Design

On 18 January 1913 Admiral Alfred von Tirpitz, Secretary of State of the German Imperial Naval Office, got Kaiser Wilhelm II to agree to a five-year expansion program of German naval airship strength. A contract was placed for the first airship on 30 January, one requirement being that the craft should be capable of bombing England. The design was heavily influenced by the naval architect Felix Pietzker, who was an advisor to the German Admiralty Aviation Department. Construction started in May. The length and overall height of the ship were limited by the size of the Navy's airship shed at Fuhlsbüttel, but Pietzker's proposals enabled the diameter of the airship to be increased without increasing overall height firstly by changing the position of the keel, moving it from outside the main hull structure to within it, and secondly by placing the engine cars closer to the hull. It was powered by four 130 kilowatts (180 hp) Maybach C-X engines in two engine cars, each car driving a pair of four-bladed propellers which were mounted either side of the envelope via driveshafts and bevel gears. The ship was controlled from a third gondola mounted in front of the forward engine car.

LZ 18 was first flown on 6 September at Friedrichshafen, and following a number of trial flights was flown to Johannisthal on 20 September for naval acceptance trial to begin, the flight of about 700 km (438 mi) taking twelve hours. The ship's tenth flight was to be an altitude trial and was scheduled for 17 October. The airship was removed from its shed in the morning but takeoff was delayed because one of the engines would not start. The delay of two hours while the engine was repaired allowed the morning sun to heat the hydrogen, causing it to expand. This caused the airship to ascend rapidly to 610 m (2,000 ft), when horrified observers on the ground saw a flame leap out of the forward engine car, causing the explosion of some of the gasbags. Halfway to the ground there was a second explosion, and as the wreckage hit the ground further explosions followed as the fuel tanks ignited. Three survivors were pulled from the blazing wreckage, but two died shortly afterwards and the third died that night in hospital. In all 28 men died, including Pietzker, and the new chief of the Admiralty Aviation Department, Korvettenkapitän Behnisch, the successor to Korvettenkapitän Metzing who had been killed in the L 1 on 9 September. The accident was agreed to have been caused by the rapid ascent leading to venting of hydrogen through the relief valves, which in Zeppelins of the period were placed at the bottom of the bags, without vent trunks to convey any hydrogen let off to the top of the ship. Some of the vented gas was then sucked into the forward engine car, where it was ignited, the fire then spreading to the gasbags.

Aftermath

The loss of the L 2 occurred six weeks after the loss of the L 1 with most of its crew. The two disasters deprived the Navy of most of its experienced personnel and led to the suspension of the planned expansion program. The death of Korvettenkapitän Behnisch led to the appointment of Peter Strasser as the new head of the Admiralty Aviation Department.

Roy Knabenshue’s dirigible offered sightseeing flights around Los Angeles and Chicago, garnering frequent press coverage, then disappeared without a trace.

Early in 1912, pioneer aviator Augustus Roy Knabenshue shared an idea with fellow birdman Charles Willard for building an airship that could carry 10 to 12 passengers on regular trips. The two had been friends since at least Sep­tember 1909, when at a flying exhibition in St. Louis’ Forest Park they came up with the idea of organizing what would become the legendary 1910 Dominguez Air Meet. 

Knabenshue first achieved fame when he flew Thomas Baldwin’s California Arrow airship at the 1904 Louisiana Purchase Exposition in St. Louis, where he won the grand prize for his record flights. He had been a professional balloonist since 1900, when he bought his first balloon and started offering flights at county fairs. His socially prominent family opposed the venture, and Knabenshue said, “I could not engage in a business that would lower and drag the family name through the mire,” so during those early flying days he went under the name Professor Don Carlos.

By 1912 Knabenshue had designed and built several successful airships, slowly increasing their size and capacity and establishing many aviation firsts, including the first powered flight in the U.S. with mult­i­ple passengers. Meanwhile he had attracted the attention of the Wright brothers, who hired him to plan exhibitions for their pilots in training. 

In 1908 Stanley Beach, aviation editor of Scientific American and founder of New York’s Aeronautic Society, invited Willard to help him build an airplane. The Beach-Willard monoplane was ultimately a failure, but it gave Willard valuable experience and spurred his interest in aviation. He then became the Aeronautic Society’s exhibition pilot, taught by Glenn Curtiss (in a single three-hour lesson) when the society purchased the Golden Flyer biplane from him. Curtiss later hired him to be part of his flying exhibition team.

Knabenshue had recently left his job as manager of the Wright brothers’ flight exhibition team when Willard quit flying for Curtiss. Willard agreed to design the new passenger airship, though his involvement in the project seems to have ended with that initial design.

On September 11, 1912, the East Oregonian announced: “Roy Knabenshue, aviator, left Los Angeles for Akron, Ohio, where he will begin construction of an airship for passenger service between Los Angeles and the beaches and Mount Lowe.” Eight months later the completed airship was transported to Pasadena and housed in a hangar on South Marengo Avenue. The construction cost was more than $40,000. 

When first built, the entire gondola framework was covered with cloth and the airship featured forward and rear biplane elevators. The first flight, on April 15, 1913, revealed some issues to fix. The forward elevators were removed, the cloth was stripped from most of the framework and significantly larger rudders were installed. The ship flew successfully for 45 minutes on May 4. 

By November 1913 the airship was making regular sightseeing flights to Los Angeles and back. The 10-mile roundtrip took 20 minutes. On Nov­ember 1 the San Francisco Call whimsically reported: “Since Roy Knabenshue began making flights here in a dirigible balloon it is noticed all the laying hens have gone on strike. Eggs are now imported from Monrovia.” Granted, no one, including chickens, was yet accustomed to flying machines regularly passing low overhead, so perhaps there was something to the story.

On November 24, while returning from a flight to Los Angeles with five passengers, the airship’s engine suddenly stopped due to a burst water pipe. The ship began to rise but Knabenshue walked up to the bow and used his weight to point the nose down again. It almost plowed into an orange grove before enough ballast could be released to clear the trees. Moments later spectators grabbed the anchor rope and towed the airship to its hangar.

The following year, Pasadena (it is unclear when exactly it was named, as early newspaper coverage simply referred to a “big dirigible”) flew regularly from its namesake city to Santa Monica, Los Angeles, Long Beach and back. One notable early passenger was Arthur E. Raymond, son of the owner of the nearby Raymond Hotel. The 15-year-old often helped to handle the ship on the ground, and finally on a slow day Knabenshue took him for a ride. This sparked his lifelong enthusiasm for aviation, and Raymond eventually became the designer of the legendary Douglas DC-3 and DC-8 airliners. 

A flight on March 6, 1914, carried a wireless apparatus operated by H.D. Hayes, director of the Los Angeles YMCA school of wireless instruction. Hayes managed to stay in constant contact with a wireless station in San Pedro, 40 miles away. 

On March 7 Collier’s magazine noted, “The sight of aircraft has become so familiar in Pasadena, Cal., that Roy Knabenshue, captain of the dirigible which docks in that port, observes that school children playing in Pasadena’s streets often do not trouble nowadays to look up when the big airship glides by.” It was no mean achievement to have safely flown over the city so regularly that even children were becoming jaded.

In April Knabenshue and Pasadena appeared in the Universal Studios picture Won in the Clouds, a “three reel special feature.” Marie Walcamp, the original action movie heroine, played the female lead, with Knabenshue appearing as himself. The film featured “a climax that fairly crashes!” noted Kansas’ Chetopa Advance.

On May 21, while staying in Washington, D.C., Knabenshue gave an entertaining interview to the Washington Herald newspaper. Still a dedicated ballooning enthusiast, he told the reporter: “It is the king of sports….There is nothing to compare to it. When I get through, all a person will have to do is go out in the garden, unhitch the family balloon, and go to see father in the next county. I hope to see the day when a self-respecting family will no more dare to be without a balloon than without a family skeleton.”

By spring of 1914, the pool of wealthy passengers who could afford the $25 ticket for trips in Pasadena was getting shallow, and Knabenshue was planning his next venture with the airship. Aeronautics magazine reported, “The ship has been in operation in Los Angeles and vicinity since August of last year; has made hundreds of trips with passengers, and was not deflated until the 1st of May when it was packed to ship to Chicago.” The magazine noted that Knabenshue might bring his “10-man dirigible” to New York after he was done in Chicago.

After Pasadena was packed up and shipped to Chicago on May 1, it was ready to fly again by the middle of June. The airship’s rear biplane elevators were replaced with triplane elevators, and the passenger gondola refitted. The airship was renamed White City after the amusement park in which it was now based. The ticket price was still $25. Knabenshue carefully documented each flight—passengers signed a form that read, “I, the undersigned, hereby express my willingness to undertake all risks in connection with the Airship Flight which I am about to take and fully release The White City Construction Company and A.R. Knabenshue from all liability.” Always cautious, Knabenshue canceled flights when he judged the wind too strong. 

On June 17 White City made its first Chicago flight, a 24-minute trip over the city’s parks and Lake Michigan with eight passengers aboard. It flew for an hour and a half on June 26. “The airship left White City shortly after 4 o’clock,” Aero and Hydro reported. “Within 30 minutes it had passed Twelfth Street. It followed the lakeshore and turned loopward just north of Grant Park. It circled over many of the famous skyscrapers, and the seven passengers looked down into the ‘wells’ of the big buildings. A photographer in the dirigible took a number of views during the trip.” The passengers that day were four women, two men and, in the back, a movie camera operator. It wasn’t unusual for movie cameramen to be called “photographers” at that time—films were “reels of pictures.” White City flew low and slow and the cameraman took clear footage of buildings, ships, railyards, automobiles and people, and of the airship being taken out of its shed and put back into it. This film eventually vanished into the National Archives and was only recently rediscovered there by Chicago Tribune reporters, but in the meantime, it would play a very important role in the next phase of Roy Knabenshue’s career. 

At some point in July, Knabenshue took his mother, father and wife for a flight. On July 11, in a publicity stunt, “Roy Knabenshue with four passengers in his huge dirigible and Jack Vilas in a hydroaeroplane, played tag over Lake Michigan, the smaller craft circling the larger one many times,” reported the South Bend News-Times. This was the last press mention of the airship, after which its fate is unknown. It was not destroyed in an accident; that certainly would have been noted. And if Knabenshue sold it, there is no record of it flying anywhere else later.

In 1916 Knabenshue made a presentation at the Navy Department in Washington of the film taken from White City, greatly impressing the gathered military representatives. Later that year, he received an order from the Army Air Service for a “special spherical balloon” and 25 observation balloons. He started the Knabenshue Manufacturing Company and leased a factory in Northport on Long Island, where he successfully fulfilled the contract. 

The following September, with famous French engineer Henri Julliot (builder of the Lebaudy airships Jaune, La Patrie, La République and others) in charge, the B.F. Goodrich Company completed its first two patrol blimps for the U.S. Navy. The Navy required a strenuous acceptance test flight, to be conducted at night. Enter America’s most experienced airship pilot, Roy Knabenshue. The eight-hour flight “over a big city” (kept secret, but likely Los Angeles) was a resounding success and the Navy accepted the blimps. This would be the last hurrah of his flying career. 

In 1924 Knabenshue tried to return to airships, this time rigid. A blueprint was drawn in March for the Knabenshue Aircraft Corporation airship California. In 1926 he told the press the “work of design and developing plans” had taken most of his time for the past five years. A large scale model of the airship was built the following year, and Knabenshue promoted the idea of airship passenger service from Los Angeles to Hawaii. His company completed another rigid airship blueprint on January 1, 1930, but ultimately nothing came of the project. 

Knabenshue eventually ended up working for the National Park Service, where he promoted the use of autogiros to monitor forests. He retired in poverty, and had to plead for a meager pension. Still, he wasn’t entirely forgotten. In 1944, on the 40th anniversary of his Louisiana Purchase Exposition flights, Orville Wright sent him a telegram: “Don’t you remember it, and doesn’t it give you a thrill when you think of it?”

Knabenshue died on March 6, 1960. Among the five honorary pallbearers at his memorial service was Charles Willard.

Willard had gone on to a successful career in aviation and lived a long life, and was occasionally invited to aviation events. On October 1, 1956, during a ceremony placing a memorial plaque honoring him at Illinois’ Decatur Airport, he said: “We weren’t show people, and that was proven by the fact that we often lost money on our exhibitions. But that didn’t matter. Our sole object was to get the public aircraft minded.”  

The Etrich Taube, also known by the names of the various later manufacturers who built versions of the type, such as the Rumpler Taube, was a pre-World War I monoplane aircraft. It was the first military aeroplane to be mass-produced in Germany.

The Taube was very popular prior to the First World War, and it was also used by the air forces of Italy and Austria-Hungary. Even the Royal Naval Air Service operated at least one Taube in 1912. On 1 November 1911, Giulio Gavotti, an Italian aviator, dropped the world's first aerial bomb from his Taube monoplane over the Ain Zara oasis in Libya. Once the war began, it quickly proved inadequate as a warplane and was soon replaced by other designs.

Design and development

The Taube was designed in 1909 by Igo Etrich of Austria-Hungary, and first flew in 1910. It was licensed for serial production by Lohner-Werke in Austria and by Edmund Rumpler in Germany, now called the Etrich-Rumpler-Taube. Rumpler soon changed the name to Rumpler-Taube, and stopped paying royalties to Etrich, who subsequently abandoned his patent.

Despite its name (Taube means "dove"), the Taube's unique wing form was not modeled after a dove, but was copied from the seeds of Alsomitra macrocarpa, which may glide long distances from their parent tree. Similar wing shapes were also used by Karl Jatho and Frederick Handley Page. Etrich had tried to build a flying wing aircraft based on the Zanonia wing shape, but the more conventional Taube type, with tail surfaces, was much more successful.

Etrich adopted the format of crosswind-capable main landing gear that Louis Blériot had used on his Blériot XI cross-channel monoplane for better ground handling. The wing has three spars and was braced by a cable-braced steel tube truss (called a "bridge", or Brücke in German) under each wing: at the outer end the uprights of this structure were lengthened to rise above the upper wing surfaces, to form kingposts to carry bracing and warping wires for the enlarged wingtips. A small landing wheel was sometimes mounted on the lower end of this kingpost, to protect it for landings and to help guard against ground loops.

Later Taube-type aircraft from other manufacturers replaced the Bleriot type main gear with a simpler V-strut main gear design, and also omitted the underwing "bridge" structure to reduce drag.

Like many contemporary aircraft, especially monoplanes, the Taube used wing warping rather than ailerons for lateral (roll) control, and also warped the rear half of the stabilizer to function as the elevator. Only the vertical, twinned triangular rudder surfaces were usually hinged.

Operational history

In civilian use, the Taube was used by pilots to win the Munich-Berlin Kathreiner prize. On 8 December 1911, Gino Linnekogel and Suvelick Johannisthal achieved a two-man endurance record for flying a Taube 4 hours and 35 minutes over Germany.

The design provided for very stable flight, which made it extremely suitable for observation. The translucent wings made it difficult for ground observers to detect a Taube at an altitude above 400 meters. The first hostile engagement was by an Italian Taube in 1911 in Libya, its pilot using pistols and dropping 2 kg (4.4 lb) grenades during the Battle of Ain Zara. The Taube was also used for bombing in the Balkans in 1912–13, and in late 1914 when German 3 kg (6.6 lb) bomblets and propaganda leaflets were dropped over Paris. Taube spotter planes detected the advancing Imperial Russian Army in East Prussia during the World War I Battle of Tannenberg.

World War I

While initially there were two Taube aircraft assigned to Imperial German units stationed at Qingdao, China, only one was available at the start of the war due to an accident. The Rumpler Taube piloted by Lieutenant Gunther Plüschow had to face the attacking Japanese, who had with them a total of eight aircraft. On 2 October 1914, Plüschow's Taube attacked the Japanese warships blockading Tsingtao with two small bombs, but failed to score any hits. On 7 November 1914, shortly before the fall of Qingdao, Plüschow was ordered to fly top secret documents to Shanghai, but was forced to make an emergency landing at Lianyungang in Jiangsu, where he was interned by a local Chinese force. Plüschow was rescued by local Chinese civilians under the direction of an American missionary, and successfully reached his destination at Shanghai with his top secret documents, after giving the engine to one of the Chinese civilians who rescued him.

Poor rudder and lateral control made the Taube difficult and slow to turn. The aeroplane proved to be a very easy target for the faster and more agile Allied Scouts of the early part of World War I, and just six months into the war, the Taube had been removed from front line service to be used to train new pilots. Many future German aces would learn to fly in a Rumpler Taube.