Developments in aircraft, such as variable pitch propellers, retractable undercarriage and higher speeds made training in cockpit drill essential. The mock-up fuselage was introduced as an aid to training in these procedures. One such device was the Hawarden Trainer, made from the centre section of a Spitfire fuselage, which enabled training in the procedures of a complete operational flight. The Links too, were developed to the stage where the instrument layout and performance of specific aeroplanes were duplicated; the U.S. Army-Navy Trainer, Model 18 (ANT-18), for example, was designed for training in AT-6 and SNJ flying.
In 1939 the British requested Link to design a trainer which could be used to improve the celestial navigation capabilities of their crews who were ferrying "surplus" U.S. aircraft across the Atlantic. Such a trainer could also be used to improve bombing accuracy during night raids over Europe. Ed Link, together with the aerial navigation expert, P. Weems, worked out the design of a massive trainer suitable for use by an entire bomber crew, and housed in a 45 foot high silo-shaped building. This was the Celestial Navigation Trainer. The trainers incorporated a large-size fuselage similar to that of the conventional Link Trainer, but which could accommodate the pilot, navigator, and bomber. The pilot flew the trainer, which included all the facilities and instruments of the smaller conventional Link Trainer, while a bomb aimer's station provided the appropriate sight and targets over which the trainer flew. The navigator was provided with all the radio aids and, in addition, was provided with an elaborate celestial view from which he could take his appropriate astro sights. The stars, of which enough (12) were collimated, were fixed to a dome which was given a movement to correspond with the apparent motion of the stars with time and changes in bomber latitude and longitude.
The first Celestial Navigation Trainer was completed in 1941, and the RAF placed an order for sixty of them. Unfortunately, only a limited number of these trainers were installed in Britain, such as at the Link Trainer School at Elstree, and at a number of special RAF stations. The balance were returned to the U.S. Air Force under Reverse Lease Lend, with the exception of three sets of components which were subsequently used for navigational trainers. However, hundreds of these devices were installed and operated in the United States.
Throughout the war instructors on various RAF stations were contributing their ideas to training and numerous "home-made" devices were constructed due to the long delivery times and low priority given to the manufacture of training aids. An early development was the "instructional fuselage". Such a device would consist of fuselage of the desired type mounted on stands inside a hangar. It could then be used to train air crews in the drills that they have to carry out in the particular aircraft that they are being trained on. Services like, hydraulic, electrical, and pneumatic, and their recording instruments were made to work in a normal manner, so that the various drills carried out by the crew were realistic. Bomb-dropping procedure and abandon aircraft drills by parachute and dinghy were also carried out; the bombs being released into sand trays beneath the aircraft, (duds presumably). :-)