Stealth technology for black helicopters?

[William Kelly]

Neither I think would many others.

I was able to find some info on noise reduction.

http://www.aviation.com/technology/070727_...r_industry.html

One area in which manufacturers are concentrating their technological development efforts is in reducing the aerodynamic noise made by helicopters' main and tail rotors. Aerodynamic noise is responsible for most helicopter noise that people on the ground hear.

Manufacturers are now designing new helicopters with four or more main rotor blades. This avoids the distinctive chopping noise that the older, twin-bladed Bell UH-1 "Huey" helicopter makes, which can be heard miles away.

This at least suggests that Bell would be working on ways to decrease noise.

We can put a man on the moon and invent a silent helicopter, but we can't invent a silent blender?

BK

[Matthew Lewis]

Neither I think would many others.

I was able to find some info on noise reduction.

http://www.aviation.com/technology/070727_...r_industry.html

One area in which manufacturers are concentrating their technological development efforts is in reducing the aerodynamic noise made by helicopters' main and tail rotors. Aerodynamic noise is responsible for most helicopter noise that people on the ground hear.

Manufacturers are now designing new helicopters with four or more main rotor blades. This avoids the distinctive chopping noise that the older, twin-bladed Bell UH-1 "Huey" helicopter makes, which can be heard miles away.

This at least suggests that Bell would be working on ways to decrease noise.

We can put a man on the moon and invent a silent helicopter, but we can't invent a silent blender?

BK

I know it was a joke but on the serious side, there is hardly any call for a silent blender. Helicopters on the other hand can benefit from decreased noise to please residents near airports and military customers. Research goes where the money is.

[Craig Lamson]

Neither I think would many others.

I was able to find some info on noise reduction.

http://www.aviation.com/technology/070727_...r_industry.html

One area in which manufacturers are concentrating their technological development efforts is in reducing the aerodynamic noise made by helicopters' main and tail rotors. Aerodynamic noise is responsible for most helicopter noise that people on the ground hear.

Manufacturers are now designing new helicopters with four or more main rotor blades. This avoids the distinctive chopping noise that the older, twin-bladed Bell UH-1 "Huey" helicopter makes, which can be heard miles away.

This at least suggests that Bell would be working on ways to decrease noise.

We can put a man on the moon and invent a silent helicopter, but we can't invent a silent blender?

BK

Not silent but very funny...

http://www.willitblend.com/

[Evan Burton]

Quiet helicopters are definitely wanted; we get lots of noise complaints and we are a rotary-wing base. Getting back to the topic, though, there are two aspects: reducing the noise, and reducing the radar signature. The importance of each depends on the operational environment of the aircraft. Typically, helicopters will conduct "nape of the Earth" flying overland, meaning very low level. This also helps hide the aircraft by being mixed up with radar ground clutter. The noise though, can give it's position away and since helicopters do not typically have high speeds, warning of approach can be passed by ground troops.

I'd be interested to find out what type of helos Jack saw; they might be quite ordinary but they might also be of an advanced design, probably demonstration models.

[Maggie Hansen]

We can put a man on the moon and invent a silent helicopter, but we can't invent a silent blender?

BK

I know it was a joke but on the serious side, there is hardly any call for a silent blender. Helicopters on the other hand can benefit from decreased noise to please residents near airports and military customers. Research goes where the money is.

I don't know about that Matthew. Seems like there are at least 2 here on this thread that would love a silent blender. Not everyone lives near an airport but there is a blender in almost every home. Still I suppose the mark up is bigger on a helicopter.

[Matthew Lewis]

We can put a man on the moon and invent a silent helicopter, but we can't invent a silent blender?

BK

I know it was a joke but on the serious side, there is hardly any call for a silent blender. Helicopters on the other hand can benefit from decreased noise to please residents near airports and military customers. Research goes where the money is.

I don't know about that Matthew. Seems like there are at least 2 here on this thread that would love a silent blender. Not everyone lives near an airport but there is a blender in almost every home. Still I suppose the mark up is bigger on a helicopter.

Perhaps. Still, no matter how quiet the blender is, I only use ours to blend ice. I can't imagine that ever being quiet.

[William Kelly]

We can put a man on the moon and invent a silent helicopter, but we can't invent a silent blender?

BK

I know it was a joke but on the serious side, there is hardly any call for a silent blender. Helicopters on the other hand can benefit from decreased noise to please residents near airports and military customers. Research goes where the money is.

I don't know about that Matthew. Seems like there are at least 2 here on this thread that would love a silent blender. Not everyone lives near an airport but there is a blender in almost every home. Still I suppose the mark up is bigger on a helicopter.

While it might have been a joke to you, when live music is played in a bar, the blender is a distinct distraction. I know Jimmy Buffet would buy a silent blender for his Key West bar Margarettivelle, if there was one.

BK

[Evan Burton]

You know, I don't think I have ever used a blender in my whole life... silent or otherwise.

[Evan Burton]

Jack,

Does this look like what you saw?

I'm guessing it almost certainly was. That is the ARH-70 (Armed Recon Helicopter). Often painted black or very dark colours, based on the Kiowa (Jetranger) airframe, built by Bell in the DFW area, designed to fulfill the role of the RAH-66 Comanche and so therefore has a reduced RCS and incorporates technology to help reduce its noise signature.

I don't necessarily know about the 300 feet altitude, though. Judging altitude when you only see an object for a few seconds is difficult, even for those in the aviation community. Most regulations say you have to be at 1000 feet over a built-up area, or 500 feet over other areas, so I think they were between 500 - 1000 feet. Of course, with 5 of them in a line astern formation, there might have been reasons for them to be low flying and thus doing so with ATC approval.

Edited July 19, 2008 by Evan Burton

[Jack White]

Jack,

Does this look like what you saw?

I'm guessing it almost certainly was. That is the ARH-70 (Armed Recon Helicopter). Often painted black or very dark colours, based on the Kiowa (Jetranger) airframe, built by Bell in the DFW area, designed to fulfill the role of the RAH-66 Comanche and so therefore has a reduced RCS and incorporates technology to help reduce its noise signature.

I don't necessarily know about the 300 feet altitude, though. Judging altitude when you only see an object for a few seconds is difficult, even for those in the aviation community. Most regulations say you have to be at 1000 feet over a built-up area, or 500 feet over other areas, so I think they were between 500 - 1000 feet. Of course, with 5 of them in a line astern formation, there might have been reasons for them to be low flying and thus doing so with ATC approval.

That is very close, BUT THEY DID NOT HAVE THAT GLOBE above the rotors.

I base my 300 feet estimate on the length of a football field, which I am

accustomed to...plus the speed with which they went from my horizon to

horizon. I could be persuaded 500 feet IF they were flying FASTER than

I thought or were LARGER than I thought (compared to other helicopters

I am familiar with).

Jack

[Evan Burton]

As I said, the doubt on altitude was based on normal regulations, so it is quite possible they were that low.

The "ball" is called a Mast Mounted Sight (MMS), and is not always fitted. The MMS contains typically a hi-resolution camera, a thermal camera, and a laser rangefinder.

If you want to be sure, I would contact the ATC section for the area and ask if any were operating in your vicinity that day. If there weren't, they can tell you what helicopters WERE in your area.