Reminded me of a full sized incident that happened locally recently. I know it's not ground resonance (muppet on ground pulls cable into main rotor), but impressive anyway. https://www.youtube.com/watch?v=v5aMT9MBfZI and https://www.youtube.com/watch?v=dEJzJqZWgmk. Note in the second video that the pilot gets thrown from his seat and falls back in to the rear seat. Talk about luck!
there are a few more example online of ground resonance specifically - has nothing really to do with balanced props, has to do with how being on the ground allows the frame to act like a tuning fork.
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Reminded me of a full sized incident that happened locally recently. I know it's not ground resonance (muppet on ground pulls cable into main rotor), but impressive anyway. https://www.youtube.com/watch?v=v5aMT9MBfZI and https://www.youtube.com/watch?v=dEJzJqZWgmk. Note in the second video that the pilot gets thrown from his seat and falls back in to the rear seat. Talk about luck!
This is more of an issue with a CH-47! https://www.youtube.com/watch?feature=fvwp&NR=1&v=D2tHA7KmRME
Although, I should point out this was a controlled test. Yet another reason not to do tethered testing with props on?
Yup, you are right Andrew! I was mislead by someone who wrote an article in local newspaper. Title changed.
wow,
there are a few more example online of ground resonance specifically - has nothing really to do with balanced props, has to do with how being on the ground allows the frame to act like a tuning fork.
This is the cause of ground resonance (http://en.wikipedia.org/wiki/Ground_resonance) not necessarily unbalanced props..
You can see a similar situation in this MacGyver Episode clip...the pilot quickly realized the problem and lifted off immediately.
https://www.youtube.com/watch?v=6vICf8l-KV0
Yeah, helicopters don't really fly, they just vibrate so badly the earth rejects them.