May 16, 2007

Breaking the Sound Barrier


An American Cobra helicopter breaking the sound barrier.



US Navy F-18 breaking the sound barrier.

18 comments:

Anonymous said...

A helicopter traveling that fast would not be nearly upright, the propeller would be tilted waay in front of the chopper.

Anonymous said...

Why is the sound barrier for the Cobra look the same as that for the F18? I think the Cobra pic is a fake! The rotors would be the first to show breaking the sound barrier. Westland modded their lynx's rotor tips to delay the tips from going supersonic, thus making the chopper faster than its' predecessors. Faster rotor rotation = faster forward speed!

blsterling said...

Please...Cobras are NOT designed for supersonic speeds. Mach 1 capable flight craft were/are built bullet shaped for a reason. Rotors would not survive such speeds. Appreciate the doctored photo for it's ironic humor and nothing more. As for the F-18 pic - stunning!

Anonymous said...

nice photoshop work. Sorry folks, that helicopter goes nowhere NEAR the speed of wound.

Anonymous said...

yeah that helicopter pictures is BS. an ah-1 cobra cannot travel anywhere near the speed of sound.

Anonymous said...

NO HELICOPTERS CAN BREAK THE SPEED OF SOUND!!! Rather than just saying "that pic is photo shopped", let me tell you WHY it's obviously faked. The "sound barrier" is the process of accelerating through Mach 1, or going from subsonic to supersonic speeds. The exact speed required to do that is not a fixed speed. It changes with altitude. At sea level, the speed of sound is 761.2 mph. At 10,000 feet, it's 734.6 mph, and at 20,000 feet, it's 707.0 mph, and in the Exosphere, the LAST layer of our atmosphere (before outer space) it still requires a speed of 310.7 mph to break the sound barrier. Now, the FASTEST helicopter in the WORLD is the Westland Lynx ZB500, and it holds this record at 249.1 mph. (There is currently a helicopter under development called the Sikorsky X2, which claims it will be able to top out at 288 mph, but that isn't confirmed). Taking the current world record of 249.1 mph, in order to break the sound barrier at that speed, the helicopter would need to be in OUTER SPACE. So...this myth is BUSTED.

Anonymous said...

Ummm..helicopters can't break the sound barrier. Nice photochop.

Anonymous said...

FAIL!!!

-D said...

ACtually, I do believe the Cobra can approach the speed of wound... now the speed of sound? lol Yeah, riiiight.

-D

Soldier's Samaritan said...

No heli in the world can break the sound barrier, kiddies. The fastest one just came out and has a maximum speed of about 435kph (270mph).

But that's just the facts. Any person who had an inch of intelligence would notice all the things that make it a piss-poor photomanipulation.

Anonymous said...

Nice Try. As a pilot with F-16 Fighting Falcon time I can tell you NO helicopter even reaches half the sound barrier. The leading rotor tips can & do - thus the "whup-whup-whup" sound.
The post above has the speeds & altitudes for breaking the sound barrier has it right.

Anonymous said...

those are both 'fake'

the cobra is photoshoped, anyone can tell, plus it wouldnt break the sound barrier. the jet in this pic and most others isn't breaking the sound barrier either,whats happening is actually a phenomenon that occurs usually over water or near water where the air is more dense with water particle, there for the air near the pressure points such as where the wings meet the fuselage, near the back tail, and over the canopy, the air is so dense it can't be pushed away fast enough, causeing this effect, wich may seem like its breaking the sound barrier when its not, it also sounds similar, its essentially the same thing happening, but its not actually flyinging faster than sound yet, its just the air is more dense, its giving that effect.

Anonymous said...

Top speed of AH-1 Cobra: 175 mph. Top speed of f/18: 1300 mph. Speed of sound: 768 mph. Go figure.

Anonymous said...

This is not posibleby any stretch of the imagination. The ONE thing that limits the forward speed of a helicopter is retreating blade stall caused by dissymmetry of lift. Forward spped is added to the advancing blade (RH side) as it is moving through the plane of rotation. On the other side LH side) the blade is retreating or 'going backward' through the air. As the forward speed of the helicopter increases, the retreating blade is forced to flap and pitch until it reaches a critical angle of attack just like a wing on an airplane. You can 'allow' the blade to flap as much as you want but when it reaches that stall angle...boom, your forward speed decreases, the nose 'balloons up', and the helicopter rolls to the right. Corrective action for this...reduce power, pull back on the cyclic, SLOWING the helicopter, level the aircraft and maintain a speed that doesn't get you into it.
The rotor blades on the helicopter would have to several times larger than a jet wing to overcome this. JUST NOT POSSIBLE!!!

Anonymous said...

pardon me...should have proof-read my posting on the retreating blade stall. Helicopter rolls left...
sorry for all the typos

Anonymous said...

That is one fast helo. I for one am both surprised and impressed that any helo could break the sound barrier.
I noticed also that our " photographer " was in the same position and time relative to the background clouds, which are identical in both pictures.
Probably just a coincidence,

Anonymous said...

both real

Anonymous said...

Come on. Airwolf did it back in 1983!