bluuebunny/crossref_metadata_2025_split huggingface dataset:
III—An Operator's View
Authors: Ormonroyd F. 
Published: January 2010

It is abundantly clear that improvement in regularity and safety of operations in poor visibility can only come about through increased precision during the non-visual phase of the approach and missed approach and through continuing use of the instrument guidance to the lowest possible height within the prescribed limitations during the visual phase. In common with most other airlines, B.E.A. is planning to introduce Category II operations in the near future and this paper deals with some of the problems which we have met and the way in which we plan to tackle them.By virtue of being an exclusively short-haul airline, B.E.A. flight times are! short compared with time spent on the ground. As a result, flight schedules need to be closely integrated to provide a high rate of utilization of both aircraft and crews, and so any serious disruption of services by the weather affects B.E.A. to a greater extent than other airlines.
‘Longitude Without Time’
Authors: Sadler D. H. 
Published: January 2010

The Executive Secretary has referred to me two notes on this subject, one by M. S. Dixon and the other by Bruno Ortlepp. Although submitted independently, and at different times, they clearly relate not only to the. same technique, but also to the same set of observations.Now much has been recently written on the determination of time, and thus of longitude, from observations of the Moon's altitude (for example, in this Journal, reference can be made to the notes by Francis Chichester, 19, 106, 1966; D. H. Sadler, 19, 107, 1966; J. J. Evans, 19, 392, 1966; and to the comments in the article by H.M. Nautical Almanac Office in 19, 133 and 1 $2, 1966) and it should be unnecessary toNrestate either the principle or the practical disadvantages of this method.
‘The Metrication of Navigation’
Authors: Sadler D. H. 
Published: January 2010

In his note (Journal 21, 81) on this subject, Ronald Turner says ‘No longer will orbital periods of the rotation of the Earth on its axis be measures of time’. This is not so, either in general or in the particular, case of navigation.Universal Time (U.T.), which is the generally accepted name for Greenwich Mean Time (G.M.T.), continues to be essential for all purposes (in astronomy, geodesy, surveying and navigation) for which are required astronomical observations related to the precise position of the observer on the Earth's surface. The Nautical Almanac must continue to tabulate the positions of the Sun, Moon, planets and stars with G.M.T. as the time-argument; and observations should be timed in a time-system related to U.T., such as the broadcast time-signals of Coordinated Universal Time (U.T.C:).
Electronic Instruments and Computers for Sailing Yachts
Authors: Gatehouse R. N. B. 
Published: January 2010

This paper contains a brief survey of a series of instruments which have been developed for use in sailing yachts. It then outlines the principles of two computers; one navigational, the other for sailing performance indication. It does not cover radio navigational aids, echo sounding or radar. The data requirements are: 1. Navigational, comprising distance run through the water, heading, leeway angle. 2. Functional, comprising speed through the water, direction of the apparent wind and speed of the apparent wind.For measuring distance run, the classical towed rotator type of log, fitted with a mechanical or electro-mechanical revolution counter has been largely superseded in racing yachts by logs employing through-hull sensors on account of drag considerations and the inconvenience of having to shorten the line when sailing slowly in shallow water. It still finds favour in cruising yachts on account of its generally lower price and its simplicity.
The Revision of the Rules
Authors: García-Frías J. 
Published: January 2010

If the present Collision Regulations are defective, it is largely because the principles underlying them are not sufficiently developed for today's circumstances. In this paper Admiral García-Frías of the Spanish Navy attempts such a development and proposes a new set of rules, adapted to present circumstances, for vessels in sight of one another. These proposals, with the set of rules previously suggested in this Journal for restricted visibility using radar, form a complete system for avoiding collisions in both situations so that it would be easy to pass safely from one situation to the other when necessary, because of the unity of principles they present.It is encouraging for certain schools of thought—which started some years ago advocating the revision of the Collision Regulations for occasions when radar was being used in restricted visibility—that there now seems to be a general dissatisfaction amongst seafarers with the lack of guidance provided in the rules. Consequently, they are at last interested in a fundamental review of the Regulations.
The Institutes of Navigation in the 1970's
Authors: Richey M. W. 
Published: January 2010

This paper was presented by the Executive Secretary at the twentieth anniversary convention of the Australian Institute of Navigation held in Sydney, New South Wales, on 10 and 11 October 1969.In July this year two men landed on the Moon, certainly the most spectacular navigational achievement of mankind. It was a voyage backed by all the massive scientific resources of a modern industrial state, in which thousands of people were directly involved. The astronauts were a single link in a navigational loop employing a host of technologies.Two hundred years previously James Cook had sailed on the first of his three great voyages, during which he discovered New Zealand and the coast of New South Wales. Cook was perhaps the most illustrious navigator of all times, even if perhaps he advanced the art more by force of character than by any specific contribution. When he started his voyages, the art of nautical astronomy was in its infancy. At their finish William Wales could comment, in 1788, that no officer who had been concerned with them ‘would not, whatever his real skill may be, feel ashamed to have it thought that he did not know how to observe for and compute the time at sea, though but a short time before these voyages…such a thing was scarcely ever heard of among seamen; and even first-rate astronomers doubted the probability of doing it with sufficient exactness’.
Pilotage or Conning Radar
Authors: Watt J. 
Published: January 2010

The paper by Captain J. P. Stewart in the July issue of the Journal, entitled as above, presents a wealth of evidence and argument for the obvious sense of designing marine radars in such a way that they can:(a) present compass stabilized radar pictures in the natural ship's-head-up orientation. This avoids the mental stress of trying to correlate the radar view and the eye-ball view of the same situation when the two may be presented in completely different orientations;and(b) simultaneously allow true bearings of targets to be read off directly.
How to Avoid Collision with Other Aircraft
Authors: Proctor J. D. 
Published: January 2010

These notes on collision avoidance by an experienced airline pilot are presented in the form of practical advice to young pilots. The paper deals first of all with blind avoidance and then with visual avoidance.Collisions are rare and about one quarter of colliding aircraft have landed safely. Collisions are not always fatal to everyone, but they are serious accidents. Pilots need knowledge, skill, good habits and/or a little luck to avoid them. Collisions have occurred for years although in many cases the investigators have proved that the approach of the aircraft and the layout of the windows around the pilots were such that some of the pilots could have seen the other aircraft. Yet they still collided, so that obviously visual avoidance is not easy. In other cases especially in the circuit the aircraft approached and collided without much possibility of seeing each other; so remember there may be someone under your nose or above your tail who can't see you either. We all know how the high closing speed of fast aircraft is too high for human visual acuity to sort out the situation and prevent collision visually. But a number of collisions have occurred at low closing speeds and a number have occurred between light aircraft (e.g. two Convair 240's over U.S.A. in August 1953, and two light aircraft over Reading a few years ago).
An Accuracy Evaluation of a Civil Inertial Navigation System
Authors: Reynolds P. R. J. 
Published: January 2010

This paper covers the performance of the Sperry SGN-10 Inertial Navigation System as demonstrated by the operation of dual systems installed in a standard operational configuration aboard four jet aircraft of Pan American World Airways incidental to a preoperational engineering evaluation programme conducted for the Federal Aviation Administration during the latter part of 1966. The primary object of this evaluation programme was to determine the system's capability of meeting the following requirements of the F.A.A.'s Advisory Circular covering the use of inertial navigation systems in U.S.- registered civil aircraft, namely:(1) Maintain a position accuracy within 20 n.m. in the across-track dimension and 25 n.m. in the along-track dimension for 95 per cent of the time on flights up to and including ten hours duration.(2) Automatically accomplish initial platform alignment in a normal manner in latitudes up to and including the highest normally used in civil aviation.(3) Perform all its designed navigational functions in a normal manner at all latitudes, inclusive of polar and equatorial overflights.
Automation in Sea Transport
Authors: Parmiter G. V. 
Published: January 2010

The word ‘Automation’ when applied to the shipping industry seems to invoke in the individual mind such matters as direct control of propulsion units, planned bridge lay-outs, cargo plan computers, engine data loggers and such other items of ships' equipment. Automation is thus limited in effect and confined entirely to the ship internally. Clearly this ensures that the ship as a unit is as economically efficient as modern techniques allow and is a reflection of the up-to-date attitude of mind of many shipowners.On the other hand there is a very large field open to automation which concerns sea transport as a whole in respect of the actual conduct of ships at sea both individually and in relation to their effect on each other. It is in this field of sea transport operations that the author sees many longterm possibilities and this paper tries to give some lead into these, which so far seem to have received little, if any, widespread thought or discussion.
Automation Problems in Civil Transport Aircraft
Authors: McKinlay W. H. 
Published: January 2010

Over the past two decades there has been a steady increase in the amount of electronic equipment carried by transport aircraft. This reflects the expenditure of a large amount of research and development effort, particularly in the automatic flight control field. Yet despite these developments complete automation has not been applied to air transport in the sense that it has been applied to some industrial processes. The attempts made to introduce partial automation have not always had complete success either operationally or economically.The reasons for this somewhat piece-meal growth of automation in civil transport aircraft are varied. The most important seems to be that any new aircraft represents an evolutionary step forward. Much of the equipment must either be carried forward from a previous generation or based on it, for a mixture of operational and engineering reasons. Inter-fleet standardization in the interests of maintenance and the need to achieve safety by building on past experience are contributory factors.
Navigational Equipment in the Supersonic Concorde in 1970
Authors: Bouar M. Le 
Published: January 2010

A great deal has already been written about the navigational problems presented by the appearance in the near future of supersonic civil aircraft; in this paper I shall try to give a quick description of the methods that will be available in the supersonic Concorde in 1970, with an account of the chief considerations that governed their choice. While there is no doubt that there is a specific navigational problem proper to supersonic aircraft, it does not present itself in as critical a form as some writers believe. When the present-day jets came into service there was not, strictly speaking, any real gap to be bridged. The conventional methods and means used in prop-driven aircraft were taken over, with whatever further adaptations were required for particular cases—such, for example, as polar navigation. In spite of the increase in speed, there was still sufficient time for the navigator to check position and heading at regular intervals.However, the 300 per cent increase in speeds now envisaged (1300 knots = mach 2.2 for the Concorde) introduces a more formidable discontinuity in relation to the standards of today. At a speed of 22 miles a minute it becomes impossible for the navigator to work as rapidly as he must if he is to deal with the information provided by his sensors and carry out the necessary corrections.
The Jet Stream
Authors: Chambers E. 
Published: January 2010

For many years there has been evidence (for instance from pilot balloon ascents and drift of cirrus clouds) of the existence of occasional very strong winds in the upper troposphere. However, it was not until about 1933, that Bjerknes, who had introduced the concept of the polar front during the first world war, produced a map of geostrophic wind deduced from upper-air temperature soundings made at a few scattered stations and showed a core of strong westerly winds at about 12 kilometres in middle latitudes in winter. No further progress was made until during the second world war when a comparatively large number of upper-air stations were set up and it was found that narrow belts of very strong winds were almost always present over some part of the Earth's surface in the 30,000/40,000 ft. altitude band. In 1944–5 American bombers encountered some rather frightening winds over the Japan area and since that time some extensive investigations of jet streams have taken place.The term jet stream is popularly applied to any strong upper-wind current (of say 80–90 knots) and it is safe to assume that such winds are in fact associated with a jet stream, which may be considered as a narrow tube containing very strong winds embedded in the surrounding atmosphere.
Aircraft Navigational Errors
Authors: Proctor J. D. 
Published: January 2010

C. S. Durst has tried to discover the frequency distribution of aircraft navigational errors from D. C. Willis's data. But how reliable are Willis's data for this purpose?D.R. errors and track-keeping errors are differences between assumed and true positions. Evidence of assumed position is ayailable, but how can true position over the Atlantic ever be discovered accurately? Willis estimated true position by post flight analysis of navigational and meteorological data, but any such analysis must be based on some doubtful assumptions, for instance that compass error or wind was constant between fixes or that the true position was at the ‘middle’ of a ‘reliable’ fix. The analysis must also comprise many delicate judgments, for instance that the true position was at A, not B, because if it were at B an abnormal wind change must have occurred for which there is only slight evidence.
Chartwork in Small Craft
Authors: Vendrell J. 
Published: January 2010

Having had for some time to navigate small craft in all weather in the western approaches to the Clyde and on the west coast of Britain, the writer would like to submit for the consideration of other small-craft navigators some modification in chartwork which has proved useful, especially in rough weather when parallel rulers are an abomination and flying dividers can be lethal.On a violently moving platform the navigator can only work with maximum efficiency when he is himself chocked off in a position in which he is sheltered, has the widest possible field of view, can take bearings and can brace himself securely to leave both hands free to carry out a limited amount of geometrical plotting with reasonable accuracy. The obvious position is of course the fore part of the wheelhouse, where there is very seldom sufficient room for a fullsized chart table with all the frills and trimmings.
Tables for Astronomical Polar Navigation
Authors: Sadler D. H. 
Published: January 2010

The special features of polar navigation are examined with a view to the design of tables for astronomical navigation in polar regions. The use of long intercepts and curved position lines is thoroughly investigated. It is shown that considerable economy of presentation can be achieved; as an example, a one-page table covering all bodies and both polar caps is given. Making the fullest use of polar astronomy, samples are given of permanent tables for the Sun and stars independent of the Air Almana.The following critical review of tabular methods for astronomical polar navigation was written originally as a comment on a proposal to extend the Astronomical Navigation Tables (at present limited to latitudes between S. 79° and N. 79°) to the poles. Although it has been slightly amended, it has not been entirely recast and it therefore still retains some of the ‘thinking on paper’ of the original version. So far as is known the tables proposed are new, but there is clearly no great originality involved.
Controlled (h/d) Let-down using Barometric Height and Radar Distance
Authors: Downes J. G. 
Published: January 2010

The method described provides glide-paths for climbing and descending aircraft by combining in a single instrument information from the barometric altimeter and radar distance measuring equipment. Preliminary flight tests have shown that the method provides a smooth path along which an aircraft can be flown within close limits, and is one that appears sufficiently promising to justify further development.Height separation has for years been a fundamental concept in the control of air traffic. It is the basic method of preventing collision during en-route navigation and in some holding procedures. The main reason for this is that a suitable instrument already exists in the form of the barometric altimeter, aninstrument which is intrinsically more accurate and reliable than any of the usual navigational aids.
The Reduction of Sights in High Speed Aircraft
Authors: Everitt P. F. 
Published: January 2010

When designing the periscopic sextant now coming into production it was realized that the conditions in the pressurized aircraft for which this sextant was designed differed sufficiently from those previously experienced to make it worth while reconsidering what methods would be most applicable to the new combination of pressurized aircraft and periscopic sextant.The conditions differ from previous experience in providing (a) a higher speed; (b) very little, if any, direct view of the sky by the navigator.
Experience in Fitting Radar to Ships
Authors: Millard B. S. 
Published: January 2010

Experience gained in equipping some 24 vessels, varying in size from 700 to 4000 tons, with radar may be of interest, and perhaps of help in avoiding some of the pitfalls that can occur.The problem of finding sufficient space in a small ship so that one instrument does not interfere with another is never an easy one. For example, to fit radar to a vessel whose wheelhouse superstructure is not more than 10 ft. long may entail building a radar tower of considerable height if the proper distance between the scanner and the magnetic compass is to be maintained. The magnetic effect of the tower on the compass will then have to be considered, and it may be necessary to build it of a non-magnetic material. Also the effect of the radar, when working, on the D.F. loop arises; a distance of 12 ft. between them is here necessary.
Radar in Ships of the United States Lines
Authors: Andrews A. H. 
Published: January 2010

AbstractThis paper described how 53 ships of the United States Lines had been fitted with 10 cm. radar and how instructions for maintenance and operation were given by the Company and the manufacturers of the equipment. Instruction in its use is given by a representative of the manufacturer, and subsequently minor adjustments and fuse replacements are made on board, all other maintenance being done under service contract in port.General instructions sent by the Marine Superintendent to the Master of each vessel fitted stressed the following points:i. For the present the equipment is to be regarded solely as a collisionwarning device.ii. The installation in no way relieves the Master from conforming to the Rule of the Road or any Pilot Rules.iii. A complete radar log in which maintenance and operational work are recorded should be kept.iv. Deck officers should acquaint themselves with the use of the equipment and should be encouraged to read the manufacturer's descriptive and operational booklet.
Some American Views on the Operation of Marine Radar
Authors: Isbister E. J. , Griswold W. R. 
Published: January 2010

AbstractMore than 1200 American radar equipments have been fitted to ships and this paper gave same American views on its operation; the views put forward were not necessarily different from those held in this country but certain experiences of inland navigation and blind pilotage which would be new to British operators were described. It was stated that when commercial production of marine radar started in the U.S., opinion was divided on the relative merits of 3 cm. and 10 cm. radar, some manufacturers concentrating on one and some on the other. Although 10 cm. equipment is still manufactured, all manufacturers now have a 3 cm. radar in production.Certain advantages of radar assisted navigation were mentioned and these included the ability to determine another vessel's course and speed by plotting and the considerable saving in fuel and time that could be achieved by the accurate knowledge of the ship's position in coastal waters no matter what the weather.Anomalous propagation in the Great Lakes region was described as being so common that shipmasters often regard the increased range of radar in the area as being the normal range of the set.The use of radar by tugs on the Mississippi and its tributary the Ohio was described. Here up to fifteen barges of 100 ft. are ‘shoved’ by the tugs into narrow locks in weather which sometimes conceals half the tow. The small bump in the trace, representing the lock, is recognized by the pilots. One of the outstanding problems of this form of radar navigation was stated to be that the bridges (of which there are 1700 over the Mississippi) were such good reflectors that discrimination between them was not possible at a mile, at which distance the tow gets into position to pass between the piers.
The Present Outlook
Authors: Hansford R. F. 
Published: January 2010

It may be useful at the end of this symposium to ask broadly what has been achieved so far in the field of navigational radar and what are the outstanding problems.In this country alone, in the four years since the end of the war, rather more than 300 commercial radars have been manufactured to an exacting specification and fitted to merchant vessels, and a much larger number has been produced in the United States; during 1949 the British radar industry states that it hopes to fit more than a ship a day.