Re: Lightning Strike out of Dorval ?

Date:         19 Apr 2001 16:40:13 
From:         David Simpson <dsimpson@dsimpson.net>
Organization: Road Runner
References:   1
Followups:    1 2
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Joe wrote:

> <snip>
>  Can anyone elaborate on this?It scared the dickens out of me.I heard
> one of the stewardesses say. " I heve never experienced anything like
> this in 32 years of flying"
>
>  Spooked Frequent Flyer

A static discharge is exactly the same as when you scoot your feet across a
carpet and touch a doorknob. You build up a static charge, and when you get
close enough to something conductive, it discharges. An airplane can do the same
thing under the right conditions, and it throws a "spark" (lightning bolt) when
the charge gets high enough. USUALLY, there is little or no damage. Certainly
not enough to break the airplane, and any damage would likely be limited to
localized scorching or pitting. About the worst-case scenario would be to have
the radome knocked off. Not a problem structurally, but you would have no
airspeed indications, since the airflow over the sensors is all fouled up. (Like
the American EP-3 that went down in China).

I did experience a lightning strike while sitting on the ground at O'Hare in a
727 years ago. Observers in the terminal said it hit the tail. No damage
whatsoever to the structure or electronics. There are actually quite a few
lightning strikes every year, and usually there is little or no damage.

You asked if the captain should have returned to Dorval, and what the procedures
were. There probably isn't any specific procedure for a strike/discharge at Air
Canada, there is none at my airline. You'll know very quickly if something is
wrong, and there will be a procedure for whatever that problem is, regardless of
the cause. Obviously your flight crew saw that their electronic equipment was
working properly, and there were no other abnormalities, so they decided to
press on. Much the same as with a bird strike, which also happens quite
frequently.

Lightning strikes and static discharges are very spectacular, and certainly
scary, but highly unlikely to do any real damage. A search of the NTSB (US
National Transportation Safety Board) database for the last thirty years showed
not a single accident that could be attributed to a lightning strike or static
discharge. At worst, one airplane (a small one) had "significant" damage, but
still landed with no one being hurt.
(http://www.ntsb.gov/ntsb/query.asp)

Most people's anxiety over flying is due to being in an environment where they
have little or no knowledge of how things work or what's going on, and it's the
fear of the unknown that is always the worst. I hope I was able to demystify the
situation somewhat for you, and you can relax on your next flight!

Dave Simpson
Captain, American Airlines