HC Deb 21 June 1951 vol 489 cc859-68

Motion made, and Question proposed, "That this House do now adjourn."— [Mr. Wilkins.]

11.20 p.m.

Mr. John Grimston (St. Albans)

In the early days of railways and roads rules had to be formulated for the safe operation of the new forms of transport. Aircraft control has now reached a stage where similar rules must be put into force to ensure the safety of air travel, and in this connection I wish to discuss for a short time a signalling system whereby aircraft entering a congested area, or flying on a busy air thoroughfare such as leads to and from London, can do so quickly without danger of collision in any weather conditions.

It is right that at the commencement of a new system of this kind we should broadly review the experience so far obtained, because we are to a large degree pioneering in this field. The problem is very much more complex in the case of aircraft than in the case of railway or road traffic, because, among other reasons, the aeroplane cannot stop when it gets into doubt or difficulty. In this country we have, the worst weather in the world to contend with, we have the first jet air-liner with its special problems; we have aeroplanes flying into congested areas, such as London, with varying ranges of speeds, from the helicopter with a zero speed at certain times, to piston engined aircraft ranging from 150 m.p.h. to 350 m.p.h. and the jet airliner with speeds of 500 m.p.h. or more. In a short time it is impossible to cover more than a few of the problems that confront us, and therefore I will refer to only two specific aspects—the strategic and the technical or tactical. There are two main methods by which one can control or signal aircraft. One is the positive method: the other is the supervisory. Carrying the analogy to the car or railway, the railway train is controlled entirely by the positive method. It is controlled by visual signals at every few hundred yards. Its direction is controlled by the rails and its speed by the rate at which it passes each signal. Supervisory control is where a motor car is driven on the left of the road. This is the rule of the road, and it is assumed that if one is conforming to the rule it is reasonably safe.

The American solution to these controls is to adopt the positive control at an early stage in approaching a congested area. This means there is great disadvantage for the operator of the aircraft, for the pilot and for the Government. The operator must accept a heavy burden in the equipment that such a system entails. The pilot must be au fait with an extremely complex organisation, with its risk of mechanical and human failure always inherent in it. Consequently, from the operator's point of view, positive control has much against it.

From the Government or political point of view, it is a very expensive matter, and no doubt Ministries, whatever their political complexions may be, will always be under great pressure to cut their expenditure. Despite the American solution, which is bound to have great effect on our policy, I believe that positive control should apply only in the final stages of the aeroplane's approach to the landing ground and that we should devise a simple, safe and cheap system of our own based on radar supervision.

The first step is to invest air traffic controllers with much stronger powers than they have at the moment, to empower them to refuse to accept, except in emergencies, aircraft which are unable to conform to their pattern. At the moment, these controllers have not these powers and must therefore accept, for example, an aeroplane flying into London which is determined to use some obsolescent procedure of its own which will involve considerable delay. This delay, which must inevitably take place in these circumstances, means that possibly 30 or 40 airliners following during the next two hours or more will be delayed and the whole traffic pattern upset. Therefore, I think that much stronger powers must be put into the hands of air traffic controllers.

As a corollary, I think that the procedures at present in operation, both by air traffic controllers and aerodrome controllers, are capable of simplifications, some of which I shall mention later. From the strategic point of view, it should be a maxim that nothing should be said over the radio-telephone which could have been said verbally or by land telephone line beforehand, or which could be signalled by visual signals at the end of the runway, or taxi or perimeter tracks, and so on. It is still possible when flying round London to hear people ordering taxis or meals, or dating girl friends and that sort of thing, on operational V.H.F. frequencies. It is the cluttering up of these radio frequencies which is imposing great strain upon the capacity of aerodromes to cope with the present situation.

Let me turn for a moment to some of the more technical or tactical points. The present system falls easily into two parts. The first part is the actual airway or corridor itself; and the second is the method of approaching the aerodrome. Whatever system of final approach is adopted, the new projection of airways or corridors along which aeroplanes fly has in my opinion come to stay. These corridors extend from one reference point to another, and flying along them is simple.

But four points of principle ought to to be put right. The first is that no point of an airway should be below ground level. If one is in an airway, one wants to find some air. I have pointed out to the Parliamentary Secretary one instance where an airway passes through the top of an extremely dangerous mountain, which is well known to all aviators in the north of Scotland, into which many aircraft have flown with fatal results.

The next point is that no airway should pass through a danger area. There are three cases where existing airways do this, and there are three cases where projected airways pass through live danger areas. The third point is that the reference points of the airway should be such that, particularly at times when the greatest accuracy and concentration is required from the pilot, the method of presentation of the reference point should be as nearly automatic as possible. It should not involve a lot of manual juggling as does a certain kind of point represented by what is known as the Kilburn intersection in London and the Dalry one at Prestwick. There, the operator, to find his position, must be continually switching about to find where he is when his attention is wanted on his instruments.

My fourth point is that a solution has still to be found to the practice which permits R.A.F. jet fighters to cross these airways without prior permission. In this connection, the present compromise is better than the original position, but I should like the Parliamentary Secretary tonight to say that he can give an assurance that that point is still very much to the fore in the mind of the Ministry.

So much for the airways themselves, which are already reasonably simple; but not so simple a matter is the entering of a zone such as that around London. These airways should, in my view, stop at an outer circle surrounding London which would form a waiting zone for aircraft wishing to enter the London zone. Inside this outer circle should be an inner circle around which there would be one-way traffic flying at one speed only.

To use the car analogy again, let us imagine Ludgate Circus with no traffic lights and with heavy traffic going by at a minimum speed of 30 miles an hour and all the hazards of vehicles passing to and fro at all speeds in a criss-cross pattern. My solution is to have a large roundabout instead of any direct right-angled crossings. This system would mean that an aircraft approaching London would be free to come in at its designated height to one of a number of holding points in the outer circle.

One series of radio messages would authorise a pilot to leave this position at a specified time and join the inner circle or one-way traffic lane around London. As all aircraft in this ring would fly at one specific speed, the pilot could turn off the ring with no risk of collision and land direct at his destination with no further messages. Among other things, this would greatly reduce the number of radio telephone messages that it is now necessary to give. The effect of freeing these radio channels would be greatly to economise the cost both to the operator and to the Ministry.

Let me mention that three years ago it was possible to fly round London with one frequency, two years ago with four, but that now one has great difficulty on ten channels. One can hardly get around on those, but sets are being built with as many as 140 channels. While on the question of V.H.F. frequencies, there is one other improvement which needs to be made, and that is to provide one special frequency to cover the whole country and, if possible, the whole of the Continent, which light civilian aircraft could call their own.

There should be a special corridor for jets; this would be a further advantage of my one-way system of traffic around London, and could be very simply introduced. This problem of handling jet civilian airliners is a very real one and ought to be overcome. The Comet for example, if it goes into service on the Atlantic, may very well start its approach to London Airport miles west of Ireland. The need for exact timing is very great, because a jet aircraft has very little reserve of fuel at low altitude and must, therefore, land almost immediately on its arrival.

To sum up, therefore, we have too many competing systems of control in operation at the moment, with the result that the expense of air travel is rising to the consumer and to the Government, and the complexity of the equipment needed is imposing a serious burden on the operating companies and on the aircrews. We need to define again the system we hope to see in operation in five years' time, which should be basically that the aircraft is responsible for finding its own way, subject to radar surveillance only, to a particular point to which it has been permitted to fly, and that when it gets there at a specified time it should join a simple roundabout system of one-way traffic, again subject to radar surveillance, so that the only positive control, which is an expensive one, that the aircraft need be subjected to is on the very final part of its approach to the aerodrome in bad weather.

11.36 p.m.

The Parliamentary Secretary to the Ministry of Civil Aviation (Mr. Beswick)

We have had most interesting and informed observations from the hon. Member for St. Albans (Mr. Grimston); indeed, in one sense they were too well-informed, because he touched upon such detail that I really felt we should be better employed around a committee table discussing them than in this Chamber. The hon. Gentleman himself said how complicated it was trying to sort out the traffic in our skies, but when he went on to give some of his own simplified suggestions, I think, that if we really got down to it with a map and considered all the details he would see that the so-called simplified one-way pattern, which has been put up to us before, was so complicated that the delays and the dangers its details would involve would mean that the simplified roundabout system he described is no better than the system we are developing at the present time.

However, we appreciate the hon. Gentleman's comments and his criticisms. We will look at them. I do not know of any Government Department that has taken such trouble to consult the industry, the organisations, and the representatives of users than my own Department of Civil Aviation. What we have done has received the agreement of these different organisations, and from time to time we review progress, invite criticism, invite complaints, and we have meetings to consider in what way we can bring about developments and improvements in the present system.

Within the short time available, I will try and deal with some of the detailed points the hon. Gentleman raised, of which he was good enough to give me some prior notice. His first complaint was that although we have consistent minimum heights for airways throughout the system there are odd points on some of the airways at which the lowest safety height is above the minimum airways height.

In particular, the hon. Gentleman asked me why we do not avoid a certain area in the Isle of Arran as well as certain danger areas in the other airways systems. The fact is that to get a pattern of airways which is at all straightforward, which avoids all danger areas, all moun- tainous areas, all defence aerodromes, and so on, would involve such a zig-zagging business that it would nullify the whole airways system. If the hon. Gentleman tried to draw a straight line across our comparatively small country to avoid all these areas he would find it was not practical planning.

We have tried to avoid the danger areas as far as possible. The Service Ministries have given us the fullest cooperation, and in some cases have moved their areas of operation or closed them down altogether. In those cases where it is necessary to pass over a danger area every precaution is taken to ensure that the pilot is aware of the safety height, and in the case of firing areas the air traffic control centres have contact with the firing control centres to ensure that firing is reduced to a minimum or stopped altogether when an aircraft is actually passing overhead.

With regard to the Arran spot height about which the hon. Member was asking, the airway takes the direction it does in order to pass over a point on which it is possible to erect a radio beacon—that is, in fact, the only practical site for providing a beacon. If we were to increase the minimum height for the entire airway it would raise certain difficult problems of control. The only way of providing control whilst the aircraft were climbing or descending to the minimum safety height of 4,500 feet would be by considerably extending the aerodrome control areas, which in this particular case is not possible for various reasons.

The hon. Member also pointed out that the spot height is not shown on the procedural map, but the document to which he refers is a diagram; it is not a map, and spot heights are not normally shown. However, I can see the difficulty to which he calls attention, and I will see if it is possible to publish these documents with a clear indication of the minimum safe cruising altitude where that is higher than the base of the airway. I hope that that will meet the point he has raised.

Then there is this very important new problem of fitting jet aircraft into the present airways pattern. When the present system was drawn up we had very closely in mind the difficulties that would arise when jet aircraft came along. We have now had a fair amount of practical experience. The operators and the manufacturers have given valuable co-operation with trials and experiments with both the Viscount and the Comet, and so far it does seem that there will be no difficulty in controlling the jet machines.

Some adjustments may of course be necessary, and there will have to be some improvements in certain equipment. What we shall need is the closest liaison between the Uxbridge Control Centre and the Radar Unit at London Airport. What I think we shall eventually achieve is a liaison to the point of complete integration, probably on the one site of the Uxbridge Control Centre and the Radar Unit at London Airport. I hope very soon that we shall be able to announce plans for a completely new and enlarged Radar Unit at London Airport.

I think the hon. Member spoke rather too optimistically about the possibility of simplifying V.H.F. frequencies. If by that he means reducing the number of frequencies, I am afraid he is overlooking the ever-increasing number of functions and services which have to be performed by radio. No one would be happier than we would to reduce frequencies, because the ether space available to us is so confined for the elaborate and manifold aids, services and communications which we have to provide that we have considerable difficulty in pressing them into these confined bands.

I do not quite follow what the hon. Member had in mind in talking about a common V.H.F. frequency for light civilian aircraft, though I do sympathise with him in his desire to reduce the weight of equipment in light aircraft and to simplify the work of the private flier. We just could not afford a separate frequency for the private flier at airports catering for different categories of fliers. What I think we might do, and what I think we should consider, is having a common frequency for those aerodromes which cater only for the private flier and light aircraft. Even there, if aerodromes were fairly close together we should have to consider the problem of interference of one with the other.

As regards the Kilburn intersection, we have got a traffic junction at Kilburn. People do not realise the very important spot above there. It is rather difficult to mark it out, and we should like a beacon. We have not a frequency for the beacon, and in any case there is difficulty in siting it. I hope we shall solve that in the course of time, although, as I say, I think the hon. Gentleman is exaggerating the problems that arise.

I was asked what progress has been made in keeping military aircraft, especially jets from public airways. We have an agreement with our Service colleagues that military aircraft not covered by radar surveillance will cross the airways at right-angles and at the appropriate quadrantal heights between 3,000 and 5,000 feet. There is no intention of changing this arrangement. If any progress is to be made it will be in the direction of ever-improving discipline, and if there are any specific examples of trouble of which the hon. Member can give me details I will have inquiries made.

Those are the detailed points that I understood the hon. Gentleman to make. If I have missed any points, perhaps he would be good enough to write to me. I will have a look at his speech in HANSARD tomorrow and follow up anything I have overlooked. I would say in conclusion that I am not complacent about these airways that we have developed. On the other hand I do feel that what we have achieved so far is something which stands to the credit of those officers who have been responsible for their creation.

One reason why the airways have achieved the undoubted success that we can claim for them has been because so much trouble has been taken in consultations and discussions with the users. In about a month's time we shall be having another full meeting with all the users concerned as to the extent of control which should be exercised over pilots of aircraft passing along these airlanes. It was not so very long ago, as I remember very well, that there used to be strong protests if anyone suggested that there should be any control of the pilot from the ground.

That state of affairs is passing, and the most interesting and healthy development is that some of the pilots are now asking that there should be a closer and, as the hon. Gentleman described it, more positive control, certainly along, these congested airways. That is a good thing. It may be that we shall be criticised for not going quickly enough, but we have been very anxious to carry the pilots along with us. I think that we have had great success, and if we listen to the kinds of constructive suggestions made by the hon. Member and others we shall, between us, develop a traffic control above our skies which will be to the credit and ensure the safety of all concerned.

Question put, and agreed to.

Adjourned accordingly at Twelve Minutes to Twelve o'Clock.