Aeroplane Construction and Operation

by John B. Rathbun

Fig. 9. Types of Aeroplane Bombs. The Tail Surfaces Guide the Bomb So That It Strikes on the Firing Pin and at the Same Time "Safeties" the Bomb So That it Will Not Explode Until it Has Fallen for Some Distance. In Falling, the Tail Blades Rotate and Release the Firing Mechanism After the Bomb Has Fallen Clear of the Aeroplane. Courtesy of "Flying."

Fig. 9-a. Curtiss "JN" Twin Motor Biplane. Observer Is Seated in Front.

In the navy the aeroplane has proved of much value in scouting and particularly in defense against the submarine. Because of its great speed it has a daily radius of action many times that of a torpedo boat, and because of its altitude the effective range of vision is still further increased. At a fair height the observer can easily detect a submarine even when submerged to a considerable depth, a feat impossible when near the sea level. For disclosing the conditions existing in an enemy harbor the aeroplane is fully the equal of the dirigible since it can approach and retreat rapidly, and without much danger at comparatively low altitudes. While the dirigible can float indefinitely at one point, it must be done at an altitude that is safely out of range of the enemy guns, and this is usually at a point where observation is a difficult proposition. It does not take long to get the range of such a target as a hovering dirigible, yet at a much lower altitude it is difficult to handle naval anti-aircraft guns effectively against a speeding aeroplane. The smaller scouting seaplanes can report the position of a submarine to a torpedo boat or "sub-chaser," while the larger machines are perfectly capable of dealing with the submarine at first hand. On the large bombing type, a three-pounder gun and a number of large bombs can be carried, either of which would be sufficient for the purpose.

Fig. 10. Explosion of a German Aeroplane Bomb Near Mesopotamia. Courtesy of "Flying."

In land defense chasers and fighters are used for patrol, and to maintain a barrage against the entrance of enemy machines into our lines. The patrol machines work along the front line trenches, while the machines maintaining the barrage are generally arranged in two parallel lines back of the trenches, the first being about five miles, and the second about ten miles from the front. All three lines are generally placed between the enemy and the principal stations and railroad centers to insure protection from enemy bombers and reconnaissance machines. Should the first line patrol fail to keep raiders from crossing the first line trenches, they will have to pass through at least two more zones of organized fighting squadrons before reaching a vulnerable spot in our lines. The machines used for patrol and barrage are of the high speed and fast climbing chaser type. The response to an attack involves rapid climbing, and a high degree of maneuvering.

Fig. 11. Caproni Triplane with Three Independent Power Plants. The Motor in the Central Body Drives a Pusher Propeller, While the Other Power Plants Are Mounted in the Two Outer Bodies and Drive Tractor Screws. This is an Example of the Larger Bombing Aeroplanes. The Gun Is Mounted in the Front of the Center Body. Courtesy "The Aeroplane."

Except for the bombers and battle planes, the machine gun or "Mitraleuse" has been the only form of arm in common use on aeroplanes. These use ammunition approximating service rifle caliber and are furnished in bands, strips or drums according to the type of gun. With larger guns, the weight of the ammunition has been found excessive with all but the largest bombing machines, and the recoil of a large caliber gun has also been difficult to overcome. In a modern American aeroplane gun of large caliber the recoil has been reduced to almost a negligible degree, even up to the four-pounder size, by a system of balanced projectile reactions. This gun has met successful tests, but whether it has met with general adoption would be difficult to say at the present time. In Europe, large caliber aeroplane guns have been used on large "battle planes" or "gun planes" for shelling dirigibles, or in destroying searchlight stations in bombing raids. The battle planes are nearly always of the "Twin" type with the gun mounted in the front end of the fuselage.