Spinner strobing as a "Bird Strike Countermeasure"

In article , says...



"Airbus" wrote in message
...
In article ,
says...


When observed directly under artifical light that "flickers", the most
obvious being a strobe light, but there are other types of artificial
lights that have flicker.

--


Fine - but which ones cause you to see the propellers turning in
apparent reverse? Do you frequently operate your airplane indoors?
Propellers are usually observed in natural light, which does not flicker.
At
night, on the rare occasions where you actually see the props clearly, it
is
from the aircraft's own lighting, which is DC. I have nbever seen the
props
turning backwards on a real plane - see it frequently in movies though.
. .


Do you really think you see and visualize motion constantly. Perhaps you
should spend a little more time around and airport yourself. Many
propellers, especially the large diameter props found on radial engines,
will appear at times to be rotating slower, or backwards. It's a fainter
image than recorded on film, but the partnership of the human eye and brain
does not realize fluid motion.


Well, I must admit I don't have much experience with large radial engines.
Moreover, I accept the argument that some AC ramp lighting at night can produce
stroboscopic effects with props - I have not seen it myself, even though I
frequently fly at night, but I do accept the principle - if you get your plane
in the right position with respect to line-frequency, AC lighting at night you
should see stroboscopic effects, which will include "backwards turning"
illusdion, depending on your prop speed. So I stand corrected on this.

In article , says...



"Mxsmanic" wrote in message
.. .
Roger (K8RI) writes:

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.

Birds have much better vision than human beings,


Demonstrably true.



and I don't believe
anyone
has tested their ability to discern stroboscopic effects.


You're out on a limb there. There has been A LOT of testing on birds' vision,
and they don't necessarily ask your opinion. . .



And the front
fan
on a turbofan is turning at around 40-50 revolutions per second, not
thousands.



Guess again.


Well, I think he made a pretty good "guess" - the GE90-115B tha powers the
777 turns (front fan) at 2550RPM, or 42.5 RPS. He probably didn't ahve to
guess much, as these facts are easily and irrefutably verified. I "guess" you
haven't learned that. . .

"Peter Clark" wrote in message
...
On Tue, 4 Dec 2007 12:29:29 -0600, "Maxwell"

If it hasn't been on a tv or computer screen, you have so little
experience
YOU don't realize it exists.

Wait, I did a KF a while back - did I read this right that now it is
trying to tell people they don't really know what they see?

Yep, that's just about the size of it.

"Mxsmanic" wrote in message
...
Paul Tomblin writes:

It tells me that the people who wrote the Wikipedia article are smarter
than you or me.

Because they agree with what you wish to believe?

I've written a lot of Wikipedia articles myself. Do you believe what I've
written because I put it in Wikipedia?

Wikipedia quotes multiple scientific papers. So far all you've quoted is
yourself.

Wikipedia usually quotes, at best, a number of sources, which may or may
not
be reliable, be they scientific papers or not.

But you are still a much more unreliable source than Wiki.

On 2007-12-05, Airbus wrote:
Well, I must admit I don't have much experience with large radial engines.
Moreover, I accept the argument that some AC ramp lighting at night can produce
stroboscopic effects with props - I have not seen it myself, even though I
frequently fly at night, but I do accept the principle - if you get your plane
in the right position with respect to line-frequency, AC lighting at night you
should see stroboscopic effects, which will include "backwards turning"
illusdion, depending on your prop speed. So I stand corrected on this.

I've seen it plenty of times.

Not caused by lighting, but you can see the strobing effect in this
video I shot, caused by the frame rate of the video camera (note, the
strobing is at 50Hz since the source video is PAL):

http://www.youtube.com/watch?v=Nf5unfWZLDA

--
From the sunny Isle of Man.
Yes, the Reply-To email address is valid.

Mxsmanic wrote in
:

Maxwell writes:

This phenomenon is apparent to the naked eye under continuous
lighting conditions.

No, it is not.

You might need to wait for a three or four blade prop, but
it DOES happen in real life.

No, it does not. Continual assertions to the contrary will not change
this.


Yes, they will


Bertie

Mxsmanic wrote in
:

cavelamb himself writes:

Or else I won't Like You any nore.

I'm not looking for friends.

Obviously.


I'm only here to discuss aviation.



No you aren't


Bertie

Mxsmanic wrote in
:

Yes - I have a name writes:

I'm sure I've seen wheels on cars that appear to be moving backwards.
Are my eyes defective?

No, but your memory is imperfect. You've never seen that in real
life, only on TV and in films, or under stroboscopic lighting.















wrong again, fjukkwit.


Bertie

Mxsmanic wrote in
:

Paul Tomblin writes:

It tells me that the people who wrote the Wikipedia article are
smarter than you or me.

Because they agree with what you wish to believe?

I've written a lot of Wikipedia articles myself.


Well, there's Wickepedia's rep completely shot now.


Do you believe what
I've written because I put it in Wikipedia?


Nope.


Bertie

cavelamb himself wrote in news:13lbscv7ajlv9c8
@corp.supernews.com:

Yes - I have a name wrote:
"Gig 601XL Builder" wrDOTgiaconaATsuddenlink.net wrote in message
...


Shut the **** up, MX.




So Say We All!




So, which way is the naked lady spinning?

http://www.sonnyradio.com/spinninglady.html


Nice figure. got her phone #?


BTW, depending on the scale used, about 140 or over is genius level,
depending on your definition, of course


Bertie