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The article provides information on the development of the different kinds of missiles in the U.S. Armed Forces. The missiles have three principal components which include propulsion, guidance, and payload system. The relative efficiency of propellants is measured by the specific impulse which is defined as the thrust produced by consuming the propellants at the rate of one pound per second. Missiles are also classified depending on the way they interact. Some of the types include the cruise missiles, aerodynamically controlled missiles, and ballistic missiles.

Aerotunelska ispitivanja protivoklopne avio-bombe (PTAB) se vrše se da bi se odredili aerodinamički koeficijenti u režimima podzvučnog i transoničnog strujanja. U istim režimima strujanja ispituje se i vreme armiranja mehanizma upaljača avio-bombe, koje direktno zavisi od uslova opstrujavanja protivoklopne avio-bombe. Krajnji cilj ispitivanja je definisanje pouzdane metode za određivanje vremena armiranja upaljača u aero-tunelu, čime se isključuju skupa letna ispitivanja. Za potvrdu metode predviđena je i verifikacija istih karakteristika protivoklopne avio-bombe u realnim letnim uslovima, nakon aerotunelskih ispitivanja. / Wind tunnel testing of an aircraft anti-armor bomb (PTAB) is performed to determine its aerodynamic coefficients at subsonic and transonic flow regimes. In the same regimes, the fuze mechanism arming time is tested, directly depending on the local flow field around the anti-armor bomb. The objective of this investigation is to define a reliable method of determining the fuze mechanism arming time. A verification of the same characteristics of the anti-armor bomb in real flight conditions will be taken into consideration to approve the method after wind tunnel testing. / Испытания в аэродинамической трубе противотанковых авиабомб (ПТАБ) проводятся с целью определения аэродинамического коэффициента в режиме дозвукового и околозвукового течения. В тех же режимах течения проходят и испытания необходимого времени для срабатывания механизма зажигания авиабомбы, которое зависит от условий обтекания противотанковой авиабомбы. Конечной целью данных испытаний является разработка точных методов определения времени срабатывания механизма зажигания в аэродинамической трубе, так как их применение позволит существенно снизить расходы, за счет исключения дорогостоящих летных испытаний. Проверка соответствия примененного метода и характеристик противотанковой авиабомбы будет проведена в реальных летных условиях, после проведения испытаний в аэродинамической трубе.

This paper presents a numerical analysis of motion dynamics of a two-degree-of-freedom of motion rectilinear oscillatory system with the motion limitations and forced excitation. The analysis of a mechanical-mathematical model with discontinued parameters is based on the numerical integration of differential equations. The forced oscillatory system has been implemented in two automatic armament systems of 12.7mm and 20mm calibers, which have been installed in the light propeller aircraft and transport-combat helicopter. The motion parameters - movement and velocity and forces have been measured on the stand. Motion parameters and force computations were compliant with the analogous values measured on the designed systems. The mechanical-mathematical model of system dynamics can be used for a prediction of the behaviour of a two-degree-of-freedom of the motion system in the stage of parameters adjustment, prior to the design of system elements. The description of the measurement and used equipment is presented as well as a possible way of further work.

Wind tunnel testing of an aircraft anti-armor bomb (PTAB) is performed to determine its aerodynamic coefficients at subsonic and transonic flow regimes. In the same regimes, the fuze mechanism arming time is tested, directly depending on the local flow field around the anti-armor bomb. The objective of this investigation is to define a reliable method of determining the fuze mechanism arming time. A verification of the same characteristics of the anti-armor bomb in real flight conditions will be taken into consideration to approve the method after wind tunnel testing. [ABSTRACT FROM AUTHOR]

Studying a guidance law, which can intercepts not only high-speed targets, but also low-speed targets with impact angle constrains, is a challenging task. In this paper, a new guidance law called united biased proportional navigation (UBPN) is proposed. The guidance law uses time-varying bias and navigation ratio, and incorporates the advantages of head-on and head-pursuit engagement. UBPN with positive time-varying navigation ratio can intercept low-speed targets which is a head-on engagement, while with negative time-varying navigation ratio can intercept high-speed targets, which is a head-pursuit engagement. To begin with, planar UBPN guidance law is proposed and exact time-varying bias is derived. Moreover, the solution to the singularity in time-varying navigation ratio is given. Secondly, in order to realize the guidance law in three-dimensional space, we derive the relation between two-dimensional acceleration and three-dimensional acceleration, and also give the solution for calculating the impact angle from two-dimensional surface into three-dimensional space. Finally, the simulation results of UBPN compared with proportional navigation, retro-proportional navigation, and bias proportional navigation guidance law are shown. It is demonstrated that the miss distance and impact angle error can meet the guidance law requirements. Capture region of UBPN is given by simulation, which indicates that it is almost two times than that of the guidance law in the head-on engagement for interception of high-speed target. [ABSTRACT FROM AUTHOR]

Highlights: [•] The failure of the star-separator is the result of low-cycle fatigue phenomenon. [•] The crack was initiated at the multi origin points on the surface layer. [•] The propagation of the crack occurs under the influence of contact stress state. [Copyright &y& Elsevier]

Abstract: This research develops an agent based simulation model for application to the sortie generation process, focusing on a single fighter aircraft unit. The simulation includes representations of each individual maintainer within the unit, along with supervisory agents that provide direction in the form of dynamic task prioritization and resource assignment. Using a high-fidelity depiction of each entity, an exploration of the effects of different mixes of skill levels and United States Air Force Specialty Codes (AFSCs) on sortie production is performed. Analysis is conducted using an experimental design with results presented demonstrating the effects of maintenance manning decisions on the Combat Mission Readiness (CMR) of a fighter unit. [Copyright &y& Elsevier]

In order to improve aircraft self protection against second-generation Infrared (IR) Man-Portable Air- Defence Systems (MANPADS), which could be widely proliferated in modern theatres of operation, a decoy dispenser pod may be fitted. This pod could have the capability of firing IR decoy Countermeasure (CM) flares in a forwards direction in an attempt to overcome the "track angle bias" counter-countermeasure (CCM) technique which may be used on missiles of this types. In this paper, two different CM flares have been considered, namely the standard flare and the propelled flare. Consideration has also been given to multiple flare firings with investigation into the timing interval required between firings. The results show a general ineffectiveness of the standard flares because of the high separation rate of this type of flare from the aircraft. It is also shown that complete platform self protection can be achieved with the propelled flare during crossing engagements due to the aerodynamic design and the thrust profile of the flare. A further investigation has demonstrated the best evasive manoeuvres that can be conducted by the aircraft after having released the countermeasures. [ABSTRACT FROM AUTHOR]

Designing decision, control and information systems is motivated, in part, by the need to support the deployment of multiple aircraft, such as combat vehicles, unmanned combat air vehicles, unmanned aerial vehicles, and weapons, in missions taking place in a dynamic, although uncertain, environment. Such systems aim at ensuring mission success without overloading the operating crew, the pilots, and the commanders. One of the main design challenges lies in obtaining some sort of coherent behaviour of the fleet, by means of solutions to potentially NP-hard problems, given incomplete and imperfect information, and despite limited computational and communication capabilities. In this context, this article proposes a hierarchical decision and information system aiming at providing, in real-time, coordinated aircraft path planning and deceptive engagement assignments. The blue-red engagement policy is obtained by minimizing, and balancing, the energy expenditure among the vehicles while constraining information exchanges to a minimum defined by a risk of inconsistency. The proposed system relies on dynamic programming, online heuristic techniques and stochastic, consistency-checking methods. Numerical simulations show that the proposed approach compares advantageously to a random process and to a law that seeks to minimize the cost of the confrontation at a given time regardless of past moves. However, there is a trade-off between increasing the level of deception and the level of energy consumption. [ABSTRACT FROM AUTHOR]

This experiment evaluated speech-based controls as an aid for Airborne Warning and Control System (AWACS) operators performing simulated Battle Management Command and Control tasks. Twelve AWACS operators were required to track a package of fighter aircraft, receive verbal target changes, and pass the verbal changes to the lead fighter aircraft in a simulated battlefield air interdiction environment. The availability of speech controls for selected human-machine interface manipulation tasks was varied. The participants' mission performance, mental workload, opinions, and real-time control modality preferences were recorded. The results strongly supported the application of speech-based controls in the AWACS interface. [ABSTRACT FROM AUTHOR]

This study examines flight management system (FMS) tasks and errors by C–130 pilots who were recently qualified on a newly introduced advanced FMS. Twenty flight tasks supported by the FMS were analyzed using a cognitive stage model (Sherry, Polson, Feary, & Palmer, 2002) to identify steps with the potential for errors. If a step was found not to have visual cues such as labels or prompts for the required action sequence it was identified as a recall step and a potential source of difficulty. If the action was supported by salient labels and prompts it was identified as a recognition step. Actual pilots using an FMS were observed and performance and errors categorized into the related task step. The greatest amount of observed difficulty was accessing the correct function, labeled as an access error. This process was found to be particularly vulnerable to recall problems. Pilots had the likelihood of .74 for committing an access error on tasks with 2 recalled access steps. This is compared to .13 for 1 recalled access step and .06 for no recalled access steps. Errors associated with formatting, inserting, or verifying entries were less common than access errors; however, these errors primarily occurred on tasks in which recall steps were required for the related step. A total of 93% of the format errors, 80% of the insert errors, and 81% of the verify errors occurred on the tasks that did not have good recognition support for each associated step. On a positive note, experience with the new FMS in the preceding 6 months was correlated with a decrease in overall errors, r(22) = –.42, p < .05, and a decrease in errors associated with inadequate knowledge to accomplish a required step, r(22) = –.61, p < . 01. [ABSTRACT FROM AUTHOR]

According to Major Sine, as technology evolves, war fighters and planners need to expand the concept of weapons effects beyond merely destructive results and develop an inclusive definition of precision weapons tailored to effects-based operations. He proposes a definition that focuses specifically on the preciseness of the weapon's effect rather than on the meaning of "precision" as it relates to the accuracy of a weapon's guidance system. [ABSTRACT FROM AUTHOR]

This paper develops an analytic model that evaluates the expected number of aircraft not operationally ready at a random point in time because of supply (NORS). The model was developed for application to the F-11I aircraft for a multilevel problem, where demand on a first-level line replaceable unit (LRU) eventually causes second-level demands for one or more modules that are components of the LRU. The model is for a single base. Since it is evaluative in nature, the inputs include item stock levels as well as item demand rates, average repair times, and resupply times. An optimization model to determine stock levels that minimize the num. ber of NORS aircraft subject to a budget constraint would be preferable to the evaluation model. The paper shows, however, that an optimization model is not mathematically tractable because the criterion function is not separable into independent item calculations. But an example using F-Ill data indicates that if the METRIC model [see Opns. Res. 16,122-141 (1968)] is used to optimize stock levels, the resulting number of aircraft NORS is within 1 percent of the minimum number of aircraft achievable with the same budget. Finally, the well-known formula of Erlang for the M/G/s service system with no queue allowed is generalized to the case where demand rates and repair rates may be a function of the number of units already in repair. This enables us to examine the sensitivity of the optimal allocation of budget across a group of items when expediting may take place. Though expediting improves system performance, the conclusion is that the optimal allocation is virtually the same as the METRIC allocation. [ABSTRACT FROM AUTHOR]