Freelance writer from Cornwall
The First World War was unusual in many ways. One was that, for the first time in military history, the air became a battlefield. No longer were combatants confined to land and sea, now they could exploit the military potential of what in 1914 was a relatively new invention – the aircraft.
The sheer speed at which aircraft evolved from barely more than powered gliders into fully-fledged weapons was staggering. In 1914 aircraft were so fragile and underpowered that carrying even the weight of a machine gun was usually beyond them. By 1918 there existed fighters, bombers, reconnaissance aircraft and the weapons and tactics had evolved.
In 1914 a typical dogfight often consisted of one aircraft from either side with pilots firing their service pistols at each other. By 1918 aircraft were stronger, faster, more agile and carried machine guns, bombs, and rockets. In only four years combat flying evolved from two pilots with pistols using the same aircraft for any and every purpose into fully-fledged air forces with custom-designed aircraft flying and fighting in huge numbers. It was a common theme among those veterans who survived that, by 1918, if there weren’t at least fifty or sixty aircraft involved in a dogfight, it wasn’t a proper dogfight.
The fighter aces became heroes overnight, but seldom lived to enjoy their celebrity. Men who became household names at the time are almost entirely forgotten today. Manfred von Richthofen (the famous ‘Red Baron’) lives on as the most famous fighter pilot of all time, but few remember Edward ‘Mick’ Mannock, James McCudden, Rene Fonck or Werner Voss. But one elite group of fighter aces are especially neglected today, the ‘balloon busters.’
So who were they, what did they do, how did they do it and what military value did they have? Simply, they specialised in flying high-risk missions behind enemy lines to destroy enemy observation balloons. So high were the risks that many balloon busters attacked either alone or with only one or two fellow pilots. Squadron commanders recognised the extreme risks by making balloon busting missions largely voluntary, although pilots could be ordered to attack balloons if they were proving particularly troublesome to friendly ground troops.
Balloons were highly valued for several reasons. They could hover at high altitudes and monitor enemy behaviour, spotting troop movements, new supply and munitions dumps, whether the enemy were stockpiling supplies and munitions and if they were moving fresh troops forward to defend against an upcoming offensive or mount one of their own. Their other standard purpose was artillery spotting. Gunners often lacked a direct view of the enemy due to distance, weather conditions and geographical factors like ridgelines and hills. To accurately shell enemy targets they needed balloons to literally ‘call the shots’ by spotting where shells landed and directing gunners accurately on to important targets. Balloons were immensely valuable for intelligence-gathering and artillery-spotting. Protecting friendly balloons while destroying enemy balloons became increasingly important as the war ground on.
Balloon busters attacked balloons in addition to flying regular combat missions. Nowadays, people thinking of First World War aces usually think about those destroying enemy aircraft, the dogfighters. One thing separating most balloon busters from regular fighter aces was that many of the war’s most famous aces actively refused to attack balloons at all. Manfred von Richthofen never attacked a balloon. Top-scoring British ace Edward ‘Mick’ Mannock scored his first ‘kill’ by destroying a balloon, but found the job so dangerous that he never attacked another. French ace Rene Fonck, top-scoring Allied ace of the war with 75 confirmed kills, never shot down a balloon.
It could also be readily argued that hindering enemy intelligence-gathering and artillery-spotting was often of greater value than pilots dogfighting, shooting down one or two enemy aircraft if they were lucky and then returning to base. Granted, deaths of famous aces such as Richthofen, Major Lanoe Hawker (himself killed by Richthofen) and American balloon buster Frank Luke caused some damage to enemy morale, but the vast majority of aircrew killed died with little recognition outside of their squadrons, families and friends. Destroying observation balloons had genuine influence on the local progress of the war. Shooting down novice enemy fighter pilots and very occasionally killing a leading enemy ace simply didn’t have the same value.
So how did they do it? They checked reports of balloons sighted behind enemy lines, examined intelligence on enemy defences, plotted the least-dangerous route to their target and attacked. Fortunately for them, pilots had some specialist weapons to assist them. These were designed to take advantage of the chronic German shortage of helium, the non-flammable gas often used by Allied balloons. In the absence of helium German balloons usually used hydrogen but, while hydrogen is lighter than air and as good as helium for lifting a balloon, it’s explosive when mixed with air and any kind of flame. Even a cigarette end could cause a hydrogen-filled balloon to explode. The first of these specialist weapons was the Le Prieur rocket designed by French officer Yves Le Prieur in 1915. This was simply a larger form of firework rocket containing a charge of gunpowder and tipped with a sharp iron spike to pierce a balloon just before the gunpowder detonated. Le Prieur rockets were unguided and woefully inaccurate at more than 120 feet from their targets, but they were also the first air-to-air missile in military history and cutting-edge weapons for their time. Pilots on both sides also used special incendiary bullets containing phosphorous. The incendiary bullets gradually replaced rockets owing to their greater accuracy and range. Using them, however, carried a particularly nasty added risk. Downed pilots whose aircraft were found carrying incendiary ammunition were likely to be summarily shot by their captors rather than taken prisoner. Some pilots carried written orders from their commanders explicitly stating incendiary ammunition was exclusively for use against balloons and not for strafing runs on trenches, infantry columns or other human targets, but this didn’t stop balloon busters risking summary execution always assuming they survived being shot down to start with. Another specialist weapon, equally likely to incur summary execution, was the phosphorous canister used by flying over a balloon and dropping the canister like a normal bomb. Ground troops had particular loathing for phosphorous canisters and especially for pilots who used them. They carried 20 pounds of white phosphorous and could easily miss a balloon entirely, landing instead among defending ground troops with horrifying results.
Pilots also evolved specialized tactics. They never flew straight and level when attacking balloons, usually preferring a shallow dive at high speed, making a single pass and escaping rather than risk a second attempt. Enemy defences were usually too heavy for any pilot wanting to survive to attack a balloon more than once. Some pilots favoured flying deep behind enemy lines before circling round and attacking from within enemy territory. Enemy gunners often opened fire much later rather than risk a friendly fire incident and pilots could make a single high-speed pass while already headed for their own lines, making a successful escape much more likely. On larger-scale raids often involving multiple aircraft and multiple targets, one group would attack the balloons while another remained as ‘top cover’, circling at higher altitude to defend against enemy fighter patrols. Enemy fighters were often assigned specifically to patrol balloons, providing both physical defence and a deterrent to all but the bravest or most reckless enemy pilots.
You might think that balloon busting was already dangerous enough without any additional risks. Unfortunately for balloon busters the job of enemy defenders was to make it as dangerous as humanly possible. Balloons were connected to the ground by a winch allowing them to an agreed height and no higher. Heavy anti-aircraft guns used clockwork shells designed to explode at altitudes set by their gunners and gunners always set them to explode at roughly the same height as the balloons they protected. As if heavy guns weren’t bad enough, balloons were almost always held below 3500 feet, the maximum accurate range of light and heavy machine guns. Balloons were invariably protected by a half-dozen or more machine guns of varying calibers. Infantry were also encouraged to fire rifle volleys at any enemy aircraft diving within range. One weapon particularly feared by Allied pilots was the Hotchkiss 37mm gun firing 5 shells at once. The shells glowed bright green as they came up in clumps, leading Allied pilots to nickname them ‘flaming onions.’
One particularly nasty weapon was the booby-trapped balloon. These were used by both sides and left at a tempting altitude for enemy fighters, deliberately so. Instead of a human observer a straw dummy dressed in uniform was placed in the basket. The remainder of the basket was filled with a 500-pound explosive charge detonated from the ground. First World War fighters were immensely fragile by today’s standards and being anywhere near such large explosions frequently proved fatal. The booby traps did occasionally backfire on their users, literally in the case of Belgian ace Willy Coppens. Coppens attacked a balloon that was strangely unprotected by ground fire and, like many pilots before him, didn’t realise the balloon was manned by a dummy until it was too late. Unfortunately for the Germans, the bomb failed to explode while Coppens shredded the hydrogen-filled balloon with incendiary bullets. The bomb-laden basket, now itself thoroughly alight, promptly descended into the middle of the German positions where the impact and fire finally detonated it causing considerable casualties on the ground. Coppens, the highest-scoring balloon ace of the war, regarded it as one of his luckiest escapes while the opinion of the defending Germans is unrecorded. This is probably just as well.
Despite the undoubtedly extreme risks, many ambitious young pilots tried their hand at balloon-busting. Given its extreme danger and spectacular nature balloon busting was the quickest route to fame and medals for young fighter pilots wanting to make their name. Many died. Some tried it once or twice before sticking to conventional dogfighting and a few made it their speciality. Belgium’s Willy Coppens was the highest-scoring balloon buster of the war. France’s Henri Bourjade, the Royal Flying Corps’s Anthony Beauchamp-Proctor and German pilots like Erich Lowenhardt and Heinrich Gontermann destroyed hundreds of balloons between them. Most famous of all was the American Frank Luke, whose career lasted only 18 days before his death, during which he destroyed 14 balloons and also shot down 4 German aircraft. For ambitious young pilots wanting fame and rapid promotion, balloon busting seemed like the fast track to immortality. For most of them it was really the fast track to their graves.