Before an aircraft is given its Certificate of Airworthiness the aircraft constructor has to satisfy the Air Registration Board that the standards laid down in the British Civil Airworthiness Requirements (B.C.A.R.s) have been met. However, if you go to B.C.A.R. and try and find something under Instrument Approach Criteria, you will be unlucky. This is because the requirements for low weather minima and blind landing operations are still in the form of A.R.B. Technical Notes and working drafts. This state of affairs has come about because of A.R.B.'s reluctance to become bureaucratic and devise arbitrary rules and regulations concerning an operation as new as automatic landing.

The following article is a summary of a paper presented by the author to a meeting of the Liverpool branch of the Institute on 26 January 1968.

Many people believe that there is a compelling need to discuss much more seriously than we do the whole way ahead into a new era in the conduct of ships; to scale the heights that lie above the chaos of detail and the log-jams of orthodoxy, and to discover where the truth is most likely to lie in this respect, for obsolete thinking is far more harmful to progress than obsolete equipment and this thinking, therefore, can often become a dominant factor.

For some years the principal maritime nations have provided sea-going and future Masters and mates with some form of radar simulator training. These training courses, although differing in duration, subject material, training method and technique, had one common aim: to familiarize responsible sea-going personnel with radar as an instrument. They taught understanding of the various instrument controls, picture or display interpretation, plotting and anti-collision tactics based on the existing international Rules of the Road and Admiralty Court jurisprudence: and all this for open-sea conditions where the Master is sole master of the situation and with no outside adviser at his disposal. Many Masters and mates have followed these very necessary and useful training courses and many more will undoubtedly follow, for nobody should today go to sea in a responsible position as Master or officer of the watch without such training. Recently, pilot authorities have started to send their pilots to the same courses and again this is a step in the right direction.

A recent survey by Burger and Corbet (Welsh Institute of Technology) has furthermore shown that those trained do not seem to obtain full advantage of the acquired knowledge, once they are back in actual practice. This fact plus the fast technical advances in electronics and consequently new radar techniques should eventually lead to the institution of refresher courses.

It is not often that a drama of the sea provides the main story in the news, and it is still more unusual for such an occurrence to continue to occupy the headlines; but the Torrey Canyon disaster was unique in having done this for a whole month and more. Day after day, there was a slow and inexorable increase in the area affected by the catastrophe and in its duration: while such protective measures as could be improvised could seldom do more than repair damage that it was impossible to prevent.

The increase in the size of ships is no new phenomenon. The nineteenth century saw a greater revolution in ship-building than that which we are now witnessing. In construction, wood gave way to iron, and in propulsion steam took the place of wind. These changes were not made without provoking a conservative reaction: when Admiral Courbet, then still a young officer, prophesied the end of sail he became the target of much sarcasm. His opponents could not admit that a free source of motive power could ever be abandoned. Everything that is really important and new begins by being regarded with a mistrust that is eventually swept aside: once the possibility of doing better than before exists in fact, no obstacle can stand in its way.

The sea imposes little restriction on the size of ships. Unlike roads, sea routes are not confined within dimensions which limit the dimensions of the traffic they carry. For ships, restriction comes in at each end of the route, in ports, where the depth of water limits their draught. In consequence, we have seen the size of ships increase, during the last decades, in two specifically characteristic ways.

The paper describes a method by which ‘history’ in the form of tracks of all vessels appearing on the PPI is projected on a flat plotting surface, and the use that can be made of such information to ascertain either the true or relative tracks of all such vessels and also the effects of own ship alterations of course or speed or both on the relative tracks of other vessels.

In a recent survey of collisions and from experience on board ships it has been found that, in heavily congested waters and low visibility, even vessels with sophisticated radar equipment and associated plotting facilities and sufficient personnel may find themselves ‘saturated’. Vessels with simpler radar and plotting facilities and less staff consequently become saturated in less heavy traffic conditions.

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.

A method of measuring wind variations along an aircraft glide path is described. The technique uses a ground-based pulsed doppler radar to measure the line of sight velocity of precipitation particles. At low angles of elevation this velocity is that of die horizontal wind component toward the radar.

Wind variations likely to be encountered by an aircraft as it lands or takes off from an airfield are estimated almost invariably from a nearby anemometer placed 10 m. above the ground. It is obvious that this wind is not fully representative of conditions at higher levels; however, winds other than near the ground are difficult to measure. This note describes a method of measuring the line of sight wind using a pulsed doppler radar and presents some observations of the wind variation along a path at an elevation of 3°, which is typical of the glide path of many aircraft. These winds are compared with those recorded by a nearby anemometer.

An area navigation capability can be of considerable benefit to users as well as providers of ground facilities. A.T.C. radar terminal service and area navigation utilizing cockpit pictorial displays are complementary from a total system viewpoint. Pictorial displays, coupled with digital computers capable of storing navigation information, will greatly reduce pilot workload. Optimum usage of A.T.C. radar service and cockpit navigation will provide maximum redundancy at least total cost and reduce controller workload.

Pictorial computer procedures will have many applications of benefit to high density terminal areas, such as (1) departure paths from a satellite airport, (2) descent paths from high altitude to a terminal area, (3) missed approach patterns, (4) approaches to satellite airports, (5) simplified holding procedures, and (6) discrete paths for descent corridors. Procedures are expected to be developed as a result of a full-scale Federal Aviation Administration operational programme for selected en-route and terminal areas permitting use of area navigation facilities, using F.A.A., airline and general aviation aircraft in a live A.T.C. environment.

In the sixteen years since the last paper on this subject was published in the Journal (1951, 4, 288), some notable changes have taken place in the design and capabilities of submarines. Nautilus, the world's first nuclear submarine, was laid down in 1952 and completed in 1955. Since then a further 120 nuclear submarines have been commissioned. Now, a large proportion of the world's submarines are ‘true’ submersibles, self-sustaining over periods of months in everything except food; capable of proceeding submerged faster than the average surface ship; and rarely requiring to surface or even to come to periscope depth.

In this paper, which appeared in an earlier version on the back of a U.S. Naval Oceanographic Office pilot chart of the North Atlantic, the author first of all examines the causes of groundings; four typical cases are then described and analysed and lessons drawn from them. Finally, conclusions are drawn about the human behaviour patterns which lead to grounding, suggestions made about the effect of these patterns and the mariner's mental and physical fitness.

There is an urgent need, both at international and national level, for more operational research into marine traffic and the associated collision casualties. At the present time marine traffic research is in its infancy and official analysis of collision is on a national basis with few attempts to correlate the two together and on an international basis. Without this basic information and research on the traffic and accident pattern, it will not be possible to plan effectively to reduce the high cost of collision casualties to ships' operators and to make the necessary improvements in safety over the next decade. This decade will see increasing carriage of dangerous cargoes in bulk, a continual large increase in the number of pleasure boats and the current trend of increasing numbers of merchant ships, fishing and other work-boats will probably continue. Due to this large increase and the trend to mammoth ships, the effective amount of sea space is being rapidly reduced and traffic control is inevitable in some areas.

In this paper, presented by the International Air Navigators Council, and written by its Executive Vice Chairman, the navigation of the S.S.T. is considered from the practising navigator's point of view. Extrapolating from present procedures the conclusion is drawn that navigation system verification should continue to be the responsibility of flight-deck management, that self-contained D.R. systems should be monitored by an externally referenced aid, that raw navigational data should continue to be available to the flight crew and finally that simplicity and reliability in navigation systems should be preferred to finite accuracy.

Consideration of an environment in which operational data and experience are limited to the military is a difficult assignment at the best of times. In order to discuss, with some degree of intelligence, the long-range navigation system considered desirable in the supersonic environment, we have relied mainly on the process of extrapolation using existing data and operational ‘know how’ to formulate practical guidelines.

The practical feasibility of blind take-off, landing and rolling to a stop has been adequately demonstrated, and both ground and airborne facilities are now being provided which will permit its progressive implementation operationally. Thus, one of the major questions remaining to be answered is the extent to which supporting airfield facilities are required to be improved in order to match the landing capability.

The present paper represents a contribution to discussion of the problems involved in ensuring that airport ground movements of both aircraft and vehicles can continue efficiently, and of the various measures which can be taken to minimize these problems. The conclusions drawn represent the opinions of the Blind Landing Experimental Unit, based upon the limited information which so far is available on this topic, and thus do not necessarily reflect firm U.K. policy since this must involve further study and investigation.

This paper describes a radar technique developed in the course of practical experience in cross-channel ferries, high-speed very manœuvrable craft. The principles of the parallel index system of radar navigation are treated in the Admiralty Manual of Navigation, Vol. I.

A practical radio operator does not have to translate consciously the sounds that he hears into morse symbols and then into letters of the alphabet. In the same way an experienced radar operator can become adept at interpreting a relative radar display without actually drawing the vector triangle; the saving of time is important in multitarget situations. The emphasis in the system described here is upon the relative motion which is directly observed on the radar screen.

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.

As air traffic is expanding rapidly, more and more people are exposed to the possibility of accident. Although safety per passenger-seat mile continues to improve; because of the increasing capacity of aircraft this does not necessarily mean that the accident rate per trip follows the same pattern. The majority of accidents happen during take-off and landing but they are not necessarily associated with loss of life. The application of crash survival factors to structure and improvement in the restraint equipment for crew and passengers; the provision of rapid exit facilities and the reduction of the chances of conflagration have all played their part in improving the chances of survival.

Accidents involving collision with high ground on the other hand are almost always catastrophic and usually fatal to all the occupants. The statistics issued by I.A.T.A. show that some 40 per cent of all passenger deaths, in the airlines contributing figures, are due to this cause. Because of this it is imperative to consider every aspect of them that might lead to their reduction.

Delays in the terminal area lead to increases in the operating cost of the aircraft involved. We assess these costs as one criterion of the effectiveness of the air traffic system in the terminal area, and to give a measure of the desirable expenditure on methods of reducing delay (e.g. improved radar, additional runways or even an extra airport). This note discusses methods of assessing the cost penalty of delays exclusively to the airline operator and gives examples for three types of aircraft, a short-range subsonic jet, a long-range subsonic jet and a supersonic transport.

Terminal area delays occur essentially because aircraft apply for use of the runway, either for take-off or landing, in a random fashion and because the acceptance rate of the runway is limited by the need to maintain safe separation between aircraft on and in the vicinity of the runway. Such delays involve penalty to the aircraft operator in terms of extra time and fuel consumed and hence of extra operating cost.

Mr. J.G. Carr and Sq.-Leader D. Scott, R.A.F., have devoted sections two, three and four of a total of 21, and a few other remarks here and there in their excellent paper, ‘The testing of airborne inertial navigation systems’ (Journal, 20, 405), to the above title as an exposition ‘first necessary’ to their main purpose, limiting themselves to ‘the types of system of which we have practical experience’. They do not otherwise identify these types explicitly, but do include them among the ‘many ways of mechanizing this concept', viz., ‘The feature which is common to all inertial navigators is the measurement of acceleration of the vehicle by measuring [and in effect they add also “or metering”] the force required to constrain a proof-mass carried in the vehicle to move with it,’ and from this deducing velocity and position of the vehicle. This statement seems well put to me and quite sound, but in the fourth paragraph of Section 4, which includes ‘Fig. 1. A Schuler tuned inertial navigator’, they imply that at least their types, if not all inertial navigators, are based also on ‘Schuler tuning [so named] after the discoverer of the principle', and here I do not follow them. (I note in passing that the by-line of Schuler's 1923 paper, Physik. Zeitschr. XXIV, 344–50, spells his name without the umlaut used consistently by them.)