摘要 |
In a method of detecting the deflection of the blades 13 of a helicopter rotor as it rotates, a beam 14 of radiation from a transmitter/receiver 11 encounters the tips of the rotating blades which send reflected signals to the receiver. The phase difference due to deflection of the blade tip can be used to give a measure of the deflection of each blade, and that can be displayed graphically as shown in FIGS. 7-10 for the various blades at various speeds. In a related method of measuring deflections of the blades 111 for a tail rotor, a laser beam transmitter 16 in FIG. 14 has its reflected beam 122, 123 from an undeflected blade 111 or a deflected blade 111' received by a particular receiver in a linear array 119 of receivers so that the particular receiver gives an indication of the amount of deflection.
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