A Complete Tank Test of a Model of a Flying-boat Hull - N.A.C.A. Model No.11-A

Model No. 11-A was designed as an improvement over N.A.C.A. Model No. 11, a complete test of which is described in N.A.C.A. Technical Note No. 464. In contrast with the longitudinal upward curvature in the planing bottom forward of the main step on Model 11-A was made as flat as practicable. Otherwise, the two models have very nearly the same form. The results of towing tests made on Model 11-A in the N.A.C.A. tank over a wide range of speed, load on the water, and trim angle are presented, both as original test data and as non dimensional coefficients. A comparison is made with similar results from the test of Model No. 11. The practical significance of the improvement obtained is demonstrated by applying the data from the new form to the illustrative design problem use in the note on Model NO. 11.