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Aviation Special Investigation Report
Special Investigation Report on
Emergency Medical Services Operations

NTSB Number SIR-06/01
NTIS Number PB2006-917001
PDF Document(2.6 M)


Executive Summary:  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 safely and 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. This special investigation report of EMS operations and accidents is not intended to burden operators with undue requirements or to handicap this vital function in any way; rather the purpose of the report is 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 1 (this number of EMS accidents had not been seen since the 1980s); 2 these accidents resulted in 54 fatalities and 18 serious injuries (see appendix B for more information). Although the number of flight hours flown by EMS helicopter operations has increased from about 162,000 in 1991 to an estimated 300,000 in 2005, 3 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. 4 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 to provide the best examples of the safety issues involved:

These seven accidents have been specifically cited, where applicable, in this report’s discussion of each safety issue. More detailed flight histories, as well as probable cause statements for these accidents, are provided in appendix A.

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 5 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. As a result of its findings, the Board issued 19 safety recommendations to the Federal Aviation Administration (FAA) and others, which have since been closed (see appendix G information about these recommendations and their classifications). Most of the recommendations to the FAA were closed as a result of the June 20, 1991, issuance of Advisory Circular (AC) 135-14A, “Emergency Medical Services/Helicopter (EMS/H),” which addressed equipment, training, crew resource management (CRM), decision-making, flight-following procedures, weather minimums, and the development of safety programs for EMS helicopter flights operating under 14 Code of Federal Regulations (CFR) Part 135. Although the Safety Board expressed concern at the time that the FAA chose to issue an AC instead of regulations, the number of EMS accidents was decreasing, thus the recommendations were closed. 6 Despite the guidance provided in AC 135-14A and AC 135-15, EMS aircraft accidents have continued to occur in significant numbers, as shown in table 1 for the 15-year period from 1990 to 2005.

Table 1. EMS Accidents From 1990 to 2005

 

Total Injuries

Year

Number of
accidents

Number of fatal
accidents

Fatal

Serious

Minor

1990

1

0

0

0

0

1991

1

1

4

0

0

1992

3

2

3

4

0

1993

3

2

5

3

3

1994

4

2

6

0

3

1995

5

1

3

0

2

1996

5

3

9

1

0

1997

3

1

4

0

0

1998

11

2

8

5

5

1999

6

0

0

6

0

2000

6

2

7

0

4

2001

13

1

1

2

2

2002

13

6

14

8

4

2003

19

3

3

2

16

2004

19

9

29

7

3

2005

13

6

13

5

5

Recent industry publications regarding the safety of EMS aviation operations are consistent with the Safety Board’s findings. For example, after an extensive 2-year safety review and risk assessment of helicopter EMS accidents, the Air Medical Physician Association (AMPA) reported in November 2002 that the time of day that flights occur could contribute to accidents. 7 The report indicated that even though 38 percent of all helicopter EMS flights occur at night, 49 percent of accidents during a 20-year period occurred during nighttime hours. The report also cited controlled flight into terrain (CFIT), in particular during the takeoff or landing sequence, as a common problem, as well as collision with objects (wires were the most common obstacles for EMS helicopters); inaccurate weather forecasts (about 26 percent of helicopter EMS accidents were weather-related, with most occurring because of reduced visibility and IMC while the helicopter was en route); and communications problems with air traffic control (ATC) or a lack of communications due to remote locations and high terrain.

AMPA’s report also cited time pressures related to the patient’s condition, rapid mission preparation, flight to the patient pick-up location, and low fuel as frequent issues in EMS aircraft accidents. According to a query of the National Aeronautics and Space Administration’s Aviation Safety Reporting System, patient condition was cited in 44 percent of the EMS accidents or incidents reports as a contributor to time pressure leading to inaccurate or hurried preflight planning. In addition, the AMPA report stated that accidents occurred more often when flight crews were en route to pick up a patient than at any other time during flight. A white paper published 8 by Helicopter Association International in August 2005 examined many of the same issues as AMPA.

This special investigation report is not intended to represent a comprehensive statistical analysis of EMS accidents. Because 14 CFR Part 135 operators are not required to maintain flight activity data, such an analysis is not possible. The purpose of this report is to discuss the safety issues identified during the Safety Board’s investigation and suggest recommendations that, if implemented, could address these issues. (See appendix C for a list of accidents that were examined during the Board’s investigation that might have been prevented by the corrective actions proposed in this report.) The Safety Board also recognizes that the use of EMS aircraft operations involves aspects of public policy (for example, the decision to use EMS aircraft instead of ground transportation, the reimbursement structure of vital services, and the economic competition among EMS operators) that will not be the focus of this report.

The Safety Board notes that the FAA has recently taken positive steps to improve the safety of EMS operations. For example, in August 2004, the FAA convened a Helicopter Air Ambulance Accident Task Force to make recommendations to reduce helicopter EMS accidents; to date the task force has not issued any recommendations or rule changes. On January 28, 2005, the FAA released Notice N8000.293, “Helicopter Emergency Medical Services Operations,” which contained information that FAA inspectors could provide to helicopter EMS operators “for a review of pilot and mechanic decision-making skills, procedural adherence, and crew resource management” (see appendix D). On August 1, 2005, the FAA released Notice N8000.301, “Operational Risk Assessment Programs for Helicopter Emergency Medical Services,” which identified possible risks and dangers to flight crews and patients and encouraged aircraft EMS operators to promote the use of risk assessment models (see appendix E). The FAA issued similar (although less detailed) guidance in AC 135-14A; however, the recommended practice of risk assessment and decision-making had not been incorporated in a formalized manner into the EMS operations that were investigated as part of this special investigation. 9 Finally, on September 27, 2005, the FAA released Notice N8000.307, “Special Emphasis Inspection Program for Helicopter Emergency Medical Services,” which provided guidance to aviation safety inspectors for the examination of operational factors that were identified as causal to EMS accidents from 1999 to 2004, such as operational control, safety culture development, and access to and use of weather information by flight crews, management, and in-flight communications specialists (see appendix F).

Despite these positive steps to improve EMS operation safety, the FAA has not yet imposed any requirements for all aircraft EMS operators regarding flights without patients on board, risk management, flight dispatch, or the use of technologies. The FAA’s recently published notices are simply information for principal operations inspectors (POI) to convey to their operators and encourage them to incorporate into their operations. Because the guidance provided in ACs 135-14A and 135-15 was not widely adopted by EMS operators, the Safety Board does not anticipate that the guidance provided in the FAA’s notices will be widely implemented. The Board is concerned that, without requirements, some EMS operators will continue to operate in an unsafe manner, which could lead to further accidents. Although the Board recognizes that the nature of EMS operations involves some risks, operators should be required to provide the best available tools to minimize those risks and help medical personnel, flight crews, and patients arrive at their destinations safely.

_________________________________________________________

1 Of these 55 EMS aircraft accidents, 41 were helicopter EMS accidents, 16 of which were fatal, resulting in a total of 39 fatalities and 13 serious injuries; 14 were airplane EMS accidents, 5 of which were fatal, resulting in 15 fatalities and 6 serious injuries. Since the initiation of this special investigation in January 2005, 9 additional EMS aircraft accidents have occurred, resulting in 8 fatalities.

2 Comprehensive activity data regarding EMS operations (for example, exposure rates and missions flown) are limited because the sources for these data are generally poor. On May 12, 2005, the Safety Board issued Safety Recommendations A-05-11 through -13 to the Federal Aviation Administration to address the integrity of general aviation flight activity data. Information about these safety recommendations can be found at the Board’s Web site at <http://www.ntsb.gov>.

3 “Improving Safety in Helicopter Emergency Medical Services (HEMS) Operations,” Helicopter Association International (Alexandria, VA: August 2005).

4 Ira J. Blumen, “A Safety Review and Risk Assessment in Air Medical Transport,” Supplement to the Air Medical Physician Handbook, (November 2002): 35.

5 National Transportation Safety Board, Commercial Emergency Medical Service Helicopter Operations, Safety Study NTSB/SS-88-01 (Washington, DC: NTSB, 1988).

6 On November 19, 1990, the FAA issued AC 135-15, “Emergency Medical Services/Airplane,” which contained guidance information similar to AC 135-14A. However, the recommendations from the 1988 study focused on EMS helicopter operations, so the closure of these recommendations was based on the issuance of AC 135-14A.

7 Ira J. Blumen, MD, and the UCAN Safety Committee, “A Safety Review and Risk Assessment in Air Medical Transport.” Supplement to the Air Medical Physician Handbook, (November 2002): 2.

8 “Improving Safety in Helicopter Emergency Medical Services (HEMS) Operations,” Helicopter Association International (Alexandria, VA: August 2005). The Safety Board has reviewed this white paper and determined that this special investigation report further amplifies many of the issues mentioned in the white paper.

9 See “Aviation Flight Risk Evaluation Programs for EMS Operations” in this report for more information.

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