Already wireless is playing an extremely important part in connection with the smooth and safe operation of the commercial aviation services of to-day and it is evident that the present-day trend is to place more and more reliance upon wireless aids for the achievements of that regularity of service in all weathers, which is looked upon as necessary for the ultimate success of truly commercial aviation.

It seems therefore desirable to review at the present juncture the functioning of wireless communication and direction finding systems as used by the commercial air services; to consider some of the problems with which designers and operators are faced, and to bring to light the limitations and possibilities of this medium of communication and direction finding, both in respect to present and future requirements.

These notes are an attempt to examine what may be achieved in the way of performance, with existing materials and knowledge of aerodynamic engineering.

No claim is made for novelty, either in the data used or in the methods of working from such data to obtain the results arrived at.

Only the simplest engineering mathematics are employed so these results cannot claim academic accuracy, in fact they are most probably considerably inaccurate. But though inaccurate absolutely, the results should be accurate enough relatively for comparative purposes.

Full details of the methods employed are given in the various Appendices. This appears advisable, as it should make quite clear how the results are obtained and leaves it open for anyone to work out further examples by the same methods or to modify the methods themselves.