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The Advanced ECS is under development for the purpose of saving fuel, improving safety, and cabin comfort. In FY2006 study, basic components (i.e. MDC, OBNOGS, desiccant units, and CO2 removers) have been improved and their performances evaluated including resistance to environmental condition (i.e. vibration). In addition, the suitable system configuration for a 90-seats aircraft has been considered to evaluate the feasibility of the system. In this paper, we show the results of the evaluated performances based on prototype components, and the analytical study of a revised system configuration.

In a 2-year program sponsored by SJAC, an aqueous electroplating process using alkaline Zn-Ni with trivalent chromium post treatment is under evaluation for high strength steel for aircraft application as an alternative to cadmium. Commercial Zn-15%Ni rack/barrel plating solutions are basis for plating aircraft parts or fasteners. Brightener was reduced from the original formula to form porous plating that enables bake-out of hydrogen to avoid hydrogen embrittlement condition. Properties of the deposit, such as appearance, adhesion, un-scribed corrosion resistance, and galvanic corrosion resistance in contact with Al alloy, were evaluated. Coefficient of friction was compared with Cd plating by torque-tension measurements. Evaluation of the plating for scribed corrosion resistance, primer adhesion, etc. will continue in FY2007.

We propose New Concept ECS as Fig.1, in which named OBNOGS is installed into the ACS, cabin air re-circulation system with re-compressing to mix with bleed air and water vapor recuperation system are performed. Therefore, it gives solutions for safety, cabin comfort and energy saving in future aircraft, a) Increasing safety: Prevention of fuel tank explosion to employ small-sized OBNOGS with re-compressed high pressure air of outflow from cabin b) Increasing cabin comfort: To keep adequate oxygen partial pressure and humidity in the cabin c) Decreasing fuel consumption: Less bleed air and more cabin air re-circulation, which are suitable for future high-bypass jet-engine or all electric aircraft, would bring reduced fuel consumption.

For the purpose of saving fuel, improving safety, and comfort, Advanced ECS is developing now. MDC, OBNOGS, Desiccant units, and CO2 Removers are involved in the Advanced ECS and are developing. System analysis of the Advanced ECS is performed to build up Non-Bleed aircraft. In this paper, we show the development of the components (i.e. MDC, OBNOGS, and Desiccant unit) and the results of system analysis as a non-bleed aircraft and system evaluation based on the regulations.

Electrical power management is a key technology in the AEA (All-Electric Aircraft) system, which manages the supply and demand of the electrical power in the entire aircraft system. However, the AEA system requires more than electrical power management alone. Adequate thermal management is also required, because the heat generated by aircraft systems and components increases with progressive system electrification, despite limited heat-sink capability in the aircraft. Since heat dissipation from power electronics such as electric motors, motor controllers and rectifiers, which are widely introduced into the AEA, becomes a key issue, an efficient cooling system architecture should be considered along with the AEA system concept. The more-electric architecture for the aircraft has been developed; mainly targeting reduced fuel burn and CO2 emissions from the aircraft, as well as leveraging ease of maintenance with electric/electronic components.

With the growth in onboard electrification referred to the movement of the More Electric Aircraft, or MEA, and constant improvement in ECO standards, aircraft electricity load has continued to soar. The airline and authors have discussed the nature of future aircraft systems in the next two decades, which envisages the further More Electric Aircraft or the All-Electric Aircraft, or AEA, concept helping provide some effective aviation improvements. The operators, pilots and maintenance crews anticipate improved operability, ease of maintenance and fuel saving, while meetings depends for high reliability and safety by electrification. As part of initial progress, the authors approach the methodology of energy management for aircraft systems.

To improve an energy optimization issue of ECS for MEA, we propose our concept in which ACS is replaced with VCS. A VCS is generally evaluated as auxiliary or limited cooling system of an aircraft. Cooling demand of commercial aircraft usually becomes large due to ventilation air at hot day conditions. In case of using conventional VCS for whole cooling demand, the ECS becomes too heavy as aircraft equipment. Though ACS's light weight is advantageous, the issue that VCS will be available for aircraft ECS is important for saving energy. ECS of commercial aircraft should work for three basic functions, i.e. pressurization, ventilation, and temperature control. The three functions of the ECS for bleed-less type of MEA can be distributed among equipment of the ECS. MDFAC works for pressurization and ventilation. Therefore, we should select appropriate system for only temperature control.

This paper describes the concept of an air/fuel integrated thermal management system, which employs the VCS (Vapor Cycle System) for the refrigeration unit of the ECS (Environment Control System), while exchanging the heat between the VCS refrigerant and the fuel into the engine, and presents a feasibility study to apply the concept to the future all electric aircraft systems. The heat generated in an aircraft is transferred to the ECS heat exchanger by the recirculation of air and exhausted into the ram air. While some aircraft employ the fluid heat transfer loop, the transferred heat is exhausted into the ram air. The usage of ram air for the cooling will increase the ram drag and the fuel consumption, thus, less usage of ram air is preferable. Another source for heat rejection is the fuel. The heat exchange with the fuel does not worsen the fuel consumption, thus, the fuel is a preferable source.