Memorandum presenting a two-dimensional wind-tunnel investigation of the effects of maximum-thickness location on fluctuating pressures and normal-force coefficients on 9-percent-thick airfoils, which indicated that for normal-force coefficients up to 0.6, the section variables had little effect on the pressure pulsations and root-mean-square normal-force-coefficient fluctuations. Results regarding pressure fluctuations and normal-force-coefficient fluctuations are provided.

Models of two types of high-speed surface craft were tested in Langley tank no. 1 to obtain rough-water data for an evaluation by the David Taylor .Model Basin of the relative merits of the designs. Time-history records were obtained of trim, rise, and normal acceleration at two points in the hulls for various speeds and two sizes of waves.

The take-off stability characteristics of a Consolidated Vultee Aircraft Corporation Skate 7 seaplane were determined in the Langley tank no. 2. Trim limits of stability, trim tracks, and elevator limits of stability are presented.

Report presenting calculations of the dynamic lateral stability characteristics of a mock-up configuration of the Douglas X-3. The oscillations were found to be stable for all calculations investigated but would not meet the Air Force damping requirements for the majority of the conditions. The use of an autopilot was found to greatly improve oscillation damping.