Soaring flight in Guinea

P. Idrac
naca-tn-13
Aug 1920


The term soaring is applied here to the flight of certain large birds which maneuver in the air without moving their wings. The author explains the methods of his research and here gives approximate figures for the soaring flight of the Egyptian Vulture and the African White backed Vulture. Figures are given in tabular form for relative air speed per foot per second, air velocity per foot per second, lift/drag ratio, and selected coefficients. The author argues that although the figures given were taken from a very limited series of observations, they have nevertheless thrown some light on the use by birds of the internal energy of the air.

An Adobe Acrobat (PDF) file of the entire report:
http://naca.central.cranfield.ac.uk/reports/1920/naca-tn-13.pdf