Spray Characteristics and Take-off and Landing Stability of Several Modifications of a 1/8-size Model of the PBN-1 Flying Boad - NACA Model 192
Abstract
Several modifications of a 1/8-size model of the PBN-1 airplane were tested in Langley tank no. 1 to determine their effect on the spray characteristics and on the take-off and landing stability. The modifications included changes in the bow (addition of spray strips) and increases in the depth of step and angle of afterbody keel. The spray over the bow at low speeds was reduced by the addition of spray strips and, to a lesser extent, by an increase in depth of step or angle of afterbody keel. The range of speeds over which spray entered the propellers was reduced by the addition of spray strips. An increase in depth of step, which increased the propeller clearance, also reduced this range of speeds. An increase in angle of afterbody keel had little effect on the propeller spray. The basic model skipped at all trims above 6 deg. This skipping was eliminated by an increase in the depth of step from 3.8 to 7 percent beam. An increase in the angle of afterbody keel from 6.25 to 7.75 deg reduceds the landing stability. The location of the main step was satisfactory for stable take-offs with neutral elevators at forward positions of the center of gravity and with -10 deg elevators (trailing edge up) at after positions of the center of gravity. An increase in teh depth of step or angle of afterbody keel did not appreciably affect the forward limit for stable positions of the center of gravity. With an elevator deflection of -10 deg, the after limit for stable positions of the center of gravity was moved aft when the depth of step was increased.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1945
- Accession Number
- ADA801572
Entities
People
- David R. Woodward
- Howard Zeck
Organizations
- National Advisory Committee for Aeronautics