made a 24-hour flight intended to test the new engine installation and modifications to the cover. R100's contract had originally called for a demonstration flight to India. The decision to use petrol engines resulted in a change in destination to Canada, as it was considered that a flight to the tropics with petrol aboard would be too hazardous. All being well, it was planned to set off for Canada on 25 May. During the flight of 21 May, the conical tail section collapsed due to unexpected aerodynamic pressure, and it was returned to the shed where the original tail section was replaced by a hemispherical cap designed and made by the Royal Airship Works, reducing the airship's length by Transatlantic voyage to Canada Shortly before R101's flights in June 1930, the Cardington engineers tentatively suggested that the long flights to Canada and India might be postponed until 1931 on the grounds that neither of the two airships was fit to make a lengthy flight at their current developmental stage. The R100 team replied that their airship was perfectly capable of flying to Canada, and that the Canadian flight was a part of their contract. R100 departed for Canada on 29 July 1930, reaching its mooring mast at the St-Hubert, Quebec Airport (outside Montreal) in 78 hours, having covered the great circle route of at an average ground speed of . The airship stayed at Montreal for 12 days with over 100,000 people visiting the airship each day while it was moored there, and a song was composed by La Bolduc to make fun of the people's fascination with R100. It also made a 24-hour passenger-carrying flight to Ottawa, Toronto, and Niagara Falls while in Canada. The airship departed on its return flight on 13 August, reaching Cardington after a 57½ hour flight. Nevil Shute Norway later suggested in Slide Rule: Autobiography of an Engineer that the success of R100's Canadian flight indirectly led to the R101 disaster. Prior to the transatlantic flight, the Cardington team could suggest that neither airship was ready for a performance of such duration. However, when R100 returned in triumph they had to either make the flight to India or admit defeat – which would have meant discredit with the consequent danger of losing their jobs. He said that his team "guessed that their ship was a bad airship, but did not realise" (because of secrecy