The British dirigible R.34 flew from the British Isles to the United States in 108 hours and made the return trip in 75 hours, a good illustration of the influence of the prevailing westerlies in trans-Atlantic flight. During the first day of the westward trip northeasterly and easterly winds furnished some assistance, but thereafter cross winds or head winds were encountered most of the time. On the return trip southwesterly and westerly winds added considerably to the air-speed of the ship. Inasmuch as it was necessary to moor the ship in the open at Roosevelt Field, arrangements were made for the receipt and study of meteorological reports in order that warnings as to expected changes in weather conditions could be given to the officers in charge. The most difficult conditions to guard against were the sea breeze, thunderstorms, and alternate heating and cooling of the gas through the interruption of insolation by passing clouds.
The experiences of the NC crews, Hawker and Grieve, Alcock and Brown, and the R.31 emphasize the necessity of wind assistance and the difficulties presented by the frequency of fog and clouds. The latter will cause less and less trouble as radio communication becomes better developed and more accurate.