Mandy Schwalbe

Incidents, accidents and fatalities in 40 years of German helicopter emergency medical system operations.

Context Currently, approximately 100 000 helicopter emergency medical service (HEMS) missions for patients are undertaken in Germany each year. Compared to the early years, risk has reduced significantly, but is still higher than commercial aviation or other airborne operations. Objective The aim of the present study was to evaluate helicopter accidents and fatalities related to HEMS operations. Design Retrospective study of HEMS accidents in Germany. Setting Analysis of accidents in the published flight accident reports of the German Federal Agency for Flight Accident Investigation (40-year period from 1970 to 2009). Data were collected by telephone interview with the operators, manual search of publications and by supplemental internet information. Main outcome measures Data were analysed per 10 000 missions. For statistical analysis, Fisher[Combining Acute Accent]s exact test was used. A P value less than 0.05 was considered significant. Results During the period analysed, a total of 1.698 million HEMS missions (1970 vs. 2009: 61 vs. 98 471) were flown by a mean of 50 ± 27 (1 vs. 81) helicopters. To date, missions resulted in a total of 99 accidents with a mean of 2.4 ± 1.7 accidents per year (range 0–7). The accident rate was 0.57 (0–11.4) per 10 000 missions and the fatal accident rate was 0.11 (0–0.5). Some 64% of missions did not result in any injuries to occupants, whereas 19.2% were fatal. From the accidents analysed, 43.4% were due to collision with an obstacle during landing, take-off or hovering. Landing was the phase of flight most often associated with accidents (44.4%). Conclusion The present study is the largest on HEMS accidents and the only one analysing an entire 40-year time course beginning with inception. In comparison to previous data, a significantly lower accident rate per 10 000 missions was found. Gathering data on the early years is nearly impossible, and further analysis is required to calculate the risk of fatality or identify injury patterns.

Helicopter emergency medical services accident rates in different international air rescue systems

Aim Each year approximately two to four helicopter emergency medical services (HEMS) crashes occur in Germany. The aim of the present study was to compare crash rates and fatal crash rates in Germany to rates in other countries. Materials and methods A MEDLINE search from 1970 to 2009 was performed using combinations of the keywords “HEMS”, “rescue helicopter”, “accident”, “accident rate”, “crash”, and “crash rate”. The search was supplemented by additional published data. Data were compared on the basis of 10,000 missions and 100,000 helicopter flying hours. These data were allocated to specific time frames for analyis. Results Eleven relevant studies were identified. Five studies (three from Germany, one from the US, one from Australia) analyzing HEMS accidents on the basis of 10,000 missions were identified. Crash rates per 10,000 missions ranged between 0.4 and 3.05 and fatal crash rates between 0.04 and 2.12. In addition, nine studies (six from the US, two from Germany, one from Australia) used 100,000 flying hours as a denominator. Here, crash rates ranged between 1.7 and 13.4 and fatal crash rates between 0.91 and 4.7. Conclusions Data and accident rates were inhomogeneous and differed significantly. Data analysis was impeded by publication of mean data, use of different time frames, and differences in HEMS systems.

Probabilities for Severe and Fatal Injuries in General Aviation Accidents

and severely or fatally injured persons were obtained from 1993 to 2007. The analysis focused on both the average number of injured and average number of killed persons and the probabilities of sustaining severe or fatal injuries. SPSS® was used for statistical analysis with p < 0:05. N 5259 general aviation accidents were analyzed. Most accidents occurred in the categories for gliders (n 1930, 36.7%) and single-engine pistons (less than 2 tons; n 1929, 36.7%). The highest probabilities of sustaining severe injury were found for hot-air balloons (72.9%), gliders (15.2%), and helicopters (12.0%). The highest probabilities of sustaining fatal injury were found for aircraft of 2-5.7 tons (23.1%), helicopters (17.1%), and aircraft less than 2 tons (14.0%). Because of a lack of common denominatordataingeneralaviation,thedevelopmentofaccidentstatisticsiscomplicated,ifnotentirelyimpossible. Probabilities for severe andfatal injuries that could be expectedshould an accident occur (conditional probabilities) were calculated. These data facilitate the understanding and improvement of aviation safety.

Helicopter type and accident severity in helicopter emergency medical services missions

OBJECTIVE Whereas accident rates and fatal accident rates for Helicopter Emergency Medical Services (HEMS) were investigated sufficiently, resulting consequences for the occupants remain largely unknown. The present study aimed to classify HEMS accidents in Germany to prognosticate accident severity with regard to the helicopter model used. METHODS German HEMS accidents (1 Sept. 1970-31 Dec. 2009) were gathered as previously reported. Accidents were categorized in relation to the most severe injury, i.e., (1) no; (2) slight; (3) severe; and (4) fatal injuries. Only helicopter models with at least five accidents were analyzed to retrieve representative data. Prognostication was estimated by the relative percentage of each injury type compared to the total number of accidents. RESULTS The model BO105 was most often involved in accidents (38 of 99), followed by BK117 and UH-1D. OfN = 99 accidents analyzed, N = 63 were without any injuries (63.6%), N = 8 resulted in minor injuries of the occupants (8.1%), and N = 9 in major injuries (9.1%). Additionally, N = 19 fatal accidents (19.2%) were registered. EC135 and BK1 17 had the highest incidence of uninjured occupants (100% vs. 88.2%) and the lowest percentage of fatal injuries (0% vs. 5.9%; all P > 0.05). Most fatal accidents occurred with the models UH-1D, Bell 212, and Bell 412. DISCUSSION Use of the helicopter models EC135 and BK117 resulted in a high percentage of uninjured occupants. In contrast, the fatality rate was highest for the models Bell UH-I D, Bell 222, and Bell 412. Data from the present study allow for estimating accident risk in HEMS missions and prognosticating resulting fatalities, respectively.

APPLICATION OF THE FIA SCORE TO GERMAN RESCUE HELICOPTER ACCIDENTS TO PREDICT FATALITIES IN HELICOPTER EMERGENCY MEDICAL SYSTEMS (HEMS) CRASHES

BACKGROUND In the past several decades, multiple studies have examined factors influencing occupant survival in aviation crashes, but only a few have addressed this question in Helicopter Emergency Medical Systems (HEMS) accidents. The four-point FIA Score is a valid tool to measure fatality risk in aviation crashes. OBJECTIVE The aim of the present study was to analyze the performance of the FIA Score when applied to German HEMS accidents, and to determine the prognostic value for fatalities and for survival. METHODS The FIA Score uses three parameters (F=fire; I=Instrument meteorological conditions; A=Away from airport) to determine the fatality risk after crashes. Data for German HEMS accidents between October 1970 and December 2009 were gathered retrospectively from the Federal Agency for Flight Accident Investigation. Accidents were graded according to the FIA Score by two emergency physician-pilots, and crash fatality rates (CFR) were calculated. RESULTS A total of 99 HEMS accidents were analyzed that occurred from September 1970 to December 2009. In 19.2% of these, at least one occupant was fatally injured. There were 63 accidents (63.6%) that took place with no injuries; 8 occurred with minor injuries (8.1%); and 9 resulted in major injuries (9.1%). A total of 72 data sets were complete and were used for analysis. Depending on the FIA Score (FIA0, FIA1, FIA2, and FIA3), CFRs of 0.0%, 8.1%, 53.3%, and 100.0%, respectively, were calculated. CONCLUSIONS The FIA Score is a valuable tool in German HEMS accident analysis. It can predict fatalities and is easy to use. Thus, it may also be a valuable tool in EMS call centers to predict survival after a crash.