Manfred Held
Without assuming any particular operational scenario, possible threats to military transport aircraft include hits from small arms, high explosive incendiary projectiles with impact or proximity fuzes, frangible armour piercing discarding sabot (APDS) rounds, and small warheads from man-portable anti-aircraft missiles or medium-to-large anti-aircraft warheads. This paper briefly describes each of these threats and their potential effect on aircraft. The hit density as a function of distance is schematically presented whereby high hit densities lead to different synergistic effects. The principal function of radar proximity sensors is briefly described, as well as the prediction of the initial velocities of fragments and their decrease in the ambient atmosphere. Some tests are proposed to define quantitatively the blast/fragmenting loads on aircraft skins with cost-effective individual fragment tests and with fragment generators for high hit densities.
David J. Purdy and Patrick J.H. Wormell
The handling behaviour of skid-steered tracked vehicles is more complex than conventional wheeled vehicles because of their non-linear characteristics. One of the traditional methods used for establishing the handling of wheeled vehicles is the constant radius test, where the variation of steer angle with lateral acceleration is investigated. There have been no comparable studies either experimentally or theoretically for a tracked vehicle for this type of test. With the introduction of a variable-steer-ratio (ratio of sprocket angular speeds) system on tracked vehicles it may be possible to perform this test experimentally. This study addresses the problem of producing a theoretical prediction for the constant-radius test for a current in-service tracked vehicle, Combat Vehicle Reconnaissance (Tracked) CVR(T) manufactured by Alvis in the UK. A model of a general skid-steer tracked vehicle is developed and validated against experimental data from a trial on CVR(T). The model is then used to predict the results for a constant radius turn for this vehicle. The results show that the CVR(T) initially understeers before going into oversteer.
Joanna Szmelter and Jia-Shyang Yeo
The purpose of this study is to develop a new method to estimate the natural fragmentation of axis symmetrical warheads. The method is able to predict the projection of fragments at various projection angles, including the fragmentation velocities, types and sizes. It is fairly close to Mott’s fragmentation predictions for cylinders, and to trial data for 105-mm and 81-mm shells. The model captures essential characteristics of natural fragmentation.
Anthony H. Dekker
In this paper, we examine the spectrum of choices between organisational centralisation and decentralisation in the presence of emerging trends in communications, information-processing, and sensor technologies. These technologies are important drivers in the current move towards Network Centric Warfare (NCW), and raise the question: should the new networks being developed be used to enable greater centralisation, or greater decentralisation? We reduce the choice to six basic questions (covering issues such as facilities, information availability, communications, and time constraints), and examine how the answers to these questions are impacted by technological change. Our analysis suggests that most new technologies can support both centralisation and decentralisation. As a result, over coming decades, the choice will be increasingly determined by a purely theoretical question, namely the possibility of a “global optimum”. This in turn is based on characteristics of the air, maritime, and land environments, with a global optimum more likely in the air and maritime environments, and less likely in the land environment.
Alan Nott
This paper discusses issues related to trans-horizon high-frequency (HF) communications from low-level airborne platforms; specifically the Australian Army’s Black Hawk helicopters. It discusses work completed and in-progress in this area, both privately and at the Australian Army’s Land Engineering Agency (LEA), and brings together a number of communications-related aspects including HF propagation, antenna aspects and frequency and altitude management, all of which need to be properly managed to obtain the best HF communications from helicopters. The possible use of genetic evolution to improve antenna design is also briefly discussed.
Patricia Dexter and Robin J.F. Nicholson
Training for the maintenance of collective or team skills is important to any organisation, particularly a military organisation. While it is generally accepted that a higher level of individual skill is advantageous to team outcomes, the details of how individual skills contribute is not well understood. A number of experiments have been carried out where the proficiencies of individual cellular automata agents are varied and collective measures of the effect are recorded. This gave an indication of the individual proficiency level required for a likely positive collective outcome. This paper focuses on investigating the effect on collective outcome of the degradation of individual combat skills, when applied to both uniform and mixed groups, using the agent-based distillation (ABD) Map Aware Non-uniform Automata (MANA), to simulate the behaviour of small teams. We used current (accepted) theory of how individual skills are lost over time to examine the training frequency required of individual skills to maintain an effective level. Several characteristics of individual skill degradation in small units have been predicted. This study has revealed the differences between the individual skills of shooting accuracy and stealth in their effect on small-unit outcomes. Terrain was shown to have little effect on unit performance for these scenarios. An important outcome was the observation of team skills decaying differently to individual skills, suggesting that a training schedule set to maintain team proficiency might differ from a training schedule set to maintain individual proficiency.
H. Binnendijk (ed), Transforming America’s Military, Center for Technology and National Security Policy, National Defense University, Washington, DC, 2002. Reviewed by Michael Ryan
Reviewed by Michael Ryan
