His Majesty's Airship R100 was a privately designed and built British rigid airship made as part of a two-ship competition to develop a commercial airship service for use on British Empire routes as part of the Imperial Airship Scheme. The other airship, the R101, was built by the British Air Ministry, but both airships were funded by the Government. R100 was built by the Airship Guarantee Company, a specially created subsidiary of the armaments firm Vickers-Armstrongs, led by Commander Dennis Burney. The design team was headed by Barnes Wallis, later famous for his invention of the bouncing bomb. The design team also included Nevil Shute Norway as the senior stress engineer (see his Slide Rule: Autobiography of an Engineer). R100 first flew in December 1929. It made a series of trial flights and a successful return crossing of the Atlantic in July–August 1930, but following the crash of R101 in October 1930 the Imperial Airship Scheme was terminated and R100 was broken up for scrap. Background R100 was built as part of a British government programme to develop airships to provide passenger and mail transport between Britain and the countries of the British Empire, including India, Australia and Canada. This had its origin in Dennistoun Burney's 1922 proposal for a civil airship development programme to be subsidised by the Government and carried out by a specially established subsidiary of Vickers. When the General Election of 1923 brought Ramsay MacDonald’s Labour administration to power, the new Air Minister, Lord Thomson formulated the Imperial Airship Scheme in its place. This called for the building of two experimental airships: one, R101, to be designed and constructed under the direction of the Air Ministry, and the other, R100, to be built by the Vickers subsidiary under a fixed price contract. Design and development R100 was constructed at the former RNAS Air Station Howden in Yorkshire, a remote location from Howden and from Hull. Design work began in 1925 while at the same time the somewhat rundown site was put in order and a hydrogen-generating plant installed. The specially established subsidiary of Vickers, the Airship Guarantee Company, faced substantial difficulties. The contract for R100's construction was a fixed price one and it was obvious from very early on that the project would incur a loss, and so economies were made; for instance, only a dozen machine tools were in use for construction of the airship.