Trials of the "America" began 23 June 1914 with Porte also as Chief Test Pilot; testing soon revealed serious shortcomings in the design; it was under-powered, so the engines were replaced with more powerful tractor engines. There was also a tendency for the nose of the aircraft to try to submerge as engine power increased while taxiing on water. This phenomenon had not been encountered before, since Curtiss's earlier designs had not used such powerful engines nor large fuel/cargo loads and so were relatively more buoyant. In order to counteract this effect, Curtiss fitted fins to the sides of the bow to add hydrodynamic lift, but soon replaced these with sponsons, a type of underwater pontoon mounted in pairs on either side of a hull. These sponsons (or their engineering equivalents) and the flared, notched hull would remain a prominent feature of flying-boat hull design in the decades to follow. With the problem resolved, preparations for the crossing resumed. While the craft was found to handle "heavily" on takeoff, and required rather longer take-off distances than expected, the full moon on 5 August 1914 was selected for the trans-Atlantic flight; Porte was to pilot the "America" with George Hallett as co-pilot and mechanic.