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Cyber-physical systems are joint instances of growing complexity and high integration of elements in the information and physical domains reaching high levels of difficulty to engineer an operate them. This happens with satellites, aircraft, automobiles, smart grids and others. Current technologies as computation, communication and control integrate those domains to communicate, synchronize and operate together. However, the integration of different domains brings new challenges and adds new issues, mainly in real time distributed control systems, beginning with time synchronization. In this paper, we present a discussion on time synchronization and their effects in distributed cyber-physical control systems. To do that, we review the literature, discuss some time synchronization techniques used in cyber-physical systems, and illustrate them via model and simulation of a system representative of the aerospace area.

The SCARLETT European Research Project has the goal to define, develop and validate the concepts of the next generation of IMA (IMA2G). Enhanced File Management capability is central to support next generation IMA Platform properties and the increasing usage of memory mass storage. IMA2G Applications require access to data stored on mass memory independent from their physical location across the Platform; Platform-wide File Services are required. We provide, in the framework of the SCARLETT project, a distributed approach to File Management, which meets the IMA2G requirements. The proposed design aims to move from a module-centric File Management, typical in IMA1G, to a Platform-centric File Management based on a distributed file stack. After examining existing IMA standard solutions concerning File Management, an overview of the ‘Platform File Management’ architecture is given.

This paper deals with the experience gained by Aeritalia on international collaborations in military, civil and space programs with special emphasis on the history of the several programs, their impact on the development of the capabilities of the Company and the lessons learned in carrying out multinational aerospace programs with other european and american partner companies.

An automated drilling and fastening system is under development at the GEMCOR Engineering Corporation for wing manufacture on a new commercial airframe program. It is the first time that cold-working and hole inspection have been integrated into an automated fastener installation system. Numerical control and monitoring of all process parameters have been integrated in the system to achieve the greatest degree of accuracy and repeatability in fastener installation and to provide real-time, in-process statistical quality control. An integral component of the system is a capacitance probe used to measure the diameter and profile of drilled holes. Measurement information obtained with the hole probe is used to monitor the drilling process and predict tooling wear. This paper briefly discusses fastener hole requirements and the effects of hole quality on fatigue life. An overview of the capacitance measurement technique is also presented.

Switching controls are those that can switch between control or plant modes to perform their functions. They have the advantage of being simpler to design than an equivalent control system with a single mode. However, the transients between those modes can introduce steps or overshootings in the state variables, and this can degrade the performance or even damage the control or the plant. So, the smoothing of such transients is vital for their reliability and mantainability. This is can be of extreme importance in the aerospace and automotive fields, plenty of switchings between manual and autopilot modes via relays, or among gears via clutches, for example. In this work, we present a first strategy for smoothing transients in switching controls of aerospace and automotive systems.

Superoxides can be used in self-contained, emergency self-rescuers, both as sources of chemically stored oxygen and as carbon dioxide scrubbers. In the work described here, a single-pass flow-system test facility was employed to evaluate the reactivity of calcium superoxide, Ca(O2)2, with respiratory gases (H2O,CO2), in concentrations simulating exhaled breath. When compared with commercial preparations of potassium superoxide, KO2, 55–60% Ca(O2)2 was found to evolve oxygen and absorb carbon dioxide at significantly lower rates under conditions where each of the superoxides was reacted with 5% CO2 streams having dew points of 37°C. Whereas O2 evolution and CO2 absorption occurred simultaneously in the case of KO2 beds, CO2 absorption lagged O2 evolution when beds of Ca(O2)2 were reacted with moisture and CO2.

This paper describes a framework for developing an Integrated Electrical Power System (EPS) Health Management System. The framework is based on the perspective that health management, unlike other capabilities, is not a self-contained, stand-alone system, but is rather an integral part of every aircraft subsystem, system, and the entire platform. Ultimately, the objective is to improve the entire maintenance, logistics and fleet operations support processes. This perspective requires a new mindset when applying systems engineering design principles. The paper provides an overview description of the framework, the potential benefits of the approach and some critical design and implementation issues based on current development efforts.

This paper presents a frequency domain multi-input/multi-output (MIMO) identification method. The accuracy, reliability and ability of handling repeated modes are verified by computer simulation and practical structures. The applications in an aircraft Ground Vibration Test (GVT) is given. The results have shown that compared with traditional multipoint sine excitation phase resonance method, operation is simplified, testing time is reduced reliability is improved and compared with time domain MIMO methods developed over the past several years, the order of the system (the number of modes) can be identified directly so that the calculating time is reduced and the user's judgement of distinguishing between structural modes and noise modes is avoided.

Solar proton events (SPEs) represent the single-most significant source of acute radiation exposure during space missions. Historically, an exponential in rigidity (particle momentum) fit has been used to express the SPE energy spectrum using GOES data up to 100 MeV. More recently, researchers have found that a Weibull fit better represents the energy spectrum up to 1000 MeV (1 GeV). In addition, the availability of SPE data extending up to several GeV has been incorporated in analyses to obtain a more complete and accurate energy spectrum representation. In this paper we discuss the major SPEs that have occurred over the past five solar cycles (~50+ years) in detail - in particular, Aug 1972 and Sept & Oct 1989 SPEs. Using a high-energy particle transport/dose code, radiation exposure estimates are presented for various thicknesses of aluminum. The effects on humans and spacecraft systems are also discussed in detail.

The authors review the requirements, describe some of the unusual design features and characteristics, and present the performance and weight data for the new McCulloch TSIR-5190 aircraft engine. This powerplant is a highly turbosupercharged, two-stroke cycle, direct fuel injection, liquid cooled, 5 cyl radial engine of 190 cu in. displacement. Maximum rated horsepower is 270 at 3600 rpm, and the brake specific fuel consumption, over the range from half-to full power, is below 0.5 lb/bhp-hr. The estimated “ready to fly” weight for the production engine is 365 lb. Some comparisons are made with currently available engines.

A highly reliable alternative source for aircraft +28Vdc power is presented. This alternative uses a permanent magnet generator (PMG) and an electronic converter/regulator (C/R). The power system includes such features as independence from the main power system, high power quality with terminal or remote point of regulation (POR), light weight, and constant power availability from engine idle to maximum rpm. Included is a brief system description, a review of steady state and transient performance, and a conclusion with a perspective on future expectations.

This paper is a review of the literature covering the history of the use of lubricants. The uses of oils derived from animals, vegetables and minerals are placed in perspective from ancient times to the Wright Brothers' flight in 1903. After that period, the discussion is confined largely to the lubrication of aircraft piston engines. The paper attempts to explain the preference for castor oil in European and British engines and the more general, but by no means exclusive, use of petroleum-based mineral oils in the United States. The British Air Ministry, in 1929, reached a decision to abandon castor oil due to availability and cost of petroleum-based oils. The simultaneous U.S. Army Air Corps recognition of the advantages of the very flat viscosity-temperature curve of Pennsylvania oils for hot running engines and for cold starting led to the world-wide use of these lubricating oils.

Modern rotorcraft must have the capability to operate in all-weather conditions. Sikorsky Aircraft has conducted icing research and ice protection system development for helicopters over the past 58 years and the pace of that work has accelerated during the past two decades. Sikorsky participated in several helicopter icing flight tests, conducted wind tunnel tests of scale models and full-scale components, tested simulated ice shapes, and developed analytical tools for use in the design, certification, and qualification for flight in icing conditions. Engine inlets, airspeed systems, main rotor droop stops, and windshields are generally protected by thermal anti-icing systems. When rotor ice protection is required, rotors are protected with electrothermal deice systems. The UH-60A BLACK HAWK electrothermal rotor ice protection system, developed in the late 1970s, has been installed in 2400 H-60 helicopters and it remains one of the most effective rotor ice protection systems.

Flying wing aircraft predate the First World War. The flying wing theoretically offers both aerodynamic efficiency and structural simplicity. Early efforts to develop the flying wing concept led to an increased interest in tailless and semi-tailless aircraft that eventually led to delta wings and swept wing planforms. Early flying wings were plagued by stability and control problems that have not been fully addressed until recently. The flying wing approach, however, still appears to be suitable only for aircraft that do not need to have high maneuverability and agility capabilities, such as long-range bombers or perhaps large transports. This paper surveys the long history of attempts to create flying wing aircraft.

After several decades of human spaceflight, the community of space-faring nations has accumulated a diverse and sometimes harrowing history of toxicological events that have plagued human space endeavors almost from the very beginning. Some lessons have been learned in ground-based test beds and others were discovered the hard way - when human lives were at stake in space. From such lessons one can build a risk-management framework for toxicological events to minimize the probability of a harmful exposure, while recognizing that we cannot predict all possible events. Space toxicologists have learned that relatively harmless compounds can be converted by air revitalization systems into compounds that cause serious harm to the crew.

This paper presents an overview of digital microprocessor-based Environmental Control System (ECS) controller development and validation at Boeing. The application of a hybrid computer simulation laboratory to the development of real-time simulation capability for ECS is described. The approach used to develop microprocessor-based ECS controllers is illustrated by describing the steps which led to the implementation of a fully automatic cabin pressure control system. The approach to validating ECS digital controllers is also discussed.

This paper provides an overview of the development of an organic matrix composite housing for an aircraft generator. The specific component discussed is the main housing for the F/A-18 C/D Generator Convenor Unit (GCU). This component fulfills both structural and thermal functions. The composite housing will be a direct replacement for the existing aluminum component, and will offer lighter weight and improved thermal performance, at a comparable cost. The composite housing will be consolidated by matched metal net molding, and will demonstrate the use of embedded metallic pin fins within the composite material to improve thermal performance. The paper addresses the design development, thermal and structural design verification analyses, material compatibility testing, and fabrication process development and tooling design.

Abstract This article explores the value of simulation for autonomous-vehicle research and development. There is ample research that details the effectiveness of simulation for training humans to fly and drive. Unfortunately, the same is not true for simulations used to train and test artificial intelligence (AI) that enables autonomous vehicles to fly and drive without humans. Research has shown that simulation “fidelity” is the most influential factor affecting training yield, but psychological fidelity is a widely accepted definition that does not apply to AI because it describes how well simulations engage various cognitive functions of human operators. Therefore, this investigation reviewed the literature that was published between January 2010 and May 2022 on the topic of simulation fidelity to understand how researchers are defining and measuring simulation fidelity as applied to training AI.

In devising a marketing strategy for the Pacific Basin, the air freight forwarder must take many different factors into consideration. These factors along with a brief history of the Pacific air freight market are presented in order to identify potential problems and several solutions that have come to light. It is clear that close cooperation is necessary between the forwarder and the carrier to solve many existing difficulties.

Laboratory, component, and engine tests have been conducted by the General Electric Co. to evaluate the various lubricant properties important to the J79 jet engine. Such properties as elastomer volume swell, oxidation-corrosion, coking characteristics, and lubricity were evaluated. The effects of these various properties on engine performance and how the laboratory results relate to the component results and engine test results are discussed.