36. Weinflash, Bernard, Christopher, Kenneth W., and Shuford, Charles L., Jr.: The Effect 



of Air-Jet and Strip Modifications on the Hydrodynamic Characteristics of the Stream- 

 line Fuselage of a Transonic Airplane. NACA RM L9D20, 1949. 



37. Weinflash, Bernard; Shuford, Charles L., Jr.; and Christopher, Kenneth W.: Hydrody- 



namic Force Characteristics of a Streamline Fuselage Modified by Either Breaker 

 Strips or Rows of Air Jets Simulating Chines. NACA RM L9L21a, 1950. 



38. Weinflash, Bernard, and Shuford, Charles L., Jr.: Investigation of the Hydrodynamic 



Stability and Resistance of Two Streamline Fuselages. NACA RM L52B11, 1952. 



39. McBride, Ellis E.: An Experimental Investigation of the Scale Relations for the Imping- 



ing Water Spray Generated by a Planing Surface. NACA TN No. 3615, 1956. 



40. Coffee, Claude W., Jr., and McKann, Robert E.: Hydrodynamic Drag of 12- and 21- 



Percent-Thick Surface-Piercing Struts. NACA TN No. 3092, 1953. 



41. Ramsen, John A., and Vaughan, Victor L., Jr.: Hydrodynamic Tares and Interference 



Effects for a 1 2-Percent-Thick Surface-Piercing Strut and an Aspect-Ratio-0.25 Lifting 

 Surface. NACA TN No. 3420, 1955. 



42. Weinflash, Bernard, and McGehee, John R.: An Investigation of a Method for Obtaining 



Hydrodynamic Data at Very High Speeds With a Free Water Jet. NACA RM L54D23, 

 1954. 



DISCUSSION 

 W. A. Schoech 



I would like to congratulate Mr. Parkinson for a timely and important con- 

 tribution to the science of the hydrodynamics of high speed water based aircraft. 

 This field is of great interest to the Bureau of Aeronautics and we have attempted to 

 keep abreast of the art with research vehicles and prototype aircraft. The Navy has 

 now flown and obtained experience with three different flying boats having hull length/ 

 beam ratios greater than 12. The excellent hydrodynamic characteristics predicted by 

 the model tests has been generally borne out by the flight tests. As might have been 

 expected, the low speed maneuvering characteristics of these hulls were unsatisfactory 

 and sparked off additional research. 



An extensive flight test program has been conducted with a variety of aircraft 

 equipped with hydro-skis. One of these aircraft, the XF2Y-1, was not only the first 

 aircraft designed with hydro-skies as part of the original concept, it was also the first 

 flying boat to exceed the speed of sound. The flight tests of hydro-skis have uncovered 

 new and novel hydrodynamic problems. Mr. Parkinson has been instrumental in 

 solving these problems and providing us with a clear physical understanding of the 

 phenomena so that they can be avoided in the future. The full scale experience with 

 flying boats equipped with hydro-skis has also clearly demonstrated improved ability 

 to operate in rough water. This is of considerable interest to the Navy. 



Some years ago All American Engineering Co., in an unsolicited proposal, sug- 

 gested the application of wheeled hydro-skis to landplanes. This concept has been 

 found to increase greatly the operational flexibility of Marine Corps observation air- 

 planes. Mr. Parkinson's work has done much to put the design of these hydro-skis 

 on a rational and straight forward basis. 



Hydrofoils have offered promise of greatly improved rough water characteristics 

 and the Bureau of Aeronautics has actively supported research in this field for at 

 least twenty years. The very great difficulty of providing both stability and control has 

 seriously hampered efforts to incorporate hydrofoils on a man-carrying aircraft. Recent 

 work by Mr. Parkinson has indicated that solutions to these problems may be in 

 sight. If this turns out to be the case, hydrofoils will open the door to much improved 

 performance. 



Mr. Parkinson's paper offers much fresh data which will be invaluable to 

 designers of high speed flying boats. Again, I would like to offer my congratulations 



208 



