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Recordings of the noise environment aboard an E-3 AWACS aircraft were made. The measurements were accomplished according to standard procedures of AFRL Aural Displays and Bioacoustics Branch. The measurements were made at various locations in the aircraft during a training sortie. The measurements were accomplished with the current hearing protection device (a David Clark HlO76 headset) and an Active Noise Reduction (ANR) headset (a David Clark H1O76-XL). It was determined that the maximum acoustic dose per day for each location was not reached in typical mission durations. But it was found that the ANR headset did provide attenuation comparable to the current headset. The "Net 4" condition, where one ear cup is worn off of the ear to allow person-to-person communication, made the aircrew reach the daily acoustic exposure in less than 16 hours for most of the positions.

On May 2, 2001, we testified on Defense Logistics Agency (DLA) efforts to purchase black berets for Army forces. These purchases responded to the Army's announcement, in October 2000, that Army personnel would begin wearing berets 8 months later. In an effort to respond to the Army's requirement in the limited% time provided, DLA contracted for production of nearly 5 million berets at a cost of about $30 million. In the process, DLA shortcut normal contracting procedures and waived restrictions, contained in the so-called "Berry Amendment," that limit Department of Defense (DOD) purchases of certain items, including clothing, to those produced in the United States or its possessions. Despite these efforts, DLA was unable to meet the Army's deadline, and it terminated three contracts because the contractors did not meet delivery requirements. In response to your request, we followed up on our earlier work in order to assess the current status of the black beret procurement as well as the status of DOD's efforts to ensure proper waivers of the Berry Amendment. To date, DOD has received about 2.1 million berets-less than 1 million of which were distributed to Army personnel. DOD still expects another 1.6 million berets to be delivered by September 2002. DOD has also taken steps to ensure that proposed waivers of the Berry Amendment are considered at an appropriate management level. DOD no longer allows the Under Secretary of Defense (Acquisition, Technology and Logistics) or the service secretaries to delegate their authority to approve Berry Amendment waivers. Requests for waivers must also be supported by analyses of why alternatives that would not require a waiver were unacceptable. Since these requirements were set, the Under Secretary has approved six waivers, all of which originated at the Defense Logistics Agency. Because DOD is taking actions to ensure proper waivers of the Berry Amendment, we are not making recommendations.

The Ceotronics, Inc., Model TC 917 Wireless Headset is a portable, battery operated, wireless headset. It allows hands-free voice communication with voice activation or push-to-talk capability. The TC 917 came equipped with 10 channels ranging in frequency from 451.5 MHz to 453.75 MHz. Each step up or down the frequency range denotes a change in frequency of 0.25 MHz. To change a channel, remove the right ear cup and place a small slotted screwdriver into the channel select arrow, rotate the arrow to the desired channel. Performs automatic self-tests and displays the results of these tests on a status indicator. The unit operates on an internal, rechargeable Ni-Cad battery and can be recharged using the single unit 115 VAC/60 Hz battery charger (P/N: 40 06 530). The TC 917 weighs approximately 1.38 lbs. The single unit 115 VAC/60 Hz battery charger (P/N: 40 06 530) weighs 2.96 lbs. The charger is 4.28 in. W. X 3 in. H. X 6 in. D.

This report documents the functionality available using Integrate 1.28, a Silicon Graphics- based software package, to visualize, analyze, and manipulate three-dimensional topographic data. The analysis capability represented by this software is robust, flexible, and instrumental in applying 3-D anthropometry toward the improved fit of protective equipment, clothing, commercial head gear, and medical devices. Tutorials are available to guide the user through representative applications.

A new sample foam insert for the Protec helmet was impact tested along with a standard insert to determine differences in impact protection. This testing was performed to ascertain the suitability of the new protective insert in the role of freefall parachute helmet. The testing showed that the performance of the new insert was better than the standard insert, but did not meet the standards set prior to testing. 1. There is a continuing requirement for a protective helmet for Freefall Parachuting within the Canadian Forces. The impact protection of candidate helmets to be used in the freefall parachute role has been identified as a major concern. As such, the Defence and Civil Institute of Environmental Medicine (DCIEM) was tasked by Director Land Requirements (DLR) to perform impact testing on a new foam liner insert for the candidate helmet (Protec). This testing was to be performed as a continuation of the previous work (Ref A). 2. The aim of this project was to measure and analyse the impact performance of a new foam insert for the Protec helmet. Comparison to the original foam insert was to be made, along with performance relative to the standards described below.

These proceedings include the Technical Evaluation Report, a Keynote Address, and 23 invited papers, of the Specialists' Meeting sponsored jointly by the AGARD Aerospace Medical Panel, the Stapp Car Crash Conference Advisory Committee and the Society of Automotive Engineers. It was held at Mescalero, NM, from 7-9 November 1996. Severe head injury resulting from vehicular accidents is a major concern to military and civilian health care workers. Significant advances have been made in the understanding of the causes of severe brain injury and in the factors, both direct and indirect, that contribute to the pathophysiological changes that follow from a severe head injury. Moreover, advances in design and the proper use of countermeasures can significantly reduce head injuries causing death. This Specialists' Meeting addressed the issues of severe head injury from the point of view of: (a) the dynamic response of the head during impacts; (b) brain injury mechanisms in diffuse axonal injury; (c) physical and computer models for assessing injury severity; (d) human tolerance and injury criteria; (e) head injury assessment and treatment; (f) epidemiology in head injury mishaps; (g) harmonization and enforcement of standards for protective head gear; (h) personal protective systems in aircraft; and (i) computer simulations for optimizing head impact protective designs. These proceedings will be of interest to military and civilian medical professionals, accident investigators, safety engineers and research scientists concerned with safety issues in vehicular crash protection. They will also benefit the research manager and scientist or flight surgeon requiring a state-of-the-art review of relevant research in the field of impact head protection., Text in English. Abstract in French and English. Presented at Aerospace Medical Panel Specialists' Meeting, 7-9 Nov 96.

In November 1995, the General Accounting Office (GAO) reported to the Congress on the Army's efforts to automate a number of battlefield functions through creation of a vast network of computers, sensors, and communications systems that would provide a common, simultaneous picture of the battlefield from soldier to commander. More recently, GAO examined the Army's Land Warrior soldier system, estimated to cost in excess of $1.4 billion, and its role in the 'digital' battlefield. The objectives for this report were to: (1) determine the status of various technology and human factor problems associated with system development; (2) evaluate the acquisition strategy for the Land Warrior system; and (3) assess plans to integrate the system with the digital battlefield. The Army developed the Land Warrior program to improve the lethality, mobility, survivability, command and control, and sustainability of infantry soldiers on the battlefield through the integration of a variety of components and technologies. Under the Land Warrior program, the Army is developing a computer/radio, software, integrated headgear (including an imaging display), weapon subsystem, and protective clothing and equipment to be integrated on the individual soldier. When developed, this equipment is expected to allow soldiers to interface electronically with other battlefield systems. The Army also plans to include a number of additional technologies later that are intended to further enhance the soldier's battlefield performance., Report to Congressional Committees.

Although head-mounted technologies have the potential to significantly enhance pilot performance, they increase the mass of the helmet considerably and may increase the risk of cervical injury during emergency ejection. The lack of adequate head restraint makes the prediction of cervical injuries more complicated than other spinal injuries because the position of the head during the acceleration is unknown. A retroactive study of data from +Gy impacts of instrumented human volunteers and manikins attempted to determine head position during peak head acceleration from the direction of the head acceleration vector. The results show that the direction of this peak acceleration is very consistent across all subjects in test runs with sufficiently high energy, and that the ADAM manikin does not accurately reproduce the responses of the human head in Gy impacts.

The mathematical modeling and comparison of manikin headforms and helmet systems requires that the mass properties be accurately determined. The specific properties that must be known are the weight, center of gravity location, magnitudes of the principal moments of inertia and orientation of the principal axes. This data is compared to the specifications of a specific program and also provides insight into issues such as helmet comfort/fit, fatigue and head accelerations/neck forces during ejection or emergency landings. The Mass Properties (M.P.) System and associated software, provide a relatively simple method for measuring these mass properties. This document is intended for use by persons responsible for operating the M.P. System. Included in this report are theoretical calculations, a description of materials required, and step-by-step procedures for system set-up, calibration and determination of weight, center of gravity, and magnitude and orientation of the principal mass moments of inertia.... Mass properties, Helmets, Headform., Prepared in cooperation with KR Systems Inc., Warminster, PA.

The effectiveness of the Army's SPH-4 flight helmet in reducing the severity of head injuries sustained during helicopter accidents was evaluated, using the accident data base at the U.S. Army Safety Center (USASC), Fort Rucker, Alabama. Analysis was restricted to severe (Class A) 1972-1988 accidents that were at least partially survivable, using USASC criteria. Occupants who were not wearing a protective helmet were significantly more likely to sustain severe and fatal head injuries than occupants wearing the SPH-4 (RR=3.8 and 6.3, respectively). Unhelmeted non-cockpit occupants faced higher risks (RR=5. 3 and 7.5). All personnel regularly participating in helicopter flight, civilian or military, should be equipped with protective headgear.

A series of experiments were conducted in which the neck muscles of volunteer subjects were dynamically and statically loaded by systematic variations of twenty-four headgear configurations consisting of eight different centers-of-gravity (CGs) times three different weights. Six subjects would rotate their heads laterally (from side-to-side) for 30 min with each of the headgear loading combinations. Immediately thereafter, the subject would position his head in an isometric head dynamometer and exert a sustained right lateral neck contraction or forward neck contraction at 70% of his maximum strength, during which endurance time (to fatigue) was recorded. The results indicate that the computer model makes reasonable predictions within the boundary conditions. Input data outside the boundary conditions is rejected. The assumption of insensitivity to vertical loading is demonstrated. The assumption of bilateral symmetric response was confirmed for the 1.45 kg and 2.27 kg helmet loads. However, this assumption was not confirmed for the 4.09 kg helmet load. It is concluded from the computer model that afterward, midline loading is the optimal CG location (i.e. maximal endurance) for heavier helmets in the 3-4 kg range.

The purpose of this investigation was to evaluate the effectiveness of a new, self-contained cooling headpiece (CHP) in reducing environmental heat stress. The CHP was designed to be worn by the soldier working under thermally stressful conditions, and requires no auxiliary sources of cool air or water. Two male subjects underwent 30 minutes of strenuous cycling on a bicycle ergometer in a climatic chamber at 104 F (40 C). Three trials were conducted on consecutive days: no CHP was worn on day 1, a warm CHP was worn on day 2, and a cold CHP was worn on day 3. The CHP was applied immediately before exercise and was worn for the entire 30 minute period. The cold CHP significantly reduced rate of esophageal temperature rise (Delta T sub es), heart rate (HR), heat strain index (SI) and heat storage (HS) in both subjects. No differences were observed in sweat rate (SR) or mean weighted skin temperature (MWST). The CHP minimizes the physiological strain of working in a hot environment by removing a significant amount of heat from the scalp face. We conclude that the CHP has the potential to reduce the risk of hypothermia in several military situations of short duration, and shows promise for further research and development.

By the summer of 1972, the Chilean Antarctic institute (INACH, Instituto Antartico Chileno) had carried out exploratory activities in the Antarctic, preferentially in the coastal zones including studies on the food chains of fishes, benthic communities, tide gauging, etc. Starting in 1973, with the definitive organization of the Glaciological Group, investigations began in this scientific discipline and made necessary going further into the continent, therefore confronting a series of new problems of a logistic variety further requiring penetration, supervision, prevention of risks, ranging inward from the coasts, compulsory self-sufficiency, etc. As a consequence of the above, the requirement exists for making adaptations in clothing as well as a number of modifications in equipment used. Recommendations derived from experimentation are presented., Trans. of Boletin, Instituto Antartico Chileno, n8 p26-28 1975.

Helmet angle sensing is a requisite for tracking the pilot's head position and placing him in the loop of a visually coupled control system. This servo system slaves a weapon to the pilot's line-of-sight (LOS) and enables him to track the target with his hands free, to keep his head up and to maintain eye contact with the target. The technique enables complete coverage and unrestricted linear movement of the pilot's head within the spherical region of the Army AH-1G and AAH aircraft and allows unobstructed safe breakaway.

Noise measurements obtained within the cockpits of 339 fixed- and rotary-wing aircraft during normal cruise are reported. The sample includes 271 fixed-wing and 68 rotary-wing aircraft that are grouped according to type and number of power plants. Mean A-weighted levels ranged from 92 to 105 dB for fixed-wing vehicles and from 98 to 106 dB for helicopters. Means and standard deviations are reported by octave-bands, all-pass (flat), A-levels, and preferred speech interference levels (PSIL, average of 500, 1000 and 2000 Hz). Also, at-the-ear A-levels are reported for generalized amounts of attenuation provided by headsets commonly worn in aircraft. (Author)

Potential in-flight emergencies on contemporary aircraft include smoke in the cockpit even without patent fire. In order to avoid eye irritation, the use of a plastic hood to isolate the face of the aviator from the smoke has been proposed. Investigation of visual psychomotor performance indicates that the hood may be marginally satisfactory for very brief time periods, but completely unsatisfactory and potentially hazardous when work for five minutes or more. (Author)