1918
Page 24
Aerial observation and aerial artillery spotting was so essential to defence and offence that controlling the air over the battlefront became a top priority for the Germans and Western Allies. Control of the air enabled the air service to provide accurate intelligence and artillery fire and, at the same time, deny these advantages to the enemy. By 1916 British, French, and German air services were fielding aircraft squadrons specifically equipped and trained to shoot down the enemy’s aircraft and win air superiority. The fighter forces, equipped with fast and manoeuvrable single-seat aircraft, quickly grew in size and sophistication and garnered the attention of the press, which featured the exploits of the ‘ace’ fighter pilots who lent a touch of individualism to a war dominated by mass operations. Yet it should not be forgotten that the primary mission of the fighter pilots was to serve as support forces to escort observation planes over enemy territory and to intercept the enemy observers.
In earlier campaigns the attacking artillery had concentrated mainly on destroying the enemy front defences. But this approach invariably failed when the defender employed artillery against the attack. The prolonged British bombardment of enemy defences at the Somme clearly signalled an attack and enabled the Germans to bring up reserves and prepare for the onslaught. In 1916–17 the normal way to strike a target was to fire a ranging shot, observe the fall of the round, and adjust fire by plane or balloon observation post. Yet ranging shots also alerted the defender. So in 1917 leaders on both sides developed a system by which the defending artillery could be neutralized without ranging shots and firing solely from map references. First of all, guns could fire more accurately if each gun was taken to a firing range and test fired to determine the precise characteristics of the gun. Intensive research created meteorological tables that determined how weather conditions would affect the course of each shot. Finally, aerial reconnaissance could provide aerial maps with the exact positions of enemy artillery, headquarters, and strongpoints. These new tactics were based on surprise and massed and centrally controlled artillery fire. Troops and guns were moved up to the front line at the last minute with all care taken to ensure cover and secrecy. No ranging shots were fired or any other actions taken that would alert the defender. A few hours before the attack the artillery, all under one command and firing according to a single plan, would initiate a massive bombardment with the primary target not the enemy trenches but the enemy artillery, whose positions had been plotted by aerial reconnaissance before the battle. The new method of gun calibration and meteorological tables enabled the artillery to fire fairly accurately to destroy, or at least suppress, the enemy artillery. Only in the last hour of the barrage would much of the artillery fire shift to striking the enemy trenches.
When the barrage lifted, the infantry, armed with plenty of firepower in the form of light cannons and mortars, and light machine guns, would overrun the enemy trenches, isolating and reducing strongpoints while maintaining an advance as rapidly as possible. During the attack air units would fly support, spotting surviving enemy artillery for counter-battery fire and using fighters and light bombers to bomb and strafe enemy artillery. Other fighter units flew high overhead to protect the observation craft. If the enemy artillery could be neutralized, then the attacker could break through the defender lines with acceptable losses.2 The ability of the air services to accurately photograph and map large areas of the front at this time was made possible by major advances in aerial photography technology, including automatic cameras.3
This new doctrine was first tried by the Germans when their Eighth Army attacked the Russian Twelfth Army south of Riga on 1 September 1917. The Germans had centralized more than 800 guns and mortars under a single carefully orchestrated fire plan. The onslaught took the Russians, dug into deep defences along the wide Duna River, completely by surprise. Having identified all the Russian artillery positions and infantry strongpoints by aerial photography, the German artillery managed to destroy or suppress the Russian artillery in a short, but very violent, bombardment.4 Six German infantry divisions crossed the river and quickly drove through the Russian defences. The Russian Twelfth Army collapsed and began a hasty retreat, abandoning its artillery, supplies, and heavy equipment to the Germans. The Germans took Riga and inflicted 25,000 Russian casualties with only 4,000 casualties of their own. The German High Command was so impressed by these new methods that it sent the authors of the plan, army commander Oskar von Hutier and artillery colonel Georg Bruchmüller, to the Western Front to employ the same methods for the 1918 attack. The German Western Front generals were initially reluctant to adopt the new tactics, but Ludendorff pushed them on his army commanders and in January and February 1918 the German High Command issued directives that the great Spring Offensive would use the methods of surprise, artillery centralization, short but very heavy preparatory fires, barrages using map coordinates, and priority of fire on enemy artillery.5
Air doctrine of the major powers in 1918
Because the primary mission of the air services was to win control of the air, and thereby to provide effective support to the ground armies, in 1917 and 1918 the Western Allies and the Germans developed an extensive body of doctrine for air operations. The air doctrine centred on the mass employment of the main elements of the air service – reconnaissance, artillery spotting, bombers, and fighters – all to be closely coordinated to support the ground battle.6 The German, French, and British doctrines made control of the air over the battlefield the first priority of the air services. By 1917 the air services had organized their air squadrons into large operational organizations with the British Royal Flying Corps organizing their squadrons (each 15 to 20 aircraft) into wings (three to four squadrons) and the wings into air brigades. The Germans in 1917 had organized their fighter squadrons into wings (Geschwader: four to five squadrons) and their specialized ground attack force into groups of three squadrons. The French also formed their fighter and bomber squadrons into groups.
Behind the fighting units each air service (the Royal Air Force would only be born as an independent air force in April 1918) had created a vast infrastructure of training units, specialist schools, air intelligence units, depots and repair units, and specialized signals units. Each air service had its own general staff and headquarters, churning out plans and doctrine for the fighting units. To ensure swift movement from one part of the front to another the German, French, and British air services became highly mobile. Air squadrons could quickly set up airfields (usually any fairly dry and flat piece of ground near the front) complete with temporary canvas-covered hangars for the aircraft. Each air service comprised a large organization in 1918, with the Luftstreitkräfte and the Aéronautique Militaire each having approximately 100,000 personnel in the army and naval air arms. By the end of the war the RAF had grown to 291,000 men and the US Air Service had 195,000.7 Every squadron required a large support force of ground personnel and motor vehicles. In short, by 1918 one can easily talk of fully fledged air forces despite their status in France, Germany, and America as being officially part of the army or navy.
The fighter forces were one of the keys to success in 1918 and the fighters had several responsibilities. As well as winning air superiority, fighters provided escort for the vital artillery and reconnaissance aircraft over the battlefield. The Royal Flying Corps also emphasized the mission of ground attack. Fighters were to attack German troop columns, artillery, and supply columns ahead of the attacking divisions. Finally, fighters and reconnaissance planes were tasked to fly ‘contact patrols’, to fly low and observe the location of friendly troops and report to the division and corps headquarters on the progress of the ground forces. Getting an accurate picture of the ground battle was essential for the ground armies and, given the lack of mobile radios in 1918, aircraft were the best means of informing the ground commanders of the battle. This low-level work was especially dangerous as the unarmoured aircraft were particularly vulnerable to machine-gun fire from the ground and anti-aircraft guns, with whi
ch the Germans were amply supplied. The Germans also relied upon contact patrols called ‘Infantry Fliers’ and in 1918 were able to field some flights of all-metal and armoured aircraft for the task. But given the small number of these planes available, contact work also fell to the fighter and observer units. This also meant that the infantry had to be trained to work with the air service. Various signals, including setting out ground panels and use of coloured flares, were used.
In 1917 the Luftstreitkräfte issued new doctrine manuals that outlined the role of the air service in major operations (Instructions on the Mission and Utilization of Flying Units within an Army) and the Germans updated their doctrine to include the use of close air support of the infantry.8 The operational manuals emphasized the need for surprise in supporting army attacks by quietly moving air units to the sector to be attacked at night, and then camouflaging and dispersing them. The infantry advance would be made under cover of ground attack squadrons, which would seek out the enemy reserves and artillery as well as carry out planned attacks on selected front-line strongpoints. Ground attack squadrons were attached to divisions based on the army aviation commanders’ assessment. The German High Command believed the morale effect of low-level bombing and strafing attacks upon enemy infantry and artillery was especially important: ‘the object of the battle flights is to shatter the enemy’s nerve by repeated attacks in close formation’.9 General Hugh Trenchard, chief of the Royal Flying Corps in France, was also a firm believer in using fighter aircraft in ground attack role and British operations orders assigned a large part of the fighter force to this duty. The French Army operations doctrine of October 1917 laid out the principles of air operations in some detail and placed a heavy emphasis on close cooperation of air and ground units through all phases of the battle and on gaining air superiority and using aircraft to provide targets for the artillery. French operations orders also assigned air squadrons to support each division in the assault.10
In the latter half of 1917 and early 1918 the Germans, French, and British pulled divisions behind the lines and trained their armies in the new offensive doctrine. One major part of the training programme was to ensure that the artillery and the supporting aircraft learned to plan and work together. In preparation for the 1918 Spring Offensive the Germans pulled their best infantry divisions to the rear for intensive training which included live-fire exercises with ground attack squadrons against mock trench lines.11 Tactical experience was assimilated by the air staff and guidance was issued in a series of ‘Tactical Guidelines’ issued by the Luftstreitkräfte which advised air unit commanders on formations, tactics, and task organization of their forces.12 While providing a highly effective training programme and detailed doctrine for the fliers cooperating with the army artillery, the Royal Flying Corps failed to create specialized aircraft or training programmes for the ground attack role – it was just another duty of a fighter pilot.13 In contrast, the German Air Service set up a special training programme for the ground attack pilots behind the front and practised group attacks upon simulated targets.14
One of the most important organizational developments for airpower came in May 1918 when Général de Division Pétain, commander of the French front armies, ordered the creation of the 1st Air Division, under Général de Brigade Maurice Duval, commander of the Aéronautique Militaire at the front. The French concentrated groups of their elite fighter, bomber, and reconnaissance squadrons into a well-balanced 600-plane division, which was highly mobile and to be deployed to support the main effort of the army, either in defence or offence. While each ground army had a complement of reconnaissance and fighter aircraft to support its operations, the 1st Air Division came under the direction of the French High Command and served as the special aerial reserve. The 1st Air Division provided a massive reinforcement capable of all air missions and designed to ensure French air superiority over the front. The 1st Air Division played a prominent role in all the French offensives and also supported the American attack at St Mihiel in September as well as the British attack at Amiens in August.15
The aircraft of 1918
Winning the air superiority battle, and being able to effectively support the ground armies through bombing and reconnaissance, depended on having superior aircraft in large quantities. Aircraft design had come a long way since the start of the war and sophisticated aircraft were fielded by the British, French, and German air forces. In early 1917 the British aircraft had been outclassed by the new German Albatros and Pfalz D III fighters. But by the autumn of 1917 the Royal Flying Corps had been re-equipped with the SE 5A, the Sopwith Triplane, and the Bristol two-seat fighter and these planes made the fight equal in terms of quality. The French also fielded the Nieuport XVII and SPAD VII fighter in 1917, easily equal to anything the Germans flew, and these would soon be superseded by the fast, manoeuvrable, and sturdy SPAD XIII, which became the main fighter of the French and American Air Service in 1918. The German fighter force at the start of 1918 consisted of the Albatros D V, a slight improvement over the D III model, and a few hundred new Fokker Triplanes, which, despite their popular fame, were mediocre fighters and much slower than the Allied models. In the spring of 1918 the German fighter force was generally outclassed.
Knowing that their fighters were inferior, the German High Command tested several new fighter designs in January 1918, with the famous Rittmeister Baron Manfred von Richthofen personally test-flying the prototypes and giving his strongest recommendation to the Fokker D7 design by Anthony Fokker. Von Richthofen, in one of his last acts before being shot down three months later, had chosen wisely. The Fokker D7 used a revolutionary wing design of a thick, internally supported wing. Contrary to expectations, a thicker wing proved superior in reducing drag and improving lift, and the internally supported wing, combined with a fuselage frame of welded steel tubes, made for a very strong and sturdy aeroplane. Equipped with the 185hp BMW engine, it proved to be a superb fighter plane. The Fokker D7 was put into mass production and began arriving at the front units in late May 1918, and through the summer much of the German fighter force was re-equipped with the D7. The new Fokker quickly put the German fighter force back in the running in the air superiority battle. It was fast, highly manoeuvrable and had the fastest rate of climb (a very important part of fighter combat) of any fighter in 1918. It was said that the D7 handled so well that it turned an average pilot into a very good one. The memoirs of the Allied fighter pilots show the D7 great respect as an opponent. Although a well-handled SE 5 or SPAD XIII could readily knock down a Fokker D7 (both the SE 5 and SPAD were faster), airmen such as US Air Service commander General Billy Mitchell called the Fokker D7 the best all-round fighter of the war.16
The fighters, which comprised 40 to 50 per cent of the aircraft in all the air services on the Western Front, receive most of the attention in literature and film. But a major portion of all the air services, and operationally the most important part, were the ubiquitous two-seater observation and artillery aircraft employed in large numbers by all combatants. After all, reconnaissance and artillery spotting was the essential mission of the air services. To fulfil this mission in 1918 the British fielded the DH 9 and DH 4, the Germans a variety of two-seater models, and the French relied mainly on the Salmson A2. The newly arrived American Air Service employed mainly the DH 4, but some observer squadrons had the Salmson A2 which French and Americans regarded as the best plane of its type. The two-seater planes were heavier than the fighters but powered by much larger engines (the Salmson had a 400hp engine) which made them as fast as many fighters. The observation planes normally carried forward-firing and rear-mounted machine guns, the latter operated by the observer. With speed and firepower fore and back, the two-seat observation planes were no easy prey for the fighters, yet destroying them was the fighter’s main mission. All the air services fielded light and heavy bombers in 1918. Often the two-seater observation planes doubled as light bombers, although many two-seat bombers were built specifically for that purpose. T
he main French light bomber of 1918 was the Breguet XIV, one of the best bombers produced in the war, which carried 300kg (660 pounds) of bombs.
Some of the specialized aircraft of 1918 bear mentioning. One of the most important of the German aircraft was the Rumpler C7 high-altitude reconnaissance plane. It was designed to fly at 20,000 feet with the pilots and observers using bottled oxygen and electronically heated flying suits to combat the extreme altitude and cold. At 20,000 feet the Rumplers flew well above the top ceiling of Allied fighters, so they could photograph Allied rear areas with relative impunity.17 Another major German innovation in aircraft development was a series of aircraft specifically designed for ground attack. In 1917 the Germans introduced purpose-built ground attack planes which were organized into squadrons and groups. The rugged Halbertstadt and Hannover two-seaters were modified with armour plate around the pilot and engine and equipped to drop small bombs. With three machine guns (two forward and one operated by the observer) these planes were used in mass to strike targets just behind the front lines, especially troop columns and artillery positions. The armour plating and the relatively fast speed of these planes made them far less vulnerable to ground fire, which caused high losses among unarmoured fighter planes that attempted this mission. In late 1917 the Germans introduced an all-metal armoured ground attack plane – the Junkers J1. In 1918 other all-metal attack planes and fighters were introduced, but only saw action in small numbers in the last months of the war.