More Wireless Services Wante col A Need That Is as Urgent as That for Aerodromes -Air-line Development Im
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prudent ithout Further Radio Facilities
IS it wise to allow a network of air services to develop in Great Britain without the provision of more wire less facilities? That is a question which a good many of the veterans of aviation, and quite a few newcomers, are asking as they read in The Commercial Motor each week of the several plans for air-line operation in the forthcoming season..
Wireless stations cost money to provide and to staff. The Air Ministry, which has established the services we now have (except the Heston weather broadcast, which it took over from the Automobile Association), naturally is reluctant to expend public funds on further Stations unless their necessity can be proved.
The point is whether the operators, for their part, ought to launch out on extensive undertakings without first making sure of the existence of wireless facilities adequately covering the routes they have in mind.
At present we rely principally upon stations at Croydon, Manchester (Barton), Lympne and Pulham. Croydon transmits and receives both telephony and telegraphy, broadcasts half-hourly coded weather reports, and has a direction finder and a beam transmitter. Barton has a new transmitter and direction-finding receiver,
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also a complete meteorological office. Lympne and Pulham are equipped for direction finding.
Additionally, Orford Ness has a rotating radio beacon which transmits the signal GFP at 8-12 minutes, 20-24 minutes and 56-60 minutes past every hour.
Heston transmits weather reports and forecasts at regular intervals. The Automobile Association started this useful service principally for private owners, air-taxi operators, etc., using aircraft equipped with only reception sets. As the broadcast gives latest Air Ministry reports of weather on the main air routes, its value has become sufficiently general for the Ministry to take it over.
We have a lot of fog and low cloud in and about these islands, especially in the winter months, and it drifts, forms and disperses very quickly and in an extremely local manner. We have. also a number of hills and areas of high land rising to 1,000 ft. and more above sea level—i.e., to heights at which much flying is done—and it is . necessary to give these a wide berth during periods of poor visibility.
Wireless, as we know it, does not appear to be the ultimate solution to flying in cloud. Some invention to enable us to see through cloud seems to be called for (perhaps on the lines of infra-red photography). At the present time, however, wireless is working wonders on the Continental routes from Croydon, and it could be developed to help internal air routes.
In foggy weather the pilot wants to • he able to fly to his destination, also to know the visibility conditions there and at alternative landing grounds. Wireless can supply both these needs, but it is clear that if, at the present time, many more of our commercial aeroplanes should be equipped with reception and transmission sets, the ground stations in existence would, on bad days, be congested with calls.
At present, wireless apparatus is demanded on every public-transport machine capable of carrying more than nine persons, including the crew. The Ministry, if it thought fit, could tighten the regulation, but it certainly seems that, to judge by the air-line plans at present in contemplation, serious congestion would soon arise if station extensions or new installations were not effected.
Sites for New Stations.
Until traffic has taken on a different character, transmitting and receiving stations with direction finding equipment located at a few more of Britain's key positions, such as Inverness, Glasgow, Hull, 'Belfast, Cardiff and Plymouth, would effect the necessary improvement. Transmitting and receiving sets on the aircraft would be necessary, and indeed it must become more and more evident to commercial operators that for serious air-line work this provision becomes a pressing need. The weight of a Marconi AD6n set is about 100 lb. The Standard ATR4 set weighs about 70 lb.
Radio beacons, such as are used on the long and well-defined American routes, and which can be worked auto matically, would serve to give bearings and could be used by aeroplanes having only receiving sets. Although such beacons certainly would relieve the congestion caused by having to assist each machine home individually, they would not tell the pilot what the weather was like when he got there.
Direction-finding ground stations, on the other hand, which, when asked, can give a pilot his bearing and tell him weather news, are a great help tothe well-equipped aircraft., Telegraphy and telephony are both available, and many consider the more urgent need (generally) as things are at present is for telephony. It is often more troublesome when a station is congested, but it meets the practical needs of the pilot who bas no wireless operator on board. Telegraphy is likely to lead in the long run, being more efficient in speed of working and the avoidance of interference.
A simple and light attachment for aircraft receiving sets is the Marconi homing device, as fitted on Imperial Airways Atalanta. machines. The weight is only 13 lb. and the device saves the need for extra transmission.
It enables a pilot to keep his craft headed towards any recognized trans mitting station, such as any B.B.C. broadcasting station, any of the 23 odd coastal beacons (for ships), or any of the numerous G.P.O. coast stations which communicate with ships.
The direction finder, as an attachment to a modern receiving set, weighs 17 lb. It also saves transmission and is in many ways ideal, but it Calls for a Separate operator, whereas the homing device can be worked by the pilot.
London's Own Problem.
In the London area, with, perhaps, six aerodromes in use, on a-foggy day a year or two hence one can anticipate interference of wave lengths, and possibly a series of low-power automatic beacons, giving hearings only, would serve the purpor better.
It is clear, however, that the prospects of such air routes as those crossing the Irish Channel, the Jersey line, the lines planned to connect Scotland with the South and the Hull connections, would be greatly improved straightaway if telephony stations with direction finding were installed at the key aerodromes instead of our relying on only Croydon, Manchester, Lympne, Pulham, Orford Ness and Heston.
In fact, as we stated at the opening of this article, it is doubtful whether it is wise to delay the installation of two or three of the more urgently needed stations, in the face of the development that is taking place in the North and elsewhere.
• The Air Ministry is now studying the problem of installing a few more stations, some of which might be of a semi-mobile nature, in case the traffic routes change. The Ministry is hampered by having to provide for all aircraft needs (civil and military) within a wave-length band of 938-822 metres.