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The purpose of this paper is to review factors related to extended range operations with twin-engine transport aircraft (ETOPS) from the viewpoint of the pilot. The review relies on the years of experience of pilots from around the world for operational insight and interpretations of historic, current, and forecast events. In particular, technical issues are addressed, present-day operations are critiqued, and recommendations are made. It is hoped that this paper will provide the reader with a real-world look at bookbound rules and regulations, computer-generated statistics about rare events, and advertised equipment reliabilities.

Two approaches have been attempted to establish an icing climatology over Europe. Firstly, a climatology has been established by using the results of SIGMA (Severe Icing Geographic identification in Meteorology for Aviation). The situations calculated by SIGMA during two winters have been studied. Secondly, a climatology of the occurrence of freezing precipitations at ground level has been established. It is based on reports of freezing precipitation in SYNOP messages from the winters covering the years 1995 to 1998. The geographical domain covered is Western and Central Europe. The frequency of occurrence of freezing precipitations (freezing rain, freezing drizzle and ice pellets) and freezing fog was computed. The results of these two climatologies show that north eastern Europe is more prone to icing phenomena.

This paper describes the effectiveness and possibility of practical use about two types of visual display systems to improve the situation awareness of the pilot, when an aircraft is approaching and landing under the condition of low weather minimum. The one of these systems, when an aircraft is on the final approach course under the condition of IMC, provides a display of simulated airport lighting to the pilot, which is just like a night view of airport lighting at visual approach. By using this system, a pilot could make approach and landing in the same feeling as a visual approach by watching this image projection on the cockpit front windshield whatever any weather condition. The second one, display the runway contour on the airborne weather radar scope by radar reflectors which are installed on the ground along runway lights of the airport. By using this system, a pilot could easily find the airport on the radar scope and approach in the same feeling as a visual approach.

Hydroponics is the cultivation of plants in water containing dissolved inorganic nutrients. Over the past two decades, hydroponics has established itself as a valued component in the overall effort to achieve closed cycle environmental systems. This has a particularly significant impact on future long-duration missions such as lunar colony and exploration of the solar system where resupply is either impossible or impractical. In order to make hydroponics a truly practical solution in the microgravity conditions found in space, it is essential that techniques be developed for separating liquid from air in a simple and effective manner.

A new type of two-phase thermal control system insensitive to some “g” acceleration is suggested for space and ground application. This system is composed of a loop heat pipe (LHP), or capillary pumped loop (CPL) and a solid sorption cooler (SSC). The most essential feature of this system is that LHP and SSC are connected to the same evaporator, but are working alternatively. Such combination can be used also for the cryogenic fluid storage, when system is out of work at low pressure and room temperature, and for cryogenic thermal control system of spacecraft on the orbit (cold plate for infrared observation of the Earth, or Space), or efficient electronic components cooling device.

The Air Force Research Laboratory (AFRL), in cooperation with the University of Dayton Research Institute (UDRI) and Fairchild Controls Corporation, is building a test facility to study the use of advanced vapor cycle systems (VCS) in an expanded role in aircraft thermal management systems (TMS). It is dedicated to the study and development of VCS control and operation in support of the Integrated Vehicle ENergy Technology (INVENT) initiative. The Two Phase Thermal Energy Management System (ToTEMS1) architecture has been shown through studies to offer potential weight, cost, volume and performance advantages over traditional thermal management approaches based on Air Cycle Systems (ACS). The ToTEMS rig will be used to develop and demonstrate a control system that manages the system capacity over both large amplitude and fast transient changes in the system loads.

NASA's Exploration Mission program is planning for a return to the Moon in 2020. The Exploration Systems Mission Directorate (ESMD)'s Lunar Architecture Team (LAT) is currently refining their lunar habitat architectures. The Advanced Thermal Control Project at the Johnson Space Center, as part of the Exploration Technology Development Program (ETDP) is developing technologies in support of the future lunar missions. In support of this project, a trade study was conducted at the Jet Propulsion Laboratory on the mechanically pumped two-phase and single-phase thermal loops for lunar habitats located at the South Pole for the LAT II architecture. This paper discusses the various trades and the results for a representative architecture which shares a common external loop for the single and two-phase system cases.

We have proposed the engine featuring a new compressive combustion principle based on pulsed supermulti-jets colliding through a focusing process in which the jets are injected from the chamber walls to the chamber center. This principle has the potential for achieving relatively silent high compression around the chamber center because autoignition occurs far from the chamber walls and also for stabilizing ignition due to this plug-less approach without heat loss on mechanical plugs including compulsory plasma ignition systems. Then, burned high temperature gas is encased by nearly complete air insulation, because the compressive flow shrinking in focusing process gets over expansion flow generated by combustion.

TWO SPECIALTY APPLICATIONS for electrochemical metallizing have recently proved cost-effective and technologically sound. Aircraft engine manufacturers and maintenance facilities find nickel electrochemical metallizing an excellent way to enhance braze-ability of super alloys on turbine engines and other components. A base nickel deposit permits even brazing at lower temperatures, avoiding heat damage to adjacent honeycomb. Aluminum helicopter rotors present bonding problems, now solved by selective electrochemical anodizing. Leading edges are often covered with a hard alloy shield or a layer of synthetic rubber, bonded to the aluminum base with high-strength adhesives. Selective electrochemical anodizing leading edges of rotors guarantees adhesion vastly superior to direct bonding.

There is a need for a space launch system that can provide ready, reliable, unencumbered access to space. The need exists for a highly reliable launch system that can operate from numerous available sites, that can provide all azimuth launch capability, that is fully reusable, and that can carry significant payloads into low earth orbit. A vehicle concept was developed to demonstrate the ability of near term aeromechanics and propulsion technology to support such a system. The vehicle was composed of two stages. The system takes off horizontally and both stages return to a horizontal landing. Turbojet, ramjet, and rocket propulsion is used. The sensitivity of the system to thrust, drag, weight, and staging Mach number was examined. The two stage system is able to accommodate a range of performance variations yet still retain significant mission potential.

The US space program is facing the dilemma of the federal government reducing in size, the Congress asking for lowered costs, and the US market share of commercial launches declining. While several new launch vehicle options have been studied and advocated, a national plan has yet to be adopted. Despite this, there may be compelling solutions that await discovery. This paper suggests a particular TSTO launch system may solve the dilemma, but only if some of the past presumptions and guidelines are viewed as impediments to be overcome instead of “realities”.

Unmanned Aerial Vehicles (UAV) require simple and reliable engines of high power to weight ratio. Wankel and two stroke engines offer many advantages over four stroke engines. A two stroke engines featuring crank case scavenging, precise oiling, direct injection and jet ignition is analyzed here by using CAD, CFD and CAE tools. Results of simulations of engine performances are shown in details. The CFD analysis is used to study fuel injection, mixing and combustion. The CAE model then returns the engine performances over the full range of loads and speeds with the combustion parameters given as an input. The use of asymmetric rather than symmetric port timing and supercharging scavenging is finally suggested as the best avenue to further improve power density and fuel conversion efficiency.

Contemporary Technical opinion is that a second generation Supersonic Transport will need to be commercially viable and meet environmental noise and emissions. Rolls-Royce and SNECMA have identified that engines with large variability (Flow Multiplication) will be needed. Two engine designs have been developed for this requirement and their characteristics identified. Both potentially reduce the cruise fuel consumption by up to 10% from that of the Olympus in Concorde and the subsonic fuel consumption by better than 15%. All this with some 35 to 45% improvement in thrust weight ratio. These two designs are a Tandem Fan system and MCV99 Mid Fan system and the essential difference is a trade of weight and friction drag due to the larger intake, nacelle and nozzle of the one, versus wave drag due to a larger maximum cross section of the other.

Discussion of attainment of mutual goals of builder and operator through pointing out some areas in which important gains can be made. Major portion of discussion is devoted to hardware and other inanimate objects or physical phenomena.

The regenerate two-bed carbon dioxide removal system, utilizing carbon molecular sieve (CMS), represents a significant advancement over the current Space Station four-bed zeolite molecular sieve baseline system. To demonstrate the feasibility of the CMS system approach. AiResearch conducted system performance tests on a two-bed system created by modifying the existing flight qualified Skylab regenerable carbon dioxide removal system. Results of the performance tests confirmed the two-bed CMS system approach as a viable candidate for Space Station regenerable carbon dioxide removal.

A method has been developed for deriving “effective” thermal properties for charring composite materials which yield accuracy equivalent to the best charring models. Such “effective” properties have application for two- and three-dimensional thermal analyses where appropriate charring codes either do not exist or would be prohibitively expensive.

This work summarizes the limitations of the Ideal Gas Law and the use of simple but accurate two-parameter equations of state for air, oxygen, and nitrogen in the operations of ECLS/EVA hardware. The equation-of-state parameters can be determined for pure gases and for mixtures by mixture combination rules. The parameters of two equations of state in Redlich-Kwong equation of state and Peng-Robinson equation of state have been calculated here. Technical evaluations for spacecraft applications and relevant ranges in temperatures and pressures have been performed. The equations are applicable for several ECLS subsystems: Temperature and Humidity Control, THC; Atmospheric Revitalization System, ARS; and Atmospheric Control System, ACS. The goal is to focus on equations of state for ECLS/EVA applications, especially in depress/repress/compression of air and gases.

Future large spacecraft such as the Space Station will have high power dissipations and long heat transport distances. The combination of these two requirements dictate the need for a new heat transport technology. Boeing Aerospace developed an ammonia thermal bus (ATB) concept using two-phase ammonia as the working fluid. Instrumentation and control systems were used to verify system performance, protect personnel and equipment safety, and run the system. The ATB was robust; thus operating procedures were simple and fault tolerant. Test results demonstrated a maximum heat load of 22 kW, a controllable turndown ratio of 44:1, and the ability to control setpoint temperatures within the range of 30 to 90°F. This paper describes the ammonia thermal bus (ATB), test instrumentation and control, procedures for operating the ATB, and test results.

This paper presents the general objectives, the design concept and the potential performances of the two-phase capillary pumping loop (CPL) as a heat transportation system. In particular the actual design of the ESA funded development program “CPL”, designed and developped by SABCA and DORNIER will be shown as well as of its development status. Results obtained with the first breadboard CPL model are reported together with comparison of predicted against tested performances.

Developing headers to uniformly distribute two-phase (liquid/vapor) flow is a difficult but important aspect in the design of advanced two-phase thermal control systems. This paper documents experimental efforts toward developing a header to equally distribute the liquid flow to parallel legs of a two-phase heat exchanger. Models of various header concepts were built and tested using air/water mixtures to simulate two-phase liquid/vapor flow. Based on the results of these tests, a Fan Header concept was designed for a specific, parallel tube heat exchanger. At flow rates within the expected range of operation, this Fan Header distributed the liquid within 16% of the equally distributed value for inlet qualities up to 25%.