Note presenting an examination of the available information on the hail phenomenon affecting aircraft in flight. Some of the components in the report include: a digest of literature on the physical properties and formation of hail, a survey of the affect of hail on aircraft in flight from 57 cases of aircraft damaged by hail, information on hail for the benefit of pilots, forecasters, and ground personnel, and an annotated bibliography of articles about hail.

"A wind-tunnel investigation was made to determine the effects of ejecting high-velocity air near the leading edge of plain trailing-edge flaps on a 35 degree sweptback wing. The tests were made with flap deflections from 45 degrees to 85 degrees and with pressure ratios across the flap nozzles from sub-critical up to 2.9. A limited study of the effects of nozzle location and configuration on the efficiency of the flap was made. Measurements of the lift, drag, and pitching moment were made for Reynolds numbers from 5.8 to 10.1x10(6)" (p. 1).

"In accordance with act of Congress, approved March 3, 1915, as amended (U.S.C., title 50, .sw 151), which established the National Advisory Committee for Aeronautics, the Committee submits its Forty-fourth Annual Report for the fiscal year 1958. This is the Committee's final report to the Congress. The National Aeronautics and Space Act of 1958 (Public Law 85-568) provides in section 301 that the NACA "shall cease to exist" and "all functions, powers, duties, and obligations, and all real and personal property, personnel (other than members of the Committee), funds, and records of the NACA shall be transferred to the National Aeronautics and Space Administration" (p. ix).