A second lighter carriage is being provided for hydrodynamic testing that will raise the 

 available speeds up to the order of 150 knots, or three times the still-water range 

 hitherto available. 



VII. Concluding Remarks 



In conclusion, it may be repeated that the present era of high-speed flight has 

 a profound influence on the relative importance of the various considerations and 

 conflicts involved in the design and procurement of water-based aircraft. Aircraft of 

 this era are transonic and supersonic with fantastic speed penalties associated with 

 departures from optimum aerodynamic design. Their water-based counterparts at 

 present may have minimum flight speeds beyond the range of past experience; at the 

 same time, they have take-off thrust-weight ratios that encourage the employment of 

 radically different hydrodynamic configurations and concepts. 



The changing picture brings with it new hydrodynamic problems, and new 

 justification for the continued attention of qualified authorities in the field. The 

 opportunity to review the state of the art in this Symposium is therefore appreciated 

 by the author and the agency represented. 



REFERENCES 



1. Carter, Arthur W., and Haar, Marvin I.: Hydrodynamic Qualities of a Hypothetical 



Flying Boat With a Low-Drag Hull Having a Length-Beam Ratio of 15. NACA TN 

 No. 1570, 1948. 



2. Carter, Arthur W.: Effect of Hull Length-Beam Ratio on the Hydrodynamic Character- 



istics of Flying Boats in Waves, NACA TN No. 1782, 1949. 



3. Carter, Arthur W., and Whitaker, Walter E., Jr.: Effect of an Increase in Hull Length- 



Beam Ratio From 15 to 20 on the Hydrodynamic Characteristics of Flying Boats. 

 NACA RM L9G05, 1949. 



4. Hodges, William W., and Woodward, David R.: Spray Characteristics of Four Flying- 



Boat Hulls as Affected by Length-Beam Ratio. NACA TN No. 1726, 1948. 



5. Parkinson, John B.: NACA Model Investigations of Seaplanes in Waves. NACA TN 



No. 3419, 1955. 



6. Whitaker, Walter E., Jr., and Bryce, Paul W., Jr.: Effect of an Increase in Angle of Dead 



Rise on the Hydrodynamic Characteristics of a High-Length-Beam-Ratio Hull. NACA 

 TN No. 2297, 1951. 



7. Schnitzer, Emanuel: Estimation of Water Landing Loads on Hydro-Ski-Equipped Air- 



craft. NACA RM L53D29, 1953. 



8. Kapryan, Walter J., and Clement, Eugene P.: Effect of Increase in Afterbody Length 



on the Hydrodynamic Qualities of a Flying-Boat Hull of High Length-Beam Ratio. 

 NACA TN No. 1853, 1949. 



9. Dawson, John R., and Wadlin, Kenneth L.: Preliminary Tank Tests of NACA Hydro- 



Skis for High-Speed Airplanes. NACA RM L7I04, 1947. 



10. Ramsen, John A.: The Effect of Rear Chine Strips on the Take-Off Characteristics of a 



High-Speed Airplane Fitted With NACA Hydro-Skis. NACA RM L9B10a, 1949. 



11. Wadlin, Kenneth L., and Ramsen, John A.: Tank Spray Tests of a Jet-Powered Model 



Fitted With NACA Hydro-Skis. NACA RM L8B18. 



12. Thompson, William C, and Fisher, Lloyd J.: Investigation of the Hydrodynamic Char- 



acteristics of the Panto-Base Chase C-123 Airplane. NACA RM SL54A28, 1954. 



13. Fisher, Lloyd L: Model Ditching Investigations of Three Airplanes Equipped With 



Hydro-Skis. NACA RM L9K23, 1950. 



14. Kapryan, Walter L, and Weinstein, Irving: The Planning Characteristics of a Surface 



Having a Basic Angle of Dead Rise of 20° and Horizontal Chine Flare. NACA TN 

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