The single-seater fighting plane has, on account of its speed, high rate of climb and power of maneuver, been commonly accepted as the most efficient fighting weapon which has yet been developed for use in aerial combat. However, the recent substitution of two-seater fighters as the equipment of one of the existing fighting squadrons of the Battle Fleet to replace its former equipment of single-seaters has served to focus service attention on the question of fighting plane types.
Prior to the delivery to the fleet in June of this year of sufficient Curtiss two-seater fighters for a complete squadron, fleet fighting and light-bombing squadrons had been equipped alike with single-seater fighters so designed as to be capable of use as light bombers, but there had existed in the service for some years a trend of thought toward the two-seater fighter idea which is now to be given its first real trial in fleet work.
It is fundamental that however fine a two-seater fighter may be produced by the advance of the aeronautic art, the same plane can, by modification of the design to exclude the rear gunner and his armament, be made into a single-seater fighter of greater speed, faster climb, and probably better maneuverability, all due to the decrease in weight. Thus the choice between single-seaters and two-seaters might be briefly stated as the choice between performance and armament. However, the contest between the merits of the two types is not as clear cut as would at first appear. When all aspects of the question are examined it is seen to be quite complex.
The single-seater fighter consists essentially of a small plane so designed as to carry a single pilot together with his primary armament, usually two machine guns, at the highest practicable speed and rate of climb consistent with construction strength requisite for combat maneuvers and endurance requisite for the particular employment for which intended. It may carry light bombs as secondary armament, or other accessory equipment, but every pound devoted to bombs, bomb racks, or increased structural strength for dive bombing detracts from its performance. A single- seater fighter loses its efficiency as such directly as it is altered or made heavier for secondary missions. It is always easy and safe to add weight in peace, but in war there is little doubt that the fighting pilot would be busy looking for pounds or even ounces to cut adrift.
The tactics of the single-seater are by force of circumstances governed by the necessity for obtaining a position of advantage relative to its opponent and of then pressing home its attack with its fixed guns. Against an opposing single-seater it attempts to secure a position behind—on the tail—whence it can shoot without being shot at. Its only defense against surprise attack on its own tail is the unremitting vigilance of the pilot. If it attempts to withdraw, except at superior speed during a favorable opportunity, it has no defense against destructive enemy fire. These conditions definitely prohibit single-seaters from fighting while proceeding along a self-chosen course. They must maneuver and head toward the target to shoot. Even a victorious engagement with enemy planes will prevent or delay proceeding on missions assigned, since fighting breaks single-seater units off from their course.
The single-seater type is tactically an essentially offensive type, so much so that it can not easily cease or attempt to withdraw from the offensive. During the World War this defect of the single-seater fighter was well recognized and two-seaters were extensively used for appropriate duties. Any war-time pilot who ever had the experience of coming home with an enemy flight on his tail was convinced of the comfort to be found in having a rear gunner to afford some show of resistance. In peace time the single-seater is the more spectacular and impressive type and its weaknesses are not exposed, while the inferior performance of the two-seater is readily apparent.
The design characteristics of a two-seater fighter include high speed, fast climb, maneuverability, a minimum of dead angles of fire, sturdy construction, and the best possible vision for both pilot and gunner. It is usual and desirable for pilot and gunner to be located as close together as possible in order to facilitate communication. Its armament includes one or two fixed, synchronized guns and a single or double free gun mounted aft.
The fighting pilot of a two-seater must have the same qualifications as the pilot of the single-place fighter with possibly a bit more ability to cooperate. The gunner must possess a maximum of knowledge and skill in the use of his weapon, be thoroughly at home in the air, and be of a most alert and aggressive type, the secret of successful operation lying in cooperation and confidence between pilot and gunner.
A very definite point of superiority for the two-seater type for certain missions lies in the fact that performance equal to that of the single-seater having been sacrificed in favor of armament, a very slight further sacrifice of performance permits of a marked increase in endurance, thus permitting two-seaters to be used as escorts and covering attack flight in connection with long-distance bombing flights or other attacks requiring endurance beyond that of the single-seaters.
The two-seater type, since it carries two men, can be relied on for more accurate navigation, an important factor in fleet operations where single-seaters sometimes have a tendency to become confused as to their position.
The definitely superior characteristic of the two-seater is, however, the free gun and its inherent ability to fire at the enemy regardless of the course of the plane. This ability enables a unit of two-seaters to fight a defensive action successfully, to retreat at will, or to cover the withdrawal of other units while maintaining an effective relative position. Moreover two-seaters in the attack on slower types are able to deliver effective fire from their rear gun while recovering from an approach firing the front gun, or if desired, to assume a position more or less steady with relation to the target, on a favorable bearing, and pour in a steady fire from the rear gun.
The great disadvantage of the two-seater fighter type as it exists at present lies in the inefficiency of the service type of rear gun and gun mount, particularly at the speeds and under the conditions of aerial combat. With planes diving at speeds near their terminal velocity and changing direction even slightly, the wind blast and forces of acceleration produced render it nearly impossible to operate the rear gun. If the exchange of performance for armament is to be worth while, both ordnance development and the skill and training of both pilot and gunner must make the additional armament effective.
While the two-seater fighter will never replace the single-seater type it is certain that it, as a type, has a definite field of usefulness and that squadrons of two-seaters will be found necessary parts of a balanced air force, afloat or ashore, until further developments in the aeronautic art introduce a superior type.
The fleet air arm of the British Air Force has recently procured a number of Fairey two-seat fighters whose rear gun is carried on a special high-speed mount. While specific performance data are not available, this type is understood to be quite successful. Probably the best known of all two-seater fighters is the famous Bristol fighter which, designed by Captain Frank Barnwell, was recognized during the war as being an unusually effective and efficient type. It functioned splendidly under war conditions on the Western Front and in Palestine. The present model, the Bristol 101, attains a speed of 150 m.p.h. and climbs to 10,000 feet in 9.5 minutes with a 450-hp. Bristol Jupiter air-cooled engine.
A very interesting two-seater fighter monoplane, the K-47, has recently been produced by the Swedish Junkers works. With a 420-hp. Bristol Jupiter engine this plane attains a speed of 150 m.p.h. at ground level and climbs to 10,000 feet in 6.4 minutes. The rear gunner sits facing aft in a rocking carriage seat which is movable in a vertical plane from 0° to 90° elevation while the gun may be traversed 18° on each side of the center line. Great ease of manipulation is claimed for this mount since the gunner and gun mount maintain a constant relative position and the necessity for struggling with a clumsy Scarff ring and assuming queer attitudes in a terrific air blast disappear.
Numerous other two-seater fighters are under experiment or are in service abroad. Moreover foreign investigation goes further than the two-seater and in the past year or two several multi-seaters have appeared. In fact, a strongly developed tendency exists in foreign air forces to favor the introduction of “air cruisers” or heavy multi-seated fighters such as the Bleriot 127 or Swedish Junkers K-37. M. Rene Sologne in Les Ailes says:
I recently visited the Technical Experimental Works at Villacoublay, and was shown around by one of the leading pilots of the establishment. As we were looking at a Bleriot 127 he said that he had piloted a fighter in the war but that he could not imagine himself attacking the Bleriot in it, and he further remarked that this new heavy type probably meant the end of the old fighter. A month later I heard a similar opinion expressed by one of the oldest pilots of the Thirty-fourth Fighting Squadron. This made me wonder which type would, in the future, hold the field, the old fighter or the air cruiser. The function of the fighter was to maintain supremacy in the air, and in the Great War it acted as an attacking as well as a protective arm. But could it wrest this supremacy from enemy aircraft such as the Bleriot 127? A singlefighter, no matter how well it might be maneuvered, would have no chance whatever of success against the heavier type; it would certainly be overwhelmed. In my opinion, the air cruiser is a machine which will become indispensable to any nation that wishes to be in the position of a real air power. It is the aeroplane of the future.
Similar opinions have been expressed by other foreign experts. Such opinions will be thought unsound by many, and over-enthusiastic by most service pilots in this country, but at the same time they furnish much food for thought. Certain it is that the multi-place fighter idea furnishes a possibility for adapting commercial types to military use in emergency and this consideration alone might justify experimenting with the type for shore based air forces. The adaptability of commercial types to military use can, of course, be increased by design just as ocean liners are designed with a view to possible military use. In fact the potential value of large commercial airplanes for military purposes is the subject of a paper recently prepared for the preparatory disarmament commission of the League of Nations by Brigadier General P. R. C. Groves (See page 864). He points out that not only are the planes capable of conversion but also that “the pilot of the air line is incontestably an aviator of the first rank,” flying as he does regularly day and night in all sorts of weather. Certainly the air cruiser is not adapted to shipboard use as will be seen from the following description, but its strength and weakness should be studied by fleet aviation personnel if only as a possible enemy weapon.
The Bleriot 127 which is a good example of the heavy fighter is a large monoplane; wing span, 73 feet; weight loaded, 9,820 pounds. It is powered with two 500-hp. Hispano-Suiza engines in nacelles under the wings. The tail of each engine nacelle forms a gunner’s cockpit while a third gun mount is formed in the nose of the fuselage. Each cockpit carries twin Lewis guns.
The Junkers K-37 mounts two fixed guns firing forward, a twin Lewis forward, a twin Lewis aft, and a bottom gun under the fuselage. The fixed machine guns may be replaced by a 2-cm. quick firer. The plane is reported to make 149 m.p.h. and this speed combined with its heavy armament should make it a formidable weapon.
If, in the future, a fast multi-seater fighter is developed with the ability to cover long distances and to develop powerful gunfire from an armament including heavier and longer range weapons than those in use today, it may well be that the type will become a serious factor in aerial warfare. At present it is an interesting experiment of great promise.
The upshot of the question of fighter types seems to be the continued use of single-seater fighters for offensive operations and the use of two-seater fighters for missions where ability to fight while withdrawing or while covering other units is a necessity. Since the two-seater fighter represents the sacrifice of performance in favor of a flexible rear gun, it is evident that this success and development of the type will depend largely upon the development and improvement of free guns and mounts suitable for use under the extremely arduous conditions of speed and acceleration which obtain in aerial combat between modern high performance airplanes.