A great deal of practice is needed before making snap judgements on sound alone, and even then there is a higher chance of error. Teaching Recognition Teaching aircraft recognition, whether in the services or a club, is an exacting task calling for method, efficiency and, above all, background knowledge of the subject. The ace spotter who can recognise anything does not necessarily make a good instructor, as he may be too far removed from the novice's problems. Sometimes a film can provide excellent material, though a particular view cannot be shown again as quickly as with the other devices. A blackboard on which instructor and students can put quick sketches is extremely useful.
Models are also good tools, both to make and look at.
Putting a plastic kit together will leave a lasting impression of the subject's shape and characteristics. The essence of the flash trainer is a shutter which flashes the image onto the screen for a brief period. With a little ingenuity it is possible to adapt an old camera shutter for use with either an episcope or a slide projector. In approaching recognition training, it is essential to plan ahead and not swamp the pupils with an excess of information. An initial test will decide the standard of the class, while discussion will reveal the level of understanding of terms and nomenclature.