1) If suit is faraday cage, how come it can be open at the face?
Thinking in terms of something like an infinite conducting plane with
small hole (see Jackson) - electric field lines will "intrude" but
maybe the potential and the size of the opening are safe here?
2) Can't tell if sitting platform is insulated from helicopter. Audio
implies helicopter is being brought to same potential but somewhat
unclear (I would think this more or less required to prevent any risk
of arc (wire to helicopter), even if possibility is remote.
3) Once charged, clamps appear to be used to maintain potential while
moving over to the line, but of interest is when copter pulls away.
He unclamps while using probe to presumably maintain potential, but
as separation occurs, significant arcing again occurs. Why exactly
would this be? Presumably the copter and line and suit are in
equilibrium at this moment just before separation. Perhaps the copter
cannot not fly off and maintain a massive charge on it (if it somehow
did, think of the landing). But why not? Why would it all arc off
right at that time and not just eventually "drain" off into the air
due to it's high electric field?
Summary:
high E-field causes initial arcing to bring to equilibrium
disconnect while at equilibrium causes equivalent arcing
If asked to have predicted what would happen at disconnect, my
(obviously incorrect) intuition would be to say "well there might be
some small arcing" but the copter would fly off charged and
consideration would have to be given to the charge eventually being
drained off into the air. What is the time constant for such a drain
- obviously MUCH shorter than I might have imagined, even considering
factors such as humidity.