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The purpose of this paper is to describe the results of a combined numerical and experimental study into the ability of supersonic particle deposition (SPD) to restore the load carrying capacity of rib stiffened wing planks with simulated stress corrosion cracking (SCC).

In this context the experimental results reveal that SCC can result in a dramatic reduction in the load carrying capacity of the structure and catastrophic failure via cracking that tears the length of the structure through buckling. A combined numerical and experimental study then reveals how this reduction, in the load carrying capacity can be overcome by using SPD.

This paper is the first to show that SPD can be used to restore the load carrying capacity of rib stiffened structures with SCC. It also shows that SPD repairs can be designed to have only a minimal effect on the local stiffness and hence on the load path. However, care should be taken to ensure that the design is such that premature failure of the SPD does not occur.

This is the first paper to show that a thin layer of SPD deposited 7,075 aluminium alloy powder on either side of the SCC-simulated stiffener has the potential to restore the load carrying capability of a rib stiffened structure. As such it represents an important first step into establishing the potential for SPD to restore the buckling strength of rib stiffened wing panels containing SCC.

THE structural design of the VC10 has been based on well‐established principles and the philosophy of low stress levels in the skins and secondary load paths to meet ‘fail‐safe’ conditions. In general a multiple load path type of structure has been employed. In any one of these load paths a crack may be allowed to develop without fear of catastrophic failure. The operator will, however, be required to maintain a high standard of inspection of the structure in order to prevent cracks developing concurrently in these multiple load paths. The operating economy will be greatly enhanced since major components will not require to be changed until the whole of their useful life has been utilized. This was not the case in structures of the ‘safe‐life’ type owing to the large factors which had to be imposed on life.

THE engineering design of the Concorde's structure has been carried out in accordance with the requirements agreed between the British and French airworthiness authorities and published in documents known as TSS Standards.

AS outlined in the description of the evolution of the Argosy design, a decision was taken to develop the Shackleton wing for the Argosy in order to reduce design development and manufacturing time. This was of fundamental importance on the structural side, as it postulated the use of a mass boom type wing spar for the first 10 Series 100 Argosies, and this same type of wing structure was used also for the fifty‐six military Argosies. The following description of the structural design of the aircraft starts with the Series 100 and is followed by a description of the changes introduced by the adoption of a box spar wing on the Series 200.

Smiths Industries is to supply the head‐up display system for the Sea Harrier. The company will design, develop and make the electronic head‐up display and weapon aiming computer system for the latest version of the HS Harrier which will operate from Royal Navy ships.

For many years it has been the College of Aeronautics' philosophy that the best way to teach aircraft design is to actually do it. To this end the Aircraft Design MSc students perform an annual group design project based on types of aircraft that are of current interest.

A Summary by Dr. Alexander Klemin of the Papers Presented Before the Fourteenth Meeting of the Institute held at Columbia University, New York, on January 29–31, 1946. AERODYNAMICS IN spite of increased wing loadings, the use of full span wing flaps has been delayed, because of inability to find a suitable aileron. The Development of a Lateral‐Control System for use with Large‐Span Flaps by I. L. Ashkenas (Northrop Aircraft), outlines the various steps in the aerodynamic development of a retractable aileron system well adapted to the full span flap and successfully employed on the Northrop P‐61. Included is a discussion of the basic data used, the design calculations made, and the effect of structural and mechanical considerations. Changes made as a result of preliminary flight tests are discussed and the final flight‐test results are presented. It is concluded that the use of this retractable aileron system has, in addition to the basic advantage of increased flap span, the following desirable control characteristics: (a) favourable yawing moments, (b) low wing‐torsional loads, (c) small pilot forces, even at high speed.

THIS year's Paris Salon was conspicuously successful, and notably justified the adherence to the international biennial show formula. The permanent building was extended with two large wings of match‐boarding, and there were nearly 200 stands, many representing groups. An increased British participation reflected the opinion that this show is becoming the most important of its kind anywhere.

At a time of transition when technical advances have to proceed in large steps, and missiles are taking over some of the military roles, considerations of cost are becoming even more important than before. In the United States the aircraft industry is adjusting its organization and methods to meet this challenge. Operations research is being used to predict future requirements. Committees are being given more responsibility and authority. Emphasis is being given to the rational selection, training and advancement of employees. Ability must be sought, rather than allowed to show itself. It is made clear what an employee's job is, and at intervals he is told whether he is achieving acceptable standards. Formal training is supplemented by coaching by supervisors. Communication by regular meetings and house journals as well as by written and personal contact is usual. Emphasis is placed on incentives other than monetary, such as pride in the job.

THE increasingly competitive nature of both the operational and manufacturing sides of the aviation business has had the effect of making the designer more conscious of the economic characteristics which he is building into his aircraft, and these have now become a major design consideration.