Helicopter wire strike accident and high voltage electrocution: a case report.

Helicopter wire-strike accidents usually involve high-voltage lines or telephone wires where the resulting impact is low velocity with minimal loss of occupiable space. Death and injury in these mishaps is often due to blunt force trauma to the head. In a recent wire strike accident investigated by the Division of Aerospace Pathology at The Armed Forces Institute of Pathology, the circumstances suggest that death of both aviators was due to high-voltage electrocution. Evidence surrounding the case and high-voltage electrocution are discussed.

Fire deaths in aircraft without the crashworthy fuel system.

Cases reported to the Armed Forces Institute of Pathology were examined for occupants of helicopters without the crashworthy fuel system (CWFS) who survived crashes but died as a result of postcrash fires. There were 16 fire deaths in the 9 such accidents which occurred between January 1976 and April 1984. All of these victims would have survived if there had been no postcrash fire. Partial body destruction by fire probably prevented inclusion of many other cases. The dramatic reduction in fire deaths and injuries due to installation of the CWFS in Army helicopters is discussed. The author concludes that fire deaths and injuries in aircraft accidents could almost be eliminated by fitting current and future aircraft with the CWFS.

Toxicologic studies on USAF aircraft accident casualties, 1973-1984.

The Armed Forces Institute of Pathology analyzed toxicology specimens on 294 cases submitted by the U.S. Air Force from 1973 through 1984. The fatal population consisted of 196 cases of which 43 (22%) had positive toxicology results. Of the fatalities, 14 (7%) had positive drug analyses. The nonfatal group consisted of 98 cases; 14 were positive for toxicology, with 6 positive for drugs. These toxicologic findings are analyzed according to aircrew position, aircraft, and accident scenario parameters.

The Armed Forces medical examiner system: a change for the better.

The armed forces of the United States of America maintain bases throughout the United States as well as in many other countries. The current situation with regard to the investigation of the approximately 2,500 non-combat deaths each year as well as other deaths occurring on military reservations in complex, confusing, and inconsistent at best. Under existing federal law, base commanders can order an autopsy on all active-duty personnel as well as on anyone dying within an area of exclusive federal jurisdiction. Base commanders unfamiliar with the law are often unwilling to order autopsies, and bodies may go to their graves leaving serious questions, such as cause and manner of death, unanswered. In an effort to rectify this situation, as well as to provide consistency in death investigations in the United States military, the Office of the Armed Forces Medical Examiner (AFME) is being established. The AFME will have its headquarters at The Armed Force Institute of Pathology (AFIP) in Washington, DC. All deaths coming under its jurisdiction will be reported in a timely manner and, when required, authorization for autopsy will be granted from the AFME. Regional deputy medical examiners will be appointed to perform autopsies and on-scene investigations. All cases and case materials will be reviewed and retained by the office of the AFME at AFIP. The quality of death investigation will be improved within the United States military by adoption of this system.

Investigation of incidents of terrorism involving commercial aircraft.

Deaths resulting from terrorism involving aircraft have occurred incident to hijackings as well as bombings. Passengers or groups of passengers have been chosen by terrorists as the recipients of violence based on citizenship, religion, and political beliefs. They have usually been segregated from other passengers and subsequently mistreated and/or murdered. Thorough documentation of the injuries of victims is essential to the investigation of such atrocities; a medicolegal autopsy correlated with a scene investigation is of paramount importance. Aircraft bombings can create extremely sensitive political situations and public demands for quick resolution. The autopsy of victims in such circumstances, if properly conducted, can yield invaluable trace evidence leading to the identification of the explosive device. The examination of any surviving victims as well as the aircraft is also critical in reconstructing the event. Deaths occurring as the result of in-flight aircraft bombings can produce injuries by five different mechanisms, viz. blast, shrapnel, decompression, impact with the aircraft, and ground impact.

The medical investigation of airship accidents.

A review of the autopsy reports for 18 of 21 victims in 3 of the 4 nonrigid Navy airship accidents during the period 1955 to 1966 revealed that the patterns of injury, complicated by postcrash entrapment, immersion, or fire, are similar to the injuries observed in the low-speed, low-altitude crashes of rigid airships and of light aircraft. With the renewed interest in the development of airships for military purposes, there is a need for improved design related to crashworthiness and to aircrew habitability, safety, restraint, and egress in order to enhance the chance for survival in the event of an accident.

Sickle-cell trait as a risk factor for sudden death in physical training.

Case reports of sudden death during exertion have not established an association between the sickle-cell trait (hemoglobin AS) and exercise-related death. To test this association, all deaths occurring among 2 million enlisted recruits during basic training in the U.S. Armed Forces in 1977 to 1981 were classified from autopsy and clinical records as non-sudden deaths or as sudden deaths explained or unexplained by preexisting disease. On the basis of known numbers of entering recruits (according to race, age, and sex) and published prevalence rates for hemoglobin AS (8 percent for black and 0.08 percent for nonblack recruits), death rates (per 100,000) were 32.2 for sudden unexplained deaths, 2.7 for sudden explained deaths, and 0 for non-sudden deaths among black recruits with hemoglobin AS, as compared with 1.2, 1.2, and 0.7 among black recruits without hemoglobin S and 0.7, 0.5, and 1.1 among nonblack recruits without hemoglobin S. Among black recruits the relative risk of sudden unexplained death (hemoglobin AS vs. non-hemoglobin S) was 27.6 (95 percent confidence interval, 9 to 100; P less than 0.001), whereas among all recruits this risk was 39.8 (95 percent confidence interval, 17 to 90; P less than 0.001). The relative risk of sudden unexplained death among all recruits increased with age (P less than 0.04), from 13 (ages 17 to 18) to 95 (ages 26 to 30). We conclude that recruits in basic training with the sickle-cell trait have a substantially increased, age-dependent risk of exercise-related sudden death unexplained by any known preexisting cause.

Pulmonary function in sickle cell trait.

Pulmonary function abnormalities, which have been reported to occur in persons with sickle cell trait (hemoglobin AS), could intensify the hypoxic stimulus for the systemic formation of sickle cells at high altitude. We sought to determine whether pulmonary function abnormalities occur as a result of exposure to high altitudes in persons with hemoglobin AS. In a prospective study, 13 men with hemoglobin AS ("cases") and 13 controls (hemoglobin AA) matched by age, sex, and race were exposed to five to seven altitude simulations (ranging from 1524 to 7620 m [5000 to 25,000 ft]) in a hypobaric chamber. Measurements of diffusing capacity for carbon monoxide (DLco), forced vital capacity, forced expiratory volume in one second, and forced midexpiratory flow were obtained before and after each exposure. Data before exposures did not differ statistically between cases and controls. Altitude had no systematic effect on DLco or spirometric values in cases compared with values in controls (p greater than 0.05). Individual declines in forced vital capacity or DLco of more than 10% occurred with similar frequency in both groups. Measurements made after the series of exposures showed no change from those made before. We conclude that short serial exposures to hypoxia at high altitudes does not acutely or cumulatively alter DLco or spirometric values in healthy, nonexercising persons with sickle cell trait.

Injury pattern analysis of helicopter wire strike accidents (-Gz load).

Injury patterns in rotary wing aircraft wire strike accidents were reviewed to determine mechanisms of injury. It was found that U.S. Army Safety Center data showed that between 1 January 1974 and 31 August 1981 there were 167 wire strikes involving Army helicopters which resulted in 60 injuries and 34 fatalities at a cost of $12,809,100. Updated data on all military rotary wing aircraft accidents investigated between 1978 and 1982 were screened by the Division of Aerospace Pathology to determine the mechanisms of injury to flight deck personnel. From 13 December 1978 to 23 June 1982, three types of rotary wing aircraft were in eight fatal accidents. These mishaps accounted for 28 casualties: 14 fatalities and 14 injuries. Aviators comprised 64.4% of the fatalities. Injury pattern analysis showed 100% had major head and neck injuries with 66% having basilar skull fractures. Two-thirds had associated mandibular fractures or evidence of impact forces transmitted through the mandible to the skull. The same number had wedge-shaped chin lacerations from impact with the cyclic control stick. We postulate transmission of lethal impact forces primarily in the +Gz direction through the mandible to the skull. This suggests either improper use and/or failure of the seat and restraint systems.