Sound-level measurements of a light airplane modified to reduce noise reaching the ground

A. W. Vogeley
naca-tn-1647
Jul 1948


An army liaison-type airplane, representative of personal airplanes in the 150 to 200 horsepower class, has been modified to reduce propeller and engine noise according to known principles of airplane-noise reduction.

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http://naca.central.cranfield.ac.uk/reports/1948/naca-tn-1647.pdf