My first bird strike

[flugholm]

Hello folks,

last weekend I had my first bird strike. A pigeon tried to fly through the PA18's prop arc at about 200 ft AGL -- without success. I saw it out of the corner of my eye, it went Bang!!!, and I landed immediately.

It took me half an hour with a sponge and bucket of water to clean the Cub. No damage, but lots of ugly stains on the prop and the wing.

Anybody else with bird stories?

[bookworm]

First flight after we had an expensive new windshield fitted, a bird collides with it on take-off. :( Fortunately, windshield 1 bird 0.

[JP1]

Not a bird strike, but a close formation of 3 birds flew in front of me from left to right at about my level on Saturday. I was quite surprized since I was at 2500 feet. They looked like ducks. Not a cloud in the sky and visibility to the horizon. They definitely had a birds eye view (no pun intended)

[sternone]

I think that with single engines, you are much safer than with twins... before a bird has to fly true the prop to the windshield in a SE....

[underread east]

2500' is not high for a bird. Geese have been observed at 26000' (pinkfooted geese I think that utilise the upper winds to make their long migration quicker and more energy efficient - and they have antifreeze in their blood)

You are ALWAYS at risk, but it does diminish the higher you get. Most airliners have a specific speed restriction below 8000' for just this eventuality.

[Dave Gittins]

I thought it was below 250 kts at less than 10,000 feet .... but that seems to be pretty regularly ignored. I think the certification requirements for 'big jet' windscreens are blasting a 14 lb turkey at 'em at 250 kts.

It makes me wonder how the practise of keeping inside the "safety envelope" works when the ground level is high.

Near Colorado Springs last Thursday at about 2,000 feet above a ground level of 8,000 I felt it prudent to take avoiding action to miss two F ing great hawks or buzzards (ornithology not being my strongest suit when it comes to bird watching).

I certainly wouldn't have wanted to hit one of them in a 172.

If an airliner is descending into (say) Denver at about 5,000 ft AMSL, should it reduce to 250 kts below 15,000 for safety from birds ?

DGG

[underread east]

B757 limited to 313KIAS below 8000' for birdstrike. Most aviation authorities dictate 250Kt below FL100, but ATC may ask you to do more, or indeed less for flow control, and some heavies on departure may not be in a clean config at 250kt so may request more, particularly on departure to be at their most efficient.

Bird hazards are an entirely seperate consideration.

[soay]

I think that with single engines, you are much safer than with twins... before a bird has to fly true the prop to the windshield in a SE....
If my maths is correct, at 100 kts, each blade of a 2-bladed prop will have moved forward about 2 feet in a second. That leaves a big enough gap for most birds to pass through in one piece.

[Arclite01]

I've been in thermals with a Harris Hawk in NZ at 10,000'

Not unsual to see them at Cloydbase on soaring days.

Arc

[rans6andrew]

soay,

how did your maths come to 2 feet in 1 second.

My sums suggest that 100 knots moves forwards by about 170 ft per second. At 2500 rpm that is about 40 turns per second. This means that the prop turns once every 4 feet or so.

I guess that a bird less than 4 feet long and not too fat might just shoot through the prop disc without impact only to die against another part of the airframe.

[soay]

rans6andrew,

Your maths agrees with mine, but my thinking was that with 2 blades, the bird has twice the chance of being sliced in one revolution of the prop.

[Kolibear]

Pulls on birding anorak & zips it up, adjusts binoculars
I've been in thermals with a Harris Hawk in NZ at 10,000
Unlikely, as Harris Hawks are American species which hunt for prey on the ground. As I have absolutely no knowledge of raptors down-under, I can't even offer an alternative.
removes anorak and wanders away to look at aeroplanes

[Dave Gittins]

Exactly why I was careful with the "buzzards" last week. There was another big bird hanging round the airfield before we left and then flew off with a mouse hanging from one undercarriage leg so I had already had a close up view of the size of the darned things thay have in the US.

I wouldn't like to meet an eagle head on.