SHORT COMMUNICATION 1148 Aviation, Space, and Environmental Medicine x Vol. 82, No. 12 x December 2011 H INKELBEIN J, S CHWALBE M, W ETSCH WA, S PELTEN O, N EUHAUS C. Helicopter type and accident severity in Helicopter Emergency Medi- cal Services missions. Aviat Space Environ Med 2011; 82:1148–52. Objective: Whereas accident rates and fatal accident rates for Heli- copter Emergency Medical Services (HEMS) were investigated suffi- ciently, resulting consequences for the occupants remain largely unknown. The present study aimed to classify HEMS accidents in Ger- many 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 in- volved in accidents (38 of 99), followed by BK117 and UH-1D. Of N 5 99 accidents analyzed, N 5 63 were without any injuries (63.6%), N 5 8 resulted in minor injuries of the occupants (8.1%), and N 5 9 in major injuries (9.1%). Additionally, N 5 19 fatal accidents (19.2%) were regis- tered. EC135 and BK117 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-1D, Bell 222, and Bell 412. Data from the present study allow for estimating accident risk in HEMS missions and prognosticating resulting fatalities, respectively. Keywords: HEMS, accident analysis, injury severity, emergency medi- cine, rescue helicopter, helicopter accident, air rescue. T RANSPORTATION OF critically injured patients by fixed-wing airplanes (7) and helicopters (7,21) was initiated as early as 1915 and 1945, respectively. Several years later, these war-driven experiments were adapted to civilian use, e.g., in the United States and Germany. On September 29, 1970, the first civilian German rescue helicopter “Christoph 1” started operating at the Hospi- tal of Munich-Harlaching. Since then, Helicopter Emer- gency Medical Services (HEMS) became increasingly important in the German Emergency Medical System (EMS). No later than 1 yr after starting rescue missions, “Christoph 1” crashed during an approach to an emer- gency scene on August 17, 1971. Two occupants were killed, one was severely injured, and the helicopter was totally destroyed. This was the first aviation accident re- lated to civilian HEMS in Germany. The calculated accident rate and fatal accident rate of rescue helicopter crashes have been extensively investi- gated using various time frames (3,7,12) for Germany (3,10,12) and other countries (10,13,14) during the last years. During a recent study on HEMS accidents in Ger- many, a total of N 5 99 accidents was identified and analyzed (18). Whereas these rates have continuously de- creased over the past decades, resulting consequences for the occupants during HEMS missions were not suffi- ciently analyzed with regard to prognostication of acci- dent severity. As compared to other aviation areas, injury risk during flight may significantly depend on the type of aircraft used (18,22,23). Therefore, the present study aimed to classify HEMS accidents in Germany to predict accident severity with special regard to the helicopter model used. METHODS Data Acquisition Aviation accidents related to German HEMS dated September 1970 to December 2009 were gathered retro- spectively in the annually published accident reports of the Federal Agency for Flight Accident Investigation (“Bundesstelle für Flugunfalluntersuchung”, BFU) as previously reported by the same group (5,13). Additional data were gathered by internet hand-search in available data bases (10,16,17). For analysis both primary and sec- ondary flights were used, since sufficient discrimination between primary and secondary flights was not possi- ble. Since survivability does not necessarily depend on the mission type (5), we omitted differentiating mis- sions. Though Search-And-Rescue (SAR) missions are covered by military helicopters in Germany, these were neither investigated by the (civilian) BFU, nor were these included in the present analysis. From the Department for Anaesthesiology and Intensive Care Med- icine, University Hospital of Cologne, Cologne, Germany; the Work- ing Group “Emergency Medicine and Air Rescue”, German Society of Aviation and Space Medicine (DGLRM) e.V., Munich, Germany; the Medical Faculty Mannheim, Ruprecht Karls University of Heidelberg, Mannheim; and the Department for Anaesthesiology and Intensive Care Medicine, University Hospital of Heidelberg, Ruprecht Karls University of Heidelberg, Heidelberg, Germany. This manuscript was received for review in April 2011. It was ac- cepted for publication in August 2011. Address correspondence and reprint requests to: Priv.-Doz. Dr. med. Jochen Hinkelbein, DESA, Department for Anaesthesiology and In- tensive Care Medicine, University Hospital of Cologne, Kerpener Str., 62, 50937 Cologne, Germany; jochen.hinkelbein@uk-koeln.de. Reprint & Copyright © by the Aerospace Medical Association, Alexandria, VA. DOI: 10.3357/ASEM.3088.2011 Helicopter Type and Accident Severity in Helicopter Emergency Medical Services Missions Jochen Hinkelbein, Mandy Schwalbe, Wolfgang A. Wetsch, Oliver Spelten, and Christopher Neuhaus