NASA-TN-D-217

Abstract

A low-speed investigation was made in the Langley 300 MPH 7- by 10-foot tunnel of the static longitudinal and lateral stability characteristics of an airplane model with multiple bodies and of a conventional (single-fuselage) model in combination with a wing of aspect ratio 4. The wing had zero sweep at the 80-percent-chord line, a taper ratio of zero, and an NACA 65AOO4 airfoil section. Several tail arrangements were tested with the three-body configuration along with a conventional-tail arrangement for both models. The results indicate that the pitching-moment characteristics for the three-body model appear to bear about the same relation to height of the horizontal tail as that which has been well established by previous investigations of conventional single-fuselage) configurations. It appears that acceptable longitudinal stability can be obtained for both complete model configurations with the horizontal tail located in or near the wing-chord plane. <br>The data show that for the multiple-body (three-body) model all tail-on configurations were directionally stable throughout the angle-of-attack range and were greatly improved over the conventional model configuration which was directionally unstable above an angle of attack of 20&#176;. The data also indicate that this improved directional stability for the complete three-body model results from the fact that with the tail off the directional stability becomes positive at high angles of attack.