Re: Bird Strike Risk

Date:         17 Dec 97 03:41:31 
From:         Iain Stuart <big-iain@big-iain.demon.co.uk>
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Using his favourites wax crayons, <airliners.1997.2941@ohare.Chicago.COM>, Laurence Huttunen <huttunen@worldnet.att.net> scrawled
>Is there any point of operation where a bird strike is of particular
>danger to the operation of modern passenger jets?
...
>This must be a relatively common occurance, but one wonders if there is
>are critical times at which the risk is greatest and what those risk(s)
>are.

Birdstrikes occur mainly on Take-Off, but can occur anywhere. I recall
seeing a report of a L1011's engine ingesting a buzzard or vulture over
India at 26,000 feet. Engine ran on, but was a bit shakey.

RISK : Depends on your categories. A 2 oz Hummingbird would cause no
problems and wouldn't even be notices. But a full size swan or goose...
All engines have to undergo bird strike testing, operating at max LP
speed. Number / weight of birds varies, as logic suggests. Either a
single 4lb bird, a small number of 1.5lb birds of a large number of
sparrows. If an engine can't survive the impacts, and continue to
produce 75% thrust for 15 mins. It doesn't enter service.

Or that's the theory...  8-)

-----------
Iain Stuart

http://www.big-iain.demon.co.uk/