The Rise of Airpower in the First World War.
How the First World War drove the development and use of airpower and shaped the way in which future conflicts have been fought.
Amongst the many technological innovations introduced as a part of the First World War, the rapid development of war in the air was one of the most significant. In this article, we will look at the development of the military use of airpower and show how the First World War acted as a catalyst for the widespread use of airpower in later conflicts.
The origins of airpower before the First World War, can be traced back to stationary tethered balloons used in the late Napoleonic and American Civil Wars. Designed as platforms from which enemy troop movements and formations could be observed and mapped, balloons allowed accurate information on troop dispositions to be relayed to commanders and to artillery. The benefits are obvious, allowing commanders to see “over the hill” and allowing artillery to fire, receive corrections and eventually bring accurate shelling on areas that would otherwise be invisible.
As with any innovation in warfare, counter measures were rapidly introduced and, due to the vulnerability of tethered balloons to enemy ground fire, this meant that balloons were deployed further back from the front or higher in the air. Whilst this reduced their vulnerability, it also limited their effectiveness as observation platforms.
To mitigate the problems with tethered balloons and their inherent limitations, the idea of steerable and powered airships developed. In this field the Germans led the world, powered by the pioneering interest of Count Ferdinand von Zeppelin. At the start of the First World War the German army possessed nine “Zeppelins”, but no concrete plans had been made for their use in wartime.
The limitations of “lighter than air” flight, essentially the limited pay-loads and the vulnerability of their highly-inflammable hydrogen gas, meant that airships were destined to be a minor part of the war effort. In order to improve their weight-lifting capability and allow them fly higher, larger airships were required. However, even larger airships were at the mercy of the weather, which led to a litany of failed raids and losses. Larger airships were also much more expensive and, over time, became easier targets to hit as entente aircraft improved.
Despite these limitations, the “Zeppelin threat” was politically explosive because of their ability to overfly defensive armies and strike deep into the enemy heartland. Following the first use of Zeppelins to bomb the city of Liege on 6th August 1914, the First World War saw a series of Zeppelin bombing raids on Antwerp, Warsaw, London and Paris which, although of limited military value, had a disproportionate morale and had a disruptive effect on the victims’ home fronts.
Although the Germans led the way in airship development, the British developed a series of airships for reconnaissance and for use against U-Boats over the North Sea. Away from the dangers of land-based small-arms fire, this represented a more practical use of the new technology. The largest class of airships was the Sea Scout, and was designed and built for naval applications. British airships were used by the navy in their fight against the new threat from the German U-Boat fleet and, by the end of the war, the Royal Naval Air Service was credited with seven U-boat “kills”.
Over the course of the war, Britain was to deploy over 200 airships of various types, mainly in naval applications. It is tempting to see the parallel use of Zeppelins as ground attack aircraft and British airships as naval support craft as reflecting the respective military heritages of the two belligerents, however, this is misleading as both nations used airships primarily for naval tasks.
Throughout the war, the primary role of the Zeppelin fleet was to spot the British naval fleet that was blockading Germany. Zeppelins were used for both offensive and defensive reconnaissance; they were supposed to spot the British force, allowing the German navy to attack when it was advantageous to do so, and to warn when a superior force was spotted. The intention was that Germany would be able to degrade their numerically superior enemy by choosing to fight only the battles that she could win.
The key advantage of the airship was their ability to stay aloft for long periods (a vital attribute when maintaining a long watch for elusive ships), but, being lighter than air, they suffered from an inability to operate in bad weather meant that they were frequently grounded. The use of airships was to disappear from future conflicts as a result of the experiences of the First World War, however, their endurance means that they are still considered for some military applications, such as acting as unmanned communication relays.
The main development in military airpower came with advances in “heavier than air” aircraft. The advantages of these aircraft over the Zeppelins more than outweighed their shorter flight duration and limited operating ceiling; capable of carrying heavier loads, less vulnerable to the vagaries of the weather, more manoeuvrable, less expensive and easier to mass produce, it was inevitable that they would supersede the airship in the war in the air.
The first powered heavier than air flights, those by the Wright brothers in the United States, were well publicised but often dismissed as little more than a clever “circus stunt”. However, some in the military were quick to see the value of the new technology. The focus was first, as with airships, on observational capabilities and only later on their use as offensive weapons.
Each belligerent nation developed their air arms in ad hoc organisations affiliated to both their armies and navies. For example, both the German army and navy had Zeppelins while the British had, by 1912, set up the Royal Flying Corps, which was comprised of an Army and Navy wing; both sharing a Central Flying School.
By the start of the First World War in 1914, the opposing sides were well-matched, with the German Army air service possessing 180 serviceable aircraft out of a theoretical strength of 230, facing a combined British and French strength of 184 serviceable aircraft.
British military use of aircraft lagged behind that of France or Germany and, whilst this presented a disadvantage in terms of readiness, it did present some opportunities. Whilst the German and French air services were already established in the military hierarchy and therefore were bound to traditional continental warfare doctrine, British flyers often thought in Imperial terms. The far flung nature of the Empire meant that the British, faced with conflict in many climates and situations, valued operational flexibility. However, flexibility could not make up for serious shortcomings early in the war, such as the absence of an aero-engine industry, resulting in total reliance on French engines for the first six months of war.
The main German plan for war in mainland Europe did not incorporate a use of airpower. Written many years before the war and updated annually, the plan envisaged that the German armies would advance to a set schedule, with initiative from local commanders mitigating the limitations of centralised command and control. In all likelihood, it probably never occurred to the military planners to include a role for the nascent air corps; when planning such a huge movement of men and material to a rigid timetable, such a minor and unproven element of the military was never going to be a priority
In practice, the German plan did not run to schedule. Local commanders were often more hesitant to exploit local opportunities than doctrine expected and men marching long distances grew tired. A deficiency in cavalry on the German right wing meant the army didn’t have adequate scouting capabilities and, whilst this could have been mitigated by aircraft, the aircraft available were assigned in such a way that an individual army’s general headquarters was unable to allocated tasks to them, depriving the commanders of the much-needed general picture.
Throughout the war, aerial reconnaissance was governed by the weather and the French, following a spell of poor weather, were able to capitalise on a clear day on the 24th August 1914 to understand the position of the German army better. On the 25th, the French commander of the 2nd army, Castelnau, was able to use this knowledge to attack the flank of the German 6th and 7th armies as they pushed past his positions. Bringing the German advance to a halt, this sudden shock, coupled with a general deterioration of the German plans in the face of determined French and British defence, led to the stable and stagnant front lines that characterised the majority of the remainder of the war on the western front.
On the eastern front, where more mobile warfare continued, the Germans were able to use aerial intelligence in the prelude to their stunning victory at Tannenburg in early September 1914. Using spotter aircraft, the Germans were able to confirm that the Russian army under Rennenkampf had halted its advance and this opened the door for an encirclement. Additionally, it can be argued that the Russian defeat was exacerbated because, in addition to having largely useless maps, the Russians had deprived themselves of aircraft by deploying the majority of their available machines to the Galician front.
Throughout the First World War the primary use for airpower was reconnaissance of enemy positions and mapping trench networks. Reliable aerial cameras emerged in February 1915 and were first used to build up accurate maps of the German trench system ahead of the British offensive at Neuve Chapelle; these maps were then distributed to all the commanders involved. The accuracy of the maps available, as well as the element of surprise that was achieved, allowed the capture of Neuve Chapelle within 45 minutes. The stunning success of this offensive meant that aerial photographic reconnaissance was recognised as an essential element in the planning process for future offensives.
The advent of “wireless” radio communication between air and land allowed the development of a much more devastating use of airpower. A system of map grid squares allowed artillery to be targeted with greater accuracy by counter-battery fire. Using “flash-spotting” from the both the land and the air, aircraft provided the “in depth” observation capability, often seeing far behind the enemy front lines. The development of this new role mean that a continual aerial presence was now needed to spot enemy artillery muzzle flashes and relay this information in the form of “Now Firing” messages. With up to the minute information on enemy dispositions, and using pre-ranged artillery, the counter-battery artillery could target enemy positions accurately. This process ended the less accurate and wasteful practice of “area bombardments” by 1918, increasing the overall effectiveness of the artillery.
As the value of aerial photography for offensive purposes increased, the need to deny the enemy the same advantage grew. The idea of “British sky” over the front, where the enemy could not go, led to combat between aircraft as they sought to deny each other the airspace. Early air combat utilised improvised weapons. In the absence of “official” aircraft armament, pilots armed themselves on their own initiative, taking pistols, rifles and even hand grenades up into the air. The next logical step was to arm the aircraft themselves with machine guns. Experiments with various configurations, such as pivoting guns and upward pointing guns were tried, but guns fixed to the front of the machine and aimed by pointing the aeroplane at the target were found to be most effective.
The problem with mounting a machine gun on the front of single-engine “tractor” aircraft (where the engine is mounted at the front of the aircraft) was that, in order to aim it accurately, the gun had to fire through the propeller. This presented a serious problem as a bullet hitting the spinning propeller blades tended to destroy it! One solution to this problem was to use “pusher” aircraft, which situated the propulsion and propeller behind the crew and pushed the aircraft forward This allowed crew, guns and photography to take place at the front, unencumbered by the presence of the engine and propeller. However, these aircraft tended to be less effective as flying machines than “tractor” aircraft, where the propeller pulled the aircraft. One of the major disadvantages of the “pusher” aircraft was the tendency of the engine to fly forward in the event of a crash, killing the crew, but manoeuvrability and power issues also existed.
Early attempts to resolve the propeller problem, whilst retaining the advantages of single-engine tractor propulsion, involved pinning armour plating to the gun-side of the propeller to prevent it getting shot off when a bullet struck the spinning blades. However, the problem was solved most effectively by the Germans who developed a mechanical interrupt device in mid-1915 which paused the gun when the blades were in front of the muzzle. When this device was rolled out onto their Fokker aircraft, the Germans achieved a period of air superiority in what was later called the “Fokker scourge”. Following this innovation, the period that followed saw the emergence of the “aces”; the most famous of all was Baron von Richthofen who had 80 kills to his name (Major Edward Mannock was Britain’s foremost ace).
This period of German dominance in 1915 was countered by the Allied development of formation flying tactics and newer, more effective, aircraft. However, in late 1916 the Germans introduced their new, purpose built, Albatross fighter. This development proved disastrous for the allies and at one point, in February 1917, new Royal Flying Corps pilots were not expected to survive for more than a few days as a vicious circle of under-trained pilots, inadequate aircraft and a superior enemy exacted its toll. New allied aircraft redressed the balance by late 1917, halting the slaughter.
Most accounts of World War One airpower concentrate on air combat because of its glamorous nature above the mud-bound war of attrition. The attraction of the so-called “knights of the air” duelling it out above the mud provides a compelling story, however, it is important not to lose sight that the core reason for air combat remained the need to obtain or deny accurate aerial reconnaissance.
Colonel Trenchard and Commandant de Peuty, commanding the R.F.C. in France and the French Air Service respectively, recognised that the only way to stop the losses of aircraft involved in army co-operation work was to keep the enemy away from observer craft. Trenchard chose to give battle over occupied territory and believed that “an aeroplane is an offensive and not a defensive weapon”. This offensive strategy mirrored the offensive stance of the army below, where active trench raids were considered an important part of trench warfare. One consequence of this policy was that British pilot losses tended to be high, when measured on a like for like basis against the Germans, as taking the fight to the enemy over occupied territory meant that a downed pilot, even when uninjured, could not expect to be safely recovered; a situation that was to be reversed during the Battle of Britain in 1940.
Belief in the value of the offensive led to the use of aircraft against ground targets, with the intent that attacks from the sky, as well as land, would damage the morale of the enemy. The Germans made use of Zeppelins against ground targets, primarily on Eastern Front, where the threat from aircraft was greatly reduced, dropping iron darts (flechettes) or bombs as a part of operations. However, once again, heavier than air machines allowed more effective attacks. Weapons developed at the time reflect this doctrine, for example, the Tracer bullet, Le Prieur rockets and Phosphorous bombs; these enabled ground targets to be attacked with greater efficacy.
The increasing offensive power of the new weaponry allowed aircraft to offer closer air support to ground forces than ever before. During the preparation for the Battle of the Somme, specific plans were included to use aircraft in a ground attack role. This early use of airpower for strafing, bombing and distracting enemy troops as a part of offensive operations planted the seeds for future conflicts. To varying degrees, this led to the use of airpower in modern warfare such as during the Spanish Civil war and World War Two by the German Luftwaffe, and later in the 1991 First Gulf War by US-led coalition forces.
Away from the tactical use of aircraft to strafe and bomb troops, the doctrine of strategic bombing represented a wholly new form of warfare, advocated by certain military thinkers as a potential “war winner”. Strategic bombing advocated bombing targets that were not directly involved in frontline battle to weaken an enemy’s war effort. Under the doctrine of strategic bombing, these targets could be logistics, strategic industries or even enemy civilians. Giulio Douhet, an Italian general, claimed that the air war must be used as a “sudden terror” against an enemy’s cities in order to demoralise the population on the home front. Thus, he reasoned, with support from home dissipated, the enemy military would be unable to continue in the field. However, during the First World War, the belligerent nations had neither the willpower to engage in such a radical step or the weaponry to carry out such a vision effectively.
It could be argued that the Zeppelins bombing raids on civilian towns were an early manifestation of strategic bombing, but the ineffectiveness of the airships meant that they were never likely to be decisive. In addition to the technological limitations of the campaign, political restrictions, such as a prohibition on bombing Buckingham Palace or the financial district of the City of London, whilst difficult to observe, betrayed a desire not to over-escalate the campaign. During the First World War, German Zeppelins killed 556 people and injured 1357 during bombing raids on England, and, while this was never going to affect the course of the war, it was clear that with more capable aircraft, strategic bombing could be a major factor in future conflicts.
More successful than the Zeppelins were the German “Gotha” bombers which inflicted greater damage, presented much smaller targets and were less susceptible to adverse weather conditions. On the 25th of May 1917, 21 Gotha bombers appeared over Folkestone and killed 95 people in ten minutes. These purpose-built bombers had three machine guns, a 500 kilogramme payload and seemed to be largely immune to the defensive measures available at the time. The psychological blow of these attacks is apparent from the outcry that followed; as F.S. Oliver said, “attacks on the capital city are in the nature of humiliations which must affect public opinion at home and abroad”.
Measures designed to combat the menace of the Gothas were implemented, and added to the feeling that the war was coming to the home front, with barrage balloons appearing on the skyline and anti-aircraft guns encircling London. In a war dominated by aircraft reconnaissance, the bombing raids of the First World War laid the foundations for the main role of aircraft in the Second, with the Allied bombing campaign against Germany and the atomic weapon attacks on Japan. In contrast, during the First World War, the tendency for using airpower beyond the front lines was to target specific military targets rather than industrial or civilian infrastructure.
The first British use of aircraft for offensive purposes away from the front lines was by the Royal Naval Air Service. In September 1914, in a break from their more usual reconnaissance role, R.N.A.S raids were directed at Zeppelin sheds at Dusseldorf and Cologne, while in October a Zeppelin was hit in its shed in Dusseldorf.
Even on Christmas Day 1914 the war continued, when the RNAS launched seaplanes from HMS Engadine, HMS Empress and HMS Riviera against the Cuxhaven Zeppelin sheds. Four seaplanes were lost in the raid, but the German ship Von der Tann was damaged when it collided with a cruiser as it tried to avoid the attentions of the enemy aircraft overhead.
Whilst the sheds were being attacked in Cuxhaven, a German Zeppelin attempted the first air to sea attack against one of the seaplanes’ carrier ships, HMS Empress. This attack was unsuccessful with the ship dodging three 110lb bombs, and leaving L-6 to limp home with more than 600 bullet holes in its skin.
However, these were not the first raids launched from ships. This honour belongs to the Japanese and their use of seaplanes during the siege of Tsingtao. Lowered into the sea from the Wakamiya, a transport ship that had been converted into a carrier, Japanese seaplanes conducted a continuous campaign of reconnaissance and offensive bombing against both German shipping and the besieged city before returning to be winched back on board.
The use of aircraft to supply troops was an important factor in later conflicts and, once again, this practice was pioneered by the air forces of the First World War. In 1914, when the Berlin-Constantinople rail route became impractical for supplying their ally, the Germans considered supplying Turkey using Zeppelins, or even free-flying balloons launched on favourable winds, but the weight of material needed meant that the plan was never enacted.
On a smaller scale, the first ever practical example of ground forces being supplied from the air was at the Battle of Le Hamel in 1918, when ammunition was supplied to isolated Australian machine gun posts by aircraft. In October of 1918, thirteen tons of rations were dropped to French and Belgian troops who had been cut off from conventional supply lines by waterlogged swampland. These first attempts at air supply were tiny compared with later examples, such as the attempted supply of the Arnhem forces during Operation “Market Garden”, the Berlin Airlift after the war or recent operations in Afghanistan, however, the potential was there and recognised for future conflicts.
Aircraft were also used in the First World War to drop propaganda leaflets. The major problem with propaganda leaflets was delivery; how to get your message to your intended readers on the other side of the lines? Once again, aircraft provided a way to solve a problem and allowed leaflets to be scattered over enemy troops behind the impassable front lines. Where leaflets were needed a long way behind the enemy lines, unmanned balloons were often used to distribute leaflets beyond the reach of the relatively short range of aircraft.
Leaflets were dropped in large numbers on all the major battle fronts, most notably along the lines confronting the forces of the Austro-Hungarian Empire. Here it was hoped that an Austro-Hungarian collapse would isolate Germany from her main ally. Leaflets dropped on this front tended to concentrate on ethnic differences within the Austro-Hungarian army, often implying that particular groups were taking the majority of the casualties, while others got easier postings. The ease of aircraft as a means of distribution allowed huge quantities of leaflets to be dropped; up to 5.5 million leaflets were dropped in just one month during 1918.
Once again, we see another aspect of airpower appearing in later conflicts. Leaflets were dropped on the beleaguered British Expeditionary Force in 1940 as they fell back on Dunkirk, dropped in huge numbers over the German Reich and it would be remiss not to mention the 50 billion leaflets dropped during the Vietnam war by the United States. Even as recently as the first and second Gulf Wars, leaflets and “safe passage passes” were dropped, encouraging Iraqi conscripts to surrender.
In reality, due to the infancy of the technology during the First World War, airpower was not the decisive weapon that air theorists hoped for. However, the war did prove an ideal testing ground for proving new techniques. As the first major conflict after the development of reliable aircraft, the First World War became a test-bed for exploring the possible uses of airpower.
The First World War drove huge advances in the evolution of purpose-built aircraft for bombing, reconnaissance and air combat, as more general-purpose craft were proved obsolescent. It is fair to say that the experiences and small-scale experiments of the First World War became predominant characteristics of the Second World War. Novelties, such as bombing of cities, the use of parachutes and supplying troops from the air, became common practice and in some cases became the modus operandi of whole campaigns, such as the German invasion of Crete or the Allied attacks on Arnhem. The original reconnaissance role of airpower evolved rapidly and developed into the multitude of specialist airpower roles seen in modern warfare.
After the carnage of the First World War it was widely perceived by military strategists that a limited war for limited objectives was increasingly difficult. Modern weapons had shifted the balance of power from offence to defence during the early part of the war and this had only been overcome in 1918. The dominance of defence had resulted in the grinding stalemate of the Western European front and gave rise of the theory of the wars of attrition or “total war”, where warfare risked becoming a bludgeoning contest with the weakest nation finding itself unable to fight once exhausted.
However, the role of the military is to find ways to win wars and, to the theorists and planners in the inter-war period, it was apparent that new weapons would have to be developed to allow less costly and decisive battles to be fought. New weapons, they theorised, would allow less damaging wars to be fought for clearly defined objectives. Airpower, as pioneered in the First World War, seemed to hold the promise that would allow wars to, once again, be won without enormous cost.
And so the cycle of military innovation turned…