French MP and billionaire Olivier Dassault dies in helicopter crash
If the lateral forces from shock loading the transmission were enough to snap off the tail boom then they probably calculated what would be experienced a similar distance forward of the rotor mast where the pilots were sitting.
The lateral forces are in any direction that aren't rotational or vertical, so the distance doesn't matter. What does matter is how much centrifugal imbalance there is from damage to the rotor blade. The helicopter body is set to orbit in opposition to the offset of the rotor CG. If that offset is 0 there is no shaking.
I doubt the blade itself is strong enough to kick-back over it's length**, but losing 2.6m will lose a lot of the most heavily accelerated mass and that will result in an unbalanced tension load the blade is certainly strong enough to withstand.
**This is in contrast to the kickback of hitting a baseball with a bat far off the "sweet spot" and having the resulting vibration hurt the batter's hands. In that case the bat is very sturdy compared to the squishy hands. The helicopter situation is like spinning while holding two heavy buckets by strings and cutting one of the strings. The person doing the spinning is very likely to fall over.
I doubt the blade itself is strong enough to kick-back over it's length**, but losing 2.6m will lose a lot of the most heavily accelerated mass and that will result in an unbalanced tension load the blade is certainly strong enough to withstand.
**This is in contrast to the kickback of hitting a baseball with a bat far off the "sweet spot" and having the resulting vibration hurt the batter's hands. In that case the bat is very sturdy compared to the squishy hands. The helicopter situation is like spinning while holding two heavy buckets by strings and cutting one of the strings. The person doing the spinning is very likely to fall over.
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I'm reminded of the accident to G-BJVX in the Southern North Sea in the early 2000's where much research was done into the out of balance forces that would have been experienced when a sizeable portion of one of the main blades separated in flight resulting in the separation of the transmission from the fuselage and loss of the aircraft.
https://assets.publishing.service.go...nc_annexes.pdf
https://assets.publishing.service.go...nc_annexes.pdf
I'm reminded of the accident to G-BJVX in the Southern North Sea in the early 2000's where much research was done into the out of balance forces that would have been experienced when a sizeable portion of one of the main blades separated in flight resulting in the separation of the transmission from the fuselage and loss of the aircraft.
https://assets.publishing.service.go...nc_annexes.pdf
https://assets.publishing.service.go...nc_annexes.pdf
The pathologist concluded that everyone had died from multiple
injuries consistent with a high vertical impact loading with some forward
motion
injuries consistent with a high vertical impact loading with some forward
motion
These days, plastic lenses incorporate UV protection. I have a yellow tint on my glasses to make it easier to see cloud wisps and haze domes - and keep my pupil diameter down for better acuity.
My opthalmologist has been muttering about cataracts for over a decade, but they're not bad enough for the op yet.
Contrast is a biggie. Rigging my glider on a nice sunny day, underneath the turtledeck is a black hole.
My opthalmologist has been muttering about cataracts for over a decade, but they're not bad enough for the op yet.
Contrast is a biggie. Rigging my glider on a nice sunny day, underneath the turtledeck is a black hole.
The lateral forces are in any direction that aren't rotational or vertical, so the distance doesn't matter. What does matter is how much centrifugal imbalance there is from damage to the rotor blade. The helicopter body is set to orbit in opposition to the offset of the rotor CG. If that offset is 0 there is no shaking.
I doubt the blade itself is strong enough to kick-back over it's length**, but losing 2.6m will lose a lot of the most heavily accelerated mass and that will result in an unbalanced tension load the blade is certainly strong enough to withstand.
**This is in contrast to the kickback of hitting a baseball with a bat far off the "sweet spot" and having the resulting vibration hurt the batter's hands. In that case the bat is very sturdy compared to the squishy hands. The helicopter situation is like spinning while holding two heavy buckets by strings and cutting one of the strings. The person doing the spinning is very likely to fall over.
I doubt the blade itself is strong enough to kick-back over it's length**, but losing 2.6m will lose a lot of the most heavily accelerated mass and that will result in an unbalanced tension load the blade is certainly strong enough to withstand.
**This is in contrast to the kickback of hitting a baseball with a bat far off the "sweet spot" and having the resulting vibration hurt the batter's hands. In that case the bat is very sturdy compared to the squishy hands. The helicopter situation is like spinning while holding two heavy buckets by strings and cutting one of the strings. The person doing the spinning is very likely to fall over.
On balance - no pun intended - I doubts this level of investigation would have taken place for a regular AS350 accident
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