Towing-tank tests on a large six-engine flying boat seaplane, to specification 10/46 (Princess) Part 2 porpoising stability, spray and air drag tests, with improved step fairing, afterbody design and aerodynamic modifications

Abstract

Further model tests were made on the Princess flying boat to: (a) improve the main-step fairing in order to reduce air drag while retaining satisfactory porpoising stability at high water speeds, (b) reduce the mid-planing porpoising instability found with the hull lines tested in Part I of this report (R. & M. 2641), (c) test the effect of increased wing and tailplane areas, (d) predict more accurately the full-scale performance of the final hull form by representing more closely the anticipated full-scale conditions of lift, slipstream and damping in pitch. The tank tests were made in sheltered water conditions in the Seaplane Towing Tank, Royal Aircraft Establishment, Farnborough, on a dynamic model, and parallel tunnel tests on the step-fairing design were made in the Saro Wind Tunnel at Osborne. The final hull form evolved is used for the first production aircraft.