Cheers:
We were discussing the title topic a few weeks ago, but today the
accident report on the glider under discussion fell out of a favourite
niche, prompting a quick review. The following (for the benefit of those
who have felt one can 'protect' oneself in GRP aircraft) is just the
excerpt on electric values:
LIGHTNING DISCHARGE RECORDINGS
EA Technology Limited, a company which has specialised over the last
decade in the monitoring and recording of lightning discharges in and
around the UK, was commissioned by the AAIB to supply discharge data for
an area of 25km radius centred near the location 9of the fuselage
wreckage N51deg 52.45min, W000deg 36.85min, for the period between 1700
and 1720 hours local on the day of the incident. Of the FIFTEEN
associated discahrges recorded, ten were identified as being of positive
polarity, two were of negative polarity and three were undetermined. Of
the ten positive, eight were recorded to have been in excess of 80kA
(80,000 amperes). The first recorded discharge occurred at 1708 hours
and 57.6 seconds; this was a positive discharge in excess of 80kA, the
location of which was the closest to the4 accident site.
I hope this cements the idea that avoidance is worth a lot more than
protection. The accident report is very clear on the damage created.
Happy Landings
Ferg #A064 (319)
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