The loss in efficiency which arises in connection with present aircraft designs has been dealt with very fully during recent years. It has been shown that the perfect streamline aeroplane would only have a drag of one-third that of a conventional machine. While it is improbable that this ideal design will ever be attained, considerable improvements can be made by refinements in design and careful revision of those items which are the cause of comparatively big losses.

Many attempts are being made to reduce parasitic drag and interference effects, for the importance of obtaining increased performance by aerodynamic cleanliness rather than by increased power is apparent.

Referring more particularly to the undercarriage component, it can be fairly stated that until quite recently the aeronautical engineer has been more concerned with the provision of a satisfactory undercarriage mechanism than the more difficult problem of providing a low resistance unit.