Power-off flare-up tests of a model helicopter rotor in vertical autorotation

S. E. Slaymaker, Robin B. Gray
naca-tn-2870
Jan 1953


This report presents the results of an experimental investigation into the problem of reducing the descending velocity of a helicopter model in steady vertical autorotation by expending the kinetic energy of the rotor in a collective-pitch flare. Test data were obtained over a wide range of operating conditions from a freely falling model rotor restrained laterally by a guide wire.

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http://naca.central.cranfield.ac.uk/reports/1953/naca-tn-2870.pdf