Chinook & other tandem rotors discussions
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I'm sure there's a Chinook driver out there can give you chapter and verse, but the HCGB organised a tour of the simulators at Benson, which included the Chinook, and this subject came up.
With two rotors independently controlled you can simply point them in different directions and get a yaw effect. Must be very cunning electronics to get the pedals to do that though.
With two rotors independently controlled you can simply point them in different directions and get a yaw effect. Must be very cunning electronics to get the pedals to do that though.
Gentleman Aviator
Yawing is indeed accomplished by "differential cyclic pitch", ie, to yaw left the front rotor banks left and the rear rotor banks right. It's all done by a "suitable system of push-pull rods and bellcranks", rather than electronics - remember the age of the basic design. The pilot input is just the same, through the yaw pedals, and the result is the same, it just does it diffrently.
And like a convential helo, judicious coordination between feet and hands can engender a spot turn around any point, inside or outside the aircraft.
Slowing one down would not be a good idea rhmaddever, as the blades intermesh!!
And like a convential helo, judicious coordination between feet and hands can engender a spot turn around any point, inside or outside the aircraft.
Slowing one down would not be a good idea rhmaddever, as the blades intermesh!!
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Teetering Head is right, although one of his terms is not quite correct.
Differential Collective Pitch refers to when you push the cyclic forward, the front rotor blades do not change pitch, but the aft ones do.
Confused? Well, consider this... if you push the cyclic forward in a conventional single rotor helo, the disc tilts, the fuselage moves forward and tilts, the pilot applies collective so the aircraft maintains altitude.
If a chinook did the same, and both rotors tilted forward, then there would be a significant fuselage profile would be presented to the relative airflow. To counter this, by moving the cyclic forward, the aft rotor's blades increase pitch and the whole aircraft pitches forward at which time the pilot applies thrust (our name for the collective) which does the same thing as in a single rotor aircraft. (There's also two nifty little DC powered motors called longtitudinal cyclic trim actuators which will tilt the rotor head forward with increasing airspeed which reduces the profile of the fuselage presented to the relative airflow).
Also, just to elaborate, when the left pedal is pushed in, then the forward rotor tilts left and the aft tilts right... and vice versa.
If the cyclic is pushed left, then both rotors tilt left and vice versa.
Like Teetering head said, it's all done with push rods and bell cranks but the pilot inputs are just the same. I recently did a MD500 endorsement and a Schweizer 300 endorsement... and the control inputs are exactly the same. The little aircraft are more squirrelly and manoueverable... but the chinook has tons of grunt and is very quick (140knots).
Hope this helps.
CB
Differential Collective Pitch refers to when you push the cyclic forward, the front rotor blades do not change pitch, but the aft ones do.
Confused? Well, consider this... if you push the cyclic forward in a conventional single rotor helo, the disc tilts, the fuselage moves forward and tilts, the pilot applies collective so the aircraft maintains altitude.
If a chinook did the same, and both rotors tilted forward, then there would be a significant fuselage profile would be presented to the relative airflow. To counter this, by moving the cyclic forward, the aft rotor's blades increase pitch and the whole aircraft pitches forward at which time the pilot applies thrust (our name for the collective) which does the same thing as in a single rotor aircraft. (There's also two nifty little DC powered motors called longtitudinal cyclic trim actuators which will tilt the rotor head forward with increasing airspeed which reduces the profile of the fuselage presented to the relative airflow).
Also, just to elaborate, when the left pedal is pushed in, then the forward rotor tilts left and the aft tilts right... and vice versa.
If the cyclic is pushed left, then both rotors tilt left and vice versa.
Like Teetering head said, it's all done with push rods and bell cranks but the pilot inputs are just the same. I recently did a MD500 endorsement and a Schweizer 300 endorsement... and the control inputs are exactly the same. The little aircraft are more squirrelly and manoueverable... but the chinook has tons of grunt and is very quick (140knots).
Hope this helps.
CB
3000 PSI hydraulics.....lots of boost there. 1500 PSI for the SAS actuators....and the engine starters, ramp, cargo winch....
It would have to be from Columbia Helicopters....they own all the civvie Chinooks built.
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Yep,
Columbia is they only civil owner operator of the Chinook these days they have all the ex British Airways and Helikopter service machines. Columbia have them spread between the western us and asia on heavy lift work, fire fighting.
The MOD has wanted a civil sourced machine to go into the Falklands for some time now to release the RAF machine. Its required to lift 12ton generator sets around the various sites on the Falklands.
Hope the info is of some assistance.
Helitemp
Columbia is they only civil owner operator of the Chinook these days they have all the ex British Airways and Helikopter service machines. Columbia have them spread between the western us and asia on heavy lift work, fire fighting.
The MOD has wanted a civil sourced machine to go into the Falklands for some time now to release the RAF machine. Its required to lift 12ton generator sets around the various sites on the Falklands.
Hope the info is of some assistance.
Helitemp
required to lift 12ton generator sets around the various sites on the Falklands
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Helimann
Why does it have to be a civilian Chinook?
Depending on what you want it for and if the money is right I'm sure the military would be prepared to get involved, we all know they love to show off their skills and hardware.
H.
Why does it have to be a civilian Chinook?
Depending on what you want it for and if the money is right I'm sure the military would be prepared to get involved, we all know they love to show off their skills and hardware.
H.
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Depending what your lifting the offshore guys can lease you a heli and i believe that there is a 212 at middle wallop being used for training AAC but if its quiet they may be able to lease it out.
Why a chinook though? Very noisy beast.
Why a chinook though? Very noisy beast.
'nough said
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Can Chinooks auto-rotate?
These things keep buzing over my house every other day - sometimes as a pair in close formation (never when I have my camera handy of course). A question that's been nagging me (not that I wish to sound fatalistic) but what happens if it should have to shut down an engine - can it auto-rotate on one rotor ?
Just curious,
amofw
Just curious,
amofw