Operational research has been developed and introduced into air transportation problems since the late 1940s, mainly in the U.K. and the U.S.A., and simulation techniques have also been used for designing or evaluating air traffic control systems. Some data on the actual operations are needed for carrying out these studies. The data on the time and motion of taxiing aircraft, especially jet aircraft, were collected at Tokyo International Airport (TIA) in 1975 and 1976 and the relation between average taxi speed and taxi distance was stated on the basis of the observed data. In this paper, a theoretical method for estimating the average taxi speed of departing aircraft is considered, using simplified models, and the results are compared with the empirical data.

Det Norske Veritas is a Norwegian ship classification society with a large classified fleet registered in 94 countries. The paper printed below was presented by Mr Cuming at an Ordinary Meeting of the Institute held in London on 18 May 1983 with Dr J. F. Kemp in the Chair.

Risk analysis is a method of evaluating potential risks which has been used for the past ten years by Det Norske Veritas, in both the shipping and the offshore fields of operations. The method is based on the systematic identification of hazards, the estimation of probability of occurrence and the evaluation of consequences.

This paper puts forward a case for more precise navigation at sea. It commences by briefly outlining existing and forthcoming navigation aids. The integration of marine navigation systems, and in particular the use of Kalman filtering is then discussed. After outlining the developments in the aerospace industries, the authors suggest why marine developments have not been so rapid as those in the air. The idea of automatic collision avoidance is also raised and a method for tracking radar targets discussed. Finally, the authors survey marine applications of Kalman filtering techniques, including some references to their own work, and assess the need for further research and development.

In May 1948 the Radio Technical Commission for Aeronautics, a cooperative association of United States government and industrial air telecommunication agencies, issued a report outlining a comprehensive scheme for the development of air traffic control facilities in U.S.A. for the next fifteen years. This report was prepared by a committee set up by the R.T.C.A., Special Committee 31, and it is generally known as the SC31 Report. It was the result of a study undertaken at the request of the Technical Division of the Air Coordinating Committee, an inter-departmental committee established by the Secretaries of State, War, Navy and Commerce, and directed by the President to examine aviation problems of mutual concern and to develop and recommend integrated policies and actions to be taken for their solution.

The Home Office in January 1977 invited submissions for inclusion in the United Kingdom proposals to the World Administrative Radio Conference 1979 (WARC 1979.) Prior to that, in August 1976 in Boston, U.S.A., the member Institutes of the International Association of Institutes of Navigation had agreed to exchange views on matters of concern to the world's navigational community which in particular might be considered by WARC. It was envisaged that any approach by the various national Institutes would be through their own administrations.

Although INMARSAT's founding charter includes provision for a space segment for radiodetermination, the organization has, to date, concentrated on the telecommunications aspects of its mission. However, a satellite radiodetermination (including radionavigation) services development programme has been under way for about two years, and includes both study and experimental activities. Early studies performed for INMARSAT on both passive and active radiodetermination provided a number of significant conclusions, including the rather obvious but important fact that all satellite radiodetermination concepts possess two common elements: the forward transmission (broadcast) of a relatively wideband timing/ranging signal, and the precise tracking in orbit of the satellites.

The paper is divided into two parts. The development of ship-borne compasses is reviewed in Part I; in this section some of the difficulties due to bad siting, &c., are mentioned and certain solutions such as the use of repeating compasses and improved methods of correction are described. Part II surveys the development of the aircraft compass and shows how its phases of development have corresponded to those of the marine compass. Some recent forms of aircraft compass and methods of development are also described.

Radar transponders and radar target enhancers have been in use in a variety of applications for many years. Perhaps the most widely-known applications of radar transponders are in Identification Friend or Foe (IFF) and its civilian counterpart, secondary surveillance radar for air traffic control, and as racons in marine navigation and, most recently, as Search And Rescue Transponders (SART) in the Global Marine Distress and Safety System (GMDSS).

Secondary surveillance radar is a combined radar and communication system, which provides aircraft position (range and azimuth) on the radar side and identity and height on the communication side. It is a main working tool in Air Traffic Control today and the information it produces is an ingredient in providing separation between aircraft in flight. This paper is concerned only with the reliability of the identity (Mode C) and the height (Mode A) data, and not with the radar position data as such. ‘Reliability’ is taken to mean ‘can the values reported by the SSR be relied upon?’ Consequently we are not concerned with cases where an interrogation elicits no response, but only with responses which are present but not correct. Furthermore, a ‘Mode C discrepancy’ is defined as a read-out that disagrees with the altimeter reading observed by the pilot, so that we are not concerned with altimeter errors, but only with the faithfulness (or otherwise) with which the SSR reproduces the altimeter reading. In cases where the Mode C read-out is obviously wrong, but no pilot's report is available, it is not always possible to distinguish between an altimeter error and a Mode C discrepancy.

The following discussion took place at an Ordinary Meeting of the Institute held at the Royal Geographical Society in London on 19 February 1960, with the President, Wing Commander E. W. Anderson, O.B.E., D.F.C, A.F.C, in the Chair. Dr. J. G. Porter is at the Royal Greenwich Observatory, Herstmonceux, Mr. D. J. Cashmore and Mr. T. McClymont are both with English Electric Aviation Limited.

Since the inauguration of the B.O.A.C. Return Ferry Service, the principles of pressure pattern flying have been followed on the North Atlantic as regards flight planning. In co-operation with the forecaster the practice developed of working out a number of flight plans to achieve the shortest possible flight time, and eventually it became possible to select the most favourable route with a reasonable degree of precision.

The advent of the radar altimeter furthered development of the pressure position line theory which I believe was first propounded by R.A.E., Farnborough, and has since been elaborately garnished and enthusiastically tested by our American friends during recent years. The words ‘altimetry’ and ‘aerologation’ have been added to our generally common language to cover flight techniques that might perhaps be more simply described as ‘pressure comparison navigation.’

It was on the river Rhine that radar started its inland waterway career, followed almost immediately by the inland waterways in the Netherlands. In those days the inland waterway fleet was composed of ships owned by a few large companies and ships owned by their skippers.

Having studied marine statistics for a number of years, especially those concerning casualties at sea and in particular collisions between ships, the opening paragraph of the Traffic Separation Working Group's report (this Journal, 19, 4) is, to say the least, lacking confirmatory evidence on two counts.

I refer to the general statements which allege that:

(i) ‘The main risk at sea today arises not as it used to from stranding and shipwreck, but from collision’.

(ii) ‘In the open sea, where nearly 30 per cent of all collisions occur…’

As both include the words ‘at sea’ or ‘open sea’ it is not unreasonable to suppose that they imply freedom to manœuvre under own power unhampered by depth of water or similar navigational restriction.

This being so, and not an irrational definition of the area of concern to the Working Party, what are the facts and how exactly do casualties at sea compare with those in other areas of marine interest throughout the world.

To find the right answer to the global problem is not easy and there are no short cuts, such as for example making a sample analysis in a limited area where traffic density is high, in order to arrive at fairly large numbers which are then used to deduce the statistical probability applicable to all areas.

This paper looks at the navigational challenges faced by William Dampier when, as Captain of the Royal Navy ship Roebuck, in 1699, he approached, and then found his way along the coast of Western Australia (at that time known as New Holland). A discussion of the methods and instruments available to Dampier is followed by consideration of how, and with what success, he went about his task. Dampier's own account of the voyage was included in his book A Voyage to New Holland (Dampier, 1703) although this is likely to have been heavily edited, and perhaps even rewritten by a “man of letters” to make it more attractive to the general public. For this reason and, bearing in mind that autobiographical work may contain omissions or otherwise be slanted to show the writer in his best light, the navigational information in his book has been cross-checked with the Roebuck's original Master's Log, held by the UK National Archives at Kew (Documents ADM 52/94). Jacob Hughes was the ship's Master, but the Log entries were written in at least two hands.

The idea of incorporating radar systems into vehicles to improve road traffic safety dates back to the 1970s. Such systems are now reaching the market as recent advances in technology have allowed the signal processing requirements and the high angular resolution requirements from physically small antennas to be realised. Automotive radar systems have the potential for a number of different applications including adaptive cruise control (ACC) and anti-collision devices. This paper summarises recent developments in test methods that have been made to satisfy the compliance requirements for emissions and immunity.

A paper by Captain J. F. Kemp under this title was published in the April number of this Journal together with some comments on these proposals. Further contributions to the discussion and a reply from Captain Kemp are printed below.

In the April issue of this Journal Captain Kemp has put forward a carefully considered proposal for making the Rule of the Road more effective. His proposal is well considered because he is aware of the audacity which its careful presentation conceals; he is also careful to suggest a change in the Rules only as a basis for discussion. His suggestion is precise, for it is simply to extend Rule 18 to all encounters, or in other words to require both vessels, when crossing or overtaking, to rotate the line of sight in the normal direction as required in Rule 18.

At the present day European ATC is exercised by a multiplicity of more-or-less autonomous control centres. ‘Flow Regulation’ is used roughly to match traffic demand to the capacity of the en-route ATC and of the destination airport. The ATC authority at the point of departure for a remote destination cannot however give any guarantee that the pilot will be able to follow his chosen trajectory. The filed flight plan and the departure clearance have been described as a ‘licence to get into the sky and see what happens’.