Fastest Helicopter
- Thread starter xtrm302
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The twin rotors spin in opposite direction to help with stability. They kinda of counteract each other.
For those of us not well versed in maritime/air units (like me):
1 knot = ~1.151 mph
So that helicopter is cruising at about 299 MPH. That's haulin' ass!
1 knot = ~1.151 mph
So that helicopter is cruising at about 299 MPH. That's haulin' ass!
I'm in love. I DO want one of those.
^^^^that is correct. If both rotors spun in the same direction the helicopter would spin uncontrollably and crash.
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I'm having fun learning about helicopters now so I thought I'd share:
"A helicopter works by means of a horizontally-aligned rotor, spinning from a central mast. In most modern designs, the rotor is partially or fully articulated, allowing the rotor to be tilted to a limited degree, transferring some propulsion from a vertical to a horizontal direction. This allows these helicopters to make more rapid changes in direction (front, back, side to side). In most one rotor helicopters, a small tail rotor is present to counteract the natural effect of having the helicopter turn in the opposite direction as the rotor. One of the advantages of the dual rotor system is that the rotors can spin in opposite directions, counterbalancing each other and avoiding this counter-rotational problem."
"A helicopter works by means of a horizontally-aligned rotor, spinning from a central mast. In most modern designs, the rotor is partially or fully articulated, allowing the rotor to be tilted to a limited degree, transferring some propulsion from a vertical to a horizontal direction. This allows these helicopters to make more rapid changes in direction (front, back, side to side). In most one rotor helicopters, a small tail rotor is present to counteract the natural effect of having the helicopter turn in the opposite direction as the rotor. One of the advantages of the dual rotor system is that the rotors can spin in opposite directions, counterbalancing each other and avoiding this counter-rotational problem."
There is another reason to have twin counter-rotating rotors.
In a single rotor helicopter, one side of the rotor is flying into the direction of flight. The other side of the rotor is flying away from the direction of flight. This means you get a whole lot of lift from one side of the rotor and almost none from the other side. The faster you go, the more pronounced the effect becomes until parts start breaking. This is one of the big reasons helos are so speed limited.
With the twin counter-rotating system, each side of the aircraft has a rotor flying into the direction of travel, canceling out the other side of the rotor flying against the direction of travel.
Jim Snover
In a single rotor helicopter, one side of the rotor is flying into the direction of flight. The other side of the rotor is flying away from the direction of flight. This means you get a whole lot of lift from one side of the rotor and almost none from the other side. The faster you go, the more pronounced the effect becomes until parts start breaking. This is one of the big reasons helos are so speed limited.
With the twin counter-rotating system, each side of the aircraft has a rotor flying into the direction of travel, canceling out the other side of the rotor flying against the direction of travel.
Jim Snover
Jim is correct, retreating blade stall is the single biggest reason to use counterrotating main rotors. Yes, the torque of each rotor counteracts the torque of the other, but that is actually much easier and practical to do with a tail rotor.
For the record, Airwolf was the fastest and most technologically advanced helicopter ever. It was able to fly faster than the speed of sound with a single main rotor while avoiding retreating blade stall.
That is a thing of real beauty!!! Thanks for posting. Probably not needed...but she begs for stub wings...maybe to help roll rate?? Sure they would have thought of that. Ooops...I.m letting form get in the way of function. So rice.
Some of the posts are coming close to the real reason for going to a counter rotator. But missing the biggest one (s).
1)The tail rotor in a single rotor helicopter take up a surprisingly large amount of power, plus they require quite a bit of maintenance to prevent control problems, or outright failure.
2)The rotor disc is much smaller for the same amount of lift in a counter rotator. This allows a lower tip speed which is extremely important at high forward flight speeds. A large rotor's tip speed can go supersonic in fast forward flight. Since the tip speed of the leading rotor is added to the forward flight speed. This generally results in the destruction of the aircraft.
3)Counter rotation allows for a thrust producing "tail rotor" where all it's power consumption goes into speed and acceleration. And a resulting decrease in the need for both pitch and main rotors velocity at the increased speeds.
1)The tail rotor in a single rotor helicopter take up a surprisingly large amount of power, plus they require quite a bit of maintenance to prevent control problems, or outright failure.
2)The rotor disc is much smaller for the same amount of lift in a counter rotator. This allows a lower tip speed which is extremely important at high forward flight speeds. A large rotor's tip speed can go supersonic in fast forward flight. Since the tip speed of the leading rotor is added to the forward flight speed. This generally results in the destruction of the aircraft.
3)Counter rotation allows for a thrust producing "tail rotor" where all it's power consumption goes into speed and acceleration. And a resulting decrease in the need for both pitch and main rotors velocity at the increased speeds.
uhmmm....could be wrong, but I thought the osprey was supposed to be pretty fast...cool bird though
reference wiki, the osprey has an "unclassified"
* Maximum speed: 250 knots (463 km/h, 288 mph) at sea level / 305 kn (565 km/h; 351 mph) at 15,000 ft (4,600 m)[134]
but it's not an actual helo helo it's pretty much an air plane that takes off vertically.
* Maximum speed: 250 knots (463 km/h, 288 mph) at sea level / 305 kn (565 km/h; 351 mph) at 15,000 ft (4,600 m)[134]
but it's not an actual helo helo it's pretty much an air plane that takes off vertically.
I had a chance to see one of them in action on base in Oceanside SD. VERY sweet in deed!!!
not impressed. it's basically a prop plane with rotors instead of wings. fail.
Can't see link. What kind of helo is it?
so the only helicopter in the world faster than my GT is this?
weak sauce....
weak sauce....
Helicopters weren't designed for horizontal speed.
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