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2007-05-23 22:35:00 · 9 answers · asked by Anonymous in Cars & Transportation Aircraft

9 answers

The fastest helicopter ever was actually the Sikorski S-69 Coaxial. This used the ABC concept that "feathered" the retreating blade. It was able to hit 321 MPH in level flight in June 1978. Although this project was scrapped with competing pressure of the Osprey (v-22) promise the record still holds. But for production aircraft the Lynx at 249.1 MPH.

An average Helo like the Bell 206 cruises at 133 MPH.

2007-05-24 07:38:33 · answer #1 · answered by Drewpie 5 · 8 0

Helicopter Speed

2016-11-09 22:21:23 · answer #2 · answered by disilvestro 4 · 0 0

Retreating blade stall, and the effects of compressibility(blade tips exceeding the speed of sound) limit the speed of helicopters. These two conditions are caused by the rotational velocity coupled with the forward velocity. There's not enough space here to talk about both, so you will have to look them up via a search engine (yahoo) and read for yourself.

2007-05-27 04:04:06 · answer #3 · answered by BM31 2 · 0 0

The 11th August marks the 20th anniversary of the Westland Lynx helicopter setting a new world helicopter speed record of 249.1 mph (400.87 kph). Although other attempts have been made, 20 years on Lynx retains the title as the world’s fastest helicopter

2007-05-23 22:44:11 · answer #4 · answered by Anonymous · 4 0

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The most basic method to measure airspeed is through a device called a Pitot tube. The tube has a small hole in the front where incoming air applies pressure in a dynamic way. This pressure is compared with one coming from a static port, which is not in the plane of motion, so as to not measure any (or as little as possible) dynamic component of the pressure. The measurement is called "indicated airspeed", which is quire different from the real speed of travel, as we will see. The first thing that makes indicated airspeed to be off is called position error. The Pitot tube is supposed to be perpendicular to the direction of motion, but being fixed on the airframe, is not always perpendicular, since an aircraft will vary is angle of attack as a function of its speed and weight, and flap deflection. Flight tests with supplementary external equipment establishes the correction error. Airspeed corrected for position error is called calibrated airspeed. But this is still not exactly the real speed, as air density and pressure changes with altitude and temperature. If one carries the correction due to air pressure (as well as compression effect when flying at speed close to the speed of sound), then we have the true airspeed. Which is not the ground speed, as airspeed is relative to the air, which moves if there is wind. Complicated? You betcha. The airspeed is what concerns the pilot for a safety point of view. How fast to go to takeoff, how fast to go when landing, and so on, is regulated by airspeed, since this is the only speed that matters for the wing. But an airplane has to go from point A to point B, and those are not affected by wind speed, or varying air pressure. Modern aircraft are equipped with gyroscopes that sense acceleration and therefore motions, and are able to derive a speed that is correlated with actual ground speed. These are futher agumented by radio emitters, which are located at known points along the way, and which allow triangulation to determine the true position. With any drift in the position relative to what was computed now being known, a better assessment of the actual ground speed is established. And recently, let's not forget GPS based equipements that can give you position and speed quite accurately. As for the wind speed, it is known from the various weather and meteorological stations. Doppler radar can measure wind speed, and recent weather forecasts are available to pilots prior to departure, and updated through radio during flight. All the available information is fed into navigation computers by the flight crew, allowing a accurate estimation of the ground speed, and thus allowing a good prediction of the time of arrival at destination.

2016-04-10 08:35:08 · answer #5 · answered by Anonymous · 0 0

The limit comes from the rotor blades. As the helicopter moves forward the blade on one side gets an increase in the air velocity over it, and a matching reduction as it swings round to the other side. The angle of the blade changes as it rotates to maintain the same lift on each side.At some forward speed the possible combination of air velocity and pitch angle becomes unsustainable and that is the limit for speed. A smaller faster rotating set of blades extends the possible speeds a bit but material strengths limit how far you can go.
The supersonic flight in TV's "Airwolf" is a scripwriters dream

2007-05-24 20:58:55 · answer #6 · answered by The original Peter G 7 · 1 2

Ah, that old chesnut.
Sure your other answers are correct at about 250mph for level flight airspeed, after which the rotor blade tips are trying to go well supersonic, and won't work properly.
However, a RAF lynx pilot did tell me once that he reckoned that given enough height, and poke it into a steep dive, then nearer 300mph is achievable, but he wasn't prepared to put that to the test. Don't blame him. We just toodled around at about 100 mph. with the doors open. Great fun days.

Bob.

2007-05-24 03:48:20 · answer #7 · answered by Bob the Boat 6 · 0 0

It is limited by the laws of physic's and the fastest helicopter's are still well under 300 mph. That is why tilt rotor's have always been a popular concept. Seem's like they will finally work. Remain's to be seen with what reliability.

2007-05-24 04:55:10 · answer #8 · answered by Anonymous · 0 1

most of them have cruising speed approx 130KTS maximum 150KTS, maximum speed for Mi 24 Hind is 330 kmph=180 KTS, Apache is still a bit faster, Lynx has the speed record, don't remember exact value.

2007-05-24 04:15:02 · answer #9 · answered by Anonymous · 0 0

In every day language typical commercial choppers would normally travel at about 100 mph

2007-05-24 10:06:20 · answer #10 · answered by Anonymous · 0 0

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