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The aerospace ecosystem is a complex system of systems comprising of many stakeholders in exchanging technical, design, development, certification, operational, and maintenance data across the different lifecycle stages of an aircraft from concept, engineering, manufacturing, operations, and maintenance to its disposal. Many standards have been developed to standardize and improve the effectiveness, efficiency, and security of the data transfer processes in the aerospace ecosystem. There are still challenges in data transfer due to the lack of standards in certain areas and lack of awareness and implementation of some standards. G-31 standards committee of SAE International has conducted a study on the available digital data standards in aircraft asset life cycle to understand the current and future landscapes of the needed digital data standards and identify gaps. This technical paper presents the study conducted by the G-31 technical committee.

During participation on EU FP7 HAIC project, Honeywell has developed methodology to detect High Altitude Ice Crystals with the Honeywell IntuVue® RDR-4000 X-band Weather Radar. The algorithm utilizes 3D weather buffer of RDR-4000 weather radar and is based on machine learning. The modified RDR-4000 Weather Radar was successfully flight tested during 2016 HAIC Validation Campaign; the technology was granted Technology Readiness Level 6 by HAIC consortium. After the end of HAIC project, the method was also evaluated with respect to newly set preliminary industry standard performance requirements1. This paper discuses technology design rationale, high level technology architecture, technology performance, and challenges associated with performance evaluation.

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.

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.

There is a growing need for high voltage direct current (HVDC) power distribution systems in aircraft which provide low-loss distribution with low weight. Challenges associated with HVDC distribution systems include improving reliability and reducing the size and weight of key components such as electric load control units (ELCUs), or remote power controllers (RPCs) for load control and feeder protection, and primary bus switching contactors. The traditional electromechanical current interrupting devices suffer from poor reliability due to arcs generated during repeated closing and opening operations, and are generally slow in isolating a fault with potentially high let-through energy, which directly impacts system safety.

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 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.