|
This might be beating a dead horse, but flutter analysis, even in mil spec or FAA certified, is a bit of a black art. There's lots on non-linear, hard-to-model structural, aerodynamic, and math mysteries. A huge amount of judgment and experience applies here.
In certified airplanes, we suspect they sample random structures off the line, over time, to verify the original flight test model. Or maybe even go back to flight test, if mishaps or other reports suggest flutter. If you are Chuck Yeager, you get to fly a notorious driven mass device, that drives the oscillation at resonance (evil smile)
( 2nd order systems are usually junior or senior level E school courses, after 2nd yr Calculus and Diff-E. Even those who survived it, forgot the technique, if not applied regularly... State-space? Anyone? Anyone? )
How would we do, either testing(not) or sampling, when all the builders have varying experience, and factories are at separate locations?
Published VNE only applies to Lance's original build and his test on one article. I'm sure we signed a waiver to that effect in this process!
It would be fairly cheap to mount an Accelerometer out on the wing, and hook it up to an analog input on the EFIS. Certain frequencies and amplitudes could trigger a warning. This is the only way to be certain, of VNE, to the level indicated above, for Mil and FAA standards.
Y'all be careful out there |