The Hastings is a long range air transport aircraft which can carry a payload of about 5 tons over stage lengths up to about 2,000 miles in length. It is being used in the Operation to provide a link with civilization by running a scheduled service to Honolulu and Australia.
      The Dakota, used extensively during and just after World War II, is no longer in service with the RAF. It is a very reliable short haul transport aircraft which only needs a short landing and take-off run. Its job will be to provide a daily service between Christmas and Malden Islands.
      Among the smaller aircraft on the island is the Auster, normally used as an Air Observation Post for artillery spotting and which can be operated from a very small landing strip. It is being used to air-spray the camp areas on Christmas Island in order to keep down the flies and other insects, but also it will be used as a light communications aircraft within the island area. .
     The Whirlwind helicopter is normally used by Coastal and Fighter Commands in an air/sea rescue capacity, which will also be one of its roles in the operational area. Besides this it will be used as an internal communications aircraft, as an airborne ambulance and for air spraying purposes.
      So much for the specific tasks and the aircraft to be used, but several problems arise out of them. For instance, how to protect the aircraft and crew of the Valiant which drops the bomb, and of the Canberra which later flies through the radio-active cloud; how to navigate accurately over long stretches of water; and how to service and maintain modern aircraft on a desert island.
      A nuclear explosion produces a radiation flash from the fire ball and an air blast from the large amount of atmosphere which is suddenly displaced. If the explosion is big enough the aircraft from which the weapon is dropped is likely to suffer damage. In the case of this Operation, a well-practised escape manoeuvre will be carried out by the Valiant aircraft to put as much distance as possible between the aircraft and the explosion. This, however, is not sufficient to guarantee safety from the thermal and visual part of the radiation flash, and some modifications have had to be made to the aircraft. Blackout shutters have been fitted to protect the crew and the aircraft has been painted white to increase the reflectivity and reduce heat absorption. Certain parts of the aircraft structure have been strengthened to withstand the extra heat.
      The only other form of protection needed is for the Canberra B.6 aircraft engaged in sampling, and takes the form of filters in the cabin air supply and in the supply for the air-cooled parts. In addition, instruments are installed to indicate the radiation dose being received by the crew.
      RAF. navigators are told that they are never lost-merely that their zone of uncertainty has become infinitely large! Before discussing the problems involved in navigating aircraft over great distances of water it may be as well to give a brief description of the art of navigation in order that any reader who has no knowledge of the subject may more readily appreciate the difficulties.
      In normal flight over the land, in conditions of good visibility, a pilot guides his aircraft with the aid of a map and a compass much as a motorist would direct his motor-car from a road map-that is by simple pilotage,