of forms, including research into accident causes and training. Since then, the industry has continued its focus on improving safety by, for example, initiating efforts to develop an industry risk profile and share weather information. In July 2008, for instance, AAMS convened a conference (summit) on safety to encourage open communication between the medical and aviation sectors of the industry. AAMS plans to issue a summary of the summit’s proceedings that will include recommended next steps. Table 1 highlights examples of recent industry initiatives. In 2007, we reported that FAA, the primary federal agency overseeing air ambulance operators, has issued guidance, expanded inspection resources, and collaborated with the industry to reduce the number of air ambulance accidents. Since then, FAA has taken additional steps to improve air ambulance safety including the following: Enhanced oversight to better reflect the unique nature of the industry. FAA has changed its oversight to reflect the varying sizes of operators.