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THE G80 has been designed as a high‐speed fighter‐trainer. It is a monoplane with central fuselage, of all‐metal construction, with two tandem seats and retractable tricycle landing gear. The prototype is powered by a de Havilland Goblin 35 turbojet. Subsequent versions with Nene and Ghost units are to follow.

IN short‐ and medium‐haul operation an aero engine is subjected to a greater frequency of full‐power cycles; these operations therefore impose more exacting conditions on an engine than docs long‐haul service. For this reason, it is important to appreciate that in designing the Spey, Rolls‐Royce has been able to call on 14 million hours of experience with short‐ to medium‐haul operation.

The purpose of this paper is to present a novel high-precision relative navigation method for tight formation-keeping based on thrust on-line identification.

Considering that thrust acceleration cannot be measured directly, an on-line identification method of thrust acceleration is explored via the estimated acceleration of major space perturbation and the inter-satellite relative states obtained from space-borne acceleration sensors; then, an effective identification model is designed to reconstruct thrust acceleration. Based on the identified thrust acceleration, relative orbit dynamics for tight formation-keeping is established. Further, using global positioning system (GPS) measurement information, a modified extended Kalman filter (EKF) is suggested to obtain the inter-satellite relative position and relative velocity.

Compared with the normal EKF and the adaptive robust EKF, the proposed modified EKF has better estimation accuracy in radial and along-track directions because of accurate compensation of thrust acceleration. Meanwhile, high-precision relative navigation results depend on high-precision acceleration sensors. Finally, simulation studies on a chief-deputy formation flying control system are performed to verify the effectiveness and superiority of the proposed relative navigation algorithm.

This paper provides a reference in solving the problem of high-precision relative navigation in tight formation-keeping application.

This paper proposes a novel on-line identification method for thrust acceleration and shows that thrust identification-based modified EKF is more efficient in relative navigation for tight formation-keeping.

IN recent times, jet thrust has been used in aircraft by two different methods, depending on the practical possibilities and design con‐siderations (1) by means of a capacity‐type manifold connecting several cylinders in an engine and (2) by means of separate reaction‐type exhaust pipes, fitted one to each cylinder.

Examples of jet‐lift aircraft powered by the diverse systems of the single lift/thrust turbofan and the multi‐engined specialized lifting and propulsion engines are now flying. With the experience gained from these pioneering aircraft, it is appropriate to review the thermodynamic characteristics required of engines for future ‘vectored thrust’ low‐level strike aircraft, having supersonic capability. The relative merits of extreme forms of power plant are discussed from the engine and power plant designer's viewpoint and these are linked with a spectrum of aircraft which lie between these extremes of design.

This paper aims to provide an overview of current and historical arcjet development. The reviewed arcjets are considered with respect to both design and thruster relevant parameters. Correspondingly, the paper enables the identification of adequate design criteria and of the probable thruster parameters.

The approach consists of a database for thruster relevant parameters in conjunction with relevant operational requirements (such as type of propellant) and specific design criteria (such as e.g. propellant injection systems).

The synopsis of both operational parameter and respectively assigned design allows for the derivation of development approaches for arcjets under given high level requirements such as power regime.

The paper is a general review. However, its strength is in the synthesis of the arcjet classification, the functional evidence of design criteria and the application scenario.

Not only basic but also specific design criteria are analyzed and evaluated leading to a recommendation feature of the paper with respect to the overall design of adequate arcjets.

Within the scope of the Clean Space initiative, new applications and scenarios from the operation of arcjets arise enabling EOL phases of spacecraft that fulfill respective levels of debris mitigation and, in addition, the requirements concerning the adequately adapted re-entry of spacecrafts that are at end of life.

The paper is a general review. However, its strength is in the synthesis of the arcjet classification, the functional evidence of design criteria and the application scenario.

This paper aims to design a new surface profile with simpler processing technology, which makes the bearing load carrying capacity (LCC) close to that of conventional tilting-pad thrust bearing.

The paper analyzes the LCC of the thrust pad with crown profile and designs a new profile, whose performance is similar to the crown profile. The laser method is introduced to fabricate the new profile. The profile with tiny crown height can be fabricated by the laser with the proper parameters.

It was found that there is an optimum value, which is best in terms of the capacity of tilting-pad thrust bearing reach. The new profile with proper parameters can replace the crown profile.

The new profile can replace the crown profile and is easier to be made. The new design method could be adopted for designing the pad surface profile of the tilting-pad thrust bearing.

THE Nineteenth Salon International de l'Aeronautiquc was principally a British and French affair, although there were notable contributions also from the Netherlands, Italy and the U.S.A. As an exhibition, however, it was patchy and many of the exhibitors showed nothing new; some because of security restrictions, but others undoubtedly because they simply had nothing new to show after two years. The restrictions and economics of today were very much in evidence, and it was even surprising how some of the manufacturers have managed to exist at all since the end of the War.

Continuous descent approach (CDA) is a method, which allows the aircraft flying its individual optimal vertical profile down to runway threshold with engines operating at low‐thrust power. The main objective of this paper is to provide less‐fuel consumption, less noise and less emission with using CDA procedures instead of conventional procedures.

Conventional and CDA procedures were modelled in the Istanbul terminal area (TMA), which has five entry points. The real speed and the real altitude limitations were maintained on these entry points. System for Assessing Aviation's Global Emissions research results were also used to determine the emission savings.

With CDA procedures, more than 40 kg fuel and 2 min time savings per flight are obtained; furthermore, regarding CO₂ and H₂O, significant emission savings are also noted.

Some of the benefits of CDA procedures are reported for Istanbul TMA by using true flight data.

Due to the merits of direct driven, high thrust density and high efficiency, PM linear synchronous motor (PMLSM) is pretty suitable for the long-stroke ropeless lifter. However, the vibration caused by detent force and difficulty of maintenance become the barriers that restrict its application. The paper aims to discuss these issues.

In order to simplify structure and improve driving performance, a novel PMLSM with segmented armature core and end non-overlapping windings is proposed. The analytical formula of detent force is derived based on energy method and harmonic analysis, which is validated by two-dimensional finite element analysis (FEA). Moreover, with erected parametric FEA calculation, the selection principles of slot-pole number combination and interval distance to this novel structure are obtained. Finally, the heat dissipation ability of conventional PMLSM and novel PMLSM are compared through thermal analysis.

In novel PMLSM, it is found that the (3m+1) and (3m+2) order harmonic components of thrust force are eliminated, which leads to a better driving performance in comparison with the conventional structure. Furthermore, the good heat dissipation ability of novel structure makes it possible for higher thrust density, which is crucial for ropeless lifter.

The novel PMLSM has excellent driving performance, simple structure for maintenance, possibility of modular production and high thrust density. It is a strong candidate for long-stroke ropeless lifter.