The wing frequency is measured by rocking one wingtip up and down, so that the opposite tip moves up and down in unison. There is a natural frequency this will occur at determined mainly by the mass of the wings and their stiffness.

It's standard practice to measure the wing frequency of a glider at each annual inspection (or after events such as a hard landing) and compare it with the measurement from the previous year (which would be recorded in the logbook.) If there is a significant change, especially if it reduces, that suggests that there is some structural damage to the wing. A cracked spar for example will reduce the stiffness and therefore the resonant frequency.

On Sunday, 6 March 2016 05:43:03 UTC+10, POPS wrote:
Could you explain what information, useful or otherwise you getting from
doing this.

Thanks



clyde@.........;922414 Wrote:
I have written an app that measures wing frequency - currently available
for Android on the Play Store he http://tinyurl.com/z4vztzn.

An IOS version will be available once I jump through the various hoops
Apple places in the way.

Video of it in action he https://youtu.be/dBJOBxGWtCQ.

Clyde.




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POPS