bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient Models of Multi‐body Dynamics
Authors: Skelton Robert E.
Published: December 2010

Spacecraft can be large and flexible, with articulated elements. Multi‐body models of these dynamics are often used in space structure design and analysis. This chapter presents multi‐body dynamics in a new form, as amatrixdifferential equation, rather than the traditionalvectordifferential equation. The model has a constant mass matrix, and the equations are non‐minimal. A specific focus of this chapter is tensegrity systems. A tensegrity system requires prestress for stabilization of the configuration of rigid bodies and tensile members. This chapter provides an efficient model for both static and dynamic behavior of such systems, specialized for the case when the rigid bodies are axisymmetric rods.
Launch Vehicle Operational Environments
Authors: Kabe Alvar M. , Kendall Randolph L.
Published: December 2010

There are numerous operational environments that a launch vehicle and its payload are subjected to during launch and flight. These include both external environments, such as ground wind loading and atmospheric pressure, as well as self‐induced, such as vibration due to engine thrust. The relative influence of these environments varies significantly during the different phases of flight, necessitating multi‐disciplinary design and analysis approaches. This chapter describes the various environments, as well as the approaches used to establish the viability of launch vehicle and spacecraft designs to survive the launch and flight environments. In addition, day‐of‐launch operational considerations for flying a launch vehicle safely through the atmosphere, while staying within its structural and control system design limits are also discussed.
The Plasma and Radiation Environment in Earth Orbit
Authors: Rycroft Michael J.
Published: December 2010

After reviewing the important properties of matter in the plasma state, the solar‐terrestrial environment is introduced. The plasma flowing out from the Sun through interplanetary space as the supersonic solar wind is considered, as is its interaction with the Earth's magnetic field to form the magnetosphere, and the energetic charged particles trapped in the magnetosphere which constitute the Van Allen radiation belts. Also considered is the thermal plasma in the ionosphere (at altitudes between ∼80 km and the F‐region peak at ∼300 km) and the plasmasphere above it. Energetic electrons and protons are lost from the magnetosphere, especially at middle to high latitudes, by precipitation into the upper atmosphere and ionosphere. The aurora australis and aurora borealis are created at altitudes of ∼110 km and above as these energetic charged particles impact the tenuous upper atmosphere near 67° magnetic latitude. Observations made from satellites enable us to understand the behavior of the radiation and plasma in near‐Earth space. Some aspects of this environment are hazardous to satellites both in geosynchronous orbit and in low‐Earth orbit, and their electronic equipment – this field of study is introduced; today it is termed “space weather.”
Space Debris
Authors: Klinkrad Heiner
Published: December 2010

Space debris are an environmental factors of growing concern that need to be taken into account in the planning of space missions, in their design, and in their operation. The probability of mission failures, or of severe mission degradation due to debris impacts can reach several percent for typical mission durations in the most densely populated orbit regimes. The following section will describe the sources of the current space debris population, its distribution in space, and its expected future evolution. For the current space debris environment the associated risk levels will be assessed for representative space missions from low Earth orbits up to the geostationary ring.
Aerodynamic Noise
Authors: Morris Philip J.
Published: December 2010

Aerodynamic noise refers to the noise generated by unsteady flow. It is also called aeroacoustics or flow noise. The noise sources can be connected with a turbulent flow, as in jet or boundary layer noise, or with the relative motion with respect to the observer of a steady flow, as in propeller or rotorcraft noise. Aerodynamic noise can contain both broadband and tonal components. To describe the noise generated by a turbulent flow, acoustic analogies have been developed that replace the turbulent flow by a distribution of equivalent sources. Turbulent flow noise can also be predicted using direct numerical simulations of the unsteady flow and the noise it generates. This chapter provides an overview of both propulsive and non‐propulsive system noise. The former systems include jets, fans, and propellers. The latter is generally referred to as airframe noise, and includes the noise generated by high lift devices, such as flaps and slats, and landing gear noise. Noise generated by the turbulent boundary layer and trailing edge noise also falls into the category of airframe noise. Though the sources of aerodynamic noise are generally nonlinear, the propagation of the sound they generate is usually a linear phenomenon. The exceptions include, multiple pure tone (buzz‐saw) noise in turbomachinery, the propagation of noise from very high speed jets, such as those found in military fighter aircraft, and sonic boom.
Propulsion System Noise: Jet
Authors: Bailly Christophe , Bogey Christophe
Published: December 2010

Jet noise remains one of the dominant contributions of aircraft noise at take‐off and thus is a major inhibitor of the growth of air transport, refer to the discussion about aircraft noise sources in Challenges and Opportunities in the Next Two Decades of Aerospace Engineering of the present part. It has been also identified as a serious problem for noise pollution from the beginning of commercial jet flights in the 1950s. Development of reliable predictions for subsonic and supersonic jet noise is directly linked to our understanding of turbulent shear‐flows. In this section, the physics and modelling levels are presented for subsonic and shock‐containing supersonic jets. The importance of providing accurate descriptions for real jets, in order to give insights into flow control and noise reduction design, is also emphasized and illustrated.
Airframe Noise–Landing Gear Noise
Authors: Dobrzynski Werner M.
Published: December 2010

Noise originating from flow around aircraft landing gears is one of the major components of aircraft noise in the approach phase. Owing to the complex structure of landing gears, they represent a cluster of aerodynamic noise sources that are difficult to deal with for the purpose of noise reduction. Moreover, a variety of safety and operational constraints must be considered. Landing gear noise intensity increases proportionally to the 6th power of flow velocity while the sound frequencies increase linearly with the velocity. Through wind tunnel tests on full‐scale gears, typical noise characteristics (spectrum and directivity) and the noisiest gear components can be identified. On the basis of this knowledge, both noise prediction models and add‐on noise reduction fairings can be developed. Such fairings, to protect complex gear structures from high‐speed inflow, provide the only limited noise reduction potential. Much higher noise benefits can be achieved for new landing gears of future aircraft, when aeroacoustic constraints are introduced as an additional design criterion, thus enabling a low‐noise design of both the overall gear architecture and of individual gear components. On top of that, both passive and active flow control means can be applied locally to gear components for further noise reduction.
Propeller Noise
Authors: Self Rod H.
Published: December 2010

Propellers consist of a number of rotating blades and produce both tonal (or harmonic) and broadband noise. However, the former is by far the dominant source as it affects community noise, certification noise, and cabin noise. Hence, considerable effort has been expended advancing efficient methods of calculating it. Isolated propellers produce tones at multiples of the blade passing frequency, whereas counter‐rotating propellers (CRPs) produce tones at frequencies corresponding to “sum and difference” frequencies of the blade passing frequencies of the front and rear rotors. In most instances, quadrupole noise can be neglected, and analytic expressions can be derived for predicting the noise from the remaining sources, which is due to the thickness of, and the loading on, the propeller blades. While the principles are well understood, good predictions depend on an accurate modeling of the flow fields.
Active Noise Control
Authors: Gardonio Paolo
Published: December 2010

The new generation of aircraft require innovative solutions for the reduction of cabin noise, which can deal with new designs of the aircraft and are also able to withstand new requirements for lightweight vehicles. Active control technologies offer interesting lightweight solutions for the reduction of aircraft cabin noise at low audio frequencies, which can be used effectively in combination with passive sound insulation treatments. In the introductory section, the basic principles of active noise control are presented. Also, the principal characteristics of feed‐forward and feedback control architectures are reviewed with reference to tonal and broadband random disturbances. The following three sections introduce the principal control approaches that can be implemented in aircraft. The active control of cabin noise is first discussed. In particular, the effects produced by feed‐forward active noise control and active noise and vibration control systems are investigated. Also, the possibility of implementing active headrests is discussed. The control of vibration transmission from aircraft engines and helicopter gearbox systems is then reviewed. In particular, active vibration control and adaptive tunable vibration absorber technologies are examined. Finally, the active control of sound transmission through the fuselage double wall structure is analyzed. Two approaches are considered: active structural acoustic control and decentralized active vibration control.
Computational Aeroacoustics
Authors: Manoha Eric , Redonnet Stéphane , Caro Stéphane
Published: December 2010

Computational AeroAcoustics, or CAA, covers the development of innovative numerical methods for the simulation of the propagation of acoustic waves in three‐dimensional regions characterized by non‐uniform mean flows around bodies with complex geometries. Such methods are necessary to describe the nearfield radiation of aircraft individual noise sources (jet, fan, propeller, landing gear and high lift devices, which modelling relies on a wide panel of methods, from the simplest semi‐empirical models to the most complex space‐time resolution of the Navier–Stokes equations), up to an external domain where the quieter flow conditions allow to resort to simpler acoustic integral methods. The present section focusses on two different CAA approaches, both relying on the space‐time resolution of the linearized or non‐linear Euler equations in perturbation, one based on Finite Difference high order schemes on multi‐block structured grids, and the other based on the Discontinuous Galerkin Method on unstructured grids. The theoretical background of both methods is presented, then several examples are given for typical configurations of airframe and engine noise.
Emissions and Other Impacts: Introduction
Authors: Dessens Oliver
Published: December 2010

Aviation emission represents only a small part of global anthropogenic emission. But this part is growing faster than any technical improvement on emissions in the civil aviation industry. Burning kerosene produces gases and particles that have different effect on the environment. Some emissions will impact on atmospheric chemistry when others will be radiatively active. This section will focus on emissions and other impacts from aviation in term of local air quality impacts, global chemistry changes, climate impacts and possible mitigations.
Impact of Airports on Local Air Quality
Authors: Bennett Mike , Raper Dave
Published: December 2010

This chapter looks at the impact of airports on local air quality. Having discussed the regulatory environment within which an airport operates, we look at the monitoring methods typically employed to ensure that legal air quality requirements are met. Monitoring is by its nature, however, limited to past and present compliance at a limited number of points. Rational planning of future developments therefore requires that monitoring be complemented by some form of dispersion modeling. Such modeling also permits source attribution as between airport activities and emissions from other nearby sources, with local emissions from motor vehicles typically being dominant. Commonly applied dispersion models are thus discussed. Air quality may be a limiting factor for airport development in respect of NO
2
(in Europe) and fine particulate (in the United States). We discuss technical and toxicological aspects of these two pollutants.
Contrails and Contrail Cirrus
Authors: Gierens Klaus M.
Published: December 2010

This chapter describes condensation trails and how they and other particulate aircraft emissions impact on climate. Finally, various mitigation options are discussed.
Aerodynamics, Propulsion, and Heat Transfer of Missiles
Authors: Fleeman Eugene L.
Published: December 2010

This chapter provides an overview of (i) missile aerodynamics in defining the aerodynamic configuration, (ii) missile propulsion system design and propulsion characteristics, and (iii) missile heat transfer/insulation considerations. Most of the material was derived from the textbookTactical Missile Design, 2nd editionand the technical course Tactical Missile Design – Integration (web site:http://genefleeman.home.mindspring.com/). Topics addressed in the missile aerodynamics section include optimizing missile aerodynamics and missile configuration alternatives. Topics in missile propulsion include a comparison of turbojet, ramjet, scramjet, ducted rocket, and rocket propulsion alternatives; rocket propellant grain cross‐section trade‐offs; reducing visual observables from rocket propellant; rocket motor performance prediction and sizing; and structural materials for the rocket motor case and nozzle. Topics in heat transfer include aerodynamic heating prediction and insulation trades.
Flight Performance, Guidance, Navigation, and Control of Missiles
Authors: Fleeman Eugene L.
Published: December 2010

This chapter provides an overview of missile flight performance; the missile guidance, navigation, and flight control subsystems; as well as the state‐of‐the‐art of missile technology in these areas. Most of the material was derived from the textbook
Tactical Missile Design, 2nd Edition
and the technical course Tactical Missile Design – Integration (
http://genefleeman.home.mindspring.com/
). Topics addressed in the missile flight performance section include drivers that limit the flight performance envelope; optimizing the parameters in the equations of motion for missile flight control effectiveness, maneuverability, speed, and range; predicting flight performance in cruise, descent, and boost; flight range comparisons of rocket, ramjet, and turbojet propulsion; and the required velocity for a homing intercept. Guidance topics include a comparison of active, semi‐active, and command guidance; line‐of‐sight rate requirement for proportional guidance; and the reduction in seeker range from atmospheric attenuation. Navigation topics include satellite Global Positioning System (GPS), inertial navigation system (INS), and data links. Flight control topics include types of flight control (tail, canard, wing, thrust vector, reaction jet) and flight control maneuver laws (skid‐to‐turn, bank‐to‐turn, rolling airframe). Finally, a discussion is provided of the role of missile system simulation in the technology development and design validation process.
Business Aviation
Authors: Torenbeek Egbert
Published: December 2010

Business aviation is a part of general aviation (GA) that focuses on the business use of airplanes and helicopters. It allows for efficient, flexible, safe, and cost‐effective access to destinations across the country and around the world. In many instances, business aviation is the only transportation option available for linking small communities and rural populations directly to population centers and manufacturing facilities. Business aircraft are offered in various categories with different levels of comfort from elementary in small entry‐level short‐range jets to spacious and luxuriously furnished stand‐up cabins in high‐capacity global‐range jets.
Unmanned Aerial Vehicles (
UAV
s)
Authors: Tsach Shlomo , Tatievsky Alex , London Lior
Published: December 2010

A new type of aerial vehicle was introduced in the twentieth century, alongside manned aviation – the Unmanned Aerial Vehicle (UAV). A UAV is either remotely controlled by a human operator or operates autonomously. A system that includes a UAV platform, a Command and Control station and, in some cases, take‐off and landing devices is called UAS.

The history of the UAV begins in parallel to the history of manned aviation. However, only recently its development and progress, hindered in the past by lack of technology, made the UAV category a major area of interest for many civilian and military applications. Dimensions, propulsion and applications of UAVs differ from manned aircraft. Nowadays, sizes of UAVs vary from several centimeters to a wingspan of over 40 m. Propulsion types are diverse as well; from tiny electrical motors to large Turbofan engines. UAVs are used today to substitute manned aircraft in missions of reconnaissance, attack or scientific survey – in many cases with better performance, lower costs and without endangering a pilot. As the widened introduction of UAVs continues, their capabilities and versatility grow, and thus present the most promising technological solution for many current and future airborne applications.

This chapter presents a short review of Unmanned Aerial Vehicle and systems. UAV characteristics, technologies, development history and future trends are discussed.
Lighter than Air Vehicles
Authors: Howe Denis
Published: December 2010

The chequered history of balloons and airships is reviewed and the various types are defined. Properties and applications of lifting gases are given together with techniques of operation both in free flight and in proximity to the ground. Airship aerodynamics, performance, and powerplant considerations are covered as also are typical component mass contributions. There is a description of construction materials and methods. Safety issues are discussed and with economic considerations are used to draw conclusions of future prospects.
Design Criteria: Resources, Constraints, and Objectives
Authors: van Tooren Michel , La Rocca Gianfranco
Published: December 2010

Aircraft can be used for many different purposes. To be able to design a successful aircraft proper discovery and understanding of objectives is essential. The same is true of all the constraints that limit the design space. Such constraints can be derived from the combination of market analysis, flight dynamics, flight performance, and airworthiness requirements. Designing superior aircraft is a multidisciplinary multi‐level systems engineering challenge. This chapter describes various objectives and constraints designers must address in order to design acceptable products. While the technologies of systems engineering and multidisciplinary optimization are not the subject of this chapter, it is important to master these technologies so that design problem definition and formulation are done properly. The presentation of objectives and constraints here reflects associated airplane design practices and the state of the art of systems engineering and multidisciplinary design optimization.
The Design Process
Authors: Price Mark , Soban Danielle
Published: December 2010

The design of a modern aircraft is a phenomenal undertaking involving the co‐operation of many individuals with expertise in a range of disciplines, many of which in themselves take a lifetime to master. Yet new aircraft are designed and each generation improves upon the last, in performance, economy, and safety. Such progression and success is due to the well‐ordered process that governs how an aircraft is designed. This chapter provides a summary of that design process, describing the traditional point design and following through the key steps in conceptual, preliminary, and detailed design. The iterative, hierarchical nature of the design process, and the flow of data and parameters through the evolving design, is brought out in the context of design as a multi‐disciplinary problem. Once the basic process is understood it is possible to review the industrial implementation of the process in the context of systems engineering considering the issues needed to manage a large enterprise.
Fixed‐Wing Civil Transport Aircraft Design
Authors: van Tooren Michel , Rao Arvind G.
Published: December 2010

Within the last 100 years, fixed‐wing aircraft developed from intriguing but shaky objects to highly efficient machines. This evolution required deep understanding of the underlying principles of human flight and continuous development of all elements of the aircraft. Starting off as a feeble contraption to allow adventurous pioneers to demonstrate their skills and guts, the aircraft developed into a very efficient and safe means of transport, delivering functions far beyond just flight. Modern aircraft provide not only lift and speed but also a comfortable cabin with life‐support systems and in‐flight entertainment. The expanded functionality is delivered with a very high economic and fuel efficiency, enabling a cost of flying that is surprisingly low, enabled by continuous improvements in, especially, aerodynamics and structures. In this chapter we look into past and current technological developments in both the architecture and the subsystems of fixed‐wing aircraft with a focus on civil transport aircraft. The discussions on subsystems include structures, aerodynamics, propulsion, flight control, landing gears, fuel systems, avionics, electrical systems, hydraulic systems, pneumatic system, weather hazard protection, and emergency systems
Rotary Wing Vehicle Design
Authors: Pavel Marilena D.
Published: December 2010

Rotary wing aircraft are nowadays reliable flying machines capable to fulfil missions impossible to accomplish with fixed‐wing aircraft. As concerns design, in rotary wing aircraft 36 to 39% of the empty weight rotates. The rotor aerodynamics strongly interacts with the airframe dynamics, power plant, drive system dynamics, flight controls, and the pilot. This transforms rotary wings design into a unique exercise in compromise involving challenging solutions. The present chapter presents the main rotor design parameters. It concentrates especially on conceptual design phase and mainly on helicopters as these vehicles are mostly representative in the class of rotary wing aircraft.
Missile Configuration and Design
Authors: Fleeman Eugene L.
Published: December 2010

This chapter provides an overview of the missile design process as well as thestate‐of‐the‐art(SOTA) of missile technology. Benefits of conducting missile design include definition of new advanced missile concepts, identification of the most important driving parameters, balanced subsystems, incorporation of new technologies, lighter weight, lower cost, and launch platform compatibility. Most of the material was derived from the textbookTactical Missile Design, 2nd edition and the technical course Tactical Missile Design – Integration (http://genefleeman.home.mindspring.com/). Topics include missile transformational technologies, missile characteristics compared to other flight vehicles, missile subsystems and their layout, the missile design process, missile missions and their attributes that drive the SOTA, launch platform integration, environmental requirements, and the development/validation process.
MAV‐Motivated Structures and Materials
Authors: Yoon Kwang‐Joon , Park Joon‐Hyuk , Widhiarini Sriyulianti
Published: December 2010

Micro air vehicles' (MAVs') development is one of the emerging fields in aerospace engineering. Due to the need of small fliers that can perform missions, such as surveillance, reconnaissance, and detection, research and development on such small vehicles have been attracting lot of research activities worldwide. In order to work in the low Reynolds number regime, MAVs need to be developed to be closer to their natural counterparts in terms of aerodynamics, control mechanisms, and structures.

This chapter focuses on the development of flapping‐wing MAVs from the viewpoint of biomimetics on bio‐inspired structures and materials. A novel biomimetic wing structure is proposed for the flapping‐wing MAV and its aerodynamic performance is investigated through wind tunnel experiments. The wing design is inspired by that of an insect, Cicada (Cicàdidae) with some simplifications made in mimicking the wing venation structures. Composite materials are employed in building the biomimetic wings. Our results indicate that by utilizing insect‐inspired, flexible wings, the aerodynamic performance of the flapping‐wing MAVs can be enhanced significantly, which points to the importance of structures and material in developing highly efficient flapping‐wing MAVs.
Insect Flight Control
Authors: Taylor Graham K.
Published: December 2010

This chapter aims to provide an overview of the integrated functionality of the insect flight control system. A key difference of insects from aircraft is their sensor‐rich feedback control architecture. Sensory inputs are therefore considered first, dealing with visual, inertial, and aerodynamic sensing in turn to elucidate some of the functional advantages of this architecture. Besides these sensors responding to rigid body motion, flying insects are also equipped with strain sensors that respond to aeroelastic deformation of the wings in flight, and which appear to be used in feedback to the flight controller. Insect wings deform greatly in flight, which complicates interpretation of their kinematics. The function of the flight muscles in relation to controlling the wingbeat is discussed and several of the most salient wing kinematic parameters are identified. Finally, the unsteady, separated flow dynamics of insects are considered from the perspective of maneuvering flight. The chapter concludes with a brief assessment of the prospects for drawing biomimetic inspiration from the extraordinary maneuverability of insects, and from the simplicity of the flight controller that appears to derive from having such rich sensor input and actuator output.
Fundamentals of Micro Air Vehicle Flight Dynamics
Authors: Żbikowski Rafa
Published: December 2010

Flight dynamics describe possible interactions between the air flow generated by the aircraft and the inertial motion of the aircraft; the nature of those interactions is the physical foundation of flight control. This chapter outlines theoretical and practical knowledge on flight dynamics available from large‐scale aviation which is relevant to professional micro air vehicle (MAV) design. The emphasis is on good understanding of flight dynamics as the cornerstone of MAV flight performance and also a key factor in MAV control design. The influence of the aerodynamics on the MAV flight dynamics is of fundamental importance and hence the meaning of aerodynamic modeling is explained in detail, together with the associated sensor technology. The MAV sensors, required for flight dynamics measurements, are essential for practical implementation at the required scale.
Autonomous Flight of Rotary WingMAVUsing Infrared and Ultrasonic Sensors
Authors: Iwakura Daisuke , Nonami Kenzo
Published: December 2010

The accuracy of small and low‐cost GPS is insufficient to provide data for precisely landing micro air vehicles (MAVs). This study shows how an MAV can land on a small targeted landing site by using rangefinders rather than imprecise GPS data. This chapter describes a proposed movable range‐finding sensor system for measuring the environment and an algorithm of position measurement. This range‐finding system consists of four infrared (IR) rangefinders, four servomotors, and one ultrasonic rangefinder. In order to measure the MAV's position, the sensor system vertically swings each IR rangefinder using the servomotors and these IR sensors detect the edge of landing target. And this sensor system calculates the position from the measured edge direction and the ultrasonic altitude. Additionally, experiments of autonomous hovering over a 52 cm × 52 cm table and autonomous landings were carried out indoors using the proposed sensor system. Our experiments succeeded, and as a result, the MAV kept flying horizontally within a 17.9‐cm radius circle, and then it landed on the table from a height of 50 cm. The IR rangefinders were selected because of the payload limitations of small MAVs. If the MAV's payload capacity were higher, then a laser rangefinder would be used since lasers can operate better in sunlight than IR sensors. Laser rangefinders also tend to have longer scanning ranges and are more accurate.
Development of Centimeter‐sized Aerial Vehicles
Authors: Sunada Shigeru , Tokutake Hiroshi
Published: December 2010

From the viewpoints of stability and safety in outdoor flights, a centimeter‐sized UAV probably has a larger possibility to be used in our everyday lives than different sized UAVs. Centimeter‐sized fixed‐wing UAVs that have already been developed can make autonomous flights. However, their flight speed, that is, their momentum, is fairly high. To use them, their flight speed must be decreased. On the other hand, centimeter‐sized rotary‐wing UAVs that have also already been developed can also make autonomous flights. However, their weight is fairly large. To use them in our daily life, their weight must be decreased. Longer flight duration is also required. For both fixed‐wing and rotary‐wing UAVs, higher reliability is also required.
Flapping‐Wing Propelled Micro Air Vehicles
Authors: Jones Kevin D. , Platzer Max F.
Published: December 2010

In recent years, several micro air vehicles have been built and flown that use flapping wings to generate lift and/or thrust. These designs can be classified as either biomimetic, trying to mimic nature as closely as possible, or biomorphic, being inspired by nature but adopting only certain features from nature. The basic physics of the flapping‐wing phenomenon is first discussed, followed by a description of the recently developed flapping‐wing micro air vehicles.
Fractionated Spacecraft: Exploring Possible Futures of Space Systems
Authors: Brown Owen , Collopy Paul
Published: December 2010

In this chapter, spacecraft fractionation is described. In this approach, a satellite is decomposed into a cluster‐flown, wirelessly linked, distributed network, which can carry out the same function as a comparable monolith. The origins of the concept are described that lead to a full depiction of the approach. The benefits of fractionation are articulated using the concepts of flexibility and robustness. Means to measure value, to include derived value from flexibility and robustness, are detailed using the net present value methodology. Finally, the technological and policy‐oriented challenges are discussed.
Electronic Warfare and Defensive Aids Systems Design and Development
Authors: Pywell Mike
Published: December 2010

Design and development of airborne Electronic Warfare (EW) systems is described, with a focus on self‐protection Defensive Aids Systems (DAS) that are essential to military aircraft and aircrew survival when going ‘in harm's way.’ Whilst much of the material is equally applicable to the individual components of EW systems and DAS, the chapter primarily focuses on platform‐level aspects of the latter. EW definitions are provided and systems described. EW's contribution to survivability is outlined. The route from military user need, through defense procurement agency requirements' expression, to equipment specification is explained. System acceptance philosophy and methods are described. The EW test and evaluation process is outlined and details are given of supporting capabilities for performance verification and customer acceptance into military service. The chapter is written from the perspective of a major international military air/sea/land platform prime contractor and systems integrator. It provides information from a U.K. viewpoint and, whilst national variations are known to exist, the design and development processes and techniques described are broadly general. In particular, the EW test and evaluation capabilities used to support the development and acceptance processes are similar around the world, although some high‐value test facilities are much less common, for example aircraft‐sized RF anechoic chambers.
Installed Antenna Performance Design And Verification
Authors: Macnamara Thereza M.
Published: December 2010

The radiation pattern of an antenna can be severely affected by the airframe on which it is installed. The installed antenna pattern is peculiar to each airframe and therefore the radiation pattern differs from that obtained on other airframes. The process used to design the antenna layout on an aircraft is outlined together with the measures undertaken to achieve interoperability between systems connected to antennas. The effect that the airframe has on the radiation pattern of blade antennas is illustrated and the formulas used to calculate the coupling between antennas are given, including empirically derived values for antenna gains developed in an EU project entitled Installed Performance of Antennas on aeroStructures. The various computational tools used to model the radiation patterns of aircraft are described qualitatively and the predicted patterns compared with measurements, to demonstrate the accuracy of these tools. A brief description of the design and qualification/certification phases is also given.
Design Aspects of Aircraft Vulnerability
Authors: Pywell Mike , MacDiarmid Ian
Published: December 2010

The introductory chapter, ‘The Survivability Balance’ (The Survivability Balance), highlights the three components of survivability, namely damage avoidance, tolerance, and repair. This chapter provides an overview of the design considerations of an aircraft to ensure that if damage cannot be avoided then, as far as possible, the aircraft will be tolerant (i.e., not vulnerable) to damage that causes mission, aircraft, or aircrew loss.

This chapter indicates the types of threat and resulting damage to be considered. The vulnerability reduction strategies that can be adopted in the design and their impact on vulnerability are introduced for airframes and systems. At a top level there are aircraft configuration considerations such as engine location, fuel tank arrangements, and flight control surface concepts. At a more detailed level in the airframe, structural integrity in the event of damage must be considered. For the system, the design and architecture (layout) of the system must be considered such that duplication, separation shielding, and isolation are considered to maintain (as far as practical), critical system functions despite damage from hostile attack.

Finally, vulnerability assessment is introduced as an activity that is undertaken throughout the aircraft design and development process. At an early stage, when the details of the aircraft design are fluid, it is appropriate to carry out qualitative and then quantitative vulnerability analyses. This approach ensures that the top level aircraft configuration is optimized for reduced vulnerability and thus maximized survivability.
An Introduction to Project Management
Authors: Faddy David
Published: December 2010

The introduction briefly explains the nature of project management and specifies its main contributing features together with the authors concerned. These are: the physiological effects of human factors, team‐working, passenger evacuation, reliability and maintainability, cost analysis, cost forecasting, scheduling and life‐cycle engineering, both theoretical and practical. Each of these topics is subsequently discussed in detail in articles by distinguished experts in the relevant field.
Human Factors for Maintenance Engineers and Others – A Prerequisite for Success
Authors: Bennett Simon A.
Published: December 2010

Crew resource management (CRM) has made commercial aviation safer by improving teamwork on the flight‐deck, in the cabin, and between the flight‐deck and cabin. Aviation, however, is a complex activity involving numerous actors whose talents must be allowed to flourish and whose actions require close co‐ordination. These actors include air traffic controllers, dispatchers, fuellers, loaders, and maintenance engineers. Maintenance, calibration, and testing account for up to 65% of human performance problems in engineering. Unlike pilots and cabin crew, maintenance engineers have generally not had the benefit of CRM training. It is argued that CRM training for engineers would reduce maintenance error: (i) by improving communication and co‐ordination (thus helping engineers maintain a
singular
mental model/situation assessment); (ii) by encouraging engineers to question instructions or practices they consider ill‐advised; and (iii) by bringing every useful resource (both physical and experiential) into play. While some engineering teams may practise certain CRM skills naturally, it is important that such skills are learned in a structured environment away from the shop‐floor. Only in this way can competencies be calibrated and a consistent standard established. Maintenance engineers must be allowed the time and space to reflect on praxis.

Since pertinent problems and their solutions are similar across virtually all organizations, this article draws upon examples across engineering in general and even beyond where this enables a point to be made with particular clarity.
Design Considerations for Enhanced Passenger Aircraft Evacuation
Authors: Grant Rebecca L. , Muir Helen C.
Published: December 2010

In the event of an aircraft accident involving fire, it is important that all passengers are able to evacuate as quickly and efficiently as possible. Unfortunately accident investigations have shown that this has not always been the case, and as a result extensive research has been conducted on passenger behavior and emergency evacuation. Consideration is given to the research that has been conducted into the factors that have been proposed to influence evacuation, and suggestions made for areas for ongoing exploration.
Reliability and Maintainability
Authors: Crocker John
Published: December 2010

Aircraft, whether civil or military, fixed wing or rotary wing, generally require a lot of maintenance. Most of this maintenance will require skilled personnel using special equipment in purpose‐built facilities. It is likely to cost the owner several times the initial purchase price of the aircraft. Anything that can be done during the design phase and subsequently through the aircraft's in‐service life to reduce these costs will very likely make the aircraft both cheaper to operate and more attractive to potential buyers. This section looks at some of the tools available to the designer to help influence these costs and what the operator might do to further reduce them while the aircraft is in‐service.

These tools range from the simple reliability block diagrams through fault‐tree and failure mode effects and criticality analyses to statistical analysis, life testing, simulation modeling, health monitoring, risk assessment, and fleet management. While there are many tools and techniques available to perform many of these tasks, it has to be recognized that the reliability of an aircraft, sub‐system or even a part cannot be determined until the last aircraft of the given type has been scrapped or re‐cycled. The reason aircraft today are more reliable than their predecessors is mainly down to experience, lessons learnt, better materials, and better manufacturing processes and controls not, in the main, because of better reliability tools.
Project Management: Cost Analysis
Authors: Pugh Philip G. , Faddy David , Curran Ricky
Published: December 2010

Virtually all decisions in management turn ultimately on the balance of costs and revenues. The article therefore first discusses the nature of costs and the various different types of cost, together with the way they can be aggregated into life‐cycle costs. It then goes on to describe the contribution of cost analysis to the periodic review of major projects required by most procurement authorities, the phenomenon of cost growth associated with the tendency to initially underestimate costs. Finally, it identifies some of the problems with ‘just in time’ practices, risk registers and the assessment of levels of technical maturity.
Project Management: Cost Forecasting
Authors: Pugh Philip G. , Faddy David , Curran Ricky
Published: December 2010

This article, recognising that a forecast of costs is an essential aid to decision‐making at every stage of a project, discusses appropriate methodologies. It describes ‘bottom‐up’, ‘top‐down’ and intermediate approaches, together with their advantages and disadvantages. It also describes the assembly of a data base of past project costs and the need to express each of them at the same economic conditions by the use of inflation indices. Methods of deriving cost estimating relationships using regression analysis and the assessment of their predictive capability are described.
Project Scheduling
Authors: Browning Tyson R.
Published: December 2010

This chapter provides an overview of ten general steps in project scheduling, an essential component of project planning. The ten steps are: (i) define the project's scope and final deliverables, (ii) define the activity set, (iii) decompose the activities and deliverables, (iv) determine the flow of deliverables, (v) determine the activity modes and their durations, (vi) sequence the activities and events, (vii) load and analyze the resources, (viii) adjust the project's duration and risk, (ix) secure commitments to perform, and (x) iterate. One may accomplish these steps with more or less rigor, and with varying methods and tools, depending on such factors as project size, novelty, dynamism, complexity, resources, and risk. Rather than providing detailed explanations of the various techniques in each step, which would require an entire book, the chapter puts these into an overall context and provides references to sources of deeper explanation.
Aerospace Avionics Systems
Authors: Atkins Ella M.
Published: December 2010

Avionics systems have become the information backbone of modern Aerospace systems ranging from micro‐air vehicle and nano‐satellite to jumbo jet and advanced spacecraft. With origins in vacuum‐based radios, the rapid evolution of electronics and software has enabled the development and integration of sensing, processing, and communication elements to perform a wide variety of monitoring, control, and communication tasks. This chapter overviews avionics systems for air and space systems, summarizing the functionality, technologies, and interfaces that have evolved. Although mission objectives and avionics designs differ from air to space systems, both rely on a common suite of interdisciplinary technology areas, including electrical engineering (sensors, communication devices, and power systems), computer engineering (processors and networks), software engineering (including validation and verification), control systems engineering (including guidance, navigation, and control), and human factors (cognitive engineering, life support). Training and education concerns are also discussed in the context of preparing engineers and pilots to design and operate next‐generation avionics systems. Avionics technologies, existing and emerging, are summarized here at a system‐level; further details of avionics subsystem technological capabilities and needs are referenced in other Encyclopedia Chapters (Embedded UAS Autopilot and Sensor Systems through Space Human Factors and Operator Interfaces).
Embedded
UAS
Autopilot and Sensor Systems
Authors: Beard Randal W.
Published: December 2010

The objective of this chapter is to give an overview of autopilot software design for small and miniature unmanned air systems. An architecture that is typical of commercially available autopilots is described. A detailed explanation of the inner‐loop control structure is described, including the lateral directional feedback loops and the longitudinal directional feedback loops. We give a brief description of the sensor package that is usually on small UAS, and describe simple filtering schemes for extracting estimates of the states needed by the autopilot. Finally, we briefly describe GPS navigation for following straight lines and orbits.
Aircraft Communications and Networking
Authors: Rankin James M. , Matolak David W.
Published: December 2010

Aircraft communications have long relied on wireless radio communications to transmit air traffic control instructions and airline operational information between ground facilities and aircraft. As the number of aircraft and ground facilities increase, there is more demand for communication capacity in the frequency spectrum allocated for aeronautical communication. This increased demand has been satisfied so far by slicing the spectrum into smaller bandwidth channels. This issue of frequency congestion is particularly acute near large airports when many people are trying to speak at once on the same channel. Frequency congestion can make it difficult for a pilot to make a radio call in a timely manner. Digital datalinks were thus implemented to transfer non‐time‐critical information. The use of these datalinks reduces the need for voice communication, which then alleviates frequency congestion. The initial use of datalinks has been for airline operations and flight information such as local weather and airport status. As the United States transitions to the Next Generation Air Traffic System, digital data links are the enabling technology that will enhance aircraft communication and networking. Data links will also be used in navigation, surveillance, and flight information services. This chapter reviews aircraft communication basics, traditional types of aircraft communication, and current and future aircraft communication and networking plans.
Space Vehicle Communication and Networking
Authors: Clare Loren P. , Clement Bradley J.
Published: December 2010

Space missions range from Earth‐orbiting satellites to deep space and planetary surface missions. Issues such as time delay, blackout periods, bandwidth limitations, and power constraints make space‐based communication a unique challenge. This chapter overviews the challenges associated with spacecraft communication and solutions adopted and advanced for spaceflight. These challenges have motivated the development and deployment of strategically placed relay stations on the Earth and in space. Spacecraft communications structure and protocols will be overviewed, and associated engineering considerations with ground systems. Data compression and onboard processing will be introduced as methods with potential to better utilize available bandwidth.
Flight Software for Space Systems
Authors: Knight Russell
Published: December 2010

This chapter discusses the challenges, solutions, and roles of space flight software. Challenges include the embedded, real‐time nature of such software, remoteness, the inherent expense of failure, and the inherent inevitability of failure. Solutions are outlined addressing each. Finally, the role of space flight software is discussed, from early guidance systems to current fully autonomous systems.