The Act of 1920 asserts absolute sovereignty over all parts of His Majesty's dominions and adjacent waters, provides for the applica- tion of the Convention by Order in Council to internal flying, the regulation of civil Hying and the supplementing of the Convention, as necessary, by general safety regulations. It authorizes any steps to be taken for preventing aircraft from flying over prohibited areas or entering the British Isles in contravention of the law, and permits the extension of the provisions of the Act to British Possessions other than the Dominions and India. The Act also provides for the pro- hibition of all Hying, and the taking over of aircraft, etc., in time of emergency; the establishment and maintenance of aerodromes by the Air Council or local authorities; purchase of land; compulsory investigation of accidents; and penalties for dangerous flying. No action lies in respect of trespass or nuisance by reason of the flight of aircraft over any property at a reasonable height above the ground, or the ordinary incidents of such flight, so long as the pro- visions of the Act and Orders made thereunder are complied with, but where damage is caused by aircraft, damages may be recovered from the owners of the aircraft. The law relating to wreck and salvage at sea applies to aircraft in the same way as to vessels.
Administration. The methods of administration adopted in Great Britain in conformity with the Air Navigation Acts were probably, in 1921, in advance of those in other countries, but they might be regarded as typical of what would be required, at least in the near future, before aircraft could be operated by companies or private individuals in accordance with the terms of the International Air Convention. Their essential points are given below.
(i) Registration of Aircraft. Every aircraft must possess a certifi- cate of registration, which lapses on change of ownership.
(ii) Licensing of Personnel. For a private pilot's licence the Royal Aero Club certificate is accepted as a certificate of competency, the Club having agreed to bring their tests for this certificate into line with those laid down in the International Air Convention. A person qualified as an R.A.F. pilot is entitled to a private pilot's licence. For a licence to fly a passenger or goods aircraft for hire or reward an applicant must undergo a medical examination, pass certain practical flying tests and a technical examination, submit proof of reasonable flying experience within the previous six months on the class of machine for which a licence is required, and pass an exam- ination in navigation and elementary meteorology. In the case of applicants who are qualified as R.A.F. pilots the tests are limited to an examination in navigation and meteorology. Licences are issued for six months. There are five grades of licences for navigators. Aerial navigators, fourth-class, are licensed only to navigate civil aircraft over land by day, those qualified for the third-class certificate are licensed to navigate only over land by day or night, whjlst those attaining the higher classes are licensed to navigate over both land and sea by day or night. Licences for ground engineers, usually valid for twelve months, are granted for the inspection and main- tenance or overhaul of aircraft or engines.
(iii) Airworthiness. In order that an aircraft may receive a certificate of airworthiness, its design, including the design of its components, must be approved as satisfying the requirements of safety in regard to both strength and stability; it must be con- structed of approved materials and by workmanship of approved quality, and its engine must be approved.
In order that such certificate may be valid on any particular occasion the aircraft must be examined before flight and be periodi- cally overhauled by a competent person duly licensed; it must be so loaded that its total weight does not exceed a given maximum, and its centre of gravity must be situated within certain given limits. If the application for a certificate is in respect of a " type " aircraft, inspection is carried out by representatives of the Aeronautical Inspection Directorate, and, in addition, such drawings and par- ticulars are required to be furnished to the Director of Research, as will enable him to approve the design. In the case of " subsequent " aircraft constructed by a firm whose inspection is approved, sole responsibility lies with the Aeronautical Research Directorate, the constructor insuring that the conditions governing the inspection of " type " aircraft are applied to " subsequent " aircraft. A certificate of airworthiness is not valid unless the aircraft concerned is regu- larly inspected by a licensed ground' engineer employed by the owner of the machine.
(iv) Aerodrome Licences. The regulations for aerodrome licences are framed to insure that only those aerodromes which are safe for passenger work receive licences.
The dimensions laid down as a preliminary guide for the classifica- tion of aerodromes are as follows: 800 yd. run in any direction,
with good approaches, etc. Suitable for any type of aircraft.
Suitable for all but the larger types of aircraft, i.e. not suitable for H.P.V. 1,500.
. . Suitable as permanent aerodrome for aircraft of Avro 5O4.K or similar types.
600 yd
300 yd. by 400 yd.
300 yd. run in any direction . Temporary aerodrome for Avro
5O4K and similar types.
Any aircraft may use a licensed aerodrome of the appropriate class, subject to the payment of the landing and housing fees approved at the time of the issue of the licence.
GROUND ORGANIZATION
(i) Air Ports, (a) Aerodromes. The early aerodromes were usually any large, level grass fields, and the first real aerodromes were established in France, England, Germany and America. Their early equipment consisted only of rough sheds for aero- planes, and fliers carried out at the local smithy or garage such repairs as could not be done on the spot or in their own homes. Repair shops were only available at a very few of the military flying grounds. As aeroplanes became more numerous, work- shops equipped with power-driven machinery were established at large aerodromes such as Farnborough and Hendon, and the occupations of " aeroplane mechanic " and " aeroplane rigger " were defined. With the increase of flying, certain rules were laid down for the control of aerodromes; aeroplanes were not allowed to be moved about the aerodrome without ascertaining that they were clear of other craft alighting, and when in the air in the vicinity of aerodromes, were obliged to conform to circuit rules, i.e. machines were made to circle round an aero- drome in one direction, which was indicated by a coloured flag hoisted in a prominent position; and some form of indicator, such as a smudge fire, was used to afford pilots a guide to the direction of the surface wind.
From these simple rules, the complex system of aerodrome control which developed during the World War was built up. While the original principles of aerodrome management remained the same as in 1914, new inventions produced much greater efficiency. With the advent of night flying new methods of visual signalling were adopted (see below) ; the bucket flares, used at the beginning of the war to indicate wind direction, were replaced by electric lights or the " Money " flare; and a stand- ardized system was introduced to permit of machines leaving and arriving at an aerodrome in quick succession both by day and night.
The results of the experience 'accumulated during the war in the control of aerodromes were embodied after the war in Annex D of the International Air Convention.
According to the regulations laid down therein, every aerodrome consists of three zones looking up-wind: a right-hand or taking-off zone, a left-hand or landing zone and a neutral zone. At night the taking-off and landing zones are marked by white lights placed in the position of an " L," as shown in fig. 25.
LIGHTS
FIG. 25.
An aeroplane must land as near as possible to the neutral zone, but on the left of any aeroplanes which have already landed, and immediately taxi into the neutral zone. No aeroplane may com- mence to take off until the preceding aeroplane is clear of the aero- drome. A flag is hoisted in a prominent position to indicate whether an aircraft which finds it necessary to do so should make a left- handed (red flag) or right-handed (white flag) circuit. Aeroplanes must comply with this rule within 500-1,000 metres of the nearest point of the aerodrome unless flying at a height above 2,000 metres. The direction of the wind must be clearly indicated, and aeroplanes must take off or alight up-wind, those flying at a greater height being responsible for avoiding those at a lower. Aeroplanes in dis-
