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#1
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Spinner strobing as a "Bird Strike Countermeasure"
The following thread on the Van's Air Force web site was of general enough
interest that I thought it worthwhile to bring it to the attention of other pilots: http://www.vansairforce.com/communit...ad.php?t=24147 Would be quite useful if it really worked. Of course there would still be strikes with inattentive and near-sighted birds. ;-) |
#2
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Spinner strobing as a "Bird Strike Countermeasure"
"Jim Logajan" wrote in message .. . The following thread on the Van's Air Force web site was of general enough interest that I thought it worthwhile to bring it to the attention of other pilots: http://www.vansairforce.com/communit...ad.php?t=24147 Would be quite useful if it really worked. Of course there would still be strikes with inattentive and near-sighted birds. ;-) I wonder about doing the candy stripe spiral on them, or painting the blades different colors... |
#3
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Spinner strobing as a "Bird Strike Countermeasure"
"Blueskies" wrote in message t... "Jim Logajan" wrote in message .. . The following thread on the Van's Air Force web site was of general enough interest that I thought it worthwhile to bring it to the attention of other pilots: http://www.vansairforce.com/communit...ad.php?t=24147 Would be quite useful if it really worked. Of course there would still be strikes with inattentive and near-sighted birds. ;-) I wonder about doing the candy stripe spiral on them, or painting the blades different colors... There is a design used on the American Airlines (and perhaps others) high bypass engines that is reported to be effective too. Might check it out at airliners.com or something. Considering visibility difference and rotation speed, the design you are testing appears even more visible. My guess is, it will work. |
#4
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Spinner strobing as a "Bird Strike Countermeasure"
"Maxwell" wrote in message ... "Blueskies" wrote in message t... "Jim Logajan" wrote in message .. . The following thread on the Van's Air Force web site was of general enough interest that I thought it worthwhile to bring it to the attention of other pilots: http://www.vansairforce.com/communit...ad.php?t=24147 Would be quite useful if it really worked. Of course there would still be strikes with inattentive and near-sighted birds. ;-) I wonder about doing the candy stripe spiral on them, or painting the blades different colors... There is a design used on the American Airlines (and perhaps others) high bypass engines that is reported to be effective too. Might check it out at airliners.com or something. Considering visibility difference and rotation speed, the design you are testing appears even more visible. My guess is, it will work. http://tinyurl.com/2yjh2c |
#5
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Spinner strobing as a "Bird Strike Countermeasure"
On Sun, 2 Dec 2007 17:02:07 -0600, "Maxwell"
wrote: "Blueskies" wrote in message et... "Jim Logajan" wrote in message .. . The following thread on the Van's Air Force web site was of general enough interest that I thought it worthwhile to bring it to the attention of other pilots: http://www.vansairforce.com/communit...ad.php?t=24147 Would be quite useful if it really worked. Of course there would still be strikes with inattentive and near-sighted birds. ;-) I rate this things right in there with the old ultrasonic deer whistles you put in your car grill. Driving down the road was supposed to put out a noise to scare the deer. Somebody made a small fortune on those before they proved they don't work. I wonder about doing the candy stripe spiral on them, or painting the blades different colors... There is a design used on the American Airlines (and perhaps others) high bypass engines that is reported to be effective too. Might check it out at airliners.com or something. Considering visibility difference and rotation That's used to let people on the ground know if the engine is still turning. An engine coasting to a stop is nearly silent and is silent if you are out on the ramp wearing hearing protection. Roger (K8RI) speed, the design you are testing appears even more visible. My guess is, it will work. |
#6
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Spinner strobing as a "Bird Strike Countermeasure"
On Sun, 02 Dec 2007 22:09:30 -0000, Jim Logajan
wrote: The following thread on the Van's Air Force web site was of general enough interest that I thought it worthwhile to bring it to the attention of other pilots: http://www.vansairforce.com/communit...ad.php?t=24147 At cruise RPM that effect would be completely lost. There's not a bird or human alive that can discern stroboscopic effects of more than a couple hundred cycles let alone over a 1000. Most of us can't even discern 60 cps. Roger (K8RI) Would be quite useful if it really worked. Of course there would still be strikes with inattentive and near-sighted birds. ;-) |
#7
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Spinner strobing as a "Bird Strike Countermeasure"
On Dec 2, 5:59 pm, "Roger (K8RI)" wrote:
On Sun, 2 Dec 2007 17:02:07 -0600, "Maxwell" wrote: That's used to let people on the ground know if the engine is still turning. An engine coasting to a stop is nearly silent and is silent if you are out on the ramp wearing hearing protection. Roger (K8RI) Incorrect. The spiral on the fan hub is a bird deterrent measure. It has nothing to do with ground personnel. |
#8
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Spinner strobing as a "Bird Strike Countermeasure"
True, but aren't we talking about 40 cps when the prop RPM is 2400?
-- Best Regards, Mike http://photoshow.comcast.net/mikenoel If any question why we died, tell them, "Because our fathers lied." - Rudyard Kipling. "Roger (K8RI)" wrote in message ... On Sun, 02 Dec 2007 22:09:30 -0000, Jim Logajan wrote: The following thread on the Van's Air Force web site was of general enough interest that I thought it worthwhile to bring it to the attention of other pilots: http://www.vansairforce.com/communit...ad.php?t=24147 At cruise RPM that effect would be completely lost. There's not a bird or human alive that can discern stroboscopic effects of more than a couple hundred cycles let alone over a 1000. Most of us can't even discern 60 cps. Roger (K8RI) Would be quite useful if it really worked. Of course there would still be strikes with inattentive and near-sighted birds. ;-) |
#9
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Spinner strobing as a "Bird Strike Countermeasure"
"Roger (K8RI)" wrote in message ... On Sun, 02 Dec 2007 22:09:30 -0000, Jim Logajan wrote: At cruise RPM that effect would be completely lost. There's not a bird or human alive that can discern stroboscopic effects of more than a couple hundred cycles let alone over a 1000. Most of us can't even discern 60 cps. "Mike Noel" wrote in message ... True, but aren't we talking about 40 cps when the prop RPM is 2400? Seems I have heard the 16 cps is all that is required for movies to appear continuous. I think the human eye loosed it around 12 or 13. However, we don't seen consciously either. Hence the reason an aircraft propeller will appear to be revolving slowly backwards at times. I can say I worked in the engine shop at American for 15 years, and we were always told it was a very cost effective bird strike tool. But that is no guarantee. We always did say if you hadn't heard a good rumor my 10:00 am, then start one. But then again, it shouldn't be needed by ground personnel. If someone can look at a high bypass engine and tell if it's turning fast enough to be dangerous, the need to be teaching English in France or something. |
#10
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Spinner strobing as a "Bird Strike Countermeasure"
In article ,
Maxwell wrote: "Roger (K8RI)" wrote in message ... On Sun, 02 Dec 2007 22:09:30 -0000, Jim Logajan wrote: At cruise RPM that effect would be completely lost. There's not a bird or human alive that can discern stroboscopic effects of more than a couple hundred cycles let alone over a 1000. Most of us can't even discern 60 cps. "Mike Noel" wrote in message ... True, but aren't we talking about 40 cps when the prop RPM is 2400? Seems I have heard the 16 cps is all that is required for movies to appear continuous. I think the human eye loosed it around 12 or 13. However, we don't seen consciously either. Hence the reason an aircraft propeller will appear to be revolving slowly backwards at times. Visual perception is funny and complex. black & white films were 16 frames/second. Color films are 24 frames/second U.S. TV is 60 fields/second, European is 50/second. This is driven more by the need for phospors that 'decay' rapidly enough to not produce 'blurred' motion than perception issues. OTOH, A significant number of people can perceive 'flicker' in conventional- tube fluorescent lamps. which is at 120 flickers/second. Also, the eye -- and brain -- 'notices' things that are too fleeting for conscious identification. Google 'subliminal' advertizing -- IIRC, lab tests showed that injected imagery with a duration of only a few milliseconds had 'measurable' effects. |
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