Hi,
Both Josok and Fred have it right, of course. Lightning goes where
it pleases AND you have to be lucky. The same was said of ground crews at
sched airports as a CuNim approached. No more. Electrical tension in tnhe
air is measured in minute amounts and when it gallops the field is shut down
temporarily. The luck is in the detection these days.
Sched flyers are probably the ones to ask. As an airline and
military driver, airframe, for 40 odd years I have been hit many times.
Approaching Heathrow from India we came under threat on final (the forecast
never mentioned Cbs). the lightning hit just opposite my left foot - sort of
the plane's cheek - and drive a half-inch eyelet through the fuselage skin
and several structural members. It did litlle other damage because (a) we
were at 400 feet and there wasn't far to go to earth, and (b) the L1011 had
a good sized external surface to dissipate the charge. On another occasion
in a DC-3 we were banged near the starboard cabin heater and a flame ball
appeared in the aisle in front of the cockpit door. It calmy blew the door
off its hinges and sauntered irregularly down the aisle avoiding all the
seats. When it got to the back (near the Stewardess) it blew a hole in the
bathroom wall and disappeared. What directed it I have no idea, but we were
told that if it had touched anyone it would have killed them. One little old
grayhead said' "I'll never fly TCA again!"
In fighters, you're in and out of cloud - rapid change of polar
tension - so fast it's impossible to avoid the odd strike but seldom badly
affected because of long stream of iodized air behind.
At 20,000 amps and Lord knows how many volts, designing equipment to
fight intrusion is impossible. However as I understand, the future strike
sets out feelers (going up or down as they do) to probe the way and the
best one wins, followed by the wham which oscillates for measureable
microseconds.
In that event, design comes to the fore by convincing the probe that
'this ain't the best way', and in so doing leaves the impression that the
lightning was quelled. I don't think so. I think it just goes looking for
another route.........and i believe that is what Dave(?) encountered.
So it seems to me the best route for good luck is to fly far away
---From threat (a minimum of 25 miles if possible), stay below the freezing
level, design electrical components which can absorb 'feelers', and in our
glass machines wear a chute.
While the western prairies often give good visual warning and forecasting is
very good, the UK and northwest Europe coasts can have vicious Cbs no taller
than 13,000 feet asl. In all cases good luck comes from good flight planning
and alertness.
Cheers, Ferg
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