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This talk will present an overview of the newly published DO-326/ED-202 "Airworthiness Security Process Specification". Presenter Daniel P. Johnson, Honeywell

Atmospheric Neutron Single Event Effects (SEE) are widely known to cause failures in all electronic hardware, and cause proportionately more failures in avionics equipment due to the use altitude. In digital systems it is easy to show how SEE can contribute several orders of magnitude more faults than random (hard) failures. Unfortunately, current avionics Safety assessment methods do not require consideration of faults from SEE. AVSI SEE Task Group (Aerospace Vehicle Systems Institute Committee #72, on Mitigating Radiation Effects in Avionics) is currently coordinating development of an atmospheric Neutron Single Event Effects (SEE) Analysis method. This analysis method is a work in progress, in close collaboration with SAE S-18 and WG-63 Committees (Airplane Safety Assessment Committee). The intent is to include this method as part of current revisions to ARP4761 (Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment).

This paper presents a novel scheme for the start-up of prime movers in starter/generator systems, such as main engine and auxiliary power units (APUs) in aerospace applications. The paper discusses this novel technique in detail for providing single-phase excitation techniques to a start exciter in a starter/generator system to increase the torque per ampere and lower the excitation voltage requirement. Simulation results are provided comparing this novel scheme with a traditional method.

This paper studies the technical characteristics of a start system for aircraft engines. By using the latest improvements in power electronics and digital controls this system eliminates the conventional Air Turbine Starter (ATS) or DC starter by driving the generator installed on the engine as a motor to achieve the start. The presented start system enables a completely new architecture in today's modern and efficient aircraft using the More Electric Architecture (MEA), since bleed air is not required to start the main engines. The MEA increases the overall efficiency of the aircraft by electrically driving the Environmental Control System (ECS) and other major systems such as anti-ice, landing gear, hydraulics etc. This start system eliminates the ATS and its equipment (bleed valve, clutch) for the larger engines or the DC Starter, while providing a start where the engine is accelerated up to 80% idle speed vs. 50-60% provided by the previous Starter.

This paper focuses on advances in active power converter topologies for power quality solutions for More Electric Aircraft (MEA). Advancements in power electronics encompass many technologies including power semiconductors, microprocessors or digital signal processors (DSPs), and component packaging. Hence, active power electronic solutions are becoming more attractive from the perspective of weight, volume, performance and cost. A particular contribution that leads to these advancements is the feasibility of implementing the robust control topologies using faster processors. In this paper various active topologies are reviewed, but a particular emphasis is given to a novel control topology for an active filtering technique where an overall reduction of current harmonics of an aircraft power distribution system can be achieved at the system level rather than at the Line Replaceable Unit (LRU) level.

Commercial transport aircraft have adopted TCP/IP based onboard networking technology to integrate information interchange. This change along with the addition of a TCP/IP based air-ground data link will permit the aircraft network to establish links with ground networks and be integrated into the airline enterprise network. There are many challenging considerations when connecting a remote network to an enterprise network. These challenges are multiplied when that remote network is constantly in motion, both physically and in terms of its link to the ground network. An important consideration in any enterprise network is the element of security. AEEC has published ARINC Report 811: Commercial Aircraft Information Security Concepts of Operation and Process Framework [1] as a guide for the airlines as they consider how to deal with this new challenge.

Thermal management requirements for aerospace applications continue to grow while weight and volume allotments remain constant or shrink. Compact, high performance and lightweight heat transfer equipment is needed to meet these high heat flux removal requirements. Several innovative heat transfer enhancement techniques are being considered for development of thermal management components that will meet these challenging demands. Honeywell, under an AFRL funded program, is developing two new heat exchanger technologies; microchannel and advanced heat transfer surfaces to improve thermal management systems for a fuel-to-air heat exchanger. Heat transfer systems in military aircraft are increasingly using fuel as a heat sink. Heat transport loops containing several fuel-to-liquid heat exchangers are used to cool electronics, engine oil, hydraulic oil, and elements of the thermal management system.

This paper reviews the characteristics of a power line network as data communication medium and studies the challenges encountered when communicating over power wiring. This technology review has been done as part of feasibility study for using aircraft power-lines for data communication. Power-Line Communication is a term which describes the use of existing electrical lines to provide the medium for a high speed communications network. Power Line Communications is achieved by superimposing the voice or data signals onto the line carrier signal using an appropriate communication technology. Power Line Communications represent a potential simplicity for communications among different devices, because it does not need additional wires for connecting devices network together. Power line cables have been used as a communication medium for many years. However, because power line cables are not designed for communication, they pose major challenges for a modem designer.

This paper discusses the problem of designing electric machines (EM) for advanced electric generators (AEG) used in aerospace more electric architecture (MEA) that would be applicable to aircraft, spacecraft, and military ground vehicles. The AEG's are analyzed using aspects of Six Sigma theory that relate to critical-to-quality (CTQ) subjects. Using this approach, weight, volume, reliability, efficiency, and cost (CTQs) are addressed to develop a balance among them, resulting in an optimized power generation system. The influence of the machine power conditioners and system considerations are also discussed. As a part of the machine evaluation process, speeds, bearings, complexities, rotor mechanical and thermal limitations, torque pulsations, currents, and power densities are also considered. A methodology for electric machine selection is demonstrated. Examples of high-speed, high-performance machine applications are shown.

Surge is a phenomenon that limits the operational range of the compressor at low mass flow rates. The objective of this research is to study effective operational range for a ported shroud compressor. The size of the compressor is typical for a turbocharger used on diesel engines. To be able to extend the operational range, the surge characteristics have to be assessed. This is done by performing measurement of the flow at the inlet to the compressor wheel and pressure fluctuations at the inlet and outlet of the compressor housing. Detailed numerical computations of the flow in the entire compressor section under similar operating conditions have also been carried out. The experimental work includes Particle Imaging Velocimetry (PIV) measurements of the instantaneous and mean velocity field at the inlet. At surge, low frequency pulsations are detected that seem to result from back flow already observed in stall.

An evaporative heat exchanger system, suitable for rejecting heat in a space environment, has been developed. The system is designed to use water as the evaporant, although other fluids are possible. The major components of the system include an evaporative heat exchanger, water spray nozzles, a back-pressure regulator, a pressurized water supply tank, and appropriate controls. The heat exchanger is a high-performance aircraft-type plate-fin design, with a proprietary hydrophilic coating applied to the evaporant-side flow passages. The hydrophilic coating promotes good contact between the evaporating water and the hot heat transfer surfaces.

Demand on the reliability of Electric Generators for Aerospace applications is assuming more importance everyday with the advent of “Fly-by-Wire” and “More-Electric-Aircraft” concepts. With today's high-powered avionics and sophisticated control systems, airline operators expect better performance and would no longer accept weak links in the system that need frequent maintenance. One of the weakest points in an electric generator is its reliance on rolling element bearings, which are subject to unpredictable and frequent failures. Huge redundancy and frequent maintenance ensure uninterrupted supply of electricity in an aircraft.

The bleed air contamination monitor was developed at Honeywell to ensure that our products provide the highest quality bleed air to aircraft environmental control systems. The bleed air contamination monitor is currently for ground based applications only. It is being developed into an on board system for future applications. Current Aircraft Cabin Air Quality measurement techniques are very labor intensive and require days or even weeks of laboratory analysis to provide results. This is unacceptable from a manufacturing and service perspective. Development of a real time analyzer began in the early 1990s and has progressed to a point where a product is ready for introduction that not only provides real time information regarding engine air contamination, but is also easy for operators to use with a minimum amount of training.

The goal of the presented research is to study the effective operational range for a centrifugal vaneless diffuser turbocharger compressor with ported shroud typically used in diesel engines. A turbocharger bench facility was designed and tested in order to define the performances of the compressor and to better understand the occurrence of instabilities in the housing. Specific emphasis was given to the low mass flow rate region of the compressor performance characteristics where instabilities occur with fluctuations that can be significantly large in the case of surge. Static pressures and dynamic pressure fluctuations were measured at the inlet, the outlet, as well as at different positions around the volute and diffuser sections of the compressor in order to assess the development and propagation of flow instabilities. The dynamic signature of the flow was measured along with the elaboration of the compressor mapping.

Current Environmental Control and Life Support Systems (ECLSS), particularly on large systems, have a tendency to include several heterogeneous processing elements. This approach is also the default in the commercial aircraft industry. However, Honeywell has been extremely successful in the past decade in using an integrated modular approach to command and data handling for aircraft avionics. This approach, dubbed “Fifth Generation Avionics” by the Air Force's Wright Laboratory, has resulted in significant reductions in the size, weight, power, and acquisition costs of the data handling subsystem. Logistics, modification, and upgrade costs also decreased considerably. While commonality is maximized in the integrated modular architecture, each application continues to be independent with internal designs completely under the control of the application developer.

Many avionics and aircraft equipment manufacturers use DO-160 [Ref. 1] Section 22 to test their equipment for indirect effects of lightning without understanding why they are testing to specific values. Many aircraft manufacturers struggle with determining the level of indirect lightning that will be acceptable for their vehicle and what level of requirements they need to pass down to the avionics and aircraft equipment manufacturers. Organizations like SAE and RTCA, Inc. work to collect data on lightning and spend countless hours assimilating the information and developing documents to help engineers use the information. They struggle with knowing what data is pertinent and how it will be received and used by the engineering community.

This paper discusses recent improvements made by Honeywell's Condition-Based Maintenance (CBM) Center of Excellence (COE) to Mechanical Health Management (MHM) algorithms. The Honeywell approach fuses Condition Indicators (CIs) from vibration monitoring and oil debris monitoring. This paper focuses on using MHM algorithms for monitoring gas turbine engines. First an overview is given that explains the general MHM approach, and then specific examples of how the algorithms are being refined are presented. One of the improvements discussed involves how to detect a fault earlier in the fault progression, while continuing to avoid false alarms. The second improvement discussed is how to make end of life thresholds more robust: rather than relying solely on the cumulative mass of oil debris, the end of life indication is supplemented with indicators that consider the rate of debris generation.

An emerging emphasis for the design and development of vehicle condition-based maintenance (CBM) systems amplifies its use for conducting vehicle maintenance based on evidence of need. This paper presents a systems engineering approach to creating an integrated vehicle health management (IVHM) architecture which places emphasis on the system's ultimate use to meet the operational needs of the vehicle and fleet maintainer, to collect data, conduct analysis, and support the decision-making processes for the sustainment and operations of the vehicle and assets being monitored. The demand for a CBM system generally assumes that the asset being monitored is complex or that the operational use of the system demands complexity, timely response or that system failure has catastrophic results. Ground vehicles are such complex systems, which are the emphasis of this paper. Developing the system architecture of such complex systems demands a systematic approach.

The operating environment of aircraft causes accumulation and build-up of contamination on both the narrowest passages of the ECS (Environmental Control System) i.e: the heat exchangers. Accumulated contamination may lead to reduction of performance over time, and in some case to failures causing AOG (Aircraft on Ground), customer dissatisfaction and elevated repair costs. Airframers/airlines eschew fixed maintenance cleaning intervals because of the high cost of removing and cleaning these devices preferring instead to rely on on-condition maintenance. In addition, on-wing cleaning is t impractical because of installation constrains. Hence, it is desirable to have a contamination monitoring that could alert the maintenance crew in advance to prepare and minimize disruption when contamination levels exceed acceptable thresholds. Two methods are proposed to achieve this task, The effectiveness of these methods are demonstrated using analytical and computational tools.

Aircraft accidents caused by explosion of the vapor within the fuel tanks have been the subject of many recent articles. Methods of either suppressing the combustion or preventing the ignition have been considered. Indeed, solutions such as liquid nitrogen, halon, and reticulated foam have been installed on production aircraft. However, these have proved to be expensive to operate or are being phased out. By working together, the authors have developed the capability to provide fully integrated On-Board Inert Gas Generating Systems (OBIGGS) based on novel hollow fiber membrane technology. An overview of the advantages of such an approach is presented together with an outline of the system design method. The importance of considering the effect of differing flight profiles, and the inter-reactions of the OBIGGS, with the Fuel System, Engine Bleed Air Management, and Environmental Control Systems in the design process are emphasized.