Drag Reductions Possible with Aircraft Employing Outboard Horizontal Stabilizers

摘要

The potential of using outboard horizontal stabilizers (OHS) to reduce aircraft drag and, hence, improve fuel economy was investigated both experimentally and theoretically. The feasibility of OHS configurations on the basis of the structural stress levels expected was also studied. The overall findings of the survey showed that from simple, low-Reynolds-number wind-tunnel tests at a wing-chord-based Reynolds number of approximately 6 x 10~4, and also from theoretical analyses for a higher Reynolds number of 9 x 10~6, lift/drag value increases in the region of 30 to 50% for wing and tail surfaces can be expected relative to corresponding values for conventional aircraft. The analytical stress-level work showed that contrary to what, on a first-thought basis, might be expected, there were no major stress problems. Flight tests employing radio-controlled, powered, model aircraft, that is, unmanned aerial vehicles, showed that aircraft of the OHS type were easily controlled in flight and were stable. An examination was made of additional areas that may contribute yet further to the development of the OHS concept.