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First used by the Revolutionary French army in 1795, captive or kite balloons, also known as Drachen (“dragons,” an Austrian analogy for Chinese kites) and “sausages,” are the oldest means of aerial reconnaissance. Even after the invention of the airplane, balloons saw their most widespread service above the trenches during World War I, since they could stay in the air longer than planes, allowing an observer to scan a large portion of the front from a safe distance behind his own lines.

Communicating by telephone or wireless with forces on the ground, balloon observers could detect frontline movements or direct artillery and mortars with murderous accuracy. As such, they constituted a very real menace to the other side’s ground forces. Destroying enemy balloons, therefore, was a key objective before any major operation was launched.

At first sight, a giant bag of hydrogen would seem an easy target, but airmen who tried to destroy enemy balloons came to learn otherwise. First and foremost, they had to fly deep into enemy territory to get at them, where they were exposed to observation, aerial interception and every enemy soldier carrying a gun. Although the balloon floated several thousand feet above the ground, when it was under attack its ground crew had a powered winch to pull it down, as well as attached antiaircraft artillery batteries and machine guns to shield it beneath a descending cone of fire.

After he reached his rapidly descending quarry, the fighter pilot could not ignite the pure hydrogen that gave the balloon its buoyancy, even with incendiary bullets, until a sustained burst of gunfire allowed some to escape and mix with oxygen. If he failed to set his target alight, the pilot had two options—give up and head for home, or make another pass through even more intense groundfire at a lower altitude. Once ignited, a burning balloon could be seen for miles, assuring confirmation for the pilot who destroyed it. But its funeral pyre was equally visible to the enemy, and the balloon buster had to run a gantlet of anti-aircraft and groundfire, as well as vengeful enemy fighters converging on his likely escape route. Adding up those factors caused many to regard balloon attacks as suicide missions, requiring as much luck as skill on the pilot’s part.

The few airmen who habitually volunteered for such missions were regarded as something of a special breed, possessed of a combination of pyromania and death wish known as “balloon fever.” Those who cheated the law of averages long enough acquired a measure of acclaim—until their luck ran out. Among the more famous balloon busters, France’s Michel Coiffard and Maurice Boyau, Germany’s Heinrich Gontermann and the United States’ Frank Luke and Louis Bennett did not survive the war. Coiffard’s frequent partner, Jacques Ehrlich, became a prisoner of war. Leading German balloon ace Fritz Röth, whose 20 accredited gasbags included a record five in one day, survived combat but fell into a postwar depression that led to suicide on New Year’s Eve 1918.

In contrast to those doomed heroes, the leading balloon buster of all time was also one of the longest-lived. Even so, Willy Coppens, Baron de Houthulst—who also entered history books as Belgium’s ace of aces—did not emerge from World War I unscathed.

Born in Watermaal-Boosvoorde, near Brussels, on July 6, 1892, Willy Omer François Jean Coppens spent the prewar years designing wheeled, sail-propelled land yachts, building seven between 1907 and 1913. From the moment he saw his first airplane in 1910, he yearned to fly, but his artist father threatened to throw him out of the house if he did. Willy settled for building and flying kites and model airplanes until 1912, when he was conscripted into military service and joined the 2nd Grenadier Regiment.

Belgium was neutral when war broke out on July 28, 1914, but Germany ignored that when it initiated General Alfred Graf von Schlieffen’s plan for a surprise invasion of France from the north. On August 4, German forces barged into Luxembourg and Belgium, and within two months they had driven the Belgian government and its small army into France, leaving Coppens’ family in Brussels and Willy imbued with a lifelong hatred of the Germans.

Transferring to the Belgian Motor Machine Gun Corps, Coppens soon acquired an equal loathing for trench warfare. On September 6, 1915, he signed up for flight training at Beaumarais. The ill-equipped Belgian school proved incapable of providing the instruction he needed, so Coppens took eight weeks’ leave and studied privately in England. He obtained a Royal Aero Club certificate on December 9, completing his training at the French Farman School at Etampes.

Coppens’ first frontline assignment, in early 1917, was with the 6th Escadrille d’Observation, flying British-built Royal Aircraft Factory Blériot Experimental B.E.2c reconnaissance planes from Houthem aerodrome. Promoted to sergeant first class on April 8, he transferred to the 4th Escadrille, equipped with obsolescent Farman F.40 pushers, later that same month. He was assigned a Sopwith 1½ Strutter on May 1, the same day he experienced his first aerial combat. Coppens’ plane had not yet had its front machine gun installed, but he did his best to evade his four attackers while his observer, Captain René Declercq, fended them off with his Lewis machine gun. The duo returned with 32 bullet holes in their Sopwith.

On July 7, Coppens and Declercq engaged a German two-seater and sent it diving away near Middelkerke. One week later the aggressive young pilot finally got what he wanted—a transfer to fly single-seat fighters with the 1st Escadrille de Chasse, based at Les Moëres. There Coppens found role models in the squadron’s myopic commander, Captain Fernand Jacquet, who had become Belgium’s first ace by attacking German aircraft in Farman two-seat pushers; Sergeant Jan Olieslagers, a bicycle racing champion and prewar aviator who was eventually credited with six victories; and Coppens’ flight leader, Lieutenant André de Meulemeester, a sharp-eyed hunter who would survive the war with 11 victories.

The 1st Escadrille was equipped with Nieuport 17s, but Coppens was assigned what was probably the last Nieuport 16 left on the Western Front. Although still inexperienced in his tricky new mount, on July 21 he attacked a German two-seater and was shot up for his trouble. Coppens was promoted to adjutant on August 19, and shortly afterward his squadron received the first of a batch of Hanriot HD.1s that the Aviation Militaire Belge had acquired because the French, sold on Spads, did not want them. de Meulemeester rejected the new fighter out of hand, as did everyone else save Coppens, whose subsequent glowing reports of its flight characteristics convinced the entire squadron to accept it. “But the HD.1 had a great defect,” Coppens wrote, “only one machine gun, because de Meulemeester, our ace in 1917, decided it better to climb 800 feet higher; with two it climbed only just over 20,000.”

On September 10, a new Spad XIII fighter landed at Les Moëres with engine trouble, and from its cockpit emerged Captain Georges Guynemer, then France’s top ace with 53 victories. “Having been forced to land at an unknown field,” Coppens recalled, “Guynemer appeared to be a little nervous, not much talkative. He was not distant nor timid, but seemed a bit uneasy because of our intense curiosity….He had shaken hands with the first of us to come to him, without knowing who we were. Then he paid attention to our mechanics at work, putting his Hispano[-Suiza engine] in order. We would have liked, all of us, to ask him questions.

“My old friend Jacques Ledure, a pilot who was very clever with motors, watched and gave good advice. He exchanged ideas with Guynemer and, to please me, succeeded to have a signature on my silver cigarette case….When his motor was in order and tested, Guynemer flew off, straight to St. Pol. None of us ever saw him again.” Guynemer was killed in action the next day.

Although confirmed successes eluded Coppens over the next several months, he gained his first measure of notoriety by making a 200- kilometer flight over enemy-held territory to Brussels on February 18, 1918. He gave his own account of the seemingly suicidal gesture: “With full tanks, I took off at 8:35 in the morning. Half an hour later, at 9:05, I was at a height of 18,000 feet above Dixmuide. The enemy anti-aircraft defense was fully busy chasing two French Spads, and I think it was thanks to those circumstances that they did not aim at me and that I passed unnoticed.”

Shortly before 10 Coppens arrived at the Belgian capital for the first time since the Germans had overrun it 3½ years earlier. Diving from 3,000 feet, he made his way to the Rue des Champs Elysées, facing the Parc Solvay, where his parents lived.

“The Hanriot made it possible to turn inside a very short radius and in this way I made a tour of the house five times, so low that I nearly touched the tops of the trees,” he said. “At the second tour, I saw and recognized my father who was looking out of one of the upper windows. I was so near that I could distinguish details of his clothing; he was wearing a brown necktie, the same color of his suit. He made wild movements of his arm and his emotion must have come up to mind. I also saw my mother, on the first floor, behind a window—the reflection of which prevented me from seeing exactly, but it must have been she. She had been the first to hear the plane and to feel sure that it was me.

“At the Place Saints-Croix, quite near, there was incredible animation, which I noticed on each tour while passing the house. An hour later the whole city knew my name, and there were even a lot of people who, later on, said that they recognized me! At 10:45 I landed on Les Moëres airfield. My folly was well acknowledged.”

This and past brushes with death convinced Coppens that he was too lucky to let fear affect his personal war against the Germans, yet he was frustrated in his efforts to damage the enemy. Then on March 17 the Germans seized two key guard posts at Riegersvliet from elements of the Belgian Cavalry Division. Belgian efforts to recover the positions were frustrated by the presence of a German balloon monitoring the sector from Bovekerke. Sergeant Major Charles de Montigny and Coppens volunteered to bring the Drachen down, and although they lacked incendiary ammunition, they succeeded in puncturing the gasbag and forcing its observer to bail out. The pair repeated their performance on a replacement Drachen, depriving the Germans of the observation posts just long enough for the Belgian cavalry to retake both.

From then on, whenever the Belgians needed a volunteer to deal with a Ger – man balloon, Coppens eagerly accepted the assignment. “I had started attacking the Drachen by sense of duty,” he explained. “I went on by pride.”

Coppens finally scored his first confirmed victory on April 25, a Rumpler two-seater that he and Captain Walter Gallez downed near St. Joris. Soon afterward Coppens managed to wangle an allotment of 20 incendiary rounds a month from his superiors, four of which he installed in his ammunition belt for each mission. To make them count, he initiated a policy of never firing at ranges greater than 150 yards.

He first tested that tactic on May 8, when he came so close to a Drachen over Zarren that he almost struck it, but succeeded in setting it afire. Returning to his aerodrome to reload with four more incendiaries, Coppens found another balloon over the Houthulst Forest. Diving on it, he burned that one as well. For that day’s double success he was congratulated by King Albert I and awarded the Croix de Guerre and Ordre de la Couronne.

During a foray on May 15, Coppens learned to his dismay that the morning dew would literally dampen his prospects of setting a Drachen alight. He made three attacks through heavy anti-aircraft fire in an effort to destroy another balloon over Houthulst that day, without result. Blipping his rotary engine to low speed, he came on once again at the Drachen’s level, firing his last 30 rounds into it. Although the balloon still refused to burn, his long burst apparently severed its cables, for just as he began climbing above it, it suddenly shot upward, colliding with his plane. Coppens immediately shut off his engine, lest his propeller foul in the fabric, and hung on in terrified suspense as his Hanriot slid and tumbled along the sagging gasbag until it finally fell over the side. At that point Coppens pointed the nose earthward to build up speed, then switched on the engine and, when it roared back to life, pulled up and away while the perforated balloon descended to the ground and exploded. When Olieslagers and de Meulemeester expressed skepticism over his claim, Coppens pointed to scars left on his propeller blades by the cables and traces of balloon fabric on his wing and undercarriage.

Four days later, Coppens roasted another sausage over Houthulst, for his ace-making fifth victory. Soon after that, he received a gift from the French—an 11mm Vickers machine gun with incendiary ammunition, specially built for balloon busting. Delighted, he installed it on his Hanriot, then used it to dispatch balloons on June 5, 9 and 10.

Disaster struck the 9th Escadrille on the night of June 13, when a German bombing raid started a fire in its hangar, destroying or damaging all of the unit’s Hanriots, including Coppens’ HD.1s Nos. 17 and 24. He got a replacement on the 18th, in the form of Hanriot No. 6, but later wrote: “It had been recovered at Beau marais (Calais), where they had camouflaged it in an asinine fashion. It resembled one of those varnished wooden snakes you saw in toyshops….At the first opportunity, I had my machine painted blue all over.” De Meulemeester had earlier flown No. 6 with twin .303-inch Vick ers machine guns, only to reject the arrangement. Now Coppens installed his 11mm machine gun on it.

Coppens destroyed another balloon over Ploegsteert and a Hannover C.L.III over Warneton on June 24, but after he landed de Meulemeester found him sitting in the cockpit, trembling. When his flight leader asked if he had been hit, Coppens whispered: “I just killed a brave man, and I killed him in the worst way I could. The balloon observer didn’t jump—he kept firing at me with a little handgun. The burning balloon just swallowed him up.”

Although that image would haunt Coppens for the rest of his life, it did not prevent him from accepting a commission as a sub-lieutenant, or from finishing June with a “hat trick” on the 30th—a balloon over Bovekerke at 0630, another at Gheluvelt at 0830 and a third over Passchendaele four minutes later.

Coppens’ royal blue Hanriot was becoming an all too familiar sight to the Germans, who began to refer to him as “der blaue Teufel.” “The result of my frequent attacks was that the balloons did not go so high anymore (about 900 meters instead of 1,200) or come so near to our lines (eight to 12 kilometers, instead of six),” Coppens noted. The Germans were also doubling and even tripling the number of gun batteries around their balloon nests.

After taking some leave, during which he was made a Chevalier de l’Ordre de Léopold, Coppens resumed his scoring on France’s Bastille Day, followed by more balloons on July 16, 19 and 20, and another triple kill on the 22nd, for which the British in that sector awarded him the Military Cross.

Coppens burned a Drachen at Ruyterhoek on July 24, but while attacking another over Reutel on August 3, his plane was rocked by an explosion. He managed to return to base, where the Belgians later learned from an enemy prisoner that the Germans had sent that last balloon up packed with explosives, specifically to blast the “Blue Devil” back to hell. “Unfortunately—for the Germans—I had dived out of the sky before the final arrangements had been completed,” Coppens wrote, “and had sent the ‘sausage’ down, nicely roasted, with its charge of explosive, into the center of the assembled spectators!”

Coppens scored another triple on August 10, and on the 22nd he was given command of a three-plane flight. Two days later he burned two more balloons, followed by more on September 3 and 4. On the 7th he donned his dress uniform to receive the Belgian Légion d’Honneur from King Albert and the Croix de Guerre from French Prime Minister Georges Clemenceau, who much to the ace’s amusement, while bending over to pin the award on the diminutive Belgian, bumped his head on Coppens’ helmet. Coppens subsequently added the French Légion d’Honneur, the British Distinguished Service Order, the Serbian Order of the White Eagle, and decorations from Portugal, Italy and Poland to his international collection.

In mid-September Coppens received two more HD.1s, Nos. 23 and 45. “No. 23 had an ugly and bad camouflage painted in Calais,” he stated. “I had it for a second plane and painted it in a beautiful royal blue, not dark, not pale….M. Hanriot very gently gave me a larger elevator of an HD.2, which I put on my blue HD.1—it rolled much better, so it turned immediately when I was attacked, made a half-roll and passed under my attacker, who did not know where I had passed, until he heard me firing at him.”

Coppens burned two Drachen over Leffinghe on September 27, and another two days later, although while returning from the latter raid he came under fire from a nervous British R.E.8 crew, for which he lodged a protest with the Royal Air Force. On October 2, he and Sergeant Étienne Hage drove a German two-seater down out of control, but its destruction was not confirmed. Returning to his forte, Coppens burned a Drachen on the 3rd and two more on the 5th, raising his tally to 35.

The Allies were advancing on all fronts by then, and with their offensive about to resume on October 14, Coppens and Hage set out at 0540 hours to eliminate the Drachen at Tourhout. Along the way Coppens spotted another gasbag 1,800 feet over Praatbos and dived on it, expending only four rounds before it exploded. Moving on to Tourhout, the two Belgians found their quarry at 2,400 feet, but as Coppens approached he was suddenly hit by a hollow machine gun round that smashed the tibia of his left leg and severed the artery. The sudden agonized spasm caused his right leg to kick the rudder bar, throwing his plane into a spin, with his machine gun wildly spraying the air. “The first of these bullets at least hit the balloon, which burst into flames,” Cop pens said, “but it was a thing I did not know at the time, and I did not claim a victory.”

Though he was in pain and bleeding profusely, Coppens was determined not to fall into German hands, dead or alive. Using his right leg to work the rudder bar, he came out of his spin and, despite a bullet hole in the inlet pipe of his engine, flew the five to six miles to Allied lines in three nerve-wracking minutes. “I wanted air, ice-cold air, to bathe my face and keep me from fainting,” he said, so he threw away his goggles and scarf, although he stuffed his fur-lined flying helmet in his coat. “I chose a small field by the side of the road, on which a fair amount of traffic told me that I should obtain help. The field, all too small, was hemmed in with hedges, and I had to put my machine down rather heavily in order to arrest its progress. My undercarriage, which had been badly weakened by the machine-gun fire, collapsed on contact with the ground.”

Stretcher-bearers rushed Coppens to the hospital at La Panne, where his left leg had to be amputated. King Albert visited the wounded airman the following day and invested him with the rosette of an Officier de l’Ordre de Léopold. Hage, Coppens later learned, had destroyed a third balloon over Roulers before being wounded in the arm.

After the Armistice and the liberation of Belgium, Coppens was made Baron d’Houthulst and persuaded to stay in the army by the king himself. When he left the service in 1940, however, he had only attained the rank of major, having spent much of his time as a military attaché in Italy, Switzerland, France and Britain. During World War II he resided in Switzerland, where he married and organized resistance efforts. In the late 1960s he moved back to Belgium and lived his last five years with Jan Olieslagers’ daughter.

Coppens’ memoir Jours Envoles was translated into English in 1932 as Days on the Wing. He also wrote a biography of Olieslagers and was working on one for Italian ace Fulco Ruffo di Calabria at the time of his own death on December 21, 1986.

An estimated 500 kite balloons were employed by each side over the Western Front during WWI, which marked the apogee of observation balloons, both as a strategic target and as a challenge to the airmen who tried to eliminate them. They were so closely associated with trench warfare that when the Armistice went into effect on November 11, 1918, a British communiqué announced it by declaring, “All along the Front, the balloons are down.” Amid the more technically advanced aerial conflict of World War II, tethered lighter-than-air craft would be put to other work, most notably serving as barrage balloons.

Willy Coppens was not only Belgium’s ace of aces and the leading balloon buster of all time, but also one of the longest-lived survivors of an extremely high-risk specialty. He and his comrades represented a unique breed from a unique time, the likes of which will never be seen again.

For additional reading, Aviation History research director Jon Guttman recommends his own book, Balloon Busting Aces of World War I, as well as Days on the Wing, by Willy Coppens de Houthulst.

Originally published in the September 2008 issue of Aviation History. To subscribe, click here