High Quality Content by WIKIPEDIA articles! His Majesty`s Airship No. 1, more commonly known as the Mayfly, was designed and built by Vickers, Sons and Maxim at their works in Barrow-in-Furness, Cumbria, England, as an aerial scout airship for the British Royal Navy. She was the first British rigid airship to be built, at a cost of $400,000 dollars, and was constructed in a direct attempt to compete with the German airship programme. When she was moved from her shed in Cavendish Dock to conduct full trials on 24 September 1911, she broke in two as a result of being subject to strong winds before she could attempt her first flight. Although Mayfly never flew, her brief career provided valuable training and experimental data for British airship crews and designers.