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Admiral346
10th Nov 2008, 20:58
The RYR at Ciampino thread has reminded me of a discussion I had recently with colleagues:

When approaching a field with lots of bird activity and there is no speed limit, Gdansk comes to my mind, I always reduce below the bottom of the clouds to at least 250kts, if not slower, to minimize the effects of a bird strike. Now while I am aware that a birdstrike may occure at unbelievably high altitudes, I have asked the question:

Do birds fly in clouds, IFR so to speak?

Does anybody on here have any zoological knowledge about this?

Thanks, Nic

Brian Abraham
11th Nov 2008, 00:19
See page 282 at Bird Migration - Google Book Search (http://books.google.com.au/books?id=_oE29KijRlAC&pg=RA1-PA282&lpg=RA1-PA282&dq=do+Birds+fly+in+clouds&source=web&ots=48kLRtLt9Q&sig=-Wo5OzerrITl7egeVlJjy8ndqbU&hl=en&sa=X&oi=book_result&resnum=10&ct=result#PRA1-PA282,M1)
Birds v. Planes - TIME (http://www.time.com/time/magazine/article/0,9171,803440,00.html)
http://elibrary.unm.edu/sora/Auk/v115n03/p0771-p0774.pdf
One suggestion is that while they may be able to fly in cloud they dislike doing so because they have difficulty ridding themselves of moisture produced by exertion in the prevailing humidity. Some book I read many, many years ago of WWII bomber crews who carried pigeons, stated that a pigeon released in cloud would adopt a gliding posture until becoming visual.

Admiral346
11th Nov 2008, 08:50
Thank you!

So I take from it that while you still might hit a bird in a cloud, it is not too likely.

Nic

Pitch&Fan
11th Nov 2008, 10:54
Or rather... The bird that one might hit is quite likely to be in a gull-like posture... gliding toward VMC!

At least we have that to console us.

(Sorry for the ridiculous posting... Just my sense of humour).

OzExpat
11th Nov 2008, 11:04
Errrm, that's probably a pretty fair statement Admiral, there's always likely to be the circumstance that goes against the rule. I truly doubt that you'll get a categorical answer to your question.

It undoubtedly boils down to the age-old adage... ya'll be careful now! Birds falling through cloud can still do a fair amount of damage but, hey... what are the odds eh? :eek:

SNS3Guppy
11th Nov 2008, 17:07
I've encountered birds in clouds. I don't believe I've ever had a bird strike while in a cloud, but I've seen them blow by the windscreen very quickly. I used to believe that they wouldn't be encountered in the soup, too...but experience has proven otherwise.

This is a common hangar flying topic, too...do birds fly in clouds. A favorite around the drop zone was whether jumpers ever hit birds on the way down, or bugs, for that matter. I've never run into anyone that's hit a bird on the way down, and while most jumpers I've spoken to insist the odds of striking a bug are very low, I've nailed a few big ones (june bugs) in free fall...anything's possible...which probably includes hitting a bird IMC.

PEI_3721
11th Nov 2008, 17:46
I have encountered many birds in foggy conditions, but not actually in thick cloud.
Many, mostly smaller bird varieties, either stayed on the ground (warm runway) or flew at low level with the ground still in sight.
Other mainly larger birds, were often just above the fog top (in the hold), these could be there in relatively large numbers and resulted in some near misses.

ChristiaanJ
11th Nov 2008, 17:50
Do birds fly in clouds, IFR so to speak?
Does anybody on here have any zoological knowledge about this?I immediately admit to no zoological knowledge on the subject whatsoever.
I've encountered birds in clouds. I don't believe I've ever had a bird strike while in a cloud, but I've seen them blow by the windscreen very quickly. I used to believe that they wouldn't be encountered in the soup....If you saw them, it wasn't soup...
My, probably useless, thought would be that birds fly at the most at something like 30 to 50 kts. So, they would stay out of the 100% solid peasoup, and just fly through the gaps in the rest, a luxury we humans do not have at 300 to 500 kts TAS....
As to the I in IFR (like Instrument... gettit?) I would think that while gliding, with a decent amount of lateral stability, they can probably feel they're level, they can certainly feel their speed, and in most cases they can probably see/perceive what's up and down. The anecdote about the WWII pigeons may well be accurate.

Brian,
Sorry, haven't explored your links yet, but will do.

CJ

ft
11th Nov 2008, 20:31
The other week, we found two large formations of geese just above a solid cloud cover (base 900 or so, tops 2500). They appeared to be joining up, probably preparing for a leg of the migration. Hundreds of them. Rather impressive, but unfortunately also smack dab in the middle of the ILS for the runway in use of a major airport.

The birds had found a 'valley' in the solid cloud cover, in which they were forming up. Nasty surprise for a jet crew coming out of the wall of said valley on the ILS, to say the least.

Not in cloud per se, but probably would appear to be to anyone unfortunate enough to fly into them.

Regards,
/Fred

ChristiaanJ
11th Nov 2008, 21:20
ft,
You rather seem to confirm what I was saying...
"Solid cloud" to us is NOT "solid cloud" to them.
You too saw them, after all.
Glad you did not have a strike.

CJ

Shore Guy
12th Nov 2008, 04:38
Annectotal story....

Happened to me this summer....

While approaching our hub airport, a tiny weak blob of green on the radar between us and the airport (inside 10 miles). No moisture in the area. Played with tilt and gain....still there.

As we met the "blob".....splat, splat, splat.....one of the forward windshields was virtually covered in "goo"....

Cicada's Cicada - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Cicada) a huge swarm.

Our arrival mechanic told us numerous aircraft had arrived with this gooey mess on the windshileds and leading edges that night.

Brian Abraham
12th Nov 2008, 05:12
A favorite around the drop zone was whether jumpers ever hit birds on the way down,
Afraid yes. Hope its readable.

http://i101.photobucket.com/albums/m56/babraham227/M0003.jpg
http://i101.photobucket.com/albums/m56/babraham227/M0004.jpg

Fark'n'ell
12th Nov 2008, 05:43
B A
Could you post the website about skydivers hitting birds(or PM me) please.
As a skydiver from way back I am rather interested.
Thanks.

Brian Abraham
12th Nov 2008, 07:12
Fark, is a scan from a magazine I have.