fleet of blimps with Zeppelin NTs, resurrecting their partnership that ended over 70 years ago. Goodyear placed an order for three Zeppelin NTs, which then entered service between 2014 and 2018. Modern zeppelins are held aloft by the inert gas helium, eliminating the danger of combustion illustrated by the Hindenburg. It has been proposed that modern zeppelins could be powered by hydrogen fuel cells. Zeppelin NTs are often used for sightseeing trips; for example, D-LZZF (c/n 03) was used for Edelweiss's birthday celebration performing flights over Switzerland in an Edelweiss livery, and it is now used, weather permitting, on flights over Munich. See also Airship hangar Buoyancy compensator (aviation) Lane hydrogen producer List of airships of the United States Navy List of Schütte-Lanz airships List of Zeppelins Zeppelin Museum Friedrichshafen References Notes Citations Bibliography Boulton, James T., ed. The Selected Letters of D. H. Lawrence. Cambridge, UK: Cambridge University, 2000. . Boyne, Walter J. et al. Air Warfare: An International Encyclopedia. Santa Barbara, California: ABC-Clio, 2002. . Castle, Ian. London 1914–17: The Zeppelin Menace. Oxford, UK: Osprey, 2008. . Cole, Christopher and Cheesman, E. F. The Air Defence of Great Britain 1914–1918. London: Putnam, 1984. . Cross, Wilbur. Zeppelins of World War I. London: Paragon House, 1991. . Dooley, Sean C. "The Development of Material-Adapted Structural Form." Part II: Appendices, THÈSE NO 2986. École Polytechnique Fédérale de Lausanne, 2004. Dürr, Dr. Ludwig. – 25 Years of Zeppelin Airship Construction, Lulu online publishing, 2013. Eckener, Hugo, translated by Leigh Fanell. Count Zeppelin: The Man and His Work. London: Massie, 1938 – (ASIN: B00085KPWK) ( extract pp. 155–157, 210–211). Liddell Hart, B. H. A History of the World War 1914–1918. London: Faber & Faber, 1934. Robinson, Douglas H. Giants in the Sky: History of the Rigid Airship. Henley-on-Thames, UK: Foulis, 1973. . Robinson, Douglas H. The Zeppelin in Combat. Henley-on-Thames, UK: Foulis, 1971 (3rd ed.). . Schiller, Hans von. – The Zeppelin Book, Lulu online publishing, 2017. Stephenson, Charles. Zeppelins: German Airships, 1900–40. Oxford, UK: Osprey, 2004. . Swinfield, J. Airship: Design, Development and Disaster. London: Conway, 2012. Willmott, H.P. First World War. London: Dorling Kindersley, 2003. . Further reading Althoff, William F. USS Los Angeles: The Navy's Venerable Airship and Aviation Technology. Sterling, Virginia: Potomac Books Inc., 2003. . Archbold, Rich and Ken Marschall. Hindenburg, an Illustrated History. New York: Warner Books, 1994. . Brooks, Peter. Zeppelin: Rigid Airships 1893–1940 .