After the first test flight with his co-pilot and mechanic onboard, Sikorsky noted, "in order to keep the engines close to the center line, they were mounted in two tandem groups on both sides of the fuselage. This was done chiefly to protect the plane from the danger of unsymmetrical thrust if one of the outer engines should stop." However, this configuration resulted in poor take-off and climb performance, due to propeller inefficiency. In June 1913, the airplane was altered so that the two rear engines were remounted outboard on the leading edges, "...transforming the installation into a four-in-line. The change resulted in a substantially improved take-off and a slightly better climb The rudders were still effective enough to hold the plane against tow engines stopped on one side." On 2 August Sikorsky flew the "grand" for one hour and fifty-four minutes with eight persons onboard. Sikorsky made a total of fifty-three flights with the "Grand" before it was damaged by falling debris from a different aircraft.