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EACH September the eyes of the aeronautical World turn towards the S.B.A.C. Air Display and Exhibition with interest unequalled by any other event. It is fitting that the…
EACH September the eyes of the aeronautical World turn towards the S.B.A.C. Air Display and Exhibition with interest unequalled by any other event. It is fitting that the Display is now held each year at the airfield of the Royal Aircraft Establishment, one of the world's most prominent aeronautical research centres. This interest becomes increasingly keen too, as the preview day comes closer, because new prototypes of unorthodox designs often appear a short time before the Show to illustrate the results of years of careful planning, development and research of the particular company. These designs often mould the path of progress for smaller countries without the economic resources to forge the way ahead alone. Most British citizens are very proud of their country's place in aviation today, both in the military and civil fields. This is understood by most foreigners because it is clear that Britain has won a place in aeronautical development second to none.
The purpose of this paper is to compare twin engine civil turboprop aircraft with their jet engine counterparts; to simplify the preliminary design process and the initial…
The purpose of this paper is to compare twin engine civil turboprop aircraft with their jet engine counterparts; to simplify the preliminary design process and the initial evaluation of twin civil turboprop aircraft; to include noise level consideration in the preliminary design; and to form a current database of design parameters for representative civil turboprop aircraft.
The paper finds linear correlations between key design parameters. It compares the corresponding correlations for turboprop and jet engine aircraft.
The paper finds direct linear relationships between design parameters including noise levels; simplified preliminary design process; and differences in the sensitivity of design parameters between turboprop and jet aircraft.
The turboprop aircraft database needs to be expanded. Also, investigation of non‐linear relations between design parameters is a next step.
Quick assessment and comparisons of existing designs is an outcome. Also, the preliminary design process is simplified and expedited. Lastly, noise regulations can affect the design right from the beginning and not at a later stage.
New correlations which simplify the current procedures for preliminary design of twin civil turboprop aircraft. In addition, the noise is included right from the beginning of the design. Direct comparison between turboprop and jet aircraft afforded via their correlated preliminary design parameters. Finally, a database of twin turboprops is formed with specially selected aircraft that are current and cover a wide spectrum of sizes.
A review of some of the progress made in lift jet installations is presented in this paper. At the heart of it all is the low cost lightweight RB162 second generation lift…
A review of some of the progress made in lift jet installations is presented in this paper. At the heart of it all is the low cost lightweight RB162 second generation lift jet which is simple and makes extensive use of glass reinforced plastics. Examples of plastic components are shown. The higher thrust/weight and thrust/volume ratio of a third generation lift jet are revealed. The weight of installed features is of comparable importance to the weight of the basic engine. Installed weight has been reduced over three lift jet generations, more than keeping pace with the improvements in basic engine thrust/weight ratio. Weight breakdowns are given for the V.T.O.L. equipment in a fighter‐type aircraft representative of all three generations. Progress on lift intake and exhaust jet deflectors is shown with reference to specific examples. Ground erosion is briefly discussed and shown to be greatly reduced by multiple nozzles and the rolling take‐off technique. Progress being made on some of the problems associated with installing eight lift jets in a V.T.O.L. strike aircraft is briefly discussed with reference to maintenance and instrumentation.
IT is generally conceded that the noise level of our acoustical environment has increased with our social and industrial growth. The increase has been gradual and has…
IT is generally conceded that the noise level of our acoustical environment has increased with our social and industrial growth. The increase has been gradual and has generally gone unnoticed or has been accepted. In the main, it can be attributed to the greater use of power, a percentage of which escapes in the form of sound energy. Not only is the number of noise‐producing mechanisms multiplying daily, but the surrounding and supporting structures are becoming lighter in construction and less able to absorb the sound vibrations.
IT does not require a very large crystal ball to envisage the growth of aviation during the next fifteen years. Sea travel has become too slow; air travel has become…
IT does not require a very large crystal ball to envisage the growth of aviation during the next fifteen years. Sea travel has become too slow; air travel has become reliable and more independent of weather conditions; world trade has forced travel into the remotest areas; industrial countries have become more affluent, and the urge for private world travel has accompanied affluence. It is not surprising, therefore, to hear the Chairman of the British Airport Authority, Peter Masefield, predict a fifteenfold growth in air traffic in the United Kingdom during the next twenty years and to find the F.A.A. confidently anticipating a doubling of passenger traffic in five years and a nine‐fold increase in small jets in the same period.
THE effect of the propulsive efficiency is analysed for all speed regions and methods for obtaining optimum propulsive efficiency for any speed and environmental…
THE effect of the propulsive efficiency is analysed for all speed regions and methods for obtaining optimum propulsive efficiency for any speed and environmental conditions are investigated for different type vehicles. Also, the importance of the propulsive efficiency is compared to other factors such as weight of power plant, specific fuel consumption, specific power ratio, specific thrust ratio, etc. Finally, on the basis of considering all power plant factors, it is shown how to achieve optimum propulsion for any vehicle at required operating conditions.
An aircraft comprises a jet propulsion plant having a jet pipe terminating in a jet nozzle for the rearward discharge of a propulsive jet stream; anchorages on the aircraft; a jet deflector comprising a canopy made of flexible metal cloth and flexible cords made of metal strands attached at their ends to the canopy and to the anchorages, and a canopy‐receiving housing on the aircraft. The canopy is foldable and unfoldable so as to be capable of being packed and stowed in the housing and of being opened up to form a chute. An axial cross‐section taken normal to a plane containing the axis of the jet stream is defined by two symmetrical arcuate portions meeting at one end on the plane at an apex and curving away from the plane one on each side thereof to edges at their other ends. Cords are attached to the apex and to the edges of the chute and are such in relation to the position of the anchorages that when the canopy is in the housing they extend from the housing to the anchorages and when the canopy is opened up they position it with the apex pointing towards and aligned with the nozzle on the plane and the concave sides of the arcuate portions facing the jet stream and the edges spaced apart by a distance greater than the transverse dimension of the jet stream measured normal to the plane.
This paper considers the short term fleet scheduling problem as described by Keskinocak and Tayur (1998). Fleet scheduling may directly affect the service quality of fractional jet aircraft business. The contributions of this paper are two: (i) we show how their model is easily implemented in a standard modeling language, LINGO, and (ii) an alternate formulation is given which is expected to perform better on large, difficult problems.
THE types of powered lift aircraft which can be conceived are many and varied. Over the last 10 to 15 years a surprisingly large number of as have been tested on…
THE types of powered lift aircraft which can be conceived are many and varied. Over the last 10 to 15 years a surprisingly large number of as have been tested on experimental machines, which have flown with varying degrees of success. The setbacks in terms of discarded or unproven concepts outweigh the successes in the form of erational types or of prototypes capable of commercial development; nevertheless, many valuable sons have been learnt. This evolutionary process has some way to go. The last few years have seen er new aircraft, but a proliferation of paper sibility studies, and their conclusions are as merous as their authors. However, at last a pattern beginning to emerge of the roles to be played by wered‐lift aircraft and the particular types which ty be best suited to fulfil them.