crews in them there will always be a requirement for one of the crew to be competent to navigate the aircraft by the basic means.
      The problem of maintaining a large force of various types of aircraft, on a coral island in the middle of the Pacific Ocean on the Equator, some 10,000 miles from the nearest maintenance unit in the U.K., might be expected to prove interesting. When the aircraft concerned, however, include both war-time transports and the latest up-to-date medium bombers, the task can at least be described as unique.
      To maintain such a force it was decided to send out to the operating area nearly 10,000 tons of ground equipment and aircraft spares, including ground radio installations and mechanical transport, making in all a total of nearly 15,000 packing cases. Fuel, lubricants, oil, compressed gases, air publications and the like, had also to be provided.
      Because of the great distances involved between the island and the sources of supply, coupled with the very tenuous lines of communications for reprovisioning, great care has had to be taken and much effort expended by the Technical and Equipment Planning Staff to ensure, as far as possible, that everything likely to be needed would already be in position before the arrival of the aircraft at Christmas Island. Not only was it necessary to provide normal aircraft servicing requirements and facilities, but special consideration had to be given to the climatic and radiological effects on aircraft and personnel. This was aggravated by the limited facilities and buildings which it was anticipated could be provided on the island.
      To maintain cabins, servicing hatches and bomb bays of the aircraft at a reasonably bearable temperature, it was decided to design and produce special cabin and canopy covers, while cooling trolleys, to provide cooling air, were requested.
      A steady wind of 15 to 20 knots was known to blow during most of the year in the operational area. This makes servicing of the aircraft and equipment difficult, often in blowing sand. Indeed,. plans had to be made to have all aircraft so positioned that engines would be into wind when running up. To facilitate changing all control surfaces on the larger aircraft, a special shelter was designed and produced under the auspices of the Royal Engineers and shipped out to the island in anticipation of the expected wind condition. Thus it is hoped to enable control surfaces to be changed in winds of up to 30 to 40 knots. To determine the shape of this shelter, special wind tunnel tests were carried out by Vickers Armstrong (Aircraft) Ltd.
      To prepare the aircraft for the Operation, a considerable number and variety of modifications had to be embodied. These were done by the aircraft manufacturers and Royal Air Force Units. The Atomic Weapons Research Establishment and the Royal Aircraft Establishment also had many modifications which had to be satisfied. Many of these were considered essential to provide adequate protection for the crews and aircraft against the effects of the weapons scheduled to be used, while others were aimed at providing photographic facilities, special navigational equipments, telemetric installations, special measuring devices and facilities for the collection of samples from the anticipated radio-active