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In your average passenger helicopter, how fast does the main rotor spin? Do they use a turboprop system and keep the engine at a constant RPM? I just saw a trafficopter fly by pretty close and it made me curious.
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OT: helicopter question
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Re: OT: helicopter question (VWVancouver)
okay.. well, I'm assuming it was a traffic helicopter.. it could have just been another charter one though...
*shrug*
okay.. well, I'm assuming it was a traffic helicopter.. it could have just been another charter one though...
*shrug*
Re: OT: helicopter question (VWVancouver)
The can control the engine revs, but the revs are typical held constant during flight and only ramp up during takeoffs or emergencies, etc. They change the amount of lift by changing the pitch on the rotor blade, allowing them to control the altitude of the aircraft, as well as compensate for changes in air density, etc. Constant revs at cruise means better economy.
The can control the engine revs, but the revs are typical held constant during flight and only ramp up during takeoffs or emergencies, etc. They change the amount of lift by changing the pitch on the rotor blade, allowing them to control the altitude of the aircraft, as well as compensate for changes in air density, etc. Constant revs at cruise means better economy.
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Re: OT: helicopter question (Double-V)
.. now, how fast is that rotor going?
quote:[HR][/HR]The can control the engine revs, but the revs are typical held constant during flight and only ramp up during takeoffs or emergencies, etc. They change the amount of lift by changing the pitch on the rotor blade, allowing them to control the altitude of the aircraft, as well as compensate for changes in air density, etc. Constant revs at cruise means better economy.[HR][/HR]
Yeah,, thats what I was saying about the turboprop design.... now, how fast is that rotor going?
Re: OT: helicopter question (lyledriver)
quote:[HR][/HR]Yeah,, thats what I was saying about the turboprop design..
.. now, how fast is that rotor going? [HR][/HR]
At the tips, at maximum rotation speed, they're travelling at near the speed of sound... now, how fast is that rotor going? [HR][/HR]
Re: OT: helicopter question (lyledriver)
Thought I'd join in this all canadian thread...
It's true, the tips of the blades stay below the speed of sound due to turbulance. The vehicle would loose lift due to the uneven airflow caused when surfaces break the sound barrier.
When you are wondering about speed, the velocity is angular, so it depends... which part of the rotor are you talking about: the tips, the shaft?
Thought I'd join in this all canadian thread...
It's true, the tips of the blades stay below the speed of sound due to turbulance. The vehicle would loose lift due to the uneven airflow caused when surfaces break the sound barrier.
When you are wondering about speed, the velocity is angular, so it depends... which part of the rotor are you talking about: the tips, the shaft?
Re: OT: helicopter question (lyledriver)
Ya know... I was watching TLC the other night and they were talkin' HEAVY LIFT VEHICLES.
There was a section on Chinooks - twin rotor jobbies. Evidently they spin slower than most single prop helos. I thought they said ~400rpm, while normally it's more like ~800rpms.
I'll write my brother. He use to fly CH-53s.
Ya know... I was watching TLC the other night and they were talkin' HEAVY LIFT VEHICLES.
There was a section on Chinooks - twin rotor jobbies. Evidently they spin slower than most single prop helos. I thought they said ~400rpm, while normally it's more like ~800rpms.
I'll write my brother. He use to fly CH-53s.
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Re: OT: helicopter question (MrRoboto)
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obin
quote:[HR][/HR]Yeah,, thats what I was saying about the turboprop design..
.. now, how fast is that rotor going?
At the tips, at maximum rotation speed, they're travelling at near the speed of sound. [HR][/HR]
correct, and if they go faster than sound... the choppers lose lift
.. now, how fast is that rotor going?
At the tips, at maximum rotation speed, they're travelling at near the speed of sound. [HR][/HR]
obin
Re: OT: helicopter question (lyledriver)
Helicopters with turbine engines use a "turboshaft" configuration, rather than the turboprop you referred to. The main differences being that turboshaft engines are designed to produce more shaft power (as opposed to hot-gas thrust) and have significantly different gearing.
I flew a Robinson R22 once. That was a blast... anyone who hasn't flown before should definitely give it a try. Go down to your local airport; you can typically get an introductory lesson for around $60. In the end, I decided to fly fixed wing planes, simply because it's cheaper. I do work with helicopters though and am constantly amazed by them... what ingenious machines!
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quote:[HR][/HR]In your average passenger helicopter, how fast does the main rotor spin? Do they use a turboprop system and keep the engine at a constant RPM? I just saw a trafficopter fly by pretty close and it made me curious.
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[HR][/HR]
Main rotor RPM varies from helicopter to helicoper, however it is typically between 300 and 500 RPM. Main rotor RPM is "controlled" via the collective, which is a stick on the pilot's left side, typically positioned like an emergency-brake lever. Raising and lowering the collective changes the pitch of the main rotor blades, which effects how fast the main rotor can spin. In flight, main rotor speed is not controlled via the engine throttle; the throttle is set at 100% before takeoff and typically remains in that position throughout the flight.
Helicopters with turbine engines use a "turboshaft" configuration, rather than the turboprop you referred to. The main differences being that turboshaft engines are designed to produce more shaft power (as opposed to hot-gas thrust) and have significantly different gearing.
I flew a Robinson R22 once. That was a blast... anyone who hasn't flown before should definitely give it a try. Go down to your local airport; you can typically get an introductory lesson for around $60. In the end, I decided to fly fixed wing planes, simply because it's cheaper. I do work with helicopters though and am constantly amazed by them... what ingenious machines!
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Re: OT: helicopter question (Mach22)
thanks for the comprehensive reply!!
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thanks for the comprehensive reply!!
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