Three Black Helicopters

ONe kind of noise cancelling is already in use in some headphones

www.thetravelinsider.info...
qualitysound.bose.com...
jeremy.zawodny.com...

And if you want make all "gadgets" yourself:
www.wize.com...

back in february of '99 i saw a black helicopter at my airport in michigan. here's the ATS thread on it: www.abovetopsecret.com... or a link to a bunch of images of it: community.webshots.com...

anyway though, was it something similar to that? that was deemed to be a DEA taskforce helicopter in the thread, but who really knows?

also, you said you may have blinked or something since the other two appeared out of no where. perhaps when you blinked something happened to obscure your vision, or perhaps triple it like that.

Originally posted by FredT
Alot of a chopters noise is made by the interaction of the tailrotor and the main blades.

what do you mean? the main rotor blades and the tail rotor blades hitting each other?

Whay I find facinating about them is that they all use naval terms. We use a BK117 for medical transports and they use terms like "ship" to describe it, port and starboard aft etc.

yeah, that's actually fairly common among pilots and aircraft as far as i know.

UM, guys I already mentioned using White Noise, and you all thought I did not know what I was talking about. Now you are talking about the same exact same thing but calling it anti-noise???

Reversing a exact duplicate sound wave and repaying it at the same amplitude is called WHITE NOISE��

They have been thinking of using it in aircraft since back 10 years ago when I was working on aircraft. I am not sure why they have not started to do this, because studies at the time showed that the white noise not only cancelled out much of the noise, but also much of the vibrations allowing aircraft parts to last longer�.

Can you use this �anti noise� in on any platform cuz this would be great for tanks and especially subs and then of course planes and choppers ans where can I buy one my neighbors are always trippin cuz I listen to music very lound

Originally posted by cmdrkeenkid
what do you mean? the main rotor blades and the tail rotor blades hitting each other?

Its not a mechanical interaction. Its about the way the air flows off of the main and tail rotors

Originally posted by cmdrkeenkid

Originally posted by FredT
Alot of a chopters noise is made by the interaction of the tailrotor and the main blades.

what do you mean? the main rotor blades and the tail rotor blades hitting each other?

No just main rotor's airflow which hits directly to tail rotor.

One way to decrease noise from it is shrouding tail rotor.
www.fas.org...

Originally posted by WestPoint23
Can you use this �anti noise� in on any platform cuz this would be great for tanks and especially subs and then of course planes and choppers ans where can I buy one my neighbors are always trippin cuz I listen to music very lound

Well, I guess you don�t know much about physics than, here is where you can by an office version to cut down on noise in office spaces (white noise generator): www.warplink.com...

Here is an article on noise cancellation:
www.school-for-champions.com...

Two equal and opposing sound waves of the same frequency and amplitude can cancell each other out. So you record the sound coming in, invert the signal and shoot it right back out a speaker. Problem is there is some delay in doing this, and there is no good way I know of to exactly match the amplitued (volume), so they are not perfect yet.

They are used a lot in big companies where there are large rooms and a lot of cubes to cut down on the ambient noise in the room. You can some times tell when you walk into somewhere that is running one, because you get this muffled sensation in your ears.

Of course they will not work on subs, water is a very different medium then air.


[edit on 7/12/2004 by defcon5]

[edit on 7/12/2004 by defcon5]

[edit on 7/12/2004 by defcon5]

The A-160 hummingbird is not a black aircraft. I think we painted one of them primer for a DARPA show and then on to more mil shows. I built all of them personally. Quite a nice bird, but I like the demo model we built more. It is called the Maverick, and SCOOM has it right now in theatre. Cheap little indestructible bird. SOCOM loves it but Boeing in their great wisdom cancelled it because it was taking eyes off of their other UAV programs (they would make less money).

BTW those are some ...."interesting" range, altitude and payload 'facts' you found on the A-160. Also, the sensor systems package they put together for the bird is awesome.


[edit on 30-1-2008 by Spirit Warrior]

In theory, I guess it could be possible to make a helicopter silent by using anti-noice (ie. soundwaves that are the opposite of the ones emitted by the helicopter).

I don't see this as a possibility. The mass of air is too great, the payload of the a/c would be quite large and have massive power requirements. If you ever get the chance, get near a helo when on approach...the air mass is astounding.

Originally posted by cmdrkeenkid
what do you mean? the main rotor blades and the tail rotor blades hitting each other?

When that happens, it's usually something called a "Class A Mishap".


I don't know about "black" helicopters, but the Army paints theirs a dark OD that looks almost black.

Man, those are all terrible pics of the A-160...does someone have a picture of the turboshaft model or the one painted primer? Oh, here is a fun fact...those guys in the picture standing at the nose of the A/C...I have no idea who they are...such is politics eh. Oh, and that model is obsolete BTW, the new ones are much better. Let me see if I can find a good pic..

Here are a couple good pics

Pic at test site
'Somewhere' in the desert

This is the A160 with the forrestor radar package
Forrestor

this is with the grey paint
Primer A160

this is the maverick, the demo for the avionics package
The Mav