From measurements in the free boundary layer of a plate the laws governing the velocity distribution and a new resistance law are derived which, by increasing Reynolds number Re(sub x) afford lower resistance values than the logarithmic law. The transverse velocities, the shearing stress, and the mixing path profiles were also defined.

A method is developed for calculating the growth of a turbulent boundary layer at hypersonic Mach numbers. Excellent agreement with experimental results from axisymmetric nozzles has been obtained by the application of this method. The method utilizes a modification of Stewartson's transformation to simplify the integration of the momentum equation. Heat transfer is taken into account by evaluating the gas properties at Eckert's reference temperature and by using a modification of Crocco's quadratic for the temperature distribution in the boundary layer. A new empirical relation is used for the incompressible friction coefficient which agrees with experimental data over a Reynold's number range from 10(superscript 5) to 10(superscript 9).

This paper briefly summarizes the more important statistical data obtained by the NACA on the subject of ground loads. The information presented relates primarily to landing-impact and taxiing loads; however, some limited data are also presented on one phase of ground-handling loads, namely, braking friction. A number of experimental and theoretical papers dealing with various aspects of the subject are listed in the bibliography.

An investigation was made to determine the effects of boundary-layer control on the landing performance characteristics of a liaison type of airplane having a payload of 1500 pounds and a flight duration of 5 hours. The aspect ratio was varied from 5 to 15, the wing span from 30 to 100 feet, and the brake horsepower from 300 to 1200. The use of boundary-layer control caused reduction in total landing distance (25 to 40 percent), ground-run distance, gliding speed, and stalling speed whereas sinking speed was increased only slightly.