An analysis has been made to determine the effect of chord size on the weight and cooling characteristics of shell-supported, air-cooled gas-turbine blades. In uncooled turbines with solid blades, the general practice has been to design turbines with high aspect ratio (small blade chord) to achieve substantial turbine weight reduction. With air-cooled blades, this study shows that turbine blade weight is affected to a much smaller degree by the size of the blade chord.

An investigation has been made to determine the effect of propeller location and flap deflection on the lift, drag, and pitching-moment characteristics of a wing-propeller combination over an angle-of-attack range from 0 to 80 degrees. The model had four propellers, the slipstream from which covered practically the entire span of the wing. The wing had a 30-percent-chord slotted flap and an 8.5-percent-chord slat. Data were obtained for flap deflections of 0, 20, 40, and 60 degrees with the slat off and on. For one propeller position the power input to the model was measured and tuft studies of the flow on the wing were made. The data are analyzed to assess the feasibility, from consideration of stability and control, of a tilting-wing vertical-take-off-and-landing airplane with the wing pivoted behind the primary wing structure to provide a desirable structural configuration. The main object of the investigation was to determine whether advantage might be taken of the forward shift of the center of gravity of the airplane, as the wing is tilted from an angle of attack of 90 to 0 degrees, to minimize the change in trim pitching moment throughout the transition speed range for such a configuration. The results indicate that with proper propeller position and programming of flap deflection, it is possible to design a configuration of this type in which essentially no change in trim is required throughout the transition from hovering to normal unstalled forward flight.