bluuebunny/crossref_metadata_2025 huggingface dataset:
All Weather Landing for the BAC One‐Eleven
Authors: Webber G.W. , Page S.L.
Published: November 2014

SUMMARY The paper reviews the requirements for all weather landing systems on a short‐haul jet from the aircraft manufacturer's point of view, with, of course, particular reference to the BAC One‐Eleven. The problems of producing a flexible system which will suit many different types of operator with differing operational environments is discussed. The basic provisions made in the aircraft and the basic automatic system for subsequent easy fitment of all weather landing systems are described and a number of possible alternative systems listed, which build up from the basic single autopilot to a fully automatic all weather landing system. The potentialities of each of these systems in terms of removing existing obstacles to lower minima are tabulated. The major firm BAC One‐Eleven development project —that of safe autoflare—is described. This project is intended to result in the autoflare system being available for airline use in 1966. It is recognized that systems which do not go as far as safe autoflare may confer some benefit—although the benefits to be obtained are hard to predict quantitatively —and may be attractive to some operators. On the other hand a fully automatic failure survival system will almost certainly be required to meet the full Phase III requirement. The ability of the BAC One‐Eleven to accommodate this wide range of possible system requirements is described.
Rotor Dynamics and Helicopter Stability
Authors: Price H.L.
Published: November 2014

SECTION (B). GEOMETRIC ASPECTS OF TRIMMED FLIGHT The Relation Between the Various Planes of Reference The preceding analytical investigation of the trimmed conditions has been based upon the use of the particular set of axes advocated in Part I. There we took as the dominant axis the axis of the rotor shaft, and regarded as the dominant plane, plane RS, the plane perpendicular to the rotor shaft. We recall that the choice of this plane as a plane of reference was dictated by the importance attached at the outset to the study of the dynamics of the blade motion. We also pointed out that, from the mechani‐cal point of view, plane SP, the plane of the swash‐plate for in the absence of a swash‐plate, the equivalent ‘plane of no‐feathering’), could alterna‐tively be regarded as the dominant reference plane. But now we sec that if we concentrate on the aerodynamic aspect, the prevalence of the ex‐pressions (?i—?0+?0?1) and (?1—?) ascribe prime importance to the axis of the flapping cone. Now just as in the case of the rotor shaft, we chose to specify its direction by a plane perpendicular to it, so here we shall specify the axis of the flapping cone by any plane perpendicular to it. One such plane is the tip‐path plane: another is the plane through the rotor hub parallel to the tip‐path plane. We shall refer to cither plane as the plane TP, and so long as we are only concerned with directions, no ambiguity will be caused. We now have three planes competing for attention, planes RS, SP and TP, and it is our object to link these planes together and see what roles they play in the description of the motion of the helicopter as a whole, having special regard in all this to the particular position of the helicopter's C.G. It may be added that the relationship between these planes is a prominent feature of certain papers [Refs. (2), (10)], and the phrase ‘the equivalence of flapping and feathering’ is there used to describe the resultant findings. It will be shown that there are two different interpretations of this phrase, and that in one sense, what is implied is no more than the equivalence of alternative geometric descriptions of one and the same motion of a helicopter rotor. On the other hand, the phrase may be taken to mean that a rotor having no flapping hinge at all [such as the one analysed by Squire in Ref. (3)] performs effectively in the same way as one free to flap. Indeed, the results of Ref. (3) are frequently used as the basis of many trim and stability calculations of helicopters with freely flapping rotors, despite the lack of a flapping hinge in the calculations of Ref. (3). We shall see that, in general, this procedure is questionable.
Representing Great Britain's Aerospace Industry
Authors: Bowyer Edward
Published: November 2014

IN less than two years‘ time—on March 29, 1966—the Society of British Aerospace Companies will celebrate the completion of fifty years’ activity. It was on March 29, 1916, that the Society of British Aircraft Constructors was incorporated, thus being younger than the Royal Aeronautical Society and Royal Aero Club but two years older than the Royal Air Force. The Society continued under that title until February 26 this year, when by special resolution at an extraordinary general meeting its name was changed to the ‘Society of British Aerospace Companies’. The new title thus retains the well‐known initials S.B.A.C. but embraces more appropriately the wide range of activities of the Society's Members— not only the manufacture of aircraft, but of engines, missiles, electronics, hydraulics, electrical equipment, and all other components and materials essential to a modern aerospace industry. The new title also brings the Society into line with comparable engineering associations in the United States, France, Germany and Italy.
Structural Design Part II—Fail‐Safe Aspects
Authors: Heath W.G.
Published: November 2014

A Presentation of the Fail‐Safe Concept including the Design as it Applies to a Crack‐Free Life, Corrosion Prevention, Simplified Inspection and Repair, and Safety after Failure. IN designing a new aircraft structure, the principal concern is to ensure that structural failure docs not occur during any stage—taxying, taking‐off, climbing, cruising, descending, landing—of any flight. This concern is not only for the safety and well‐being of the travelling public but also for the economics of airline operation, since the operator demands a long working life from his aircraft, and a good re‐sale value.
The Propulsive Duct
Authors: Tharratt C.E.
Published: November 2014

A Theoretical Approach to Assessing the Thermodynamic Process Within the Combustion Chamber of the Propulsive Duct, an Examination of the Potential of the Duct with Special Reference to the Application of Feedback and Spark Discharge Techniques. Development of the propulsive duct has been retarded by the absence of a suitable theoretical analysis. This paper, based on four years of experimental investigation by the author, discusses the problems involved and puts forward a theory which closely follows practical results. The theory is then used to examine the potential of the duct and it is shown that by applying feedback and spark‐discharge techniques, a low specific fuel consumption and unlimited thrust, outside the audible range, is theoretically possible. Finally, it is shown that the marriage of the duct to electrical power generated from atomic sources otters attractive possibilities for V.T.O.L. and aircraft propulsion of the future.
A Review of Problems and Research on Components for Hypersonic Air Breathing Engines
Authors: Hawkins Roy
Published: November 2014

IN modern aeronautics each generation of aircraft is aimed at higher goals of performance and capability. To achieve these technical advances more refined techniques have to be applied in every aspect of design. A great part of these new techniques will be derived from basic research. Such research, to be effective, has to be initiated a considerable time before its results will be needed for practical application. This necessitates having a clear appreciation of the probable trend in future aircraft development if the basic research is to be meaningful. It is most important also that such enterprises should be co‐ordinated in time scale and also in respect of their influence upon each other.
Structural Problems Associated with Variable Geometry
Authors: Alexander Marvin M.
Published: November 2014

This paper presents a broad survey of the structural problems associated with variable geometry for aircraft. Variable sweep allows an aircraft to fly throughout a broad regime of speed and altitude efficiently and without excessive power requirements. Tailored lift drag, improved ride quality, lessening of fatigue damage, and reasonable control sensitivities are advantages. Structural problems fall into two general categories: (1) Because of the number of wing positions, the equivalent of many fixed‐wing aircraft must be investigated, analysed and tested; (2) there are unusual problems which have heretofore not been important considerations in design. Category (1) presents the problem of managing and assimilating large amounts of data. Computer pogrammes and a family of cross‐plots assist greatly. Category (2) presents new fail‐safe criteria, a large lumber of possible flutter‐critical configurations, unavoidable free play in mechanisms which affect flutter speeds, dynamic loads, pivot mechanism bearing life, and requires high reliability in materials. Analyses and wind‐tunnel tests have shown that free play in mechanical joints may or may not cause significant service problems depending upon the mechanical arrangement selected and the actual degree of free play under service conditions.
Acoustic Fatigue
Authors: Townsend N.A.
Published: November 2014

IN order to prevent acoustic fatigue cracks occurring in structure subjected to jet noise the various airworthiness authorities are proposing to lay down appropriate design criteria. It may not be long therefore before airframe manufacturers are required to show to airworthiness authorities that either:
The Turbomeca Astazou XIV Powerplant
Authors: Lee G.H.
Published: November 2014

THE Sociéte Turbomeca Astazou, shown in the cutaway drawing, fig. 2, is a fixed shaft engine, running at the constant speed of 43,000 r.p.m. It has a three‐stage compressor, two axial stages followed by a centrifugal stage, after which there is the annular combustion chamber and finally the three‐stage turbine. The reduction gear, a two‐stage step‐down spur gear with three layshafts (or ‘stationary planets’), delivers 1,783 r.p.m. at the propeller shaft. Fuel flows along the main shaft from the front and enters the combustion chamber via a slinger ring, thus giving adequate vapourisation without the need for unduly small injection nozzles.
Dry Film Bearings for Aircraft Applications
Authors: Underwood E.W.
Published: November 2014

DRY film bearings have only recently been used, and then only for limited applications, in United Kingdom aircraft. Designers have been hesitant to accept such a radical change in what has been the practice for so many years of employing hearings which need grease or liquid lubrication.
Selection of Sealants for Integral Fuel Tanks
Authors: Duell A.A.
Published: November 2014

THE advent of the integral fuel tank over twenty years ago presented considerable sealing problems, due to both deficiencies in design and lack of suitable sealing compounds.
Aircraft Landing Gear
Authors: Hoare R.G.
Published: November 2014

WHILE an aircraft is in flight, the landing gear is a liability which, by virtue of its weight and size, and demands upon power supplies, reduces the efficiency of the aircraft. However, at two of the most critical and dangerous parts of the sortie, namely take‐off and landing, the safety of the aircraft depends to a very great extent upon the landing gear working effectively. Even V.T.O.L. aircraft do not seem to be able to dispense with landing gear. In fact, with an increasing emphasis on S.T.O.L. aircraft, and the use of rough airfields, the demands on landing gear seem to be increasing. The landing gear designer is still, therefore, faced with the problem of providing equipment of minimum size and weight, to meet a specification which, in some parts, is not very well defined. In common with other members of the aerospace industry, he is constantly seeking methods of improving his product.
Research and Development
Authors: Rapson J.E.
Published: November 2014

THE phrase ‘research and development’ could be applied to all the activity in the hovercraft field from the time of C. S. Cockerell's original coffee tin experiment. Such an interpretation is obviously beyond the scope of this paper. It also appears to be impracticable to attempt to define the boundary between research and development. It is important, however, to consider the extent of the R. & D. effort which should be devoted to this entirely new form of transport.
Integration of Aircraft Auxiliary Power Supplies
Authors: Wotton John
Published: November 2014

THE development of air transportation since World War II has been dramatic, consistently exceeding the predicted rate of expansion resulting from market surveys throughout the period. This has been at least partly due to the boost given to originality and inventiveness by a continually expanding market, and the present speed, comfort, reliability and economy of modern aircraft far surpass the wildest dreams of pioneers. At the time of writing there is no indication of a slackening off in the rate of progress, indeed, rather the reverse, and the scope for imaginative exploration in all areas of aircraft design and operation has never been so wide as at the present time.
The Choice between One Engine or Two
Authors: Higgins R.W.
Published: November 2014

THE current discussions to define a multi‐role aircraft for the mid 1970s have been notable for dissension of opinion on the choice between one engine or two. This remarkably basic choice has been with us since pioneer days — Lindbergh's acid comment on the value of two engines was ‘twice the trouble’, while the very fact that there are many aircraft in use of both layouts indicates that there has not been a clear case for choosing cither. Not, that is, until very recently, when statistics on the loss rate of both single and twin‐engined aircraft have confirmed that a definite margin does exist. This is the key to the whole choice between two engines or one, for it is necessary to compare not only the initial costs, but also the maintenance and operating costs, replacement of lost aircraft, and pilot training costs to achieve a realistic comparison on an overall cost basis. As with most cost‐effective arguments a strong danger exists of losing sight of primary objectives in a welter of tenuously related facts. The objectives in the choice between two engines and one is simple; which configuration fulfills an operational requirement at the least overall cost.
Developments in Transport Aircraft Interior Design
Authors: Barfield Norman
Published: November 2014

BY common consent, air transport is heading for a dramatic expansion in the decade just dawning, and by 1980 the volume of air traffic in the free world is predicted to be at least three times what it is today (around 300 million passengers in 1970). This means that around a 1,000 million passengers will be travelling by air per year by 1980 and air transport will almost certainly be the world's biggest industry.
The Technology of an Era
Authors: Barfield Norman
Published: November 2014

AIRCRAFT ENGINEERING was born in March 1929 of the belief that the emerging technology from which it took its title would become a fundamental element of engineering progress. The keystone of its policy was that it would attempt to meet the needs of engineers and students working in this field and that its contents should be ‘written by engineers — for engineers’. That this venture was fully justified has been amply vindicated by the achievements of the industry during the ensuing 41 years — as recorded in the first 500 issues of this Journal, the major milestone celebrated this month. This is a propitious occasion on which to review the record to date because, although aviation has always been about looking forward, history is instructive and it is the impressive performance of the aerospace industry to date that inspires and motivates confidence in its future.
Decompression of cabins
Authors: LANGLEY CEng MARCUS
Published: November 2014

IN 1954 when two Comet 1 aircraft were lost in unusual circumstances, an intensive study of possible causes was made and everything pointed to there having been explosive decompression of the cabins of both aircraft. Research into metal fatigue was given a much higher priority and the official requirements for the design of such cabins were tightened up. It was hoped that there would be no repetition of such disasters.
Use of cycloconverters and variable speed alternators as engine starters
Authors: BURNS D.O.
Published: November 2014

IN VARIABLE SPEED constant frequency (VSCF) generating systems for aircraft, the variable frequency generator, usually six phase, is directly coupled to a main propulsion engine. The output of this generator is converted to three phase constant frequency, usually 400Hz, for general aircraft use by a cycloconverter using thyristors as switching devices.
Resistant finishes
Authors: LEWIN J.B.G.
Published: November 2014

HIGH PERFORMANCE is demanded of aircraft finishes because of the severity of the environmental conditions to which they are exposed. Many aircraft today operate long range, and encounter a wide variety of climatic conditions. Cyclic condensation occurs during the various temperature and pressure fluctuations, and keel areas may contain large quantities of water containing dissolved salts as well as aggressive fluids such as phosphate ester hydraulic fluids, ester lubricants, fuels, etc. Skin temperatures can change rapidly during flight and may even reach 130°C, by kinetic heating. Erosive influences are met whilst flying through rain, dust and hail, and as the whole structure is vibrating under changing stress, cracking tendencies of coatings are accentuated. C. E. Moey has reviewed aircraft finishes against this background.
RB 211 Progress and Prospects
Authors: Ford Terence E.
Published: November 2014

Evolution of a range of advanced turbofan engines must of necessity, be a fairly lengthy process. Not only has the required technology to be established in current production versions, but a high level of reliability has to be demonstrated over a period of years if the development potential of the powerplant is to be fully realised. The data fed back from operators to manufacturers is of prime importance in this context, and generates the confidence which enables a trouble‐free entry into service of more powerful variants of the engine.
DOPPLER MLS The UK Solution
Authors: Ford Terence
Published: November 2014

The need to provide precision approach guidance over wider angular coverage than is possible with the present Instrument Landing System (ILS) and the wish to avoid siting problems sometimes encountered with the current equipment has prompted work on new systems in various countries. Using existing technology, independence of site conditions can, to a large extent, be achieved by the employment of microwave frequencies.
A Review of Concorde in Operation
Authors: PARRY A.G.
Published: November 2014

The firm establishment of transatlantic Concorde operation provides a basis for a review of the last year and for a look at the future. Much has been spoken and written on the engineering and technological achievements of designing and producing Concorde and, perhaps less objectively, on the social and environmental factors which have aroused strong emotions for and against its operation. The author believes that the team expertise demanded by competitive airline operation is no less than that to be found in design and production. The review therefore makes no apology for presenting the airline aspects, problems and achievements of the British Airways Concorde operation.
Tensile Properties of Die‐Forged Material after Heat Treatment
Authors: MARSHALL L. , LANG M.T. , WHEALE M.
Published: November 2014

Zinc‐Containing Duralumins: Earlier Restricted Use The zinc‐containing duralumins have been around for quite a long time now. However, it is only within the past two decades or so that they have played a major role in aircraft construction, their design use having been restricted by certain aircraft companies because of occasional unpredictable service performance. Accepting the fact that some of the earlier, high strength, aluminium‐zinc alloys had a marked susceptibility to stress corrosion, and that some structural failures were directly attributed to this, it is now an established fact that some real and concrete progress has been achieved in reducing this susceptibility and the status of the modern variants of these alloys, when used for aircraft design purposes, is no longer a question of doubt. The informative article “New High Strength Aluminium Alloy”, by H. A. Holl published in Aircraft Engineering, January 1975, records significant progress in this direction. It covers the successful, sponsored development of 7010, high strength, aluminium‐zinc alloy, by the British Ministry of Defence.
Two Decades of Progress in Damping Technology
Authors: JONES DAVID I.G.
Published: November 2014

The aim of this paper is to review, briefly and selectively, some highlights of the progress made in the development of damping materials technology for vibration control, in the past two decades, with particular emphasis on the developments sponsored by the US Air Force Materials Laboratory at Wright‐Patterson Air Force Base.
A Scientific Approach to Defeating Helicopter Vibration
Authors: TRIGG N.E.
Published: November 2014

Helicopter vibration is like toothache; many operators put up with it because the cure might be painful, but the more enlightened seek treatment. No operator likes to counterance the down‐time and disruption caused by traditional diagnosis and tuning methods. Nowadays, thanks largely to pioneering work carried out in this country, the cure for excessive vibration can be quick, sure and inexpensive. This article describes how the situation has been changed by the evolution of scientific tuning methods over the last fifteen years.
Airworthiness — A Systems Approach
Authors: MAJOR E.R.
Published: November 2014

This article is written by Mr. Major at the invitation of the publishers of AIRCRAFT ENGINEERING as an introduction to the series that is being published during 1980, (as was said in the Comment in the January issue), on the important subject of Airworthiness. Mr. Major says “My comments are not intended to be an official expression of views of the Society of which I am President, and they are based on experience in civil air transport covering technical development, aircraft maintenance and ground operations and, in the aircraft manufacturing industry, covering structural and detail design, production and after‐sales liaison with military users. This fairly diverse experience and some of the events which have occurred in the course of acquiring it, have led me to the view that many (perhaps most) of the airworthiness shortcomings that occur are due to the ‘gulfs’ which develop between specializations, or to the lack of communication (in the widest sense — and both ways) between the elements contributing to ‘total’ airworthiness.”
Flight Recording in the UK
Authors: FORD TERRY
Published: November 2014

A system which has been in service with Trident and other types of aircraft for some years is the Plessey PV 726A which was one of the first to incorporate expanded facilities to acquire AIDS information. It consists essentially of a data entry panel which permits the insertion of flight identification data, self‐test facilities, ON/OFF switching and fault indication, an acquisition unit, transducers, DFDR or accident recorder, and the quick access recorder.
Mission Adaptive Wing Research Programme
Authors: DeCAMP R.W. , HARDY RICHARD
Published: November 2014

Ground testing of representing components is being conducted on the Mission Adaptive Wing (MAW) programme in Seattle, Washington. Phase 2 of a three‐phase wind tunnel programme has been completed and has verified the aerodynamics and loads used for the initial design concept. Unless a major problem is encountered in the ground test programme, a research F‐111 airplane will fly with variable camber wings in August of 1982.
Safety: The Responsibilities of Government, Manufacturer and Operator
Authors: FRY R.A.
Published: November 2014

We are all concerned about satety but are not always conscious of all the factors necessary to ensure it. However, aviation of one kind or another has been with us right through this century and the painful experience of accidents has taught us lessons: enabling us to establish procedures to limit the likelihood of re‐occurrence.
Aircraft Wheels and Tyres
Authors: Dowty George H.
Published: November 2014

The need for drastic standardisation of aero wheels and tyres in England is long over‐due. The U.S. Air Services have standardised five sizes of tyres for their needs, and these five sizes use only four axle diameters. In contrast, the English standards, covering the same range, list nineteen standard tyre sizes and fifty‐two axle diameters and length combinations.
Aviation in Alaska
Authors: SMITH D.K.
Published: November 2014

In June 1980 I had the opportunity of visiting Anchorage, the largest city in Alaska with a population of 202,000. A city that started as a Base Camp for workers building the Alaskan Railroad in 1914, was devastated by one of the largest earthquakes on record in 1964 and emerged a year later rebuilt as the ‘All American’ city that it is today.
Powerplants — 2
Authors: FORD TERRY
Published: November 2014

Among the large turbofan engines being developed for commercial applications is the General Electric CF6—80C for which certification is scheduled for June, 1985. Testing began this year and a thrust rating of 56,000 lb. is anticipated on entry into service with potential for further increases up to 62,0001b. Expected engine performance criteria have been met or exceeded on test, with temperatures, pressures and stresses as predicted and the new active clearance control system in the HP turbine having demonstrated its ability to reduce the sfc. The CF6—80C is being proposed as a powerplant for the Airbus A300–600, the stretched upper deck Boeing 747–300, advanced versions of the Boeing 767, the McDonnell Douglas DC‐10–30 and a number of military applications.
Safety Topics
Authors: Mayday
Published: November 2014

A problem that is always with us is that of bird strikes on aircraft and it is no small task to collect information from such incidents, analyse it and give advice to flight crews, operators and other bodies. The size of the problem may be appreciated when it is realised that 3,975 incidents of this type were reported to ICAO in 1981. This total came from 36 states, chiefly from Europe, North America and the Pacific area. Only about one‐fifth of ICAO's members were reporting bird strikes and, taking into account the sparseness of some other parts of the world, it is conservatively estimated that the annual total of such occurrences may be said to be about 10,000.
Confidence in South East Asia
Authors: Ford T.E.
Published: November 2014

A balance of commercial factors as well as appreciation of its position at the “crossroads” of the East has enabled Singapore Airlines to surmount the recession which has affected so many of the world's carriers. An advanced technology fleet is of prime importance with replacement taking precedence over certain considerations. This process can be said to have begun in earnest in 1967 when new Boeing 707 and 737 aircraft were ordered. Before that time, the airline could not afford such expensive acquisitions.
Safety Topics
Authors: Mayday
Published: November 2014

With new technology now in service on the flight decks of commercial aircraft, such benefits as micro‐processors, digital systems and cathode ray tubes (CRTs) provide the pilot and crew with a flexibility never before contemplated. Monotonous monitoring tasks no longer need to be performed and attention can be concentrated on those at which the human can excell (for example, decision making and problem solving). The only condition under which the pilot is overloaded is when equipment is degraded — which, according to one theory, may lead to a consition of underloading. In other words, decreased crew work load and efficient utilisation that result in increases in performance and safety need to be balanced against the possibility of a work load that is too low to motivate the crew, with perhaps a reduction in the ability to deal with emergencies properly.
Safety Topics
Authors: Mayday
Published: November 2014

Specialist information on the survivability aspects of post‐crash fires has been provided by Dr. John Hors‐fall, who is a member of the UK Air Safety Group and also of the Parliamentary Advisory Council for Transport Safety.
Harrier II
Authors: Ford T.E.
Published: November 2014

Progress of the joint Anglo‐American Harrier II programme will be marked in 1985 by the formation of the first US Marine Corps (USMC) operational squadron of AV‐8Bs and the first flight of the Harrier GR Mk. 5 for the RAF. The latter aircraft will vary slightly from those for the USMC in that they will be equipped to meet the close support role in Central Europe which necessitates the inclusion of a moving map display and two additional underwing weapon stations, as well as other differences.
Safety Topics
Authors: Mayday
Published: November 2014

Recent discussion and review of information on rejected take‐offs by the UK Flight Safety Committee seems to indicate that a strong case can be made for taking advantage of present technology to develop cost‐effective equipment that will identify suspect tyre pressures and temperatures and suspect acceleration. This is in the knowledge that there is still room for improvements, perhaps in procedures.
Safety Topics
Authors: Mayday
Published: November 2014

THE addition of fuel system protection during post‐crash ground fires and design features which would ensure shutoff of engine fuel in such circumstances are the subjects of an Advnaced Notice of Proposed Rulemaking recently issued by the FAA. This is the result of information from public hearings and recommendations of the SAFER Advisory Committee. Comments have to be received by January 25, 1985. This Advanced NPRM has been issued since it has been found that reasonable outside inquiry is necessary to identify and select a tentative or alternative course of action or where public participation may be helpful.
Long Distance Twins
Authors: Ford Terry
Published: November 2014

AIRWORTHINESS and operational approval for extended range operations by twin engine transport aircraft in commercial service had been expected for some time to be obtained by late 1984. For this to take place, it has been necessary for the relevant authorities to be satisfied that power and systems reliability, dispatch requirements and the regulatory work had reached the advanced levels required.
Airworthiness Technology
Authors: Ford Terry
Published: November 2014

ATTENTION has been focussed on aspects of helicopter airworthiness by the publication of the HARP Report. In this document, existing requirements for public transport helicopters were reviewed and recommendations made for improved safety standards and it has been stated that a series of accidents in recent years, some of them related to North Sea operations, are believed to be reason for the request to the ARB which led to the setting up of the Panel. A contributory factor was the realisation that these kind of public transport operations were in their infancy and enormous expansion can be expected.
Why Tungsten Carbide?
Authors: Kieman Jonathan S.
Published: November 2014

THE introduction of tungsten carbide as a suitable material for precision gauge blocks began almost by accident.
A Better Approach
Authors: Ford CEng Terry
Published: November 2014

Approved for worldwide implementation and scheduled to supplant the Instrument Landing System (ILS) by 1995, the Microwave Landing System (MLS) is a precision approach aid that overcomes the basic limitations of its predecessor by using frequencies in the 5000MHz range instead of the very low values employed in the ILS. Designed for unattended operation, MLS can easily be installed on oil rigs, at heliports and in other confined areas where it was not possible to have the previous system.
Safety Topics
Authors: Mayday
Published: November 2014

Chinook Accident ON the return flight to Sumburgh from Brent Field a Boeing Vertol 234 LR (Chinook) was only some four miles from the airport when the crew remarked on a noticeable increase in the noise level on the flight deck. One of them described it as a roaring noise. This was followed by a ‘bang’ and the aircraft pitched nose up to a near vertical attitude, went out of control and crashed into the water. Two survivors out of the total of three crew and 44 passengers were rescued and an intensive air and sea search involving Service and civilian aircraft and vessels failed to find any more survivors. Search and recovery operations continued ad some four days after the crash, about 75% of the fuselage and 95% of the transmission had been recovered.
‘Maintenance ‐Operations and Economics’
Authors: Ford Terry
Published: November 2014

PREDOMINANT areas of concern to the Licensing Authority with relation to the above conference were defined as the maintenance requirements and procedures relating to Transport and Aerial Work Category aircraft, with particular reference to large transport types and helicopters. All UK transport operators must hold an air operators certificate and it is the responsibility of the Airworthiness Division of the CAA to set the maintenance requirements and standards and the subsequent monitoring. The importance of control procedures cannot be over‐emphasised and it is considered by the CAA that work planning play a major role in maintenance and is a key activity for a successful and safe maintenance operation. The legal liability problem is making itself felt in all aspects of aircraft maintenance work as well as design engineering and makes vital the meeting of all legal requirements including appropriate history records.
Safety Topics
Authors: Mayday
Published: November 2014

The latest expertise in escape systems was shown on the Martin‐Baker stand at the Paris Show, highlighted by the company's Mk 14 which is the world's first microprocessor controlled electronic ejection seat. Currently undergoing testing is the variant for the United States Navy Aircrew Common Ejection Seat (NACES) programme, which will be standard equipment for the F/A Hornet, F‐14 Tomcat, T‐45 Goshawk and A6F Intruder. Versions are also being proposed for the European Figh‐ter Aircraft, French Rafale B and the USAF Advanced tactical Fighter.
Safety Topics
Authors: Mayday
Published: November 2014

CONCERN about the development and implementation of collision avoidance systems has occupied companies and authorities for many years in various parts of the world and particularly in the USA where the density of all kinds of air traffic has increased substantially and will continue to do so into the foreseeable future. Although increases of density occur worldwide, the vast amount of private and business flying in North America makes it essential that any workable scheme of collision avoidance must have mandatory general aviation participation. The necessity for such a system has been underlined by mid‐air collisions which have happened over a considerable period of time and growing pressure has meant that the FAA in 1987 issued a Notice of Provisional Rulemaking (NPRM) in which comments about its contents were to have been received before the end of 1987.
Safety Topics
Authors: Mayday
Published: November 2014

WORK is being done by the Civil Aviation Authority (CAA) on a variety of measures aimed at protecting passengers from smoke and fire, one of the most recently publicised being the decision on smoke hoods. After extensive research and study and consultations with other authorities the CAA has made it known that it will not make smoke hoods a mandatory requirement for British airlines. It believes that no fully adequate design capable of doing everything thought to be necessary is yet available. Unless a smoke hood meets all essential requirements of protection against smoke, fire resistance, performance duration, weight ease of donning and availability, it could not be relied upon at a moment of crisis and in the full range of circumstances. Further work requires to be undertaken in several important areas and when the case for regulatory action comes to be reviewed, other fire protection developments such as water sprays, will have to be taken into account.
Safety Topics
Authors: Mayday
Published: November 2014

HAVING left Aberdeen and flown to two semi‐submersible rigs in the East Shetland basin, the helicopter was refuelled and departed for the return flight to Aberdeen with 18 passengers. After flying for about an hour and when the aircraft was 128 n miles from Aberdeen and 48 n miles from Sumburgh, three distinct ‘thumps’ were felt throughout the airframe. The commander turned the aircraft towards Sumburgh and almost immediately severe vibration developed, loss of control was feared and immediate plans for ditching were made. The commander had lowered the collective pitch lever and heard the high rotor rpm audio warning indicating a rotor speed (NR) of at least 290 rpm. He re‐applied about 12.5° of collective‐pitch and found that the level of vibration reduced and therefore he decided to try to maintain flight and make for the nearest land.
Safety Topics
Authors: Mayday
Published: November 2014

A particular problem which has caused a number of accidents and incidents over a long period to Piper PA 28 series aircraft was the cause of an accident last year when one of these aircraft was destroyed, but fortunately the crew of two escaped with minor injuries.
Safety Topics
Authors: Mayday
Published: November 2014

A Hughes 390SH helicopter was to fly from its operating base to its maintenance base for a 50 hour inspection. The forecast for the flight indicated that the intended route would be affected by fog and low stratus. The aircraft flight manual states ‘Use engine antiicing when OAT is below + 5°C and visible moisture conditions prevail’. Another aircraft in the area reported that there was no discernable horizon between the top of the fog layer and the base of the stratocumulus. Visual flight between the layers was possible but reference to flight instruments was required to prevent disorientation. The ground became visible at 350 feet agl on descent in the accident area.
Civil Aviation Operations
Authors: Ford Terry
Published: November 2014

HELD in London the third European Aerospace Conference was organized by the Royal Aeronautical Society and similar professional bodies in France, Germany and Italy and provided an opportunity for wide ranging discussions embracing the operation, maintenance, regulation and technological considerations governing civil aviation today. The Conference was subtitled Problems, Solutions and Actions and many of these were aired by the manufacturers, operators and airport authorities who are directly affected by whatever regulations and constraints may be imposed from time to time.
A Technology Challenge
Authors: Ford CEng Terry
Published: November 2014

THE title of this report comes from the Keynote Address to the recent International Powered Lift Conference organised by the Royal Aeronautical Society. Attention at this gathering was focussed entirely on short take‐off and vertical landing (STOVL) technologiesf for fast jet combat aircraft. The strong international collaboration particularly between the USA and the UK has been a main feature of the evolution of these types. Seven areas of work have been outlined at the last conference of this nature and these largely remain the central themes. These are: plenum chamber burning; hot gas reingestion during VTOL manoevres; ground erosion; near field jet noise; powerplant controls; aircraft controls and flight/ powerplant controls integration; and airframes. It has been concluded that the most promising configuration for a future aircraft would include the two specific features of remote vertical lift in jet‐borne flight and conventional mixed flow propulsion for wing‐borne flight.
Safety Topics
Authors: Mayday
Published: November 2014

An Optica aircraft commenced its take‐off roll from approximately one third along the runway (due to the activities of a gliding club). The take‐off and initial climb were normal until at an altitude of about 160 ft there was a loud ‘bang’ followed by a severe vibration. The pilot immediately lowered the nose of the aircraft and throttled the engine back to idle in order to reduce the vibration. It was apparent that a forced landing was necessary but the pilot assessed that the remaining runway ahead was insufficient and would result in an overrun onto a public road. He therefore put the aircraft into a 30° banked turn to the left with the intention of making a downwind landing on another runway. The observer made a radio call informing the tower of the pilot's intentions. With full flap selected, the aircraft touched down two thirds along the runway although not aligned with it, at an airspeed of 60 knots. With a wind of 230/15 knots this resulted in a ground speed of 75 knots. The engine was still at idle rpm as the aircraft rolled onto the grass on the left side of the runway and came to a stop. There were no injuries and no apparent additional damage although a small amount of fuel was observed to be leaking from the bottom of the engine pod.
Cabin Integrity and Passenger Safety
Authors: Mayday
Published: November 2014

RECENT conference statements and the publication of the Kegworth report by the Air Accident Investigation Branch (AAIB) have highlighted many issues affecting passenger safety. Yet again, emphasis has been laid on the very welcome reduction in the statistical rate of jet transport accidents over the past few decades and the lack of a corresponding improvement in the survival rate in these accidents.
Safety Topics
Authors: Mayday
Published: November 2014

AS readers of ‘Aircraft Engineering’ will be aware there has been a considerable amount of discussion, criticism of decisions and controversey over means to improve passenger survivability. The Civil Aviation Authority (CAA) has published a review of those improvements that relate specifically to aircraft fires. In particular and although the House of Commons Transport Committee recommended the mandatory carriage of the best smoke hoods currently available, the CAA feels that it is an unnacceptable safety risk and will not require their provision. On the subject of water sprays, the Authority considers that serious consideration should now be given to introducing regulations requiring the installation of such systems in large transport aircraft. These two issues are among a number discussed in the report but are those which have attracted the most publicity.
Advanced Aerospace Composites
Authors: Ford CEng Terry
Published: November 2014

REPLACING metal parts by composites has been undertaken for some time in the aerospcae industry and there has been gradual acceptance of these materials for use in primary structure. Du Pont Kevlar para‐aramid and Nomex meta‐aramid have been used for many applications where low weight, strength and durability are the most important qualities. They are used alone or in combination with carbon in hybrid laminate constructions which achieve a weight saving of 15 to 30% over the metal parts that they replace.
Safety Topics
Authors: Mayday
Published: November 2014

TWO incidents are described, both involving bleed air ducts but in dissimilar aircraft with different engines. One incident concerned a Boeing 747–136 in which at just after the decision speed V1. a loud ‘bang’ was heard followed by severe vibration from all four thrust levers. The take‐off was continued normally and the aircraft rotated normally at Vr and entered the climb. The landing gear was not immediately retracted due to the possibility of burst tyres, however, shortly after the aircraft became airborne the No 4 engine generator failure warning lights illuminated, the engine oil temperature indication decreased off‐scale and the exhaust gas temperature (EGT) also reduced to a low reading. Suspecting an engine failure, the commander ordered the landing gear to be retracted. However, since the No 4 engine N1, N2 and fuel flow indications remained normal, the commander decided not to shut down the engine. As the aircraft climbed through 500 ft, the right wing overhead warning light illuminated. At a safe height the flaps and leading edge devices were retracted, control was transferred to the co‐pilot and the flight engineer, monitored by the commander, completed the wing overheat and single generator inoperative check lists. While these were being completed, Heathrow ATC advised that debris had been found on the runway. The commander decided to return to Heathrow and radio vectors were requested for fuel jettison.
New and Emerging Technology
Authors: Ford CEng Terry
Published: November 2014

A recent ERA Technology conference considered the provision of affordable avionics systems in the civil, military and space sectors. Included in the presentations were developments and projects indicating the advances made in each of these fields and the efforts made to design for specific needs. One contribution featured a small jet transport projected by Deutsche Airbus which is intended for service in the latter part of this decade. Cockpit and avionics details were featured for an aircraft seating 90 with a later enlargement to 130 seats envisaged. The configuration is low wing with two turbofan engines.
Safety Topics
Authors: Mayday
Published: November 2014

A final rule has been issued by the FAA that mandates what is already an existing industry practice, as required by airworthiness directive. This amendment to FAR's is based on NPRM 90–7 issued on March 5, 1990 which proposed to require that an inert gas, such as nitrogen, be used in lieu of air, for inflation of tyres on certain transport category aircraft.
Establishment of Lift on an Aerofoil with a Jet Flap: A Theoretical Note Relating to a Wing with Trailing Edge Jet with Extension to Cover Wings of Finite Span
Authors: Hirsch R.
Published: November 2014

The circulation which is established around an aerofoil section which has i trailing edge jet, and thus also the lift, is directly dependent on a trailing edge condition similar to the Joukowski condition in conventional steady and unsteady flow. There is a downwash made up of elementary vortices but in this case the vortex density is not zero when the sheet extends to infinity. The problem is govcrnec by an equation similar to the Wagner equation, into which is introduced the curvature of the downwash at the trailing edge. Certain precautions have to be taker when calculating this. The law governing the movement of the elementary vortices in the downwash plays a very important part. It is directly dependent on the viscous damping of the vorticity. This effect has also had to be taken into consideration, and the drag law of the jet behind the nozzle established. Other results follow concerning the solution of the transient case, and the determination of the circulation up to the moment of reaching its steady limit value, which is achieved in finite time. The velocity distribution on the aerofoil can be found at any instant, and thus also all the properties concerning the aerodynamic forces. The method has been applied to two cases, and a comparison is made with experimental results. An extension to the case of a conventional aerofoil (without jet) is possible; in this case the circulation must have a slightly lower value than in the Joukowski case, the difference depending on the Reynolds number. There is a potential drag resulting from the existence of the downwash and its loss of momentum. In Part II the finite span case is considered. The basic equations are established, and an approximate solution of the steady How case found, where the distribution of circulation is elliptical. A wing interrupted by a fuselage is also considered, and comparison with experimental results given.