Recognition: Field Manual, FM 21-80 - Recognition Training - 3. Training Aids

Chapter 3: TRAINING AIDS

Section I. GENERAL

36. OBJECT. a. The purpose of this chapter is to list the War Department recognition training aids most frequently available; to give instructions for the construction of improvised training aids to be used in the absence of the issue aids, or to supplement them; and to suggest how these training aids may be used.

b. The various ways in which training aids may be employed are not limited to the uses outlined in this chapter. Ingenious instructors and staff officers will find many other ways of utilizing them, adding the interest of variety to their training programs.

37. ACTUAL OBJECTS. a. From the very beginning of recognition training, all personnel must observe and attempt to recognize all planes, armored vehicles, and naval vessels seen. This will require only brief interruptions in other training. Thus soldiers will become aware not only of the changing appearance of familiar planes, vehicles, and vessels in different angles of approach, but of the relation of angular speed to distance and size. Field experience indicates that when using field glasses, most types of equipment can be readily recognized at ranges at which they can just be seen with the unaided eye. To provide further recognition practice at long ranges, field glasses may be reversed to increase the apparent range of equipment close by.

b. Experienced spotters can easily distinguish fighters from other single-engine aircraft merely by the relatively high cruising speed. This is manifest to the spotter principally by the length of time it takes the plane to cover a distance equal to its own length. At medium ranges, heavy bombers (because of great size, the greater distance at which they may be discerned, and lower cruising speeds) appear to "crawl" across the sky even though the actual speed may be fairly high. This same phenomenon is apparent to lesser extent in vessels and vehicles.

c. Arrangements may be made locally, or through higher headquarters, with air force and armored units to give recognition demonstrations with the use of actual aircraft and vehicles. When properly planned, such demonstrations give practice not only in learning the identity of such materiel, but also provide troops with additional training on their characteristic tactics and maneuvers.

d. It is often advisable for unit commanders to require each of scattered groups to keep a journal showing the approximate number, time and type of each aircraft, vessel, or vehicle passing within its field of view. Periodic inspection and comparisons of such diaries disclose immediately any lack of training of a particular small group.

Section II. TRAINING AIDS ISSUED

38. GENERAL. Current War Department Training Circulars list the training aids available for teaching recognition of aircraft, vessels, or vehicles, and give the basis of issue to ground and service force units. Distribution to Army Air Force units of training aids listed in current appropriate War Department Training Circulars, as well as special AAF training aids not listed therein, is prescribed by the Commanding General, Army Air Forces. The issue of additional training aids will be announced in changes to FM 21-7, 21-8, or in War Department Training Circulars.

39. RECOGNITION JOURNAL. The War Department and Navy Department jointly publish a monthly magazine, "Recognition Journal," devoted to the recognition of aircraft, armored vehicles, and naval vessels.

a. The purpose of this monthly magazine is to

(1) Stimulate interest in recognition training.

(2) Provide means for the interchange of ideas on recognition teaching and training methods.

(3) Provide means of disseminating recognition information on new airplanes, vessels, and vehicles prior to inclusion in Field Manuals or other training aids.

b. Copies of the Recognition Journal should be distributed within the unit so that they are available to the maximum number of troops for study and review during free time.

c. Instructors will find in this magazine pictures and silhouettes suitable for flash cards (par. 49), baloptican views, and current background material and battle records of friendly and enemy materiel.

Figure 14. Using the manual to contrast silhouettes.

40. FIELD MANUALS. a. Pictorial recognition Field Manuals, FM 30-30, 30-40, and 30-50 are the standard references on recognition and should be distributed to be available to as many troops as possible.

b. Instructors should advise the soldier as to how the manuals may best be used for off duty study and review. To contrast silhouettes of two aircraft, the pages may be folded (taking care not to crease) as is illustrated in figure 14. A soldier may review FM 30-30 from back to front, and thus see each illustration

Figure 15. Using the manual and a mask for an impromptu drill.

tration and decide on its identity before he turns the page to confirm his answer. Soldiers may pair off, giving each other an impromptu drill by using a simple mask (fig. 15) to cover all but one picture or silhouette view at a time. The instructor may use such a mask also for a review similar to a flash-card drill (par. 49C).

c. Silhouettes found in the manuals may be used as guides for sketching (sec. V, ch. 2).

d. Under some circumstances it may be advisable to remove from the manuals all pages on aircraft, vehicles, or vessels not covered in the course, so that self-study time will be devoted to the types being studied. In this case, due precautions should be taken to assure that the pages removed are preserved and reinserted when instruction is completed.

e. Changes to these manuals are distributed periodically. Unit commanders should insure that amendments are inserted in the manuals immediately upon receipt, unless this conflicts with the practice mentioned in the "d" above. In such event, amendments should be preserved and inserted at a later date.

Figure 16. Posters mounted on an easel.

41. POSTERS AND "BUMP CHARTS." a. Of all War Department recognition training aids, aircraft and armored vehicle posters, and naval vessel, "bump charts" have the widest distribution. They are suitable for initial presentation because, on one sheet, they show all of the basic silhouette or "bump" views. Some posters also show wash drawings and photographs. Aircraft posters may be seen clearly from a distance of 40 feet. Views on vehicle and vessel posters are smaller. Class size must be adjusted accordingly.

b. It will facilitate the manipulation of posters if sets are fastened at the top between strips of wood, with hooks affixed so the complete set may hang on an easel. Thus mounted, the posters are protected and each sheet is quickly available for reference (see fig. 16).

c. Extra poster silhouettes, pictures, and drawings may be cut up and mounted on uniform pieces of cardboard. This gives the instructor a set of large flash cards (par. 49) for tests and drills. By having separate cards for each silhouette view the student is compelled to learn each of the basic silhouettes separately. If he learns them all together on one poster, and is tested in the same way, he inevitably learns only the easiest view, and does not become familiar with the others. In aircraft and vehicle posters the view neglected as a result of this practice is the incoming silhouette. This is not only most difficult to learn, but in many cases, the most important to know. For drills and tests, cut-up posters may be used most effectively in a poster viewing box (par. 54).

d. Extra posters must be placed where men will see them regularly, as in latrines, day rooms, mess halls, and on bulletin boards (if protected from the weather). Use only one to three in each location, and change them frequently. They should not be used as "wallpaper" for barracks, orderly rooms, and odd buildings.

e. Instructors should use their ingenuity to produce special posters for displays to coincide with scheduled teaching of given aircraft. These posters may be made up from photographs and silhouettes of aircraft, ships, and tanks taken from various publications.

42. MODELS. a. The models most widely distributed for recognition training are of aircraft. These are 1/72 scale models with the obvious advantage of three dimensions. They offer all possible angles of view. Being made to the same scale, they give the impression of relative size of various types.

b. During the initial presentation, as a supplement to silhouettes, models may be hung in the front of the classroom before a light background of cardboard or a sheet, or used in a shadowgraph. When so used, after the initial discussion of silhouettes, the model should be turned so the class may see it in intermediate and changing attitudes. The instructor may add a dramatic note to his presentation by using the model to illustrate some of the airplane's tactics. The model may be passed around the class for closer inspection if the class is small, or if such procedure will not interrupt training. Plastic models are fragile and can be broken by improper handling.

c. Hanging models from the ceiling of the classroom provides an interesting display but is of no value unless some means is employed to draw the student's attention thereto. To suspend the models on numbered hooks in such a manner that their position can be changed every day is one method. The instructor then can ask "Which plane is on hook No. 15 today?"

d. Models may be hung in day rooms, mess halls, at bulletin boards, and in other places where they are seen often. From one to three are in each location. They should be changed frequently. Unit officers and noncommissioned officers, by questions and other methods, should take every opportunity to direct the soldier's attention thereto.

e. Aircraft models may he used for model shadow drills (par.50).

f. Models may be displayed and used in many other ways. It is essential that models always are used as demonstration aids for instruction and testing, and not as exhibits.

43. FILM SLIDES. a. Two- by two-inch transparent film slides offer a wide variety of views of aircraft, vessels, and vehicles. In many instances these will be the training aids principally relied upon for drills and reviews. They include both silhouette views and pictures, and therefore are excellent for initial presentation and for drills.

b. Used with the projector PH—222, slides may be shown on any white surface (screen, sheet, cardboard—even on the side of a building) that is not in direct sunlight. They may be shown in an improvised projector (par. 51) in the dark.

c. Exposures as fast as 1/2 second may be controlled by a piece of cardboard held in front of the lens. For faster exposures, the speed shutter in the AAF recognition kit may be employed, or a shutter may be improvised (see fig. 33).

44. FLASH CARDS. a. Four- by 6-inch flash cards of important United States Army aircraft are available. (See current War Department Training Circulars for basis of issue.) Each card has one silhouette view and, on the reverse side, the name, designation, a list of distinguishing features and interesting performance and combat record data. A soldier may shuffle a set of the cards and test himself, or soldiers may pair off, giving each other an impromptu drill. Before small groups cards may be used for the initial presentation and drill.

b. Cards are excellent for individual study and review. Instructors should make every effort to insure their availability to the maximum number of soldiers. If sufficient quantities of regular issue cards are not available, soldiers should be encouraged to make their own sets of flash cards by cutting out silhouettes and photographs from commercial publications.

45. TRAINING FILMS. a. A list of Training Films and Film Strips pertaining to aircraft, armored vehicle, and naval vessel recognition training may be found in FM 21-7.

b. Although no instructor should rely entirely on films for recognition training, they are an essential part of the course.

c. Films concerning individual aircraft are a useful aid to effective presentation. However, they must be supplemented by the description of size, performance data, and other details.

d. Three types of aircraft recognition films are available.

(i) Introductory films, dealing principally with nomenclature, and intended for use in the elementary stages of training. One such film will serve the desired purpose.

(2) Films dealing with the recognition of individual types of aircraft. This type shows many close-up views, essential before aircraft can be recognized from a distance. Flying shots are combined with close-up stills, diagrams with cartoons, andall are joined with a commentary which helps to direct the student's eye.

Figure 17. Flash card drill in a field position.

(3) The "Quizcraft" series. This type shows flying views of various aircraft. Although designed for use in relatively advanced stages of training, these films will not present serious recognition problems to advanced students. The primary object of this series is to give the opportunity to see aircraft under conditions as realistic as possible. Emphasis, therefore, is on distant shots under all conditions of visibility. The "test" element is secondary and is introduced only to maintain interest.

e. A fourth type of aircraft recognition Training Film, the Testcraft series, is now being developed and will become available at a later date. Each Testcraft film covers approximately 30 aircraft. Each aircraft is shown several seconds in motion with several seconds being allowed between the exposure of each aircraft to permit trainees to set down the correct answer. Each film of this type is a real examination in recognition.

f. Each recognition film is a complete unit. Its effectiveness, however, will depend largely on the skill with which the instructor plans its use and drives home its instructions. The following are some suggestions to the instructor for making recognition films most effective:

(1) Preview the film before showing, to make sure of its content.

(2) Make certain that the film has not been shown to members of the class during some previous stage of training.

(3) Set up and test the equipment before class time.

(4) Introduce the film with a few remarks about its subject. Help the film to emphasize important points by mentioning them in advance.

(5) Allow time for a brief discussion following the showing and for the addition of data not covered in the film.

(6) Do not show too many films in any one class period. The amount of material which can be absorbed in a given time is limited. Ordinarily, not more than two aircraft films and one "Quizcraft" are shown during any one hour of instruction.

(7) The commentary in some earlier Training Films is at variance with present recognition training methods, but their pictorial content is excellent. When such films are shown, the sound may be turned off and the instructor may supply the commentary, after appropriate rehearsal.

(8) Above all, do not expect a film to take the instructor's place. The film is one of the tools of instruction. To expect good results, use it wisely.

g. Individual films on friendly and enemy armored vehicles only may be available. A few films of a general nature are available on naval vessels.

h. Signal Corps and Army Air Forces film libraries may be consulted for detailed information on the content of film bulletins. Many film bulletins contain excellent material, of "newsreel" nature, useful for recognition training.

46. FILM STRIPS. a. Appropriate Film Strips are useful for nomenclature and introduction to aircraft, vehicles, and vessels (pars. 12 and 16). Film Strips such as FS 4-220 may be used for aircraft drills. Film Strips are available on armored vehicles by nationality, rather than by individual type, and may be utilized for presentation, review, or limited drill. Film Strips of the introductory type are available on some types of naval vessels.

b. Film Strips are listed in FM21-7.

c. Film Strips may be used in outdoor locations if a shaded area is available for setting up the screen. A shadow box may easily be improvised for this purpose. (See par. 164c, TM 21-250.)

47. OPAQUE PROJECTOR. a. Small flash cards (par. 49b(1)) may be projected with an opaque projector such as the PH-132 or the PH-223.

b. A completely darkened room is necessary to the effectiveness of the opaque projector unless a rear projection unit is used, as the image it casts is much less brilliant than the image projected by the strip and slide projector PH-222.

c. A piece of cardboard held in front of the lens may be used to control exposures as short as 1/2 second. An improvised shutter may be employed for "flash" exposures (par. 53).

Section III. IMPROVISED TRAINING AIDS

48. GENERAL. In the absence of many issue training aids, it is possible to conduct a complete and interesting program with aids improvised from materials at hand. A number of these are listed in following paragraphs.

49. FLASH CARDS. a. A creditable recognition training program may be built around improvised flash cards.

b. Improvised flash cards are pictures or silhouettes, preferably mounted on cardboard, used chiefly for drills, reviews, and tests. They are of several types:

(1) Small cards, up to 6 inches square, which may be circulated around the class, used before small groups, or projected in an opaque projector such as the PH-132, PH-223, or in an improvised projector.

(2) Larger cards, up to 18 inches square, which may be used before larger groups.

c. Sources of material for flash cards are:

(1) Cut-up silhouette posters. When used for drills, tests, or reviews, these should be mounted with no more than one view to each card.

(2) Commercial aircraft and tank recognition packets.

(3) Pictures and silhouettes to be found in service, trade, technical, and popular: magazines. Those in- the "Recognition  Journal" are particularly well adapted to this use. Silhouettes found in other than service sources must be carefully checked for currency and accuracy before being used.

(4) Extra or obsolete copies of appropriate Field Manuals. Obsolete copies must be carefully checked. Only pictures or silhouettes of types still current will be used.

d. Some pictures, including quartering views as well as presenting side, incoming and overhead attitudes, may be converted into "syllographs" by inking in, preserving the outline, but obscuring all detail. Like model shadows, syllographs may more nearly resemble the actual object than do pictures which show detail. Syllographs impress upon the soldier that, for example, in a crossing course the position of a wing and number of engines are seldom an aid to recognition.

e. When used for a regular flash card drill, the cards are held before the class for an appropriate period, following the general drill procedure outlined in paragraph 19.

f. The small flash cards may be used for "pass-around" drills with groups of any size. Cards are numbered, and are passed from one member of the class to another at the instructor's command, 1. READY, 2. PASS. At the command, READY NOW, each soldier looks at his card until the command, OVER, then turns the card face down, and writes the proper name or designation after the corresponding number on his paper. At the end of the drill, the instructor calls off the answers.

g. In the absence of other training aids, flash cards may be used for the initial presentation.

h. Large magazine pictures of aircraft, tanks, or naval vessels may be used to ornament mess halls and day rooms, but should be changed frequently. New pictures attract attention.

Figure 18. (1) Aircraft picture .. .

 
(2) . . . Painted in becomes a "syllograph."

50. SHADOWGRAPHS. a. When used in an improvised "shadow box," aircraft models produce one of the most realistic of all training aids, particularly useful in advanced stages of training.

b. A source of illumination with a narrow-angle beam, such as a PH-222,SVE projector from AAF recognition kit, flashlight, automobile headlight, or an ordinary light bulb in a "tin can lamp" (see fig. 20), is placed 8 to 10 feet behind a translucent screen such as a bed sheet or a piece of tracing paper. The model is hung or held between the screen and the light so a shadow of the model is cast on the screen. For a sharp image, the model must be as close as possible to the screen.

c. By placing the model in various attitudes of flight, it is possible to achieve a close approximation to the appearance of an actual plane in the sky. Model shadows may be made to duplicate phenomena encountered in combat spotting. In certain angles of flight, wing dihedral changes the apparent shape of the leading or trailing edge of the wing. In an incoming, climbing view, for example, a wing with pronounced dihedral and a tapered leading edge may appear to have a straight leading edge. The instructor may use model shadows to illustrate and explain such phenomena.

Figure 19. Model shadow.

d. For formal drills the light source may be covered or turned off and on to vary exposure time.

e. A model shadow box may be one of a number of types.

(i) It may not be a box at all, but a sheet hung at one end of a room or in a doorway. The model, then, may hang on a string, or may be fixed at the end of a stiff wire, inserted into the small hole in the under side of the fuselage (see fig. 24). In either case, the model may be turned slightly during an exposure to simulate a changing attitude of flight. It must be remembered, however, that in the actual time limit for recognition, the

Figure 20. "Tin can" spotlight.

Figure 21. The Wellington wing has taper in both leading and trailing edges.

attitude of flight of an aircraft in the sky will change only slightly. An impression of flight may also be obtained by moving the light a few inches from side to side during the exposure.

(2) A simple portable shadow box, behind which models are placed, is illustrated in figure 25.

Figure 22. But in an incoming-diving course the trailing edge appears straight.

Figure 23. And in an incoming-climbing course the leading edge appears straight.

(3) A more intricate but easily improvised type is illustrated in figure 29. The model is suspended on a string from a hook at the top of the box. Threads, held taut by small weights, make it possible to set the model in any position. If the box is large enough, and additional hooks are screwed into the upper part of the frame, the shadow of more than one model may be shown at a time. (See fig. 7.)

(4) A "moving model shadow box" may be easily constructed from a few pieces of wood, some thread, and a spring. (See fig. 29.) Threads are strung between two short strips of wood so that a model may be placed with a thread under each wing at the root, another under each wing at the tip, and yet another above each wing at the root, the latter thread passing under the tail plane. The wooden strips are fastened to brackets behind a translucent screen, so the threads are parallel to it, and at an angle of about 20° from horizontal. At the lower bracket the strip is fastened by a spring, to keep the threads taut. The model is placed among the threads as indicated, and is pulled back so

Figure 24. Model mounted on wire for presentation of shadow drill.

the tail is resting on the upper strip of wood. By pressing the lower strip lightly to ease the tension on the threads, the model will slide down, casting a moving model shadow. By turning the lower strip slightly, the model may be made to appear to bank away.

(a) Such a moving model shadow box is practicable only for fighter size models.

(b) For the "check," one of the lower, inner threads put above the tail plane will hold the model in place.

(c) In all moving views, all movements toward or away from the screen will appear reversed to the class. In other words, if

Figure 25. Portable model shadow box.

the model is made to bank toward the screen, the shadow will appear to bank away. Likewise, for a fixed incoming view, the model must be placed with the tail toward the screen.

f. While model shadows simulate the combat spotting situation more accurately than other training aids, there will always

Figure 26. Detail of another type of model shadow box.

Figure 27. Moving model shadow as it appears on screen.

be more distortion because parts of the airplane away from the screen will appear disproportionally large and less distinct compared with parts close to it. The farther the light from the screen, the less will be the distortion of the image; the narrower the angle of the beam, the more distinct it will be. These difficulties cannot be eliminated completely, and all model shadow drills must be arranged and carefully rehearsed so that no views will be unfairly difficult.

 
Figure 28.- View of moving shadow box from behind screen.

51. SLIDE PROJECTOR. a. Using any folding, miniature, or other camera with a hinged or removable back, and a good lens, it is possible to improvise a satisfactory slide projector, without damaging the camera. (See fig. 30.) In the illustration full dimensions are not given, as some will depend upon the size and type of camera used.

b. The body of the projector is a box, inclosing a 100-watt frosted lamp. For good ventilation, 1-inch holes must be drilled near the bottom of the box, and masked to prevent light escape; and, above the lamp, a chimney, which may be constructed of two tin cans, one larger than the other, fixed concentrically, with holes drilled near the bottom of the larger can.

c. A hole is cut in the front of the box, opposite the lamp filament. The camera is mounted on a table, supported between

Figure 29. Detail of moving shadow box.

two arms, so that the camera back, if hinged, may drop between the arms. Grooved strips of wood are nailed above and below the opening so a slide changer will fit into them.

d. The slide changer may be constructed of three thin strips of wood, or metal, as indicated, the inner strip cut-outs being 2 by 2 inches (the size of a slide) and the cut-outs in the outer strips being 1 1/2 by 1 1/4 inches.

Figure -30. Improvised slide projector.

e. The slide changer must be so positioned that the slide, while being projected, will be as near as possible to the position the negative would occupy if the camera were loaded. Some experimentation may be necessary.

f. Distribution and intensity of light will be greatly improved if one or preferably two condenser lenses are fixed immediately behind the slide. Ordinary magnifying lenses of 3 inches or greater diameter will serve this purpose.

Figure 31. Use of translucent screen with improvised slide projector.

g. The bulb should be 3 inches from the nearest condenser lens, or 3 inches from the slide if no condensers are used.

h. Half a tin can, placed behind the lamp as a reflector, will increase the illumination appreciably.

i. If it is found that the improvised projector does not give an image of the desired brilliance, the projector may be placed behind a translucent screen, such as a bed sheet or a piece of tracing paper. Such an arrangement will give a much brighter image.

52. OPAQUE PROJECTOR. a. A home-made opaque projector (also known as baloptican, episcope, epidiascope and delineascope) will enable the instructor to project any picture or silhouette (including small flash cards) on a screen.

b. It consists of little more than a box, a lens, and two lights, of at least 100 watts each, with reflectors (see fig. 35).

c. The picture fits into a hinged door in the back of the box. Reflectors may be improvised from tin cans, and are directed so good cross lighting is on the picture. Filaments of the lamps are on a level with the center of the picture.

Figure 32. Improvised opaque projector.

d. A map tube of appropriate size serves as a lens barrel. It must be installed so it can slip forward and back for focusing. If the lens barrel does not extend far enough into the box to prevent all direct light from the lamps from entering the barrel, baffles may be placed as indicated in the drawing.

e. There are several possible sources for a suitable lens. The best may be taken from an old 8- by 10-inch view camera, or even from a large roll film folding camera. A 4.00 diopter meniscus lens obtainable from an oculist will do. An ordinary magnifying lens will function adequately, and probably will be easiest to obtain. The lens from an SVE projector in the AAF recognition kit likewise can be utilized.

f. The focal length of the lens selected must approximately equal the distance from the picture to the lens, and will deter-mine the size of picture which may be projected. Measure this distance approximately by placing a ruler upright on a table directly under a ceiling light, and measuring the distance above the table that the lens must be held in order to focus the image of the ceiling light on a piece of paper lying on the table.

Figure 33. Improvised shutter for PH-222.

g. In general, to obtain a sharp image on the screen, the diagonal of the picture to be projected cannot exceed the focal length of the lens. Even so, to get a reasonably sharp image from a relatively crude lens, such as a magnifying glass, the diagonal must be somewhat less than the focal length. This indicates a lens with a focal length of 8 to 10 inches as being the most practicable. However, if no other is available, a magnifying glass of 4-inch focal length will satisfactorily cover small silhouettes and pictures.

h. Distortion can be controlled by cutting a disc of cardboard to fit against the lens. A hole about half the diameter of the disc is cut in the center. Stopped down in this manner, the projected image will not be as bright, but will be considerably sharper, particularly about the edges. Distortion can be further controlled by building a curved mount for the picture, so that the edges, in one plane, will be the same distance from the lens as the center of the picture.

Figure 34. Improvised shutter for opaque projector.

i. Ventilation holes and a chimney may be similar to those suggested for an improvised slide projector.

j. All pictures of silhouettes to be projected are pasted on cardboard of uniform size, cut to fit the projector.

k. At best, the image will not be as brilliant as that from a slide projector. Therefore the room must be completely darkened. The placing of white cardboard into the projector beam will reflect sufficient light into the room to write answers to drills or tests. If an overhead light is turned on between views, it will be difficult for the students' eyes to readjust when lights are turned off.

Figure 35. Viewing box.

l. If the image, when cast on the screen in the usual manner, is not sufficiently brilliant, a translucent screen may be employed, as described in paragraph 5Ii. Also, with this arrangement, the image is not reversed, as when cast on a screen in the usual manner.

53. IMPROVISED SHUTTER. An improvised shutter may be used with a slide (see fig. 33), or opaque projector (see fig. 34) to give "flash" exposures. Masks of various sizes, as indicated in the drawing, give a choice of exposure times. If the brilliance of the image is decreased, the exposure time must be correspondingly lengthened.

Figure 36. Card for "bingo" type game.

54. VIEWING BOX. a. Large flash cards when used for drills may be placed in a viewing box (see fig. 35). In a darkened room, light may be turned on and off to regulate exposures as fast as 1/5 second.

b. A viewing box may be constructed to accommodate full size posters, mounted on cardboard, and used during the initial presentation.

55. DISPLAYS. As suggested in foregoing paragraphs, models, posters, or "bump charts," and pictures may be displayed throughout the unit area. Such displays make the material available for self-study. Any display not consistent with this objective should not be used. Two cautions should be observed:

a. Display only training aids of objects being studied that day, or to be studied the following day.

b. Use the same well-frequented locations each day, so soldiers will form the habit of looking there.

56. "PLANE-OF-THE-DAY." After all aircraft, vehicles, or vessels to be included have been presented, and the training program is devoted to review, a "plane-of-the-day" (vehicle or naval vessel) is displayed prominently in the unit area. This consists of a single model, poster (with all identifying names and designations obscured), or picture of a plane, vehicle, or vessel which has been included in the training program. It is changed every day. Unit commanders will require that every member of the unit be prepared to give its proper name and designation, and any other important data required to be known (for example, in some branches, the wing span of aircraft) when questioned by unit officers or noncommissioned officers.

57. COMPETITIVE GAMES AND CONTESTS. a. To help sustain interest in recognition training and to encourage individual study, various games and contests may be useful.

b. Model building contests may be promoted as group or individual projects. Any soft wood will do, and posters may be used for plans. The soldier will learn a great deal about the airplanes he builds, even if the finished product is far from perfect.

c. Small groups may compete in aircraft recognition drills. Similar to the old-fashioned spelling bee, either among them-selves or with other groups.

d. Plane-O. An instructive game modeled after the familiar "bingo" may be devised, by using small silhouettes or pictures on the cards, instead of numbers. Players cover their cards as the game leader calls the names of planes, vehicles, or vessels drawn from a box. Each card must be different from all others, both as to arrangement and subject. If photographic facilities are avail-able, 1½- by 1 ½-inch negatives may be made of each view to be used, and the negatives reshuffled for each print. Sets of commercial or Special Services "Aircraft" playing cards may be cut up to provide a ready source of silhouettes. The individual silhouettes are mounted on cardboard as indicated in figure 36.

e. Baseball game. The class is divided into two teams, the number of men on each team making little difference. The first team arranges itself in a "batting order" and one man at a time is asked to recognize a slide, silhouette, photograph, or model. As this man comes up to bat, he is given a choice of trying for a single, a two-bagger, a three-bagger, or a home run. If he chooses a single, a very easy test will be given him. If he chooses a home run, a difficult test will be given, with the relative difficulty of a second or third base hit staggered in between. No matter which he chooses, he strikes out if he cannot give the correct name. However, just as in baseball, a home run "with the bases loaded" will result in four runs added to the team's score. Likewise, three strike-outs will result in bringing the other team up to bat.