Air Safety Regulations (Report) (Hansard, 24 October 1956)

§ Mr. Birch

Yes. The findings are summarised below.

Civil and military air traffic have the same fundamental interest: to fly safely and without delays. Military traffic, however, in addition to requiring freedom of movement from place to place, requires also as much freedom of manoeuvre as possible in order to enable operational and flying training to be carried out economically and efficiently. Research establishments and manufacturers also have special problems.

34W

It would theoretically be possible to ensure safety from risk of collision by controlling all aircraft from the ground at all times. But at present neither the Air Traffic Control Organisation nor all aircraft are equipped to provide such control. In clear weather, therefore, the responsibility for avoiding collision must for many years remain largely with the pilot, as is the practice throughout the world. Nevertheless, certain changes in the rules governing flying in dear weather have been found desirable.

The principal change is that a more stringent definition of what constitutes clear weather flying conditions has been adopted. The pilot will now accept primary responsibility for avoiding collision only if visibility from his aircraft is at least five miles and the aircraft is 1,000 feet vertically, and one mile horizontally, clear of cloud. Previously the corresponding figures, which are still accepted by the International Civil Aviation Organisation, were 3 miles, 500 feet and 2,000 feet. My right hon. Friend the Minister of Transport and Civil Aviation and I believe that the introduction of these clear weather minima is the most important immediate step which can be taken to increase aircraft safety.

Arrangements are also being made to require pilots flying along airways in clear weather to file a flight plan and periodically to report their position. The Air Traffic Control Organisation will thus be able to pass on essential traffic information to the pilots of other aircraft on the same airway. The rules governing the crossing of airways in visual flight conditions have been made more stringent. Civil aircraft will be required to notify their intention to cross airways and will do so only in level flight. Other traffic will be informed of these crossings by the Air Traffic Control.

For practical reasons, including the limited control capacity available, it is not possible to apply the same rules to pilots of military aircraft, but such pilots have for a long time been forbidden to carry out aerobatics in controlled air spaces. This rule has been amplified to include all manoeuvres which might reduce or obstruct their view. Aircraft having to fly through control zones will avoid areas of special danger such as holding areas, and approach and take-off paths. The Inter-departmental Committee which undertook this review has 35W recommended that measures should be taken to make aircraft more conspicuous by day as well as by night, e.g., by the careful choice of colours, and that there should be an immediate study to decide what constitutes the minimum acceptable field of vision from aircraft cockpits.

With the adoption of the more stringent definition of what constitutes visual flight rules, the number of occasions on which instrument flight rules will apply will be increased. The Committee examined fully the conditions governing flying in instrument flight conditions and concluded that they were satisfactory except in relation to the present rule which in certain circumstances permits military aircraft to cross airways at specified heights without air traffic control clearance. They consider that as soon as the necessary ground and air facilities can be made available the aim should be to require military aircraft to obtain clearance by one of the following methods before crossing an airway:

(a) by a military ground-controlled interception (G.C.I.) controller when the aircraft is flying under direct G.C.I. control;
(b) by a radar controller from an air traffic control unit;
(c) by an airways controller at an air traffic control centre;
(d) where the above methods are impracticable, by reservation of defined portions of controlled air spaces for military aircraft.

The Committee recommend that the upper limit of airways should be raised to provide adequate controlled air space to cover the altitudes predominantly used by transport aircraft. They also recommend that all aircraft intending to fly in the vicinity of controlled air space should, unless under radar control, be able to fix their position by means of aids or by visual reference to the ground.

My right hon. Friend and I accept the recommendations in the Report. The new visual flight minima and the restriction on manoeuvres in controlled air spaces are already in force: the remaining changes are in process of negotiation with the other interests affected. In particular special consideration will require to be paid to the needs of manufacturers and research establishments testing aircraft under development.

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It is clear that apart from measures already adopted the main hope of improving the safe and expeditious control of air traffic lies in the greater employment of radar, and an examination has begun to see what additional radar units require to be established. Planning for this has been in hand for some time but it will be some considerable time before the full radar cover ideally required can be provided, and research is needed on the problem of how best to present to air traffic controllers the information given. Meanwhile the changes which have been introduced or which are in train as a result of this review will result in higher safety standards.