AVIATION

Stratford Evening Post, Issue 34, 12 February 1929, Page 8

AVIATION

AERODROME REQUIREMENTS!.

OFFICIAL DEFINITIONS

The following deJiniti'ons regarding construction of aerodromes are taken from the notes prepared by the Air Branch of the Defence Department, and l'crwarded to the Stratford Chamber of Commerce by the Minister of Defence (Hon. T. M. Wilford):

Landing Strip.—A landing strip

is an area at least 450 feet wide, forming part of an aerodrome, and which is suitable, by natural conditions or artificial construction for

the landing or taking "off of aero-

planes. Runways.—An artificial landing strip or portion theer'of. When the natural condition of the ground is unsuitable for regular Operation of aeroplanes, artificial preparation with somo material which will present a satisfactory surface under

any weather conditions, is necessary. The artificial runway may be laid down upon a landing strip, but it need not cover the entire area of the landing strip. Runways should n'ot be less than 100 feet wide. DIRECTION OF LAMING. Aerodromes are called two-way, four-*'way, six-way, all-way, etc., according to the number of directions in which aeroplanes may land

and take off. A ground which permits landing along its longest dimension 'only is a two-way aerodrome, as it may be approached from'only two directions. A ground crossed by diagonally by two landing strips permits of four-way landings. A triangular aerodrome having landing strips parallel with its sides is a six-way gipund. The ideal aerodrome is one of which the entire area is available for B landing and taking off in' all directions. Such a ground is called an all-way aerodrome.

Location.—To serve a given urban 'area, an aerodrome should be within the shortest pssible distance from the centre of that area, and the means of communication with the area should be the best the circumstances permit. Exposure—An aerodrome should not be s'o located that it is exposed to abnormally irregular or violent winds or squalls. APPROACHES. > Clear approaches.— Aeroplanes should be able to approach easily and safely," gliding at an angle of 7 to 1, from all directions. The presence of any obstacles on the boundary line reduces the available landing area hy a distance equal to -seven times the heights of the obstacle. : . !;•!''(]

Size of aerodrome. —At a public aerodrome the circular area available for tbe landing and taking off of machines should not be less than 440 yards in diameter, and it is desirable that, if possible, it should provide clear runs of approximately COO yards in the principal directions due to prevailing winds. Since it is usually "difficult and costly to expand small landing grounds, and as the larger modern passenger aircraft require a run l of approximately 800 yards, it is advisable in selecting a site that future developments and requirements should be borne in mind, and provision made to enable an aerodrome suited for present-day demands to be enlarged if and when necessary. Trees may be cut down, depressions filled, and mounds levelled, etc., but real estate developments ' and neighbouring bills and streams may prevent ex-

pansion. SHAPE AM) SURFACE. Shape and surface Of landing areas.—The ground surface should tie smooth, both within the actual landing area and in any area lying between it and the hangars or any other point to or from which machines may require to taxi. The surface should also, within nattow limit's, be level. Th e mean slope •>f tbe surface should not be more ban 2 per cent.—in no part should any slope exceed a maximum of 21 per cent. Changes in grade should he infrequent, and transitions fr'om gradient to gradient should in all cases be very easy. The quality of the surface should be such that it is sufficiently firm to support the ■weight of a machine on its landing wheels without undue displacement in any weather and in any season. It should not, however, be of such a nature as to pulverise easily, since wind-borne dust is likely t'o injure engines. Hard grazing land, with a. sub-soil of a porous nature, causing it to dry readily after rain, is to bo preferred. Where tbe nature of the surface of the aerodrome does not. permit of the entire area being used for landing or taking off, landing strip* t runways should be artificially constructed.