The following is an attempt to point out the importance of aircraft for the navy, and to discuss briefly the duties which they can perform. After some experience, both at home and abroad, I have been struck with the suspicion, and, in some cases, downright antagonism, with which some officers and others in authority among the Allied nations regard all naval aviation.
This has been carried to an extent which has seriously handicapped the flying personnel in carrying out duties outlined below; both because of failure to supply material and personnel, and also a general restriction of all aerial operations.
A great many officers who are far-seeing and progressive believe in the future of aviation, but they have only the haziest ideas as to what aircraft should and can, do.
Aircraft, due mainly to the reliability of the present-day motor and their large cruising radius, have now reached a point where, with skilled personnel, they can carry out all the duties outlined below.
Any fleet which has a number of aircraft squadrons will have a tremendous advantage over one which is not so equipped. We must get carriers in our fleet and aircraft bases at strategical points or we will invite disaster when the next crisis comes.
The following duties, in order of importance, are those which should be performed by naval aircraft:
I. Bombing enemy's men-of-war and bases. Shooting up bridges, tops, balloons, etc., with cannon and machine-guns. Attack with torpedo-planes.
II. Protection of own fleet from hostile aircraft.
III. Scouting.
IV. Reporting on movements of enemy over smoke screens, in low visibility and over the horizon.
V. Detecting mine-fields, torpedoes and submarines.
VI. Spotting.
VII. Escort.
I. Bombing Enemy's Men-of-War and Bases
All offensive action must be carried on by heavier-than-air craft until a practical non-inflammable gas is in use for lighter-than-air craft. At present, dirigibles are easy targets, as one incendiary bullet will set them in flames. They must keep away from hostile aircraft.
Offensive action against surface craft was not of much use in the war, but will become increasingly important, and, it is believed, to an extent that will revolutionize the construction of men-of-war. The reasons for the limited number of successful air attacks on vessels were: Lack of opportunity, small size of bombs, poor bomb sights, untrained bombers, insufficient number of planes and material, and a poor development of aerial strategy and tactics.
Some good work was done against submarines, and one R. A. F. Squadron (No. 217) sank at least two German destroyers, using DHS and only 230-pound bombs. A Handley Page Squadron (No. 214) that was operating from our aerodrome at St. Inglevert was dropping 1650-pound bombs. They were loaded with about 1100 pounds of T.N.T., as against only 29 pounds for 14-inch A.P. shell. If heavy bombs were made armor-piercing, they would sink any but capital ships and undoubtedly put dreadnoughts out of action.
Bombing campaigns would be carried out by large bombers, such as Handley Page, getting off a large flush deck carrier; by two-seaters, such as DHs, also operating from a carrier; and by large seaplanes hoisted overboard from a carrier. Of course, any type could operate from a shore base if the enemy were within their cruising radius. Shore bases, while necessary for supplying material, repair, etc., and for protection of the coast, do not take the place of carriers. Bases have the same fault as fixed coast defences—the enemy will always "come where they ain't." Carriers are like railroad artillery, they can always meet the enemy no matter where the attack comes from, and, in addition, can accompany the fleet and attack as well.
If hostile aircraft are to be encountered, the large bombers, seaplanes and torpedo-planes must be, and the two-seaters should be, convoyed by fighters for day work.
All "day bombing" should be formation work, and should be concentrated.
With the present inaccuracy of anti-aircraft fire from ships, bombers could go over as low as 4000 feet in the daytime. At night, both bombing and torpedo work are much easier, as surface craft can generally be seen in any but the darkest nights, whereas aircraft are invisible and could go over as low as 2000 feet.
Bombs must be suited to their objectives just as projectiles are. Against capital ships and concrete, the largest possible bombs should be used. As already stated 1650-pound bombs were used in the war, and 3300-pounders were being experimented with when the armistice was signed. Against light cruisers, destroyers and bases not under concrete, a number of smaller bombs would be more effective; the 230 and 520 were mostly used. Against personnel, a large number of small bombs with good fragmentation, such as the 20-pound Cooper, are the best.
For action against surface craft and land objectives, heavy case bombs should be used, as the destructive effect of the fragments is important; whereas against submarines, light case with a correspondingly larger amount of explosive should be used, as the force of the explosion is the only consideration. For both submarine and surface craft bombing, a delayed action fuse is necessary; in the one case to get under water, and in the other (coupled with a heavy armor-piercing nose) to get through the upper decks.
With the accuracy of our new sights and the application of proper tactics and material, the importance of the future of bombing cannot be overestimated.
Gunnery work from aircraft against any enemy except other aircraft is secondary to bombing, but undoubtedly much damage could be done by both single-seater and two-seater fighters against bridges, tops, etc., with machine-gun and cannon. The 1½-inch automatic cannon now in use and the 3-inch semi-automatic now being constructed, will greatly increase an aircraft's offensive powers.
There is undoubtedly an important use for torpedo-planes, especially for night work. It is understood that in recent maneuvers six British torpedo-planes attacked destroyers at 25 knots and made four direct hits.
II. Protection of Own Fleet from Hostile Aircraft
As the offensive use of aircraft outlined in I is increased, there must be a corresponding increase in defence. There is no doubt that the primary defence against hostile aircraft is fighting air craft of your own. These give a much greater protection than is possible with anti-aircraft fire, which for many reasons is not nearly as efficient from ships as ashore. Fighting aircraft not only protect vessels from direct attacks, but if in sufficient numbers and properly handled, should prevent the enemy's planes from carrying out any of their duties, such as scouting, escort, spotting, etc.
There was no general aircraft fight at sea during the war, for the reason that the British did not realize the value of planes with the fleet until after Jutland, and never had another chance. The Germans did not develop seagoing aircraft sufficiently to attack, and the Zeppelins were too vulnerable. Both sides were getting ready for a very large aircraft offensive in connection with their fleets towards the end of the war. The British had a number of aircraft carriers with a large number of planes, converting some of their largest ships for this use. In addition, they had planes on all battle and light cruisers, and were putting them on some of their dreadnoughts. In October, when they thought the enemy's fleet was coming out, they were concentrating all available planes at their North Sea bases. The Grand Fleet was to be accompanied by an overwhelming number of aircraft (many hundred), both for protection against Zeppelins and large bombers, to attack the enemy, and for the other valuable duties of scouting, spotting, etc., which could best be performed by aircraft.
This engagement was only prevented by the mutiny in the German Fleet when it was ordered out in October, 1918.
Efficient fighting aircraft are at present single- and two-seater, light fast planes, but undoubtedly in the future there will be a large flying boat which will be armored around the vital parts, and will carry cannon as well as machine-guns. French flying boats are already carrying 3-inch guns. This craft will have no "blind spots," and will be able to put out such a volume of fire that no small fighter can get in on her.
Lighter-than-air craft should make formidable fighters, owing to their stability and the heavy armament they can carry, but only after a non-inflammable gas is adopted.
Aircraft in contact with the enemy must keep always in a proper formation. This is the secret of successful aerial fighting and bombardment.
III. Scouting
For scouting and long distance reconnoissance aircraft are far ahead of surface craft because of their great speed. We now have seaplanes with a radius of 1200 miles. It is easy to see the efficient work a squadron of such planes could do with their speed of 60 miles per hour, coupled with efficient radio work. Dirigibles are also valuable in scouting, but at present are more liable to be weather bound than seaplanes, as the latter can now go out in nearly any weather.
For scouting near the fleet, say up to 150 or 200 miles, the two-seater bombing and fighting planes could also be used, operating from the carriers.
Many valuable reports as to the movements of the enemy were made both from lighter- and from heavier-than-air craft.
Scouting altitude and distance (distance between planes) depends upon the visibility and the type of craft that it is expected to meet. It ranges from 1000 feet altitude and a few thousand yards apart for submarine search, to several thousand feet altitude and a 50-mile or more distance for surface craft. In clear weather, high altitudes and greater distances give the most efficient results. Often it is necessary to come down very low to get under the clouds or low visibility. Often it is possible to go over or around a rain-squall or mist, and still have good visibility. If fog is encountered, it should always be run away from, or if in a proper place, a landing made before it closes in. On any patrol, if fog or heavy clouds are encountered, different altitudes, determined beforehand and at least 500 feet apart, should always be taken at once to avoid collision.
IV. Reporting on Movements of Enemy Over Smoke Screens, in Low Visibility, and Over the Horizon
Reporting enemy's movements overlaps scouting, but reports when in contact or almost in contact with the enemy can be made by nearly any type of aircraft including heavier-than-air craft, dirigibles and balloons. The great value of aircraft for this work was proved in many maneuvers in the Grand Fleet. Many times when the fleet was absolutely blinded, due to smoke, poor visibility or distance, all the information desired by the admiral was sent down from the air. Types of ships, formations, base courses, changes in base courses, etc., are easily seen. Radio telephones should always be used for all communication work up to their distance limit, and then radio telegraph. Visual signals are only secondary in case of radio failure.
V. Detecting Mine-Fields, Torpedoes and Submarines
In detecting mine-fields and submarines from aircraft, two factors must be considered: the clearness of the water and the condition of the atmosphere. Ability to see under water varies with these two factors. Under the most favorable conditions, such as can be found in the Caribbean, very clear water and a strong sun overhead, it is possible to make out a shape over 100 feet under water. In muddy water, such as the Chesapeake in the spring, nothing can be seen a foot under the surface, and under-water visibility varies between these two conditions.
In general, in blue water, mines can be picked up some fathoms under, especially if there is a bright sun behind, and submarines to a greater depth. Of course, submarines light or awash are easily seen and the V wake from a periscope is visible a long distance in moderately smooth water.
The wake of a torpedo is easily picked up, and if the aircraft is connected with the ship control by telephone, directions for avoiding it are of great assistance.
For detecting submarines, mines and torpedoes, dirigibles and balloons are probably more efficient than heavier-than-air craft, owing to their ability to stay in one place, and their greater ease of observation. A great deal of this work was done in the war by all three types of aircraft. Mine-fields and floating mines were reported frequently, and many submarines discovered and attacked, or reported to surface craft.
VI. Spotting
It is thought that two new factors when properly developed will mean a great deal to gunnery in the fleet. These are the use of star shells at night and aircraft spotting by day. The former was developed by the enemy on the Belgian coast. Star shells as large as 8 inches were used both against aircraft and men-of-war. The latter was brought to a high state of efficiency for land work on the Western front, practically all efficient long-range shooting being controlled by aircraft.
The Grand Fleet was using aerial spotting for long-range work and an efficiency of at least 300 per cent higher was obtained from aerial spots than from ship spots. Our latest 14-inch 50-caliber gun can shoot over 28,000 yards, and undoubtedly will open fire at at least 25,000 yards in the future. It is not believed that ship spotting can be accurate at over 18,000 yards, whereas aircraft spotting is efficient for any distance and is not affected by smoke screens.
Kite balloons have the great advantage of direct telephone communication, but the disadvantage of giving away your position to the enemy. They also have a bad whip when a salvo is fired, and cannot be used in bad weather.
Dirigibles seem the best aircraft for this work, using radio telephone, but they also are liable to be weather bound.
Heavier-than-air craft are handicapped by the difficulty of keeping the plane in a position such that the observer can always see the target. Planes having the best visibility (flying boat with a front cockpit) should be used and radio telephone for communication. This should be connected with plot, and the gunnery officer connected in with one earpiece.
The altitude depends on conditions of visibility. In general, from 1000 to 5000 feet.
The procedure would be as follows for front cockpit boats:
(a) Planes leave the carrier (or report from base) 15 minutes before opening fire, and get the altitude that will give them the best visibility; in clear weather, about 3000 feet.
(b) Test out radio phones. Must be able to talk clearly with plot. Test out radio telegraph and other secondary signal systems in case the phone fails. Signals that have been used with varying success are different colored smoke puffs, maneuvering the plane, and flags and streamers.
(c) Notify plane to stand by three minutes before first salvo. Plane will then maneuver so as to pass over firing ship in line of fire, flying towards the target, at the instant first salvo is fired.
(d) Notify plane which target ship is firing at, and keep him informed if aim is shifted.
(e) Notify plane of approximate range.
(f) At instant of firing sing out "fire" to spotter so that he does not have to strain his eyes watching for the blast or splash.
(g) Plane should pass over firing ship as first salvo goes and spot for first salvo in this line of flight. Spotter always uses standard terms, as "up 100, right 02," or "down 100, left 3." Spotting must be quick and accurate, and when using radio phones should be in as soon as the ship spotter's corrections. Only trained spotters should operate. A good spotter with some air experience should increase spotting accuracy several hundred per cent, whereas the best aviator in the world, if not an expert spotter, would be sure to make a mess of things.
(h) After first spot is out, turn to right or left, and fly back and forth in front of the firing ship, always turning towards the target. In order that each turn does not increase the distance from the firing ship, and so decrease the strength of the phone and get into the trajectory, each leg must incline towards the firing ship. As each "fire" comes over the phone the pilot can kick the nose toward the target and then back again after the spot is out. This prevents the wing from obscuring the observer, and by maneuvering in this manner every salvo should be spotted. Care must be taken not to get too far from the firing ship, or the plane, unless very high, will get into a dangerous part of the trajectory. For a 14-inch 50-caliber, at 20,000 yards, the maximum ordinate is 4600 feet, and for 25,000 yards is 7300 feet. A rough rule, good up to an ordinate of about 2000 feet, is that the range is equal to the ordinate times the cotangent of the angle of elevation. For instance, for a 20,000-yard trajectory, then
X = 1000 cot 12° 57’.5
= 1000 log 10.63803
= 1445 yards.
From this it can be seen that if a plane flew 1445 yards in front of the firing ship at 1000 feet, she would get into the trajectory of the projectile. The data for this formula can be obtained for any gun from the range tables, and will always keep the plane above the projectile, as it is accurate for the straight path and thereafter the curve is down, or away from the aircraft. A safety allowance should be added to this to provide for high shots and air disturbance.
VII. Escorts
Escorting surface craft and submarines has been one of the most important duties performed by aircraft. There were almost no cases of submarines attacking a convoy when there were aircraft present, as the German commanders always submerged when a plane was seen or heard. The Dutch and Channel convoys, and, towards the end, the French coastal convoys, were nearly always escorted by planes as well as surface craft.
Dirigibles are more suitable for convoying than planes, owing to the greater ease with which they can remain over the convoy. This obtains always, provided no contact is made with the enemy's aircraft, when dirigibles would probably be shot down.
Pilots must remember that the mission of escort craft is to get the convoy to its objective, and must not leave their station for any reason except motor failure. There is no excuse for chasing an enemy sighted on the horizon, and then have a hostile submarine come up and get several ships.
The tactics of escorting convoys, scouting, searching for mines and submarines, etc., were brought to a high state of perfection under Commander Kenneth Whiting, U. S. Navy, at our North Sea Air Station at Killingholme. The deep sea (submarine and mine search) and the convoy squadrons were always in the air; the latter escorting convoys having as many as 150 ships. About 6200 ships were convoyed by our planes from this one station, in the less than four months of our regime, with only one ship sunk, and this when the escort planes were down with motor trouble. This was done in the most active submarine zone, the East Coast of England. Letters from the Admiralty and the Vice Admiral commanding that part of the coast, testify to the British Navy's high opinion of the importance of this work.