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The RTCA SC-230 committee began working on minimum operational performance standards (MOPS) for ice crystal detection using weather radar in 2018. The resulting MOPS document will be released in 2023. This paper presents the rationale, summarizes key requirements, and discusses means of validation for an ice crystal detection function incorporated in an airborne weather radar system.

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.

Suppliers and integrators are working with SAE’s HM-1 standards team to develop a mechanism to allow “Health Ready Components” to be integrated into larger systems to enable broader IVHM functionality (reference SAE JA6268). This paper will discuss how the design data provided by the supplier of a component/subsystem can be integrated into a vehicle reference model with emphasis on how each aspect of the model is transmitted to minimize ambiguity. The intent is to enhance support for the analytics, diagnostics and prognostics for the embedded component. In addition, we describe functionality being delegated to other system components and that provided by the supplier via syndicated web services. As a specific example, the paper will describe the JA6268 data submittal for a typical automotive turbocharger and other engine air system components to clarify the data modeling and integration processes.

Laser Based Powder Bed Fusion, a specific application of additive manufacturing, has shown promise to replace traditionally fabricated components, including castings and wrought products (and multiple-piece assemblies thereof). In this process, powder is applied, layer by layer, to a build plate, and each layer is fused by a laser to the layers below. Depending on the component, it appears that only 3-5% of the powder charged into the powder bed fusion machine is fused. Honeywell’s initial part qualification efforts have prohibited the reuse of powder. Any unfused powder that exits the dispenser (i.e., surrounds the build or is captured in the overflow) is considered used. In order for the process to be broadly applicable in an economical manner, a methodology should be developed to render the balance of the powder (up to 97% of the initial charge weight) as re-usable.

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.

The comparison between a proposed aircraft cabin and cargo heater control system and conventional control schemes is presented together with the key performance figures of the systems. An active AC/DC converter comprising a Phase-Locked Loop (PLL) is proposed to control the energy supplied by the AC Variable Frequency (VF) source to the heater loads instead of controlling the energy by means of a Pulse-Width Modulated (PWM) AC power flow. The proposed system eliminates problems associated with interharmonics generated in the AC VF PWM case - a material advantage. It draws a close to sinusoidal current from the VF source, features a near unity power factor, and operates within the VF range due to the use of PLL.

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.

A passive gas removal device, i.e. gas trap is used in the Internal Thermal Control System (ITCS) of the International Space Station (ISS) to remove non-condensable gases to prevent the cavitation or air locking of the pump and malfunction of the pressure and flow sensors. Since the non-condensable gases are always ingested into the ITCS during the routine maintenance and/or replacement of components in the ITCS, it is necessary to have an efficient and reliable gas trap in the liquid coolant loop of the ITCS. To increase tolerance to particulate and microbial growth fouling, extend the operational life, reduce the cost and on-orbit maintenance, and decrease crew workload, an alternative gas trap composed of only one type of membrane is developed. This paper describes the efforts involved in this development, which include the design concept of the alternative gas trap, performance modeling, and the preliminary performance test of the alternative gas trap in the relevant environment.

In this paper a method of predicting the power dissipation in a hybrid Silicon Carbide IGBT power module using primarily the information available from the datasheet is shown. Mathematical modeling of the switching device is accomplished using MathCAD for the purpose of power dissipation calculation. The power dissipated is calculated on a pulse-by-pulse basis to allow for any arbitrary waveform to be studied. The mathematical model is validated by way of comparing the results with the power dissipation results calculated by manufacturer's proprietary software.

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 examines why large aircraft engines are started the way they are today, and why that may all change in the not too distant future. Electric starting of aircraft engines and Auxiliary Power Units (APU) has been limited to 28 VDC battery systems, with starting power typically under 10 kW. Above this power level the very high battery currents, and resulting voltage drops, make the approach less and less practical. Large engines for commercial transports may require more than 100 kW to start so low voltage battery starting will not be an option.