BLIND LANDINGS

Wanganui Chronicle, Volume 79, Issue 279, 28 November 1935, Page 5

BLIND LANDINGS

TRIAL OF RADIO BEACONS A wireless system to guide aircraft on to their landing-ground in bad visibility is to be set up at Heston airport, writes the aviation correspondent of the Times. It will be the fust of its kind in this country, though it was given a wide trial on German air routes last winter and will be test ed this winter at 19 European airports. It provides the pilot with a succession of benms which lead him down from a height of 600 ft. at a distance of 3000 yards from the aero drome to 45ft. at 300 yards, and finally to 25ft. at the aerodrome boundary. This enterprise of the authorities at Heston will require the interest of air operators and of aero-engine manufacturers if it is to be of anv value to British commercial flying. The system uses very short wave-lengths, and these are easily affected by the fields of force radiated by the ignition systems of engines. Careful screening is necessary before the method can be adopted. The receiving appartns, expensive under the existing cond’tions of import, is to be made in this country, and there rv y be some operators who will be ready to go to seme trouble and expense to test, for themselves the value of this device as safeguard against mishap or the cancelling of services.

The installation at Ileu.ton will be used as soon as it is ready, to introduce the system to British pilots and operators. The Deutsche I uft Hansa Companv has had about 50 of its aeroplanes equipped with the receiving apparatus, and arrangements will probably be made for them to visit Heston 0:1 demonstration duty. The installat’on w’U consist of a main beacon at one corner of the aerodrome and two marker beacons 300 yards and 3000

yards away respectively. The approach ing aeroplane may best begin to make use of the outer beacon at a rc.nge of ten miles, and thereafter aural and visual signals combine to keep the machine on the proper approach path. Method Of Approach Each beavon produces distinctivl signals in the cockpit and distinctive .indications as to the direction of any deviation from the true path. These affoid guidance in the lateral plane and provision is made for 'similar guidance in the vertical plane. The altimter is used to bring the aeroplane over the first marker beacon at about the p.oper altitude. Thereafter a verfval scale on the dashboard assists in the presentation of a regular rate of descent. When the aeroplane arrives over the outer beacon the position of the pointer against the vertical scale is noted and the pilot tries to keep it at’ that reading throughout his glide. There should not be any serious diffl cultv finding the beam. The marker beacons mav be n’uke<k up at a distance of about 500 yards on either side of the centre of the’r beams. Onee p'-’.ed up the path of the aero plane should not deviate more th**n three degrees on either side of the centre line, and this pt the boundary of the aerodro-me repre ents not n»or», than 150 yards on cither side of the beacon. In the Heston sot no attempt w H be mad n to guide thp aeronin t” right on tn the ground. It is intended to bring the aeroplane over the bonrdarv at a hn’ght nf 25ft.. If the pilot c-'iinot see the "round pt that he'ght. this particular instnllntmn can do nn mom fpp him. but jt w ;i l be no=siblp tn modify the apparatus for whollv blind landings if this s v »n”' , q be desired. The apparatus will be s«t n n bv th* eomnan- which owns the Brit’sh r’ghts in the Lorentz svstom, in aceordar*’»! with plans prepared bv Mr. Roderick Denman, technical director of air work, Limited.