: Birds and aircraft occupy the same air space and collisions between the two are inevitable. As aircraft speeds have increased, the severity and importance of bird/aircraft impact have also increased. As a result, efforts have been made to reduce the probability of collision by controlling the movement of birds and by changing the flight paths of aircraft. These actions can and have reduced the probability of collision but have not eliminated it. Therefore, the Air Force has initiated programs designed to increase birdstrike resistance of aircraft and aircraft components. This report describes a program which was conducted to establish the loads which birds exert on aircraft transparencies in collisions. The loads as derived in this program were to be used as input for the structural analysis computer code of windshield response to bird impact.

: This report describes the experimental section of a program to investigate the damage that a .50 cal ogive inflicts on typical jet engine fan blade materials. Three materials, titanium, graphite epoxy composite and boron aluminum composite, were perforated by .50 caliber ogives at 488 m/s. The impact obliquities were investigated, 90 degrees and 60 degrees to trajectory. The momentum transfer during the impact was measured by use of a ballistic pendulum on which the targets were mounted. The momentum transfer was greatest for titanium, considerably lower for boron/aluminum and even lower for graphite expoxy. The results agree favorably with the calculated values at 90 degrees but differ at 60 degrees.

: The interaction of water drops of diameters in the range of 20 to 200 micrometers with reentry vehicle bow shocks was investigated with a microscope/Q-spoiled laser camera system. A single stream of water drops was generated on the trajectory of a Mach 12 projectile launched from a light gas gun. The microscope/Q-spoiled laser camera was used to obtain high resolution photographs of the nose tip region of the projectile as it encountered the water droplets. An analytic study of the droplet/bow shock interaction was undertaken. Calculations showed that droplets above about 20 micrometers in diameter should remain intact and impact the projectile nose tip in the stagnation region. In the stagnation region droplets of this size should experience little deviation from a straight trajectory (i. e., no sweeping action would be expected). These predictions were confirmed experimentally using the techniques described in this report. (Author)