In the late 1970s, a similar cross-flow fan research program led by Hancock was carried out at the Lockheed-Georgia Company [14]. Hancock showed that the performance of these fans varied greatly with fan and housing design, with some of the designs in the first phase of the program having efficiencies as low as 40%. Fig. 24 shows the general layout of the cross-flow fan housing design with the highest performance tested by Hancock in the second phase. This housing has many similarities to the one used by Harloff and Wilson [13], particularly the “initial” design of the PVC and SVC. Other changes made in the second phase included better impeller cascade flow area distribution, along with decreasing the fan diameter ratio from 0.9 to 0.7, which is the value used by Harloff and Wilson. The fan tested by Hancock had a diameter of 0.254 m (10 in) compared to the 0.305 m (12 in) fan diameter tested by Harloff and Wilson, and the span was 0.254 m (10 in), which is significantly longer than the baseline fan tested by Harloff and Wilson.