I posted a thread a few days back wondering about how a helicopter bonds to a transmission line and I'm still not quite clear on the matter. I'm approaching this as simply as I can.
In the education section on this website there is some great information regarding how birds can land on transmission lines without getting shocked. They don't get shocked because the voltage is the same at every part on the line. Even the points of the line on which the bird's feet land are electrically common so even though a path exists between the bird's feet for current to travel, there is no voltage between the bird's feet and therefore no current.
Moving to the helicopter I thought I could just thing of the helicopter as a large bird that experiences the same thing when 'landing on' or touching the transmission line.
But when I watch the Youtube videos, a fairly substantial arc occurs whenever the helicopter contacts or removes contact with the line (I'm referring to the stick the lineman uses). I'm assuming that there is current travelling between the line and the helicopter and I'm assuming it's quite a bit of current as the arc seems quite substantial. Is this wrong?
In the initial post several people said that the helicopter can be thought of as one plate of a plate capacitor (the ground being the other plate). I'm not really able to fully comprehend a capacitor of this size (compared to capacitors I'm familiar with the gap between the ground and helicopter seems quite large and how is the area of the ground plate determined?) so I'm not sure if the capacitance would be large or small.
Even so, I'm not sure what capacitance has to do with the scenario anyway. If the helicopter is one plate of a capacitor and the arc represents the charging and discharging to match the voltage of the line, is current still not flowing through the helicopter during the charging and discharging processes? And again, if so, it seems like quite a bit of current judging by the arc. Wouldn't this be bad for the workers inside the helicopter?
In the education section on this website there is some great information regarding how birds can land on transmission lines without getting shocked. They don't get shocked because the voltage is the same at every part on the line. Even the points of the line on which the bird's feet land are electrically common so even though a path exists between the bird's feet for current to travel, there is no voltage between the bird's feet and therefore no current.
Moving to the helicopter I thought I could just thing of the helicopter as a large bird that experiences the same thing when 'landing on' or touching the transmission line.
But when I watch the Youtube videos, a fairly substantial arc occurs whenever the helicopter contacts or removes contact with the line (I'm referring to the stick the lineman uses). I'm assuming that there is current travelling between the line and the helicopter and I'm assuming it's quite a bit of current as the arc seems quite substantial. Is this wrong?
In the initial post several people said that the helicopter can be thought of as one plate of a plate capacitor (the ground being the other plate). I'm not really able to fully comprehend a capacitor of this size (compared to capacitors I'm familiar with the gap between the ground and helicopter seems quite large and how is the area of the ground plate determined?) so I'm not sure if the capacitance would be large or small.
Even so, I'm not sure what capacitance has to do with the scenario anyway. If the helicopter is one plate of a capacitor and the arc represents the charging and discharging to match the voltage of the line, is current still not flowing through the helicopter during the charging and discharging processes? And again, if so, it seems like quite a bit of current judging by the arc. Wouldn't this be bad for the workers inside the helicopter?