The Air War 1914 - 1918

A General Introduction

by

Hans Appel

1 / 19 16-11-19 © Hans Appel Air War 1914 - 1918

Preface The First World War (The Great War) receives much less attention in the Netherlands than, for example, in England, Belgium and France. In itself not so strange because the Dutch were not directly involved in the conflict. The Netherlands were neutral, but the consequences of this war in neighboring countries were enormous.

If one delves into this war, the great technological innovation in aviation between 1914 and 1918 stands out. An unprecedented technical innovation from which we are still reaping the benefits.

But you also look back with astonishment at the things that happened and with admiration for the people involved. In this article I want to share with you something of my surprise and admiration. This will not be a dry story with dates and battles that have been worked out in detail. This will be a more general approach to flying in those days.

War In those days (1914) people still waged war with only ground troops, so infantry, artillery and cavalry. The third dimension, the sky, was not thought of. Remember, that in 1903, ten years earlier, the Wright brothers made the first manned flight. A 12-second flight at a height of 4.5 meters over a distance of 36 meters.

Flying was seen as an insignificant activity, toys for daredevils and eccentrics. For professional officers it was bad for your career to focus on flying. Although it was precisely this group of people who were experimenting with the new phenomenon. At that time, many professional officers were both noble and rich. They bought planes, learned to fly, and tried to convince the Generals of the usefulness of planes.

At the beginning of the First World War the Generals were very reluctant, but during the conflict they started to think differently. In the beginning, the aircraft was only used for observation and reconnaissance, but when the aircraft became more stable, faster and better armed, they also started fighting each other. They were confronted with fighters, bombers and seaplanes. Strategies were devised and set out.

A great technological innovation took place during the war. In 1914 a plane needed 30 minutes to rise to 2000 feet (600 m), in 1918 it was possible in just 2 minutes. Fragile controls had made way for reliable, more robust systems. Fokker had constructed an interruption mechanism (more about that later) for machine guns and Hugo Junkers made the first all-metal aircraft, with a cantilevered wing (monoplane). Ultimately, many of these innovations would be invaluable for the development of civil aviation.

2 / 19 16-11-19 © Hans Appel Balloons The first steps of an "army in the air" were already taken in the second half of the 19th century with the use of the balloon. The balloon was used for artillery observation to track where fired shells were dropped. The observation balloon was anchored to the ground at around 1,000 meters behind its own lines. At the height of the war, there were about 170 balloons from the English channel to Switzerland with a gap of two miles (3 km). Almost the entire front could therefore be observed from the balloons. There was communication via a field telephone and from 1915 an AM radio system was used. Simplex first (like with a walkie-talkie, talking in turns) and later duplex (like with a telephone).

Observation balloons were very sensitive to the weather and even rifle bullets could cause havoc. Photographs were also taken from observation balloons. The Kodak celluloid film was already available but the resolution and contrast were still insufficient, hence glass plates were used in the early days.

Figuur 1: An observation balloon

Airships Rigid airships that were controllable were deployed throughout the war. In the frame, which had the shape of a large "cigar", bags of hydrogen gas were attached. This gas is extremely flammable, making the airships very vulnerable. But because of this light gas, they were able to fly at an altitude of 15,000 feet (4,500 meters), an altitude that was certainly impossible to reach for fighter aircraft at the start of the war.

When planes were able to operate at that height a little later, the air turned out to be so thin, that it was impossible to set fire to those airships with the standard grenades. Only

3 / 19 16-11-19 © Hans Appel when tracer ammunition (phosphorus) became available, were fighter aircraft effectively deployed to combat rigid airships.

The first airial bombing ever took place from an airship: in January 1915 on cities in Norfolk. The shock effect was very great for the English because they thought they were unreachable on their island. However, that turned out to be an illusion.

The following bombardment flights were carried out on England during the war: • 16 attacks were carried out with Zeppelins, resulting in 557 deaths and 1,346 injuries. • 32 planes during the day with aircraft, result: 358 dead and 841 injured. • With aircraft at night, 20 attacks were carried out with: 453 dead and 1,008 injured.

Figuur 2: The airship ‘Graf Zeppelin’

Aircraft production At the start of the First World War on July 28, 1914, only Germany had a reasonable air force, with 450 aircraft. The English Royal Flying Corps (RFC) with 50 and the French with 142 aircraft had significantly fewer aircraft. Only two years later in July 1916 would the RFC be able to deploy around 410 aircraft at the front! This does not alter the fact that during the WWI huge numbers of devices were produced by the various countries (and huge numbers were also destroyed). (see table on the next page)

4 / 19 16-11-19 © Hans Appel Produced Destroyed After the war Percentage over destroyed

France 67.987 52.640 4.500 77%

England 58.144 35.973 3.300 62%

Germany 48.537 27.637 2.390 57%

All in all, it is a production of 175,000 aircraft, of which 115,000 were destroyed. 15,000 aircraft were destroyed during pilot training alone! Unimaginable numbers of destruction, not only on material but also on people killed or wounded in this air war.

It may be clear that the necessary efforts had to be made to make as large a production as possible. Few companies were involved in building aircraft. The designers were also few. Remember that the plane as a phenomenon only existed for ten years. That also meant that aviation technology was still at an embryonic stage. From aerodynamics to wing construction, from engines to armament, from instruments to communication and navigation equipment, everything had to be invented in practice.

In those days, the Netherlands was well known in the field of design and aircraft construction. Frits Koolhoven offered his services to the English during the First World War and designed successful planes for them. On the other side of the front, Anthony Fokker produced very successful aircraft for the Germans in his factory in Germany.

Exploration and observation The first deployment of aircraft was exploration and observation. The various armies on both sides of the front were given a few aircraft under their command, which they could deploy at their discretion.

In those first days of exploration and observation, the Germans, English and French, each remained on their side of the front. The pilots of all parties waved at each other when a meeting took place in the air. After all, they were gentlemen! Only after an Englishman realized that it was actually a war started shooting with his gun at an opponent, armament was considered.

The first reconnaissance and observation aircraft had a crew of two: an observation officer and a pilot. The observer always had to be an officer, the pilot could be a petty officer. In the air the pilot was the commander, so that it could happen that an officer received instructions from a non-commissioned officer. An unprecedented situation!

This clearly indicates that the differences with the air force and other parts of the army were big (and still are). The air force from then and now must operate as one team, lives are directly dependent on everyone's efforts.

5 / 19 16-11-19 © Hans Appel A reconnaissance aircraft in those days was equipped with two cockpits. The observer was in front of the pilot and the pilot was directly in front of the propeller. The use of a push propeller had the advantage that the observer had an unobstructed view and, moreover, that there was no wash from the propeller. The disadvantage was that the pilot had poor visibility, which was especially true at take-off and landing. Moreover, the aerodynamic profile of this configuration was poor. The observer therefore had to duck into his cockpit during starts and landings.

Figuur 3: A reconnaissance aircraft

An observer was not strapped in a safety belt. To be able to observe properly, he had to be able to move as much as possible freely. If the fragile device made an unexpected movement and he fell out of its cockpit, he would fall to its death, because a parachute was not available.

The pilot also had no parachute at his disposal. An RFC committee had determined that parachutes should only be used in observation balloons. In airplanes, that would have a negative influence on the pilot's fighting spirit. He would leave his device earlier and not bring it back for repair. And besides that, a captain at sea also went down with his ship !! Parachutes were not allowed until 1918. These parachutes were in the shape of an umbrella and they first had to be removed from a casing.

When the reconnaissance and observation panes were armed with one or two machine guns, it was the task of the observer to operate them. When equiped with two machine guns, one was on the upper wing, which the observer had to operate by sitting on his knees in his chair. Operating a machine gun on the edge of his cockpit was also no easy task. At the beginning of the war, his cockpit was not equipped with a sliding rail, so that every time a different shooting position was chosen, the machine gun, which easely weighed 40 to 50 kg, had to be placed in a different anchoring hole.

Later in the war when the Royal Aircraft Factory B.E.2a became available as a reconnaissance aircraft, the pilot was in the front. But that meant that the observer in the

6 / 19 16-11-19 © Hans Appel back, got stuck between all kinds of cables and struts, so that he had to sit on his knees again when operating the machine guns.

Figuur 4: The Royal Aircraft Factory B.E.2a

The communication with the artillery was initially done by throwing down weighted bags or message lashes (streamers). Also aerial photos were made. This happened just like with the balloons on glass plates and were a welcome addition to the bad or completely absent staff cards.

A system was devised in which the fire of the artillery guns could be accurately adjusted. Photographs were used to accurately determine the location of the target and the impact of the grenades was monitored from the air. In the contact with the artillery on the ground, it was indicated exactly where the impacts were and how to correct in the event of a deviation. The attitude of the artillery officers was not always positive. It sometimes happened that people did not listen to the observer or that they were very slow in processing the given information. The communication had to be short and clear. The following system was devised for this purpose: Three imaginary circles were drawn around a target that were 25 feet, 50 feet and 100 feet apart, denoted by the letters X, Y and Z. Furthermore, the clock hours were used to indicate from the direction. Deviations were passed on using Morse code. So Y12 meant that the grenade had landed about 50 feet over the target.

It took considerable time before the observers were assigned the role to which they were entitled. The generals still believed in reconnaissance by the cavalry and that this could be done with the help of airplanes, the army command admitted only reluctantly.

The planes were not allowed to go behind enemy lines and when French pilots did so at the Battle of Verdun, the army command did not believe the pilots' data. That was in January 1916 with a war that was going on for almost two years! It may therefore be clear that this did not help with the motivation of the French pilots. They were less and less eager to venture behind enemy lines. The English general Hugh Trenchard, who strongly supported an offensive air war, finally managed to convince the staff of the importance of this type of flight.

7 / 19 16-11-19 © Hans Appel The final result was, among other things, that during the Battle of the Marne in 1918, a mass of reconnaissance aircraft were deployed for tracing targets for lack of good staff maps.

Fighter aircraft The fighter aircraft did not exist at the start of the war. Each of the warring parties remained on the "own" side of the front, so defending against intruders was not an issue. But as reconnaissance aircraft on the enemy side of the lines started operating, the defense against these invaders became important. In addition, single reconnaissance aircraft were also used and had to be protected against enemy attacks.

A major problem for single fighter aircraft at the time was that the machine guns could not be placed directly in front of the pilot, so that he could give out fire accurately. After all, if that position were to be used for the machine gun, the propeller's would be destroyed. The machine guns were therefore mounted on the upper wing, so that in addition to being unable to aim properly, there was also the problem of reloading and fixing a jam.

At the outbreak of the war, the well-known French demonstration pilot Roland Garros stayed in Berlin to provide a number of demonstrations during an exhibition. He was immediately arrested and not allowed to leave his room in the hotel. However, he managed to escape from that room at night and reach the exhibition grounds. He stole a few cans of gas and managed to escape with his plane to France. Arriving in his home country, he immediately reported himself to join the French Air Force.

He invented a system in which steel armor plates were placed on the propeller, so that the fired shells would bounce off. The system was not really reliable because the grenades, which broke off uncontrolled, could fly in all directions. So you could also hit your own plane. But despite that, it was still used.

On April 1, 1915, the first aireal fight took place on the western front, between Roland Garros and a German opponent in an Albatros C.1. Garros successfully closed that first encounter and shot another Albatross on the same day. Within two weeks he managed to take down another three German planes, bringing his total to 5. Roland Garros became the first "Ace" with those 5 wins. It goes without saying that there was some panic on the German side and they did not know what the French had devised to enable shooting by the rotating propeller. Until 18 April then, because then Roland was shot down and he did not get the chance to burn his plane. Garros disappeared into captivity, but it was much more important to the Germans that they had received an undamaged plane. The aircraft was immediately shipped to the Fokker factory in Germany.

Fokker discovered the armor plates, but this system could not be used by the Germans. The cores of the German shells were made of armor steel and there was no question of bouncing. The propeller would be shot to shreds with defection plates and all.

8 / 19 16-11-19 © Hans Appel But within five weeks, on May 20, 1915, Fokker came up with a much better solution to the problem: an interruption mechanism (the Fokker Stangensteuerung). This interruption mechanism prevented the machine gun from firing when the propeller passed. The speed of the propeller had to be between 1,000 and 1,100 rpm. Two Fokker E.I aircraft were equipped with the system and as the English called it, the "scourge" or "torment" of Fokker was born. Not only born, but the "scourge" lasted nine months! It caused the average chance of survival of the English pilots on the front not exceeding eleven days!

Figuur 5: The Fokker E-I with a synchronized machine gun

Thanks to the fact that single fighter aircraft were used to protect the reconnaissance and observation aircraft, the latter increasingly infiltrated behind enemy lines. It had since become clear that the information obtained in this way about troop movements and the construction of defenses could determine the ultimate success of a battle.

Now the opponent tried to prevent the penetration of scouts by constructing a "defense curtain" consisting of fighter aircraft. That defensive curtain was erected by fighter planes who patrolled continuously along the front line. This in turn resulted in the fighters of the various parties attacking each other. At this moment the "dog fight" was born.

Dog fight or Kurvenkampf The circumstances under which the "dog fights" took place in those days were no fun. To start with, the pilot was in the open air. He was stuck in the wind at 200 km / h behind his propeller. That was no fun in the summer, but in the winter at -17ºC it was pretty hard. The temperature decreased even further with the flight altitude, by 2ºC per 1000 feet (300 meters). Your only protection was a leather cap and aviator glasses! And don't forget, in those circumstances you had to fight for your life.

9 / 19 16-11-19 © Hans Appel Incidentally, the technicians who kept the aircraft deployable in the winter did not have a simple job either. The "hangars" were often no more than a few large tents, so there was plenty of work to be done in the cold. In those days the technology was of course in its infancy. A good example of this: antifreeze was not yet available, with the result that the engines of the aircraft that had landed had to be drained immediately. And when in the winter conditions te engines had to be restarted, cooling water was first heated to just below boiling point and then poured into the cooling system. In this way freezing of the engines was prevented and a successful start was achieved.

After the start of a "flight" aircraft, they rose to 500 feet (150 m) to form a formation at that height. It took some time to reach the operational altitude of 15,000-16,000 feet (almost 5,000 m) with those aircraft, but because most airports were about 30 km behind the front, that altitude was reached before the penetration into enemy territory. The aircraft continued to fly 20 to 30 meters apart in the formation. They could not communicate with each other because they had no radio on board. If they were lucky they would fly higher than the enemy, but in the early years of the war that was often not the case for the English. This, due to the poor performance of their aircraft (e.g. RAF BE 2c). Once in combat, 30 to 40 grenades were fired in a short burst. There were no adequate aiming means, so the pilots monitored the impacts of the tracer ammunition they fired in order to aim more accurately. Incidentally, the fights usually lasted no more than 5 to 10 minutes.

The German aviator ace Oswald Boelcke (40 victories, Pour le Mérite, Blue Max) has set up the first rules along which a dogfight was to be fought. In addition, it is nice to note that those rules still apply. His rules were as follows:

1. Always ensure you have a favorable position with regard to your enemy before you attack. Climb before and during the approach of your enemy, this to surprise him from above, dive quickly at him when the attack moment comes.

2. Always try to attack your enemy from behind.

3. Try to place yourself between the sun and your enemy. Your enemy gets the glare of the sun in his eyes, which makes it difficult for him to see you and makes it impossible for him to shoot with any accuracy.

4. Attack your enemy when he least expects it by being busy with other things such as reconnecance, photography or bombing.

5. Never turn your back on your enemy, never flee. If you are surprised by an attack on your tail, turn towards him and use your machine guns.

6. You must always complete an attack that you started.

7. Only fire up close (50 meters) if you have the enemy in sight.

10 / 19 16-11-19 © Hans Appel 8. You must always keep looking at your enemy and not be tricked by him. If your enemy appears to be damaged, follow him down until he crashes, so that you know for sure that he is not kidding and pretending that he has been eliminated.

9. If that doesn't work, fly straight to your enemy (who has the best nerves).

10.If your enemy dives, you dive with him.

11. Do not attack one enemy with multiple planes at the same time.

12.Take into account the position of the observer (front or rear cockpit).

13.Stupid heroic deeds always result in death. The pilots of the Jasta (Jagdstaffel = squadron) must fight as a team.

14.The commands and signals of the leaders must be obeyed.

As noted earlier, everything was invented in practice like the use of new flight movements. Take the "Immelmann", a flight maneuver that Max Immelman would have thought of. With the Immelmann, the aircraft makes a half loop followed by a half roll as soon as the top of the half loop is reached. All this to quickly change direction. At the top of the half barrel, the plane flies upside down, but the roll returns the plane to its normal position. This maneuver can be performed when you fly straight at your enemy and pass him. Because of the Immelmann you will eventually end up behind the enemy, which in turn is a favorable starting point for an attack.

Figuur 6: A so-called fur-ball. An aerial combat with a large group of aircraft.

11 / 19 16-11-19 © Hans Appel The machine gun was particularly important in the dogfight. You want to be able to aim accurately and the operation must be simple. At the start of the war, they were reconnaissance aircraft that attacked each other and their crew consisted of a pilot and an observer / gunner. The observer / gunner usually had two machine guns available. One on the edge of his cockpit and a second one on the upper wing of his aircraft. It has already been noted that it took quite some effort to get the machine guns into a good shooting position. In addition, a "Lewis gun" was used with the British. This machine gun made use of cartridge drums that contained 47 cartridges. If they were finished, the cartridge drum had to be replaced, which entailed a lot of pulling and lashing.

Later, even single fighters were equipped with these Lewis guns on the upper wing and the pilot had to loosen himself and stand on his seat to replace a cartridge drum. He had to fix his control stick as good and as bad as that, which was hardly possible with the kind of fragile and unstable aircraft. It often resulted in a flight down at a speed of 60 to 80 knots (100 to 140 km / h). A later applied mechanism, invented by a sergeant Foster (RFC Engineers), was a major improvement. Hereby the Lewis gun was turned a quarter turn back, so that the pilot could remain seated.

The Germans used Spandau machine guns. These were fed with cartridge bands that contained 500 grenades. In addition, the Germans were able to shoot their machine guns through the rotating propeller. This was possible with the help of the interruption mechanism invented by Fokker All in all, this was a big advantage in an air fight.

And hence the fact that the so-called "Fokker scourge", as already stated, brought more than 9 months of benefit to almost every aerial combat.

Figuur 7: Two synchronized Spandau machine guns in a Fokker fighter aircraft

12 / 19 16-11-19 © Hans Appel Bombers As the war progressed, the generals became increasingly convinced of the ideas of Hugh Trenchard, the British general responsible for the Royal Flying Corps. He wanted to use fighter aircraft defensively, while he saw the role of bombers offensive. The fighter aircraft had to be used to protect their own territory, against intruders and as an escort for reconnaissance aircraft and as tactical support for the ground troops.

The role of the bombers was the bombing of factories, railway yards, bridges and cities. Trenchard saw this as a means to make the citizens turn against their own governments.

By the way, in those days people thought a bit very simple about throwing bombs at a target. It was thought that it was sufficient to make a hole in the bottom of the aircraft with the idea that when the target becomes visible through that hole, to drop a bomb!

The British had organized their bombers within the Royal Naval Air Service (RNAS) and in November 1914 the RNAS already bombed cities such as Düsseldorf, Cologne and Friedrichshafen.

The Germans organized their bombers in so-called "Schlachtstaffeln" (fighter-bomber squadrons). For the benefit of the Western front, they were stationed in Ostend, Belgium, and were referred to as "Brieftauben Abteilung Ostende" for camouflage (carrier pigeon section Ostend).

The planes designed and used for this purpose were made available to the warring parties in 1916.

Riesenflugzeuge or Riesenbomber (giant bomber) Already in 1915 the Germans developed their first Riesenflugzeug (giant airplane) that made its first flight under the name VGO I on April 11, 1915. Ferdinand Zeppelin, the German aviation pioneer in the field of rigid airships, had a visionary view and assumed that a large, strategically deployable bomber would be needed in the war.

These aircraft, the Zeppelin-Staaken-R VI "Riesenflugzeug", were housed in the so-called Riesenflugzeug-Abteilung (Rfa) 500 and 501.

The Riesenbomber were initially designed to be used only at night. Furthermore, one of the design requirements was that the engines must be able to be maintained during the flight. After all, it was assumed that four to six engines would be used on such an aircraft and that long-term flights would be carried out. Given the unreliability of the engines at that time, that possibility of maintenance in the air was therefore not a superfluous luxury.

A company was set up in Germany specifically to design Riesenflugzeuge: "Versuchsbau Gotha-Ost GmbH" (VGO) with Zepplin as director and as driving technical force the 28- year-old engineer Helmuth Hirth.

13 / 19 16-11-19 © Hans Appel Hirth had to build an aircraft that was at least three times as large as the aircraft known until then, and that did not mean that all dimensions could be multiplied by three! For example: if you make wings 3 times as large, the upward force (lift) will increase by 9 times, but the forces that will work on the wings will become 27 times as large!

To cite another design problem: synchronizing the engines was not possible at that time. As a result, engine behavior could only be predicted to a limited extent, which naturally had an effect on the baseline values of the technical calculations. Would the machine still be able to fly straight ahead and stay at a height if a motor fails?

Figuur 8: The "VGO I" Riesenflugzeug

The propellers had to be very large, they had never been made so large. What would the chassis do when landing? Incredibly large forces would work on it and remember, there were no airports with beautiful concrete runways. Would things stay intact?

The structure had to be able to handle, absorb and distribute these forces, which meant that many detail problems had to be solved. How large did the ailerons have to be and where did they have to be placed on the wing? The aircraft had to remain well manageable and the power to control the controls should not be too great.

The "VGO I" took off on April 11, 1915. It was equipped with three Maybach-Motor HS engines of 240 hp each. It was a bi-plane with a wingspan of 42.2 meters and a take-off weight of 11,485 kg. The plane was about 6 meters high. At this first start on a grass meadow, the plane only needed 22 meters to get off the ground.

The used Maybach-Motor HS engines were actually designed to power airships. At the VGO I they had to run at full speed and they were quickly overheated. Daimler-Benz engines were later used that worked better. The engines were placed in engine nacelles, two per gondola, a pull and a push motor. In addition, a flight engineer accompanied every gondola to work on the engines during the flight if necessary. And to be honest, that was badly needed due to the poor quality of the engines at the time.

14 / 19 16-11-19 © Hans Appel The performance of the used engines decreased considerably at higher altitudes. A solution was found for this: Experiments with an additional engine that was built in the cabin and that was linked to a compressor. Pipes to the aircraft engines created a reduced pressure with compressed air in the carburetors and fuel supply pipes, so that more fuel was supplied. This solution worked satisfactorily. Without the additional compressor, it took 2.5 hours to reach a height of 4,000 meters, with a compressor going to 6,000 meters in 1.5 hours.

Figuur 9: Zeppelin-Staaken R.VI

The result of this first series of successful test flights with a Riesenflugzeug constructed by Zeppelin was ultimately the construction of the Zeppelin-Staaken R.VI, of which around 18 were built from 1916 to 1919. Initially these Riesenflugzeugen were deployed on the Russian front and later, more towards the end of the war, they got a base in Ostend, Belgium.

The Zeppelin-Staaken R.VI was a real Riesenflugzeug. The aircraft was a biplane and had a wingspan of 42.2 meters (upper wing), was 22.1 meters long and was no less than 6.30 meters high! There could be a bomb load of 2,000 kg. be taken along. He also had a machine gun at his disposal as protection against enemy aircraft. The engines that were used were the Mercedes D.IVa or Maybach Mb.IVa engines.

The engines made a lot of noise, so that the commander used a "ship's telegraph" when communicating messages to the men in the engine nacelles. The messages to the tail gunner and fuel technician were sent via "tube mail".

To keep a Riesenflugzeug operational, about 50 people of ground staff were needed. The crew consisted of 8 people: • a commander also navigator • two pilots • two flight engineers in the engine nacelles • a fuel technician who kept an eye on the fuel during the flight and, when necessary, pumped it from one tank to another to avoid disturbing the trim of the device • a tail gunner • a radio telegraph operator.

15 / 19 16-11-19 © Hans Appel In addition to radio communication for messages to ground stations, the first steps were taken in the field of radio navigation. By using a 1500 watt transceiver on board, a range of 450 to 600 km was achieved, making radio navigation possible.

Fighting this type of aircraft was a major challenge for the British. The British deploy their fighters and their night fighters. But it was hardly possible to fight those bombers. There were no technical means for detecting them in time, and once they had been "caught" in searchlights, it took the fighters far too long to reach such a bomber at their cruising altitude.

Giant bomber The English were of course not stay behind with the design of large bombers. The O/400 was built in 1916. This aircraft had a wingspan of 30.48 meters and could carry around 2,000 kg of bombs. At a maximum speed of 157 km/h, this aircraft was able to stay in the air for more than 8 hours at an altitude of 2,600 meters and fly for 1,120 km. A special feature of the O/400 was that the wings could be folded along the hull so that it was easier to put in a hangar.

Figuur 10: Handley Page O / 400

At the start of the war, the bombs were no larger than a few dozen kilos, which were thrown out of adapted reconnaissance aircraft. At the end of the conflict it was made possible by these giants to take bombs of more than 900 kg.

When the large bombers were not yet available, so-called “flechettes” were used in addition to small bombs. These were a kind of arrows (similar to darts) made of steel that were taken in a drum of 250 or 500 pieces. They were scattered above the trenches to injure or kill the soldiers.

16 / 19 16-11-19 © Hans Appel There has even been a French pilot who took 18,000 flechettes in a bombardment and scattered them!

Incidentally, it must be borne in mind that accurate bombing at that time was out of the question. In addition to the aerodynamic properties of a bomb, data is also important such as the drop height, the speed of the aircraft, the wind speed and direction of the wind and the weight of the bomb, to name just a few. There were no accurate instruments available that could measure this type of data. However, people had learned that you would bomb more accurately if you were flying at a low altitude. Which of course was more dangerous due to enemy fire from the ground.

With all this, there was also the navigation problem. Hardly any instruments were available for navigation either, and often there was a lack of reliable maps. They flew "house-to-house", what we now call "visual flight rules" and / or dead reconing. If pilotes had lost their way or if they were in doubt as to their correct position, they would fly so low over railway stations that they could read the names in order to be able to orient themselves again.

During the first years of the war, the bombers were often sent out on their own and had to protect themselves by using machine guns, but towards the end of the war they were increasingly operating in "swarms", which were protected by their own figters against enemy fighters. A new discipline within aviation was born: "Bomber Command".

War above the sea The use of the third dimension in the navy was very old. The Royal Navy was and still is an innovative defense component. In 1806 the frigate “Pallas” on the French island of Île d’Orléron used a kite to drop pamphlets over the island.

And in the nineteenth century the Admiralty already used kites and balloons to which people were attached. This is to perform reconnaissance of a coast with enemy batteries.

Flying above the sea requires extra reliability and constructively strong aircraft. It was also important to be able to cover long distances and therefore stay in the air for a long time. Should a problem occur with the aircraft, it was then possible for a land plane to land, correct the problem and take off again. With planes above the sea that was out of the question.

Navigation was also extra difficult. There were no instruments that supported navigation above the sea and navigating the house-to-house flying as happened above land was of course not possible. Navigating the stars was not practical, if not impossible.

And how were you supposed to attack another ship? Firstly, there was the problem of tracing an enemy ship and, moreover, there was no experience of the effective use of a bomb or a torpedo.

17 / 19 16-11-19 © Hans Appel That the Admiralty understood the usefulness of airplanes in the RFC Naval Wing (later the RNAS) can be seen very early on from the fact that in August 1914 it already had 39 land and 52 seaplanes. Altogether more than what the "land" part of the RFC possessed.

The tasks to be performed by the aircraft included:

• observing the fire of one's own ship's cannons • exploration of enemy ports • search for enemy ships • attacks on enemy ships • anti-submarine patrols • rescue of shipwrecked sailors

Use was made of land planes equipped with inflatable balloons, which were inflated when landing on the water. But after some experiments it soon became clear that planes equipped with floats were the future.

These aircraft were able to take off and land from and on the water. They were pulled out of the water for maintenance by their accompanying ship and put back in the water when needed. A calm sea was required for these procedures. All in all a complicated and lengthy process. There were no aircraft carriers that made it possible to take off from a ship and land on it again.

The solution that was devised was constructing a "runway" on top of a ship's turret. A kind of large platform was made on the cannons of about 18 to 24 meters in length. An existing land plane that only needed a short runway, for example the Sopwith Camel that only needed 6 meters of runway to start, was equipped with inflatable balloons and voila the first seaplane was born.

Figuur 11: Left a take off from a battle ship, right a take of from a carrier

At the start the ship was turned in the wind. The barrels of the guns gave some elevation, giving the track a favorable angle. The pilot ran the engine at full speed and gave a signal to the starting team leader that the anchoring of the aircraft could be thrown loose. And the plane was gone.

18 / 19 16-11-19 © Hans Appel With the need to deploy larger aircraft with more extensive tasks and the emergence of floats and wheeled seaplanes, there was a need for real aircraft carriers that, in addition to a longer runway, were also equipped with a catapult launcher. In 1916 the British Admiralty therefore ordered such an installation that could give an acceleration of 2.5 g to a weight of 2,500 kg. The aircraft thus reached a speed of 60 mph within a distance of 25 m.

A dredger was converted into an aircraft carrier and on 18 June 1918 a Fairey N.9 seaplane from this ship was successfully launched for the first time with the help of a catapult. A special feature is that despite the proper acceleration, the pilot's seat was not equipped with a headrest. With people, at that time it was clearly dealt with differently than we are used to today!

Conclusion With this introduction only main issues have been discussed. The "Air War 1914-918" is an interesting area to delve deeper into various topics discussed. This introduction is therefore intended to arouse the interest of the reader to investigate.

19 / 19 16-11-19 © Hans Appel