Women aboard a major combatant: the U.S.S. Dwight D. Eisenhower experience.

Women are now being assigned aboard U.S. Navy combatant vessels. The author describes his experiences aboard the nuclear-powered aircraft carrier U.S.S. Dwight David Eisenhower during its 6-mo cruise in 1994, the first such cruise with women integrated into the entire crew. Both medically and operationally, the deployment was an unqualified success, and the ship and its crew fulfilled the directives of the National Command Authority with distinction.

Mishap trends and cause factors in naval aviation: a review of Naval Safety Center data, 1986-90.

Although the mishap rate in naval aviation has declined substantially over the period from 1950-90, there remains a residual number of mishaps per 100,000 flight hours. Many of these mishaps represent human error. There seems to be an additional risk in certain air-frames and in specific missions. We reviewed mishap trends and causes for all naval aircraft over a 4-year period, 1986-90. These were graphically represented and compared, both statistically and with other methods. The mishap rates contained a significant portion of aircrew error mishaps. Of 308 total Class A mishaps, 179 (58%) were attributed to air-crew error. There were 145 (47%) attributed to supervisory error, another form of human mistakes. Thus, the most common cause factors were directly related to human failure. The effect on training is already being seen with the establishment of air-crew coordination training as one of the top priorities in the Fleet Replacement Squadrons. Studies, both underway and in press, appear to indicate a positive response to this training.

The effect of trans-cockpit authority gradient on Navy/Marine helicopter mishaps.

Navy and Marine Corps helicopter mishaps which had a pilot causal factor assigned were examined to determine if the relative military rank of the pilot and copilot was associated with the rate of occurrence per 100,000 flight hours. All class A and B helicopter flight mishaps for the 11 calendar year period 1980-1990 were examined. Although no statistically significant differences were noted, pairing pilots who were of equal rank yielded the lowest rate, seemingly refuting Elwyn Edward's notion that a flat "trans-cockpit authority gradient" may lead to greater problems in the cockpit than his hypothetical "optimum gradient." Moreover, when copilots flew with pilots who differed by two or more ranks, the largest pilot error rate was revealed. This last finding seems to support Edward's hypothesis that a steep "trans-cockpit authority gradient" may be detrimental to aviation safety.

Cervical injuries during high G maneuvers: a review of Naval Safety Center data, 1980-1990.

As aircraft capable of sustaining high "G" maneuvers enter the U.S. Navy Fleet, the reported incidence of cervical injury to aircrew seems to have increased. To determine the extent of the problem, personal injury reports submitted to the Naval Safety Center were reviewed for the 10-year period from 1980 to 1990. In addition, confidential questionnaires were sent to flight surgeons supporting fighter/or fighter-attack units. The data collected were statistically analyzed. The incidence of cervical injuries, defined as at least one day's absence from the flight schedule, was computed. Other subjective factors, such as the type helmet worn, the cockpit position flown and the type of mission profile completed, were examined. As might be expected, the most common offender was air combat maneuvering. The most common aircraft was the F/A18, but the radar intercept officer position in the F14B was also a significant contributor. The most common injury pattern reported was a simple muscle strain. Cervical pain after high "G" missions poses a potential threat to combat readiness. However, the use of the newer lightweight helmet seems to have reduced the severity. Muscle strengthening exercises appear to help in prevention. Treatment is successful in most cases with minimal or no residuals noted. As yet, there exist little official data to support the notion of a major problem.

Loss of cabin pressurization in U.S. Naval aircraft: 1969-90.

During the 22-year period from 1 January 1969 to 31 December 1990, there were 205 reported cases of loss of cabin pressure in US Naval aircraft; 21 were crew-initiated and 184 were deemed accidental. The ambient altitudes varied from 10,000 ft (3048 m) to 40,000 ft. (12192 m). The most common reason for crew-initiated decompression was to clear smoke and fumes from the cockpit/cabin (95%). The most common cause for accidental loss of cabin pressure was mechanical (73.37%), with aircraft structural damage accounting for the remaining 26.63%. Serious physiological problems included 1 pneumothorax, 11 cases of Type I decompression sickness, 23 cases of mild to moderate hypoxia with no loss of consciousness, 18 cases of hypoxia with loss of consciousness, and 3 lost aircraft with 4 fatalities due to incapacitation by hypoxia. In addition, 12 ejections were attributed to loss of cockpit pressure. Nine of the ejections were deliberate and three were accidental, caused by wind blast activation of the face curtain. Three aviators lost their lives following ejection and seven aircraft were lost. While the incidence of loss of cabin pressure in Naval aircraft appears low, it none-the-less presents a definite risk to the aircrew. Lectures on the loss of cabin/cockpit pressurization should continue during indoctrination and refresher physiology training.

Through the canopy glass: a comparison of injuries in Naval Aviation ejections through the canopy and after canopy jettison, 1977 to 1990.

Two methods of ejection from tactical aircraft are commonly used: jettisoning the canopy prior to seat travel, and ejecting through a closed canopy. This report compares the ejection injury experience of Naval Aviation in each mode during January 1977-August 1990. During that period, 336 through-canopy and 580 canopy-jettison ejections were accomplished. The former group sustained 10.7% fatal injuries, and only 17.0% egressed injury-free. By comparison, the latter cohort incurred only 4.7% fatalities and fully 31.9% egressed without injury. Analysis of patterns of injuries confirms higher G-forces in through-canopy ejections, resulting in not only more injuries, but more severe injuries. In spite of these findings, we discuss the compelling tactical and financial reasons to consider through-canopy systems.

Spatial disorientation in naval aviation mishaps: a review of class A incidents from 1980 through 1989.

Spatial Disorientation (SD) has long been a major aeromedical factor contributing to naval aviation mishaps. In the past, it has been viewed as a generalized phenomenon, described by its vertigo-related symptoms. More recently, however, three distinct types of SD have been identified, each based on whether the aviator recognizes and responds to its onset. In the current retrospective study, Flight Surgeon and Mishap Investigation Report narratives from 33 Class A mishaps occurring from 1980 through 1989 were reviewed. SD was determined to have been a causal factor in all cases. The mishaps were examined to categorize SD into the three descriptive types and to describe the relationship (if any) between SD and various mission-related factors. Aircraft type, phase of flight, time of day, pilot experience, and flight topography were all considered. The results indicate that Types I and II SD could be identified as causal factors in all 33 Class A mishaps. Further, most Type I SD was experienced primarily by helicopter pilots at night while most Type II SD incidents affected jet pilots during day missions.

Flight experience and the likelihood of U.S. Navy aircraft mishaps.

Although the flight experience level of U.S. Navy pilots has not declined in recent years, current budget constraints will eventually lead to reductions in flight hours per pilot. This implies an eventual shifting of the distribution of flight hours. Analyses show that the rate of aircrew factor and pilot error mishaps tends to decrease as pilots' flight experience in model increases. Aviation loss rates are higher during a pilot's first 500 hours in model. This seems to be true no matter if the pilot is simply inexperienced overall or a highly experienced aviator transitioning to a different aircraft. These data suggest, therefore, that if the in-model experience levels of naval aviators decline sufficiently, the mishap rate will increase.