turbo

turbo

Well Known Member
i saw a rv-10 that had painted his spinner from the tip back 2/3 black and 1/3 white. he said that under 2,500 rpms the buzzards would see the pattern and move out of your way. has anyone heard of anything like this. he had hit one and totaled a wing. this was a solution for him. he says it works great. what do you think? turbo
 
old thread

There was an old thread here about two years ago about that. If I recall, it was claimed the Germans did this in second world war. The thoughts were that the strobe effect deterred birds. No idea, but there were several posts with good pics if you can find it.
 
The alternating color striped spinner as fairly common on Allied aircraft as well. Such as this P51D.

http://www.wwiifighteraircraftfoundation.org/missy.jpg

The only explanation that I have heard for this spinner teatment was as a bird deterrent. Who knows whether it actually worked of not. Lots of fighter aircraft during WWII used the pattern, so there were certainly people who believed that the theory was plausable.

George
 
Ed's description sounds like a radial pattern, and George's picture shows a circular pattern (which wouldn't "strobe" but would show rings in flight as well). Ed, are you asking about a radial pattern?

I'd be surprised if birds could make out a 2500rpm strobe. I think it would look to me like a grey blur, are birds' eyes capable of resolving that fast a movement?
 
Here You go. At a local museum, can't remember which airplane...German though

P1090008.JPG
 
Last edited:
Works (I hope)

turbo said:
i saw a rv-10 that had painted his spinner from the tip back 2/3 black and 1/3 white. he said that under 2,500 rpms the buzzards would see the pattern and move out of your way. has anyone heard of anything like this. he had hit one and totaled a wing. this was a solution for him. he says it works great. what do you think? turbo
Click to expand...

I painted the spinner on my 8, 2/3's red and 1/3 white.
It clearly works since I haven't hit any birds in 38 hours (first flew in Dec.):D
I'll let you know if it keeps working.
 
jferraro17 said:
Here You go. At a local museum, can't remember which airplane...German though

P1090008.JPG
Click to expand...

this is just like the 10 had. i know birds eyesight is superior to anything we know. who knows it might get there attention like a strobe light to us. there are an awful lot of turkey buzzards in florida. would be a fun test to fly at some and see if they act any different that now. thanks for the pic.
 
thats it!!!!!!!!!

jferraro17 said:
Here You go. At a local museum, can't remember which airplane...German though

P1090008.JPG
Click to expand...

this is just like the 10 had. i know birds eyesight is superior to anything we know. who knows it might get there attention like a strobe light to us. there are an awful lot of turkey buzzards in florida. would be a fun test to fly at some and see if they act any different that now. thanks for the pic.
 
I had my spinner painted that way and never hit a bird. Trailers, on the other hand, don't move out of the way for it. :(
 
the A-320's at my job have a white spiral on the centerbody "nose cone". these paintings are per manual. of course not all of them have it. same explanation, bird deter, works really good....they hit the eng inlets and leading edges instead of the eng fan blades....lol
 
I can't say I've ever seen such a spinner from the front during actual flight, so I don't know how it actually appears in real life, but...

video is normally 30 fps, so are you really just seeing an artifact of the video frame rate vs. the prop/spinner RPM here? A la the "stopped" or "backwards spinning" props that we see in most videos? Essentially, stroboscopic effects of the camera itself?
 
Spinner

I painted my spinner this way but only to get the strobe effect. I've had my flying buddies observe it at idle and in flight and I get absolutely no strobe effect that the human eye can detect. Does look cool though :D.

Canon%20006.jpg
Canon%20007.jpg
 
Anti-Bird Strike Spinner

The Doll has been flying with her anti-bird strike spinner for nearly ten years, and 1200 hours now, and I'm happy to report no Bird or Elephants strikes!
 
danny,

do you notice any movement of the birds getting out of your way from the strobe effect of the prop. there are a lot of birds here in florida and i am thinking of painting my spinner. thanks turbo
 
49clipper

I know for sure, Hawks eyes can detect changes and process movement five times faster than humans. In other words, if we look at something for a split second, they would see fives times as much movement. Not sure how to explain that but they could possibly see the strobe effect where we could not.
 
This thread has my interest piqued! I almost hit a bird while flying on Sunday. I've come close before, like within 30 feet of a wingtip, but 2 days ago I think I was about 5 feet from a Seagul (not sure why there are Seaguls in Idaho, BTW).

The funny part is that as I looked at the Seagul for the 1 second that I saw him, he was completely oblivious to me. Hawks, on the other hand, see me and typically pull wings in and dive. Makes me wonder if some birds are more likely to be hit than others.
 
49clipper said:
I know for sure, Hawks eyes can detect changes and process movement five times faster than humans. In other words, if we look at something for a split second, they would see fives times as much movement. Not sure how to explain that but they could possibly see the strobe effect where we could not.
Click to expand...

Assuming that's true (and I have no reason to doubt it is), then just run an engine with a bicolored spinner at 1/5 the in-flight speed and see if your eye detects some visual effect...say, around 500 rpm.

500 RPM is 8-1/3 revs/s. Hmmm....maybe you might see something, that's below the "refresh rate" of the human eye (about 1/15 of second, which is why film is shot at, at least used to be, 24 fps minimum).
 
Do whatever it takes...

..to miss big birds. Believe me, I've spent more money because of buzzards and hawk strikes on my Air Tractor than I care to remember.

Which color should be the 1/3? The lighter color, or the darker? My Air Tractor is soon getting this treatment. The airplane is yellow with a Navy-blue stripe, as in my avatar,

Thanks,
 
With great interest, I've read this and a similar thread on the same subject in Dec. 2007:
http://www.vansairforce.com/community/showthread.php?t=24147&highlight=bird&page=2
and suspect that given the relatively high RPMs our Lycomings operate in cruise settings, the strobe effect produced regardless of the
ratio of light to dark contrasting colors may not render a result nearly as pronounced compared to say...WWII fighter planes fitted
with slower turning radial engines and such. I wonder if an appropriately proportioned spiral pattern painted on our higher turning
engine/spinner would produce a dramatic effect? Anyone tried that? Thoughts?

21dpms5.jpg
 
Patty Wagstaff ...

may have an answer for us. Here is a pic I took of her plane at Airventure a few years back.
11-08263.jpg
 
ignacio said:
the A-320's at my job have a white spiral on the centerbody "nose cone". these paintings are per manual. of course not all of them have it. same explanation, bird deter, works really good....they hit the eng inlets and leading edges instead of the eng fan blades....lol
Click to expand...

Rick6a said:
Snip>...I wonder if an appropriately proportioned spiral pattern painted on our higher turning
engine/spinner would produce a dramatic effect? Anyone tried that? Thoughts?
Click to expand...

I was always under the impression that the spiral stripe was to alert ground crew to a turning engine...no spiral, or moving spiral...stay clear. Never heard it as a bird deterrent, but that doesn't mean it aint so!

pierre smith said:
..to miss big birds. Believe me, I've spent more money because of buzzards and hawk strikes on my Air Tractor than I care to remember.

Which color should be the 1/3? The lighter color, or the darker? My Air Tractor is soon getting this treatment. The airplane is yellow with a Navy-blue stripe, as in my avatar,

Thanks,
Click to expand...

Pierre, if I had to hazard a guess, I'd say the lighter should be the 1/3...seems the lighter color would reflect more light and the smaller part would give more strobe effect. But that's an absolute lay guess.

It is a facinating discussion, and an important topic. Wonder what the "frame rate" of a bird's eyeball is. Maybe we can run a ground test with a parrot at 500' and see which spinner makes him say "Whoa" first! :D And that's not a poke at the topic...it is an important one. I'd really like to know the frame rate of a Canadian Goose's eyeballs! ;)

It'd be neat to find out how to really test this...but even without tests, the spinners look cool that way, so why not...might have to try it. FWIW, I've also been taught that landing lights and weather radar are effective deterrents as well. No radar in my RV of course, but I use it at work if ATIS mentions birds, and use the LLs there and in the RV. Can't say I've never hit a bird, though thankfully only a couple small ones (that lost the fight, poor buggers) and none in the RV so far!

Cheers,
Bob
 
http://farm3.static.flickr.com/2487/3915512205_88a8be1e46.jpg

here is a pretty good shot of a similar paint job in action....

My weekend job has me flying the tow plane here...we paint the spinner 1/2 black and 1/2 white and have alternating stripes on the
front of the blades. Side benifit is that its very visible on the ground (from the front).
Since we spend all day every day in the pattern and haven't had a bird strike in years (that I recall) I would have to say its a winner.
 
FWIW, I've hit birds with and without that paint scheme on the spinner. Towed banners in college and we tried it, still mowed them down like grass.

I've also sucked birds down the motor of a 40K # Hornet in the landing pattern. They don't care what your paint job is, how big it is, etc. It's all a **** shoot. If you don't like the look, don't paint it. I personally don't think it buys you anything. Most big buzzards and what not are looking down most of the time anyway. I've seen literally hundreds not dive away until after I had passed them.
 
being constructive

I've hit birds with and without that paint scheme on the spinner.
-Sig600
Click to expand...
More than one paint scheme has been discussed. Which paint scheme do you mean by "that scheme"? what were the colors? what was the spacing?, or pattern(s)? what was the spinner size? what was the speed(s) at time of impact? what were the bird species hit?, raptors?, prey birds? otherwise your comment isn't of much constructive use.
 
I hope this idea makes sense...but why would you have to paint the spinner 1/3 white, 2/3 dark? If our engines spin too fast to have a strobe effect, wouldn't it make sense to make the pattern smaller, like 1/6 white on a black spinner? I don't know...maybe it's too late at night for my brain to be thinking about this stuff! :D
 
I went 1/4th white and 3/4 blue. We have an old B-24 pilot here who told me they tested several patterns during WWII and the most effective was the 25%/75% color ratio.

We'll see. Ain't hit a bird yet.

P1010089.JPG
 
Checkerboard

I used to have a red-white checkerboard pattern on my spinner. The turkey buzzards complained to the tower that it made them dizzy and nauseous!
 
not for birds?

I've been reading this thread with some interest, and while there is evidence that the spiral pattern may have some bird deterrent, the white and black spiral on the spinners of German late war aircraft was a recognition device from about 1943 on, especially over Germany.

The Japanese did something similar with the yellow painted leading edges of their aircraft wings.

Ryan in Madison
 
prop, not spinner

There's been an F4U Corsair at the Reno air races that has one blade painted white and the other three black on the front side. As he comes toward you turning that huge prop at about 1200 rpm, it makes it looks as if its wobbling!
 
The discussion about the spinner painted 1/3 with contrasting colors caused me to do some research. Birds it turns out have up to 5 times the visual ability of humans. They see colors better and see more colors and can see UV. But what about seeing a strobe effect of a painted spinner. It turns out they see at a higher flicker rate than we do also! So a 40Hz flicker (2400rpm)on a spinner is no problem for a bird to discern. I found this in Wikipedia "Birds can resolve rapid movements better than humans, for whom flickering at a rate greater than 50 Hz appears as continuous movement. Humans cannot therefore distinguish individual flashes of a fluorescent light bulb oscillating at 60Hz, but Budgerigars and chickens have flicker thresholds of more than 100 Hz. A Cooper's Hawk can pursue agile prey through woodland and avoid branches and other objects at high speed; to humans such a chase would appear as a blur."
So, it is reasonable to conclude birds could easily see a strobe effect on a spinner of our airplanes. What we don't know is if they see it will they stay away? I don't know but I would rather they see me coming than not .
I used an LED to see how much flicker I can see and around 1500 rpm it turned into a blur.
 
You must log in or register to reply here.