Complete Spotter's Guide

For a good many years, aviation enthusiasts here and abroad have, like members of the Audubon Society, found pleasure in identification of the species in flight. Playing a pseudoscientific guessing game with no apparent risk or reason, they found no reward beyond a slight boost to self esteem, no penalty in failure to spot planes correctly. But Pearl Harbor changed that. A year ago, aircraft identification became a serious business here as it had been in Great Britain for nearly five years. Draftees who had previously paid little attention to German plane types hastily resurrected their plane spotting handbooks. Army and Navy officials began searching dust-covered files for photographs and silhouettes of Japanese planes. Enlisted men and officers suddenly playing for keeps in the embattled Pacific Islands fired ack-ack and fighter plane guns with a prayer — a hope that their target was foe, not friend. Now, less than a year later, nearly two million civilian men and women have cast their patriotic lot with the air forces as ground observers.

Unfortunately, actual progress in the training of military and civilian spotters has trailed far behind the enthusiasm of the spotters involved. Silhouettes of American types were, at first, difficult to obtain even though model kit makers had, for many years, received full manufacturer cooperation in the matter of three-view specifications. Drawings and photos of enemy types could be found only in the excellent British publications. At least a dozen different identification systems and texts appeared in the US but too many false raid alarms, too little accurate spotting material, too few opportunities for Americans to see various planes in actual flight encouraged military officials to enlist every available aid in the preparation of a full program of identification training. Starting from scratch six months ago, the US now excels every Axis nation in this important aspect of war, may soon match even the British who have plenty of practice on real aircraft and a nation-wide spotting interest dating to prewar days.

When Air News inaugurated the "Spotter's Quiz" last February, it seemed unlikely that enemy planes would ever appear in large numbers in American skies. That may still be true, despite some reports that German airmen have already attempted the Atlantic crossing on more than one occasion. With this in mind, text and treatment of the Air News "Spotter's Section" is rudimentary, assumes that all readers are beginners at plane spotting. But because combat pilots now leaving for overseas service will have no opportunity to analyze the enemy's planes on first meeting, many of the photographs used show plane views seldom encountered by ground observers.

What To Look For

Novices sometimes complain that all airplanes, like all Japs, look alike. Actually, planes are as distinctive as human faces — and considerably more so than modern automobiles. If there is any secret to accurate spotting, it lies in the knowledge of what to look for. With distinguishing characteristics in mind, and with constant practice, actual identification of each type becomes automatic, instantaneous. An Army pilot, who spots a Warhawk as readily as he spots his best girl without analysis of individual features of either, knows that identification is determined by the personality of a mass. Accurate aircraft spotting requires merely the exercise of observation and memory. Every individual has his own methods of remembering but here is a list of factors which beginners should observe:

Because the wing is the chief structure of an I airplane, it supplies the principal individual point of recognition. The Air News "Spotter's Quiz" embraces monoplane design exclusively because the few biplanes in service as trainers, carrier-based scouts, and combat planes in a few remote sectors hardly constitute a spotting factor. In general, it is important to know the following points:

Wing Position. Depending on where the wing joins the fuselage in a head-on view of the plane, it may be designated as a high-wing, mid-wing, or low-wing design. Attached slightly above or below the fuselage center, it may be further classified as high or low mid-wing. Attachment of the wing above the fuselage on a superstructure, as in the case of Consolidated's PBY-5, produces a parasol wing. The presence or absence of wing bracing determines its classification as cantilever or braced wing design.

Wing Shape. Because wing shapes are as varied as the men who design them, a simplification of types is impractical, although the official Army classifications are extremely helpful. A wing without taper on either leading or trailing edge is described as straight; one which tapers only on the leading edge is classified as swept-back; one having taper only on trailing edge is tapered; while a rounded trailing edge produces an elliptical wing. There are other types, but these are the most common structures. In some cases, the aspect ratio — relation of wing length and width — provides an identifying feature. In a head-on view, the angle at which the wings join the fuselage is significant. If the wings angle upward from fuselage to tip, they are dihedral; if they angle downward, they, are described as anhedral. When wing sections of dihedral and anhedral are combined, they result in a gull wing (as on the Martin PBM-3) or an inverted gull wing (apparent on the Junkers 87B and the Vought-Sikorsky Corsair).

Wing Size. Planes now flying over the US have wingspans ranging from 30' to the 212' of the Douglas B-19. Wingspan is, obviously, of superficial importance to the ground observer, inasmuch as a Piper Cub flying at 1,000 feet appears larger than a Boeing B-17 at 20,000 feet. Wing size is of paramount importance to the fighter pilot, however, for the size of an object in his gun sight reveals its distance away from his guns. Only when that distance corresponds with the range of his converging gunfire can he fight effectively.

Number of Engines. Current war planes are fitted with one, two, three, four, or six engines, with the first two predominating, of course. Until recently, so few service types carried three, four, or six engines that their spotting was relatively simple. However, rapid extension of fronts and communication lines has already led to the introduction of a half-dozen new multimotor planes and this trend is expected to continue during the coming year. Only the trimotor now serves exclusively with the enemy forces.

Engine Type. With only the liquid-cooled and air-cooled engines in wide service at this writing, external engine outlines can be safely classified as pointed- or snub-nosed. That special engine cowlings can alter the engine lines is apparent, however, in the Heinkel 177 and the highly efficient Junkers radiator may appear on still more German planes powered by inline engines.

Engine Position. In multimotor planes, note the relation of engine nacelles to the wings and fuselage. They may hang completely below the wing, intersect it midway, or on low-wing planes to be on top of the wing. They may, in rare instances, project forward as far as the fuselage nose or only a very short distance in front of the wing leading edge. Some nacelles will have straight sides, as on the Martin Baltimore, while most of them will taper to a broad point near the wing trailing edge. Note any which actually extend behind the trailing edge, as on the North American B-25.

Fuselage Size. The length and width of a fuselage in relation to its wing span can often supply the missing link in full recognition. For instance, the Brewster Buffalo, still in service in some war zones, is almost barrel-shaped while the Dornier 217-E retains the flying pencil slimness of its Do-215 and Do-17 progenitors.

Fuselage Shape. Generally speaking, American planes have fewer external excrescences in the form of braces and structural bumps than planes of other nationalities. British planes, on the contrary, are completely functional, with English designers preferring to sacrifice something in air speed and performance for speed on the production line. The results are apparent in slab sides, protruding gun turrets, and irregular canopy lines in the larger planes. Unfortunately, Japanese designers have copied the best products of other nations so faithfully that dependence on fuselage lines for identification can bring always serious, sometimes suicidal consequences. No small amount of the Nipponese success in Java has now been explained by the fact that the Mitsubishi Zero so closely resembled the Fokker 58 flown by Dutch pilots that Dutch ground batteries seldom knew whether to fire or not to fire.

Although many authorities on plane identification consider the undercarriage as a primary recognition point, it actually has no importance to either the ground observer or the pilot. In the first place, nearly all existing combat types are fitted with retractable gear, with a notable exception in the Junkers 87B and its Italian counterpart, the new Breda 151. But the fact that wheels can be drawn up does not oblige a pilot to retract his landing gear. In fact, the hydraulic system operating the retraction equipment is frequently damaged in takeoff or in combat, causing pilots to fly with their wheels down.

Tail Shape. Horizontal tail surfaces which have no taper on either the leading or trailing edge are straight, while those which taper only on the leading edge are sweptback. Some tail assemblies have both tapered trailing edge and sweptback leading edge, as on the Vought-Sikorsky Vindicator, while the slightly tapered and sweptback tail of the Vultee BT-15 is more accurately described as rounded, because of the tail width and length ratio. The P-40 has sweptback leading edge along with curved elevators, a combination usually described as a wasp tail. With both leading and trailing edges rounded, the Heinkel 111K and the Brewster Buffalo have true elliptical tails.

Fin and Rudder Shape. Visible in the profile view of a plane, the size and shape of fin and rudder can be helpful as the final factor in accurate recognition. Too many types exist for complete analysis here, but the common types are:

Rounded or oval vertical assembly, a triangular or pear shape, the elliptical or wasp shape, and a tail on which either the fin or rudder has a vertical edge.

Prepared in the interests of the Aircraft Warning Service and the 1st Fighter Command, US Army Air Forces, this special "Spotter's Issue" of Air News is complete within the limitations of military security. As combat types are removed from the restricted lists during the coming months, their pictures and silhouettes will appear in Air News, each issue of which will continue to carry a regular spotter's section.

The printing format has been planned for the spotter's convenience. Complete pages can be removed and, with inexpensive reinforcements for the indicated looseleaf binder holes, can be preserved in complete page form in regular binders. Or each page can be cut in quarters, each section then folded in half and mounted with mucilage or library paste on standard three-by-five-inch file cards.

This article was originally published in the December, 1942, "Complete Spotter's Guide" issue of Air News magazine, vol 3, no 8, p 17.