Tony Russell wrote:
"I reckon most of them, the smaller ones anyway, get chewed up by the fan
blades."
Not so Tony.
I have many years experience in picking up wildlife that's been struck by
aircraft, and thankfully the vast majority of birds and bats die of blunt
trauma, not chop sui (bats through the blades are ordinary to say the
least!). There are also many that appear to have not been struck directly
(i.e. no reports made by aircraft as to a suspected strike, but more likely
seen by following aircraft traffic on the ground or picked up during routine
runway inspections), but rather get smashed to the ground by the wake
turbulence created by the wings of the aircraft and jet blast of the
engines.
Belinda Forbes wrote:
"One wonders why the birds don't take the evasive action. Surely a loud,
large plane bearing down is hard to miss, and birds have considerably better
maneuverability than a plane."
I once witnessed a Silver Gull getting struck by a B747 on a bright sunny
day. There was no noticeable wind at the time and the gull didn't try to
take evasive action until the last few metres, by which stage it was never
going to miss.
I can only imagine that for aircraft on final approach where the flight path
is very constant and direct, the birds don't really distinguish between a
constant shaped silhouette that looks much the same at 3 miles away as it
does at 2 miles away, and it still looks pretty much the same at 1 mile
away, just a little bigger, and by the time they realise the shape has got
much larger it's becoming way too late to avoid it.
Another issue is for raptors like Kestrels and Black shouldered kites where
they use an into wind position from which to hunt. The short grass
surrounding runway strips is an attractive place to hunt for mice and
insects, and the asphalt often provides good 'lift' when the wind just isn't
blowing. Aircraft also prefer to take off and land into wind for safety
reasons, so for the birds like Kestrels and kites, they have their backs to
the aircraft, so to speak. i.e. they just don't see it coming!
Cheers
Nigel
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