General aviation aircraft avionics: integration & system tests

The avionics of current-day aircraft is termed as modular integrated full glass cockpit. Unlike lots of dials and gauges, the pilot will interact with Multi-Function Displays (MYD). This means that the systems are coupled with multi-function displays, communication and navigation radios with control units, multi-mode interactive instruments for control and navigation, recording and fault management systems, airframes and health monitoring diagnostic capabilities. Pilot Vehicle Interface (PVI) is an important measure of good avionics and cockpit layout, which implies the optimization of man-machine interface, enhancement of the economy, and safety of flight operations. This presents the avionics architecture of a 14-seat Light Transport Aircraft (LTA) for general aviation, which has multi-role commuter capabilities. LTA is a twin turbo-prop, multi-role aircraft, with air taxi and commuter services as its primary roles. The avionics is built on the digital communication mode for both command and control with current requirements of TCAS, digital Autopilot, and AMLCD multi-purpose glass displays. The LTA Avionics suite is grouped into six major groups based on functionality: Display System, Communication System, Navigation System, Recording System, Radar System, and Engine instruments and other cockpit displays. This paper also covers details about the extensive tests carried out to prove the avionics design in terms of functionality, inter-operability, interference, and compatibility. Various practical integration and flight-test issues, methodologies, and details of the scenarios is presented herein.     

Insertion of controller-pilot data link communications into theNational Airspace System: is it more efficient?

This paper proposes an application of the Total Airspace and Airport Modeller (TAAM)² tool for determining the impact of new Communications, Navigation, and Surveillance (CNS) ground-based and avionics technology on the efficiency of the National Airspace System (NAS). TAAM presents an opportunity to attack this problem by simulating aircraft movements using rules that mimic actual operations. The rules can be tailored to represent local procedures, restrictions, and conflict resolution strategies, producing a realistic picture of aircraft movement. This paper describes a novel method for manipulating TAAM output to produce a measure of the voice channel occupancy (VCO) in a sector. This method can be applied for current conditions, where all communications use the voice channel, and for the future case in which Controller-Pilot Data Link Communications (CPDLC) is used to issue controller/pilot instructions. TAAM could then be used to examine the benefits of CPDLC in terms of relieving restrictions or reducing vectoring and holding. Overall system benefits such as reduction in delays or distance traveled could be estimated from the TAAM results     

GPS/INS integration on the Standoff Land Attack Missile (SLAM)

The Standoff Land Attack Missile (SLAM) is a worldwide, all-weather, precision-strike weapon system deployed from carrier-based aircraft. In the primary mode of operation, target location and other mission data are generated from intelligence sources available on the aircraft carrier and loaded into the missile prior to aircraft takeoff. After missile launch, the SLAM inertial navigation system (INS) guides the missile along the planned trajectory. Updating the missile INS from the Global Positioning System (GPS) during flight provides precise midcourse navigation and enhances target acquisition by accurate, on-target pointing of the SLAM Maverick seeker. The GPS/INS avionics and software integration used for SLAM are described in detail, along with some of the design tradeoffs that led to the approach. The avionics configuration integrates the Harpoon midcourse guidance unit, which includes a strapdown inertial sensor package and digital processor, with a Rockwell-Collins single-channel, sequential GPS receiver processor unit (RPU), a derivative of the GPS phase-III user equipment. In addition to the GPS receiver elements the RPU contains the navigation processor, which executes the SLAM navigation, Kalman filter algorithms, and other guidance algorithms including seeker pointing. Flight-test results of the SLAM GPS-aided INS are also included     

Digital Flight Control Research Using Microprocessor Technology

The Flight Research Laboratory at Princeton University is engaged in an experimental program to investigate a variety of approaches to digital control by actual flight test. Experimentation is being conducted with Princeton's 6-DOF variableresponse research aircraft (VRA), which is equipped for direct side-force control, direct-lift control, feedback of all motion variables, and multiple-pilot command modes. VRA avionics have been augmented by a microprocessor digital flight control system (Micro-DFCS), which uses off-the-shelf computer components capable of operating in parallel or in series with the existing variable-response system. The digital control laws operate in conjunction either with the "bare airframe" dynamics of the VRA or with the dynamics of a simulated aircraft, provided by the existing variable-response system. The initial flight control computer program CAS-1 provides three longitudinal control options: direct (unaugmented) command, pitch rate command, and normal acceleration command. The latter two options are "Type 0" systems designed by linear-quadratic control theory. Future Micro-DFCS software will provide a variety of increasingly complex control options, including "Type 1," logic, gain scheduling, coupled 3-axis control, and "CCV" command modes.     

Stability and control [A century of powered flight 1903-2003]

Aircraft stability and control has evolved from stick and rudder through stability augmentation to redundant digital flight control systems (FCS) and finally to digital fly-by-wire (FBW). Substantial advances in avionics have occurred as aviation progressed from biplanes to civil transports to sub/supersonic military craft and finally the Space Shuttle. Aircraft stability can be defined as aircraft control by maintaining a favorable relationship between center of gravity (CG) and the center of pressure (CP).     

Achieving Nextgen's air traffic management operational improvements

A significant amount of attention has been paid to the functional and ground components in the evolution of the NAS to achieve the Next Generation System (NextGen) but there has been less attention paid to the aircraft equipage side of the equation. This is now changing with the recent establishment of an aircraft working group within the Joint Planning and Development Office (JPDO). The MITRE Corporation's Center for Advanced Aviation System Development (CAASD) has been working over the past year to provide input to the FAA and JPDO which will help inform the avionics evolution and provide more insight into the aircraft equipage considerations for evolving to NextGen.     

基于效能的先进战斗机航电系统动态重构方法

为满足未来先进战斗机全战斗过程的对敌压制能力需求，分析了作战任务与航电系统支持能力间的关系，建立了"作战任务-航电能力-资源需求"间的关系矩阵和航电系统效能模型；以最大化全飞行阶段航电功能整体效能和飞行安全为目标设计了针对不同作战场景的航电系统动态重构策略及重构流程；通过数值分析，对比了动态重构航电系统与静态配置航电系统在不同作战区边界的效能，表明动态重构特性能有效提高战斗机各阶段的作战效能，提高有限资源条件下的阶段优势。     

基于车载平台的飞行管理系统DR/GPS 导航试验验证

飞行管理系统是民用飞机的关键航空电子系统。飞行管理系统制造商有责任对飞行管理系统开展大 量的试验以验证飞行管理系统功能和性能的符合性。考虑数字验证的局限性和飞行试验验证的巨大代价,本文 利用车载平台开展飞行管理系统综合导航功能的验证,试验结果表明设计的飞行管理系统DR/GPS 导航方法能 够满足95% 的飞行时间水平方向达到0.1 海里的导航精度要求,为实际的飞行测试提供了试验数据参考。     

Design by extrapolation: an evaluation of fault tolerant avionics

Over the past 30 years, safety-critical avionics systems such as Fly-By-Wire (FBW) flight controls, full-authority digital engine controls, and other systems have been introduced on many commercial and military airplanes and spacecraft. Early FBW systems, such as on the F-16 and Airbus A320, were considered revolutionary and introduced with extreme caution. These early systems and their successors all make use of redundant and fault-tolerant avionics to provide the required dependability and safety, but have used significantly different architectures. This paper examines the different levels of criticality and fault tolerance required by different types of avionics systems, establishes architectural categories of fault-tolerant architectures, and identifies the discriminating features of the varied approaches. Examples of discriminators include the level of redundancy, methods of engaging backup systems, protection from software errors, and the use of dissimilar hardware and software. The strengths and weaknesses of the approaches will be identified. The paper concludes with some speculation on trends for future systems based on this evaluation of previous systems     

Communication System Architecture for Air Traffic Management and Weather Information Dissemination

The authors present the communication system architecture for air traffic management and weather information dissemination as viewed within the context of the overall National Airspace System (NAS) and the services it provides. This presents the architecture in the 2015 time frame when the final phases of transition take place from analog voice to digital data exchange of common data via integrated networks. The results of this transition are an integrated collection of systems and procedures that efficiently use the capacity of the NAS while balancing access to all user classes and maintaining the highest levels of safety. Efficient collaboration among users is built on a foundation of common data. This information base provides common situational awareness to all participants. All users are accommodated and will receive benefits commensurate with equipage level. This architecture development provides a technical framework for decision-making, research, and analysis of communication technologies     

Design for testability for future digital avionics systems

The authors describe an integrated testing approach called the Maintenance and Diagnostic System (MADS), which was developed for digital avionics systems using VHSIC and semicustom devices. Mission/operational requirements dictate high availability with capability to detect 98% of all faults and isolate 90% of these faults to a line replacement module (LRM) or 95% of the faults to two LRMs. MADS achieves these goals by defining a module maintenance node (MMN) chip set for each LRM in the system and the design for testability concepts for hardware. The MMN aids parallel, high-speed testing of LRMs, isolating the fault(s) to a module/chip level while incurring less than 10% overhead. It uses the concepts of scan set design, pseudorandom test vector generation, output response compression, and separate scan set loops to test the SSI-MSI logic on the LRM. It also stores interim test results and run-time fault information to isolate the hard-to-reproduce failures and performs verification of interchip and intermodule wiring     

Digital Avionics?The Best is yet to Come!!!

This paper reviews some of the history and background of digital avionics and offers some tantalizing possibilities for the future. There are payoffs in many areas from digital avionics; however, the ultimate benefits are increased mission effectiveness and lower costs. Two major U. S. Air Force avionics programs designed to increase mission effectiveness are reviewed. Major barriers to the expanded use of digital avionics in civil transports as a means to lower operating costs are examined. The paper also examines lightning effects, architectures, optical components, displays, and voice interactive control which are current research areas that promise to yield significant advances for digital avionics systems. Finally, in a notice of optimism, it is concluded that the best is yet to come. As good as contemporary avionics are, we have only begun to visualize their ultimate potential.     

A Digital Map Set for the Night Attack Aircraft

There has been much interest recently in applying cartographic digital data bases to advanced avionics systems as a solution to specific problems associated with night attack aircraft missions. The tremendous computer horsepower required to accomplish this task in real-time in an airborne environment is well documented. Hardware implementation of complex algorithms traditionally has produced custom devices which accomplish a specific function on a specific data structure. Historically, this has resulted in powerful but inflexible systems incapable of adapting to the changing requirements of military missions. In an age of evolving technology, these pitfalls must be avoided by incorporating expected changes into the design of digital map systems. If they are made to accommodate a variety of cartographic data bases and allow for programmable manipulation of those bases, this new class of digital map sets can be reconfigured at the software level to meet the changing requirements of aircraft missions. This paper addresses current design concepts for such a map system on a Night Attack aircraft. The focus is on issues concerning the development and handling of existing map data products to meet current system requirements. This system, called the Digital Map Set (DMS), is being designed to accomplish the classical manipulations of Defense Mapping Agency Digital Land Mass System data. Additionally, aeronautical charts, aerial reconnaissance photos, flight plan data, and other two-dimensional bit mapped graphics also are accommodated. Mission requirements relating to the cartographic data bases shall be discussed along with ground support station and airborne system design issues.     

FLILO (FLying Infrared for Low-level Operations) an enhanced visionsystem

The advanced avionics and flight controls group of advanced airlift and tanker systems is dedicated to integrating, prototyping, demonstrating, evaluating and testing advanced state-of-the-art technologies Vv that are candidates for future aircraft use (for new and in-service aircraft), or that are solutions to old or new/upcoming requirements and needs. The group's mission is to transition the applicable technologies into Boeing platforms. One of the research areas investigated is that of Enhanced Vision Systems (EVS)     

The Business Case for System-Wide Information Management

In today's National Airspace System (NAS), when an application requires information from another application, a custom application-to-application interface is built. This results in an increasingly complex system, where applications are tightly coupled and expensive to develop and maintain. System-Wide Information Management (SWIM) addresses these shortfalls by implementing a shared infrastructure for managing NAS information. SWIM is based on a service-oriented architecture, a fast growing trend in information technology. It will help the Federal Aviation Administration (FAA) meet the information-sharing needs of the Next Generation Air Traffic System (NGATS) and the federal government's E-government Initiative. SWIM will reduce the cost, complexity, and cycle time for building new applications and help the FAA implement SWIM-enabled applications that increase FAA and user productivity.     

Pilots's Associate Demonstration One

A brief overview is given of the DARPA- and AFWAL-sponsored Pilot's Associate Demonstration One project. The project developed prototypes for four avionics expert systems, with an emphasis on a crew station information manager (CSIM) system. CSIM operated on information from three supporting subsystems: a situation assessor, a mission planner, and an integration controller. These expert system (ES) prototypes were demonstrated in both a stand-alone environment on an symbolic processor and integrated with an engineering flight simulator. Some of the lessons learned during the project and potential future research directions for avionics ES are examined     

Avionics cost of ownership

The cost of ownership of avionics includes not only the development and acquisition cost, but also the yearly operating and support (O and S) (maintenance) cost of hardware, software, and support equipment. This paper presents an avionics cost of ownership methodology developed for USAF, its data sources, and business metrics computed for USAF decision makers as we move toward operating avionics as a business. The business model is used to determine which existing avionics are candidates for replacement with new technology and to prioritize the replacements. These avionics are often used on multiple aircraft types which necessitates analysis of the causes of the high cost of ownership on each type. Databases are used to document the processing functions, data flow, and constraints of the item being analyzed. These constraints include physical, environmental, electrical, and data interfaces. Databases containing alternatives are evaluated against standard mission scenarios for aircraft utilizing these high cost avionics to determine their impact on performance, O and S costs, and mission effectiveness. The results of the foregoing analyses steps are then used in life cycle cost analyses which consider different retrofit scenarios for each alternative for each aircraft type against the avionics being analyzed for replacement. The alternatives are prioritized and a risk analysis performed considering technical, schedule, and cost growth risks. The avionics cost of ownership methodology described in this paper processes data from USAF maintenance organizations. This has revealed the very large expenditures being made to support highly unreliable avionics. These methods can be applied to all military and commercial aircraft systems to determine not only the cost of ownership of existing systems, but also the cost of ownership of new systems when they are retrofit     

Integrated flight control systems: a new paradigm for an old art

The automatic flight control computer was a revolutionary development in the early days of flight, even in its primitive electromechanical form. It evolved into an electronic computing device, starting as an analog computer and maturing into software run on a digital, general-purpose microprocessor. The current accepted industry standard is to use a dedicated microprocessor in its own enclosure for this function that is essentially firewalled from the rest of the systems on the aircraft. This paper will explore the opportunity to integrate the flight control function into an integrated processing platform, which is a robustly partitioned platform that supports multiple functions of dissimilar design assurance levels. This approach provides all of the benefits of an integrated system, while still maintaining the separation provided by a stand-alone unit. The paper will consider both the advantages and disadvantages of this approach. The discussion will describe each of the alternatives in general and then focus specifically on autopilot and flight control functions that have potential for integration. The end goal of the paper is to impress on the reader an understanding of the different alternatives available for autopilot, flight control, and avionics modernization in general. This includes the development of a selection matrix that will assist the reader in making decisions on how best to implement these functions according to criticality and the volatility of their future requirements     

Integrated modular avionics for next generation commercialairplanes

The goals are objectives of integrated modular avionics (IMA) are discussed. One candidate computing architecture for IMA, the Boeing 777 Airplane Information Management System (AIMS), is presented. The cabinet architecture, fault tolerance characteristics, backplane bus, and functional growth provisions are considered. The integration concepts developed for AIMS represent a first step in real-world application of the IMA technologies     

An environment for the integration and test of the Space Stationdistributed avionics systems

An approach is described to supplying an environment for the integration and test of the Space Station distributed avionics systems. Background is included on the development of this concept including the lessons learned from Space Shuttle experience. The environment's relationship to the process flow of the Space-Station verification, from systems development to on-orbit verification, is presented. The uses of the environment's hardware implementation, called Data Management System (DMS) kits, are covered. It is explained how these DMS kits provide a development version of the Space-Station operational environment and how this environment allows system developers to verify their systems performance, fault detection, and recovery capability. Conclusions on how the use of the DMS kits, in support of this concept, will ensure adequate on-orbit test capability are included