20 August 1919: The first airship built after World War I, Bodensee, LZ 120, made its first flight at Friedrichshafen, Germany, with Captain Bernard Lau in comand. LZ 120 was built for Deutsche Luftschiffahrts-Aktiengesellschaft, DELAG, (German Airship Travel Corporation) especially to carry a small complement of passengers. It was hoped that this would generate favorable publicity and help to restart intercity travel by air.
Bodensee was the first fully-streamlined airship. Its teardrop shape was developed by engineer Paul Jaray and had no cylindrical sections. The shape had been tested with scale models in a wind tunnel. LZ 120 was the first airship to have the gondola was attached directly to the bottom of the envelope, decreasing aerodynamic drag.
LZ 120 was a rigid airship, or dirigible, with a metal skeleton structure covered with a cotton fabric envelope. Twelve hydrogen-filled buoyancy tanks were contained within the structure. A crew of 12 operated the airship and it could carry 20 passengers.
LZ 120 was 396.33 feet (120.8 meters) in length, with a diameter of 61.38 feet (18.71 meters). The airship had a volume of approximately 20,000 cubic meters (706,000 cubic feet). The airship had an empty weight of 13,646 kilograms (36,698 pounds) and a gross weight of 23,239 kilograms (51,233 pounds).
LZ 120 was powered by four water-cooled, normally-aspirated, 23.093 liter (1,409.2 cubic inches) Maybach Motorenbau GmbH Mb IVa single overhead cam (SOHC) vertical inline six-cylinder engines with a compression ratio of 6.08:1 and four valves per cylinder. The Mb IVa produced 302 horsepower at 1,700 r.p.m., but was derated to 245 horsepower. Two engines were mounted in the aft centerline engine car and drove a two-bladed propeller with a diameter of 5.2 meters (17.1 feet) through a reversible gear train. Each of the other engines were mounted near the center of the airship, outboard. They each turned a two-bladed propeller with a diameter of 3.2 meters (10.5 feet), which were also reversible.
LZ 120 had a maximum speed of 82 miles per hour (132 kilometers per hour).
After two test flights under Captain Lau, Bodensee entered scheduled passenger service on 24 August 1919 under the command of Dr. Hugo Eckener. It flew from Friedrichshafen to the Oberwiesenfeld at Munich, then on to Berlin-Staaken.
In 1921, Bodensee was turned over to Italy as war reparations. It was renamed Esperia and continued in operation until 1928.
11–14 May 1926: The famed Norwegian arctic explorer, Roald Engelbregt Gravning Amundsen, departed Ny-Ålesund, Svalbard, Norway, aboard the semi-rigid airship Norge.
The airship had been designed by Colonel Umberto Nobile and built at the Italian State Airship Factory at Rome, originally named simply N1. In discussions between Amundsen and Nobile, it was determined that N1 was not suitable for an arctic flight, but Amundsen didn’t want to wait for a new lighter-than-air craft to be be built, so Nobile modified it. Amundsen purchased N1 and re-named it Norge.
According to an article in the 20 March 1924 edition of Flight, the airship was 106 meters (347 feet, 8 inches) in length, 26 meters (85 feet, 3 inches) in height, with a maximum diameter of 19.5 meters (64 feet). Buoyancy was provided by 19,000 cubic meters (670,700 cubic feet) of hydrogen. The airship had a useful load of 10,850 kilograms (10.5 tons). Its maximum speed was 100 kilometers per hour (62 miles per hour).
Norge was propelled by three water-cooled, normally-aspirated 23.093 liter (1,409.225 cubic inch) Maybach-Motorenbau GmbH Mb.IV inline six-cylinder overhead valve (OHV) engines with four valves per cylinder and a compression ratio of 6.88:1. The engine was able to produce 240 pferdstarke (236.7 horsepower) at 1,400 r.p.m. The engines were placed in gondolas suspended by cables under the hull, and drove propellers through a clutch. A reverse gear was available.
With a 16-man expedition and Umberto Nobile as pilot, Amundsen departed Ny-Ålesund at 9:55 a.m., enroute to Nome, Alaska, via the North Pole. Norge arrived at the Pole at 1:25 a.m. GMT, 12 May, and descending to an altitude of 300 feet (91 meters) dropped three flags, Norwegian, Italian and American, then proceeded south to Alaska. The explorers arrived at Teller at 3:30 a.m., 14 May, and due to adverse weather conditions, ended their flight at that location. Norge had covered 3,393 miles (5,460.5 kilometers).
Amundsen’s flight began just two days after that of Richard E. Byrd and Floyd Bennett aboard their Fokker F.VII/3m, Josephine Ford. Byrd’s flight has been the subject of some controversy as to whether they actually had arrived at the North Pole. The flight of Norge is undisputed.
12 February 1935: The United States Navy rigid airship USS Macon (ZRS-5), under the command of Lieutenant Commander Herbert Victor Wiley, crashed into the Pacific Ocean off Monterey Bay, on the central California coastline. The airship soon sank to the sea floor, approximately 1,500 feet (457 meters) below. Of the crew of 76 men, 74 survived.
Lieutenant Commander Wiley was a 1915 graduate of the United States Naval Academy, Annapolis, Maryland. He had previously served aboard the U.S. Navy’s first rigid airship, USS Shenandoah (ZR-1) and then commanded USS Los Angeles (ZR-3), 1929–1930. He had been assigned as executive officer of USS Akron (ZRS-4) and had been one of only 3 crew members to survive the wreck of that airship off the coast of New Jersey, 4 April 1933. He took command of USS Macon in June 1934. During World War II, Captain Wiley commanded Destroyer Squadron 29 (consisting of thirteen Clemson-class “flush-deck” destoyers) with the Aisatic Fleet, and later, the Colorado-class battleship USS West Virginia (BB-48). He rose to the rank of rear admiral before retiring in 1947.
USS Macon was built by the Goodyear-Zeppelin Corporation at Akron, Ohio. It was launched 21 April 1933, and commissioned 23 June 1933.
Macon was constructed of duralumin ring frames and girders, covered with a fabric envelope. The rigid airship was 785 feet (239.3 meters) long with a maximum diameter of 132 feet, 10 inches (40.488 meters). The overall height was 146 feet, 2 inches (44.552 meters). The airship displaced 7,401,260 cubic feet of air (209,580 cubic meters). Lift was provided by 6,500,000 cubic feet (184,060 cubic meters) of non-flammable helium gas contained in 12 rubberized fabric gas cells.
Macon had a dead weight of 108.2 tons (98,157 kilograms) and a useful lift of 160,644 pounds (72,867 kilograms).
Propulsion was provided by eight water-cooled, fuel-injected, 33.251 liter (2,029.077-cubic-inch-displacement) Maybach VL-2 overhead valve 60° V-12 gasoline engines producing a maximum 570 horsepower at 1,600 r.p.m., each, or 450 horsepower at 1,400 r.p.m. for cruise. In addition to gasoline, the VL-2 could also use blau gas (similar to propane) as fuel. The engines were reversible and drove Allison Engineering Co. out-drives, which turned three-bladed fixed-pitch, rotatable propellers. The VL-2 is 6 feet, 5 inches (1.96 meters) long, 3 feet, 0 inches (0.91 meters) wide and 3 feet, 2 inches (0.97 meters) high. It weighs 2,530 pounds (1,148 kilograms).
The airship had a maximum speed of 75.6 knots (87.0 miles per hour, 140.0 kilometers per hour).
USS Macon was armed with eight Browning .30-caliber machine guns for defense. It also carried five Curtiss-Wright Airplane Division F9C-2 Sparrowhawk reconnaissance airplanes in an internal hangar bay. These were small single-place, single-engine biplanes, with a length of 20 feet, 7 inches (6.274 meters) and wingspan of 25 feet, 5 inches (7.747 meters). The Sparrowhawk had an empty weight of 2,114 pounds (959 kilograms) and loaded weight of 2,776 pounds (1,259 kilograms).
The F9C-2 was powered by an air-cooled, supercharged, 971.930-cubic-inch displacement (15.927 liter) Wright Aeronautical Division Whirlwind R-975E-3 (R-975-11, -24 or -26) nine-cylinder radial engine with a compression ratio of 6.3:1. The R-975E-3 had a normal power rating of 420 horsepower at 2,200 r.p.m., and 440 to 450 horsepower at 2,250 r.p.m. for takeoff, depending on variant. These were direct drive engines which turned two-bladed propellers. They were 3 feet, 7.00 inches to 3 feet, 7.47 inches (1.092–1.104 meters) long, 3 feet, 11 inches to 3 feet, 11.25 inches (1.143–1.149 meters) in diameter, and weighed from 660 to 700 pounds (299–317.5 kilograms).
The Sparrowhawk had a maximum speed of 176 miles per hour (283 kilometers per hour), a range of 297 miles (478 kilometers) and a service ceiling of 19,200 feet (5,852 meters).
The airplane was armed with two fixed Browning .30-caliber machine guns, synchronized to fire forward through the propeller arc.
Four of Macon‘s fighters, Bureau of Aeronautics serial numbers A9058–A9061, were lost when the airship went down.
During an earlier transcontinental flight, USS Macon had encountered severe turbulence while crossing mountains in Arizona. A diagonal girder in one of the ring frames failed. Temporary repairs were made, but permanent repairs were deferred until the next scheduled overhaul.
On 12 February 1935, the airship flew into a storm near Point Sur, California. The ring frame failed and the upper vertical fin was lost. Pieces of broken girders punctured several of the aft helium cells.
With the loss of helium, Macon lost rear buoyancy and began to settle. To compensate, all engines were run at full power and ballast was released. The airship began to climb with a nose-up pitch angle. When it passed 2,800 feet (853.4 meters) altitude, it reached its Pressure Altitude Limit. At this point, expanding helium began to vent from the gas cells. Macon continued rising until reaching 4,850 feet (1,478.3 meters), by which time it had lost so much helium that the engines could no longer keep it airborne and it again began to settle toward the ocean’s surface. The descent took twenty minutes.
One sailor jumped from the airship, but did not survive the fall. Another swam back to the sinking ship to collect personal belongings and drowned. The rest of the crew was rescued by the light cruiser USS Richmond (CL-9).
USS Macon was the U.S. Navy’s last rigid airship. For the next twenty years, all lighter-than-air craft were non-rigid “blimps”.
19–20 January 1915: The Kaiserliche Marine (Imperial Germany Navy) airship L3, under command of Kapitänleutnant Hans Fritz and Leutnant zur See v. Lynckner, departed Fuhlsbüttel, Hamburg, Germany, at 11:00 a.m., in company with L4 and L6, on a reconnaissance flight over the North Sea, then continued on to Britain, planning to attack during darkness.
L3 reached the British coast at 8:50 p.m. and proceeded to the area around Norfolk. At 9:20 p.m., Captain Fritz and his airship had reached Greater Yarmouth. Flying in rain at 5,000 feet (1,524 meters), over the next ten minutes they dropped six 110 pound (49.9 kilogram) bombs and seven incendiaries on the city below. As L3 turned to leave the area, another four 110 pound bombs were dropped. Completing the attack, L3 returned to Germany, arriving at the airship base at Fuhlsbüttel at 9:30 a.m.
L4, under the command of Kapitänleutnant Magnus von Platen-Hallermund and Leutnant zur See Kruse, dropped eleven bombs on Sheringham and King’s Lynn.
L6 had returned to Germany prior to the attack.
Reports are that a total of 4 people were killed and 16 wounded. Damage was limited.
In the short history of aerial warfare, this was the first time that a civilian population center was the target. It would not be the last.
It was plain that the source of the disturbance was aircraft, though precisely of what kind could only be conjectured. The opinion is generally held that it was a dirigible, for what appeared to be searchlights were seen at a great altitude. Others, however, say that the lights were not the beams of a searchlight, but the flash of something resembling a magnesium flare.
— The Times, Wednesday, 20th January 1915, at Page 8.
Luftschiff Zeppelin 24 was the third airship built for the Imperial German Navy, which designated it L3. It was operated by a crew of fifteen. The dirigible was 518 feet, 2 inches (157.937 meters) long with a diameter of 48 feet, 6 inches (14.783 meters).
Buoyancy was created by 18 gas cells filled with hydrogen, which had a total volume of 794,500 cubic feet (22,497.3 cubic meters). The empty weight of the airship was 37,250 pounds (16,896 kilograms) and it had a payload of 20,250 pounds (9,185 kilograms).
Three water-cooled, normally-aspirated, 22.921 liter (1,398.725 cubic inches) Maybach C-X six-cylinder inline engines, each producing 207 horsepower at 1,250 r.p.m., gave L3 a maximum speed of 47.4 miles per hour (76.3 kilometers per hour).
The Zeppelin’s maximum altitude, limited by the gas cells’ ability to contain the hydrogen as it expanded with increasing altitude, was 6,560 feet (2,000 meters). The maximum range was 1,366 miles (2,198 kilometers).
L3 made its first flight at Friedrichshafen 11 May 1914. On 17 February 1915, the loss of two engines in high winds forced it to ground at Fanoe Island, Denmark, where the crew abandoned it and Captain Fritz set it afire. The crew was interred for the duration of the war.
L4 (Luftschiff Zeppelin27)was of the same airship class as L3. It was very slightly heavier and its Maybach C-X engines slightly more powerful. It was retired from service 17 February 1915, the same day that L3 was lost.
17 October 1913: On the morning of a scheduled test flight at Flugplatz Johannisthal-Adlershof, an airfield south east of Berlin, Germany, Marine-Luftschiffes L2, the second rigid airship built for the Kaiserliche Marine (Imperial German Navy) by Luftschiffbau Zeppelin at Friedrichshafen, was delayed by problems with the engines. The morning sun heated the hydrogen contained in the airship’s gas bags, causing the gas to expand and increasing the airship’s buoyancy.
Once released, L2 rapidly rose to approximately 2,000 feet (610 meters). The hydrogen expanded even more due to the decreasing atmospheric pressure. To prevent the gas bags from rupturing, the crew vented hydrogen through relief valves located along the bottom of the hull.
In this early design, the builders had placed the relief valves too close to the engine cars. Hydrogen was sucked into the engines’ intakes and detonated. L2 caught fire and a series of explosions took place as it fell to the ground.
All 28 persons on board were either killed immediately, or died of their injuries shortly thereafter.
At the time of the accident, L2 had made ten flights, for a total of 34 hours, 16 minutes.
A contemporary news article described the accident:
AIRSHIP AND BALLOON NEWS.
The Wreck of the Zeppelin.
ELSEWHERE in this issue we comment upon the terrible catastrophe which befell the German Navy’s new Zeppelin L2, on Friday last week, just outside the Johannisthal aerodrome, near Berlin. From the following official account it appears that the airship was making a trial voyage:—
“She started this morning for a high flight, with twenty-eight persons on board. After three minutes she had attained a height of two hundred metres (over 600 feet) when flames burst forth between the fore engine-car and the envelope. In two or three seconds the whole ship was on fire and an explosion occurred. At the same time the airship fell slowly head downwards, until she was forty metres (130 feet) from the earth. Here a second explosion took place, presumably of benzine. When the vessel struck the earth a third explosion occurred, and the framework collapsed. A company of pioneers and guide-rope men hastened to the scene, and doctors were immediately in attendance. Two of the crew were picked up outside the ship still alive, but they died shortly afterwards. Lieut. Bleuel, who was severely injured, was taken to hospital. The remaining 25 of the crew had been killed during the fall of the airship or by the impact with the earth. The cause of the disaster appears to have been, so far as is at present known, an outbreak of fire in or over the fore engine-car.”
The commanding officer was Lieut. Freyer, and he was assisted by Lieuts. A. Trenck, Hansmann, and Busch, with thirteen warrant and petty officers. There were also on board as representing the German Navy, Commander Behnisch, Naval Construtors Neumann, and Pretzker, and three secretaries, named Lehmann, Priess, and Eisele. The Zeppelin Co. were represented by Capt. Glund and three mechanics, and Lieut. Baron von Bleuel was a passenger. The last mentioned was the only one rescued alive, and he died from his injuries a few hours later.
One of the first messages of sympathy was addressed by President Poincare’ to the German Emperor.
Extraordinary scenes, showing the way in which the calamity was regarded in Germany, were witnessed at the funeral service of 23 of the victims, held on Tuesday at the Garrison Church. Upon each of the coffins Prince Adalbert placed a wreath from the German Emperor and Empress, who with the Crown Prince and princess, and Princes Eitel Friedrich, Adalbert, August Wilhelm, Oscar and Joachim attended in person, while the Government was represented by the Chancellor, Admiral Tirpitz, the Chief of the General Staff, Field Marshall von Moltke, and many other officers. Count Zeppelin was also present.
— FLIGHT, First Aero Weekly in the World. No. 252. (No. 43, Vol. V.), 25 October 1913 at Page 1179
The Marine-LuftschiffesL2 had been designated LZ 18 by the builders. Both identifications are commonly used (sometimes, L.II). Technical data for L2 is limited and contradictory. One source describes it as having a length of 158 meters (518 feet, 4½ inches), with a diameter of 16.6 meters (54 feet, 5½ inches). Another states 492 feet.
Eighteen hydrogen-filled gas bags were placed inside the rigid framework and covered with an aerodynamic envelope. The airship had a volume of 27,000 cubic meters (953,496 cubic feet), and a lift capacity of 11.1 tons (24,471 pounds).
Four water-cooled, normally-aspirated, 22.921 liter (1,398.725 cubic inches) Maybach C-X six-cylinder inline engines were carried in two cars beneath the hull. They produced 207 horsepower at 1,250 r.p.m., burning bensin (gasoline). Each engine drove a four-blade propeller through a drive shaft and gear arrangement. These engines weighed 414 kilograms (913 pounds), each.
L2 had a maximum speed of approximately 60 miles per hour (97 kilometers per hour). At reduced speed, L2 had a 70 hour radius of action.