Showing papers in "Aircraft Engineering and Aerospace Technology in 1970"
TL;DR: In this article, the authors discuss the importance of bearing damage early enough to replace the bearing during a scheduled servicing period, and that unscheduled servicing of the machine should be prevented.
Abstract: THE breakdown of any kind of machinery always causes additional expense, not only because repairs are costly, but also because of the loss of operating time and production. Bearings are a particularly critical component and their serviceability is usually essential for the operation of any machine into which they are fitted. Thus it is important that bearing damage should be detected early enough to replace the bearing during a scheduled servicing period, and that unscheduled servicing of the machine should be prevented. This is particularly so where safety is a factor, as in aircraft engines, and certain parts of the process industries.
11 citations
TL;DR: The intention of the original requirements was to record parameters describing the aircraft flight path; as an example the current U.S. regulations call for four parameters to be recorded with with respect to time i.e. airspeed, altitude, vertical acceleration and heading.
Abstract: SOME ten years ago, the regulatory authorities in the United States prepared legislation enforcing the carriage of flight data recorders on commercial passenger‐carrying aircraft above 12,500 lb all‐up weight Since that time other countries have introduced similar regulations The intention of the original requirements was to record parameters describing the aircraft flight path; as an example the current US regulations call for four parameters to be recorded with with respect to time ie airspeed, altitude, vertical acceleration and heading The present British regulations also require pitch, and the French specify marker beacon flyover
7 citations
TL;DR: In this article, it was shown that steadystate pressure distortion considerations are no longer sufficient to determine if the inlet/engine components of the propulsion system are compatible and operate in a stable manner for all flight conditions.
Abstract: DEVELOPMENT efforts in both the B‐70 and F‐111 programmes have demonstrated that steady‐state pressure distortion considerations are no longer sufficient to determine if the inlet/engine components of the propulsion system are compatible and operate in a stable manner for all flight conditions. Modern high speed aircraft operate in modes where the effects of shocks and boundary layers produce an inlet distortion environment which has considerable temporal variation. Early in a programme, the engine manufacturer must determine design requirements to enable operation with combined steady and unsteady flow distortions.
5 citations
TL;DR: A number of simple semi‐quantative micro‐biological tests have been developed and have been used in the field with some success, particularly when dealing with oil emulsions.
Abstract: IT has always been part of the philosophy of work in this laboratory on microbiological problems in petroleum products that the product user must eventually be responsible for anti‐microbial measures. To enable him to do this a number of simple semi‐quantative micro‐biological tests have been developed (Refs. 1 & 2) and have been used in the field with some success, particularly when dealing with oil emulsions.
5 citations
TL;DR: In this article, a wind tunnel was designed to fit into the Aeronautical Laboratory space and two such models were designed and built, the second of which overcame some of the difficulties encountered in the first layout, which is described here.
Abstract: WHEN the new building, to house the Faculty of Engineering in the University of Bristol, was completed some years ago, a relatively large low speed wind tunnel was one of the items of equipment to be designed to fit into the Aeronautical Laboratory space As compact a design as possible was desired and after a general layout had been decided upon it was proposed to build a one‐third scale model to check on the performance of the design In fact, two such models were designed and built, and it is the second of these, which overcame some of the difficulties encountered in the first layout, which is described here
4 citations
TL;DR: In this article, the effect of higher turbine inlet temperature on the performance of an aircraft gas turbine engine can be quite dramatic, and it can be used to increase the exhaust velocity of a dry turbojet to providea higher specific thrust; increase the bypass ratio of a turbofan engine to improve its propulsive efficiency; optimize the thermodynamic cycle at a higher pressure ratio to improve the specific fuel consumption; reduce the amount of afterburner fuel flow in an augmented turbojet.
Abstract: THE effect of higher turbine inlet temperature on the performance of an aircraft gas turbine engine can be quite dramatic. It can be used to increase the exhaust velocity of a dry turbojet to providea higher specific thrust; to increase the bypass ratio of a turbofan engine to improve its propulsive efficiency; to optimize the thermodynamic cycle at a higher pressure ratio to improve its specific fuel consumption; to reduce the amount of afterburner fuel flow in an augmented turbojet to improve its specific fuel consumption, or to increase the work output of a turboshaft engine. If the thrust or power of the engine is held constant, a size, cost and/or weight reduction can result. If the size of the engine is held constant growth capability can be provided.
4 citations
TL;DR: Cockrell and Markland as mentioned in this paper presented a review of conical diffuser performance in this journal, and a reappraisal by Cockrell et al. (Ref. 2) was given in 1963.
Abstract: IN 1938 a review of conical diffuser performance by Patterson (Ref. 1) was published in this journal, and a reappraisal by Cockrell and Markland (Ref. 2) was given in 1963. The two articles are widely referred to for design purposes, although other reviews have appeared more recently (by Reneau et al (Ref. 3) in 1964, and Cockrell and King (Ref. 4) in 1967). Cockrell and Markland also included some preliminary results from an investigation which they instigated at Nottingham University, and it is the continuation of this work which is the subject of this paper.
3 citations
TL;DR: The term mixed frequency generation (MFG) as mentioned in this paper refers to an electrical generating system for an aircraft where the main generators are directly coupled to the engines and deliver a variable frequency over the engine speed range.
Abstract: THE term ‘mixed frequency generation’ is of American origin and refers to an electrical generating system for an aircraft where the main generators are directly coupled to the engines and deliver a variable frequency over the engine speed range. A part of the generator output is used directly for such loads as de‐icing and galley loads which are not at all frequency sensitive. Other loads which require a constant frequency of supply (generally 400 Hz.) are supplied by rotary or solid state inverters (called ‘converters’ in the U.S.A.). Direct current loads (generally 28 V.) are obtained from transformer rectifier units.
3 citations
TL;DR: In this paper, a rolling bearing is damaged as a result of fatigue, spalling occurs cither on the ring tracks or on the surface of rolling elements, which are depressions in the surfaces of the rings also known as flaking, impacts occur.
Abstract: WHEN a rolling bearing is damaged as a result of fatigue, spalling occurs cither on the ring tracks or on the surface of rolling elements. As a roller or a ball rolls over these spalls, which are depressions in the surfaces of the rings also known as flaking, impacts occur.
3 citations
TL;DR: A review of carbon fiber processing, properties and some of the ways in which it could be used in conjunction with conventional materials can be found in this article, where the importance of the utilization of carbon fibres in commercially useful as well as experimental structures is discussed.
Abstract: A review of CFRP dealing with its processing, properties and some of the ways in which it could be used in conjunction with conventional materials. The importance of the utilization of carbon fibres in commercially useful as well as experimental structures is discussed. This may be achieved by using the fibres in conjunction with conventional sheet metal components, as a preliminary step toward the 100 per cent reinforced plastic structure. A few such applications are described, together with a brief summary of the fibre processing and properties as an aid to preliminary design studies.
2 citations
TL;DR: In this paper, for the purposes of improving future noise evaluation of commercial jet aircraft, adjustments to current evaluation techniques are suggested, for the purpose of improving the quality of the evaluation.
Abstract: ADVANCES in engine technology are evaluated herein, and, for the purposes of improving future noise evaluation of commercial jet aircraft, adjustments to current evaluation techniques are suggested.
TL;DR: In this article, Boorer and Davey reviewed the characteristics and some of the operational problems of V/S.T.O. aircraft and argued in favour of initial civil S.T-O.S.L.A. commercial operations appear to be just around the corner.
Abstract: IN a previous article (Ref. 1, 1966), Chichester‐Miles of H.S.A. discussed some of the advantages and opportunities offered by the use of V.T.O.L. aircraft in short haul air transport. In a more recent article (Ref. 2, 1969), Boorer and Davey of B.A.C. reviewed the characteristics and some of the operational problems of V/S.T.O.L. aircraft, and argued in favour of initial civil S.T.O.L. aircraft leading to V.T.O.L. developments as an effective part of the overall ground and air transport system of the 1970s, on the basis of a foreseeable market demand for such aircraft at ranges between 50 and 300 miles. Quoting from their conclusions: ‘S.T.O.L. commercial operations appear therefore to be just around the corner. V.T.O.L. commercial operations may be a decade or so away but, as and when a S.T.O.L. inter‐city transport system develops, the improvement of S.T.O.L. performance toward V.T.O.L. may well become attractive and perhaps even necessary.’
TL;DR: The demand in the non-communist world for military aircraft and missiles with their spares during the next decade could well amount in value to some £50 billion as discussed by the authors, taking into account that defence expenditure is showing little sign of declining anywhere in the world, and that air defence is likely to absorb an increasing proportion of defence budgets.
Abstract: THERE are at present some 45,000 aircraft of various types in service in the air forces of the non‐communist world. Most of these aircraft will need to be replaced in the course of the next decade. A growing number of the world's air forces are also being equipped with guided missile systems. It is not easy to put a monetary value on the business which will arise from this. But taking into account the fact that defence expenditure is showing little sign of declining anywhere in the world, and that air defence is likely to absorb an increasing proportion of defence budgets, the demand in the non‐communist world for military aircraft and missiles with their spares during the next decade could well amount in value to some £50 billion.
TL;DR: The Islander was a winner from the very first moment it leapt into the air on June 13, 1965 as discussed by the authors, and the reliability was phenomenal; from that first flight, June 13 to the evening of Wednesday, June 16, the aircraft completed twelve flights totalling 7 hours 25 minutes over a wide range of e.g. positions and flight regimes in order to acquire the Special Category Certificate of Airworthiness that was required for attendance at the Paris Air Show.
Abstract: THE design team knew that the Islander was a winner from the very first moment it leapt into the air on June 13, 1965. The reliability was phenomenal; from that first flight on June 13 to the evening of Wednesday, June 16, the aircraft completed twelve flights totalling 7 hours 25 minutes over a wide range of e.g. positions and flight regimes in order to acquire the Special Category Certificate of Airworthiness that was required for attendance at the Paris Air Show.