Chinook rescues helicopter

Pav89 · 7 Jul 2008 at 20:09

I've always wondered this....the 2 rotor blades overlap on dual rotor helicopters. Why do they never touch or bang into each other. When I first saw a dual rotor helicopter I was like :eek:

the blades are going to hit each other and the helicopter will fall!

GeForce · 7 Jul 2008 at 20:12

Pav89 said:
Why do they never touch or bang into each other.

One rotor is mounted slightly above the other. By spinning them in opposing directions, the need for the stabilising tail rotor is eliminated too

Jon

Lashout_UK · 7 Jul 2008 at 20:12

Pav89 said:
I've always wondered this....the 2 rotor blades overlap on dual rotor helicopters. Why do they never touch or bang into each other. When I first saw a dual rotor helicopter I was like the blades are going to hit each other and the helicopter will fall!

The rotors are geared in such a fashion that they can't clip eachother - they run in phase

Ross1234 · 7 Jul 2008 at 20:13

GeForce said:
One rotor is mounted slightly above the other. By spinning them in opposing directions, the need for the stabilising tail rotor is eliminated too

Jon

Lashout_UK said:
The rotors are geared in such a fashion that they can't clip eachother

oooh, opposing answers

Pav89 · 7 Jul 2008 at 20:13

GeForce said:
One rotor is mounted slightly above the other. By spinning them in opposing directions, the need for the stabilising tail rotor is eliminated too

Jon

But they are like centimetres away from each other? :eek:

GeForce · 7 Jul 2008 at 20:15

Ross1234 said:
oooh, opposing answers

Hmm. Come to think of it, I think it's a combination of both. Simply looking at pictures seems to show they are not mounted on the same level.

But they are probably geared to, simply because when accelerating vertically upwards the blades will bend upwards, so the simple height difference wouldn't prevent them hitting each other.

Jon

Edit: They must be geared together. Simply because the Chinook has two turboshaft engines, but if one fails, the other can power both rotors.

Lashout_UK · 7 Jul 2008 at 20:17

Despite the different heights of the blades, they would still hit if they weren't synchronized. The blades do flap and it also has something called cyclic trim in which the heads tilt fore and aft for flight at different airspeeds to maintain a level fuselage attitude in flight. During ground taxi, the forward head also tilts forward, to pull the aircraft along.

The synchronization is accomplished by a shaft that runs between the forward and aft transmissions. Both heads rotate together at the same speed and stay meshed due to this synch shaft. Failure of this shaft is most likely catastrophic to the rotor blades as they get out of synch.
1 year ago
Source(s):
CH-46 pilot

You can see the CH47's drivetrain in some detail here : http://www.chinook-helicopter.com/standards/areas/drive_train.html

Pav89 · 7 Jul 2008 at 20:22

tar chuck

Indy500 · 7 Jul 2008 at 20:36

Greenlizard0 said:
FAIL if it, erm, fails *shudders*

Perhaps, but then having it there is better than going down with the helo.

Chabsy · 7 Jul 2008 at 20:37

I love the sound of a Chinook it is unmistakable

kitfit1 · 7 Jul 2008 at 20:39

GeForce said:
One rotor is mounted slightly above the other. By spinning them in opposing directions

Lashout_UK said:
The rotors are geared in such a fashion that they can't clip eachother - they run in phase

The main reason they don't collide is that they are controlled by sophisticated software. The reason the Chinook's that the MOD has sat around doing nothing, is that some smart a*s* thought he might save a few bob. So they bought the Chinook's, but not the software that is needed to fly them. Don't you just love our government eh ?

Chabsy · 7 Jul 2008 at 20:55

kitfit1 said:
The main reason they don't collide is that they are controlled by sophisticated software. The reason the Chinook's that the MOD has sat around doing nothing, is that some smart a*s* thought he might save a few bob. So they bought the Chinook's, but not the software that is needed to fly them. Don't you just love our government eh ?

Could we not just get our version or nero out any copy the software from chinnoks we have bought before?

Or maybe there is a news group somewhere with some dodgy Chinook software?

kitfit1 · 7 Jul 2008 at 21:04

Chabsy said:
Could we not just get our version or nero out any copy the software from chinnoks we have bought before?

Or maybe there is a news group somewhere with some dodgy Chinook software?

ROFL

Nah, that would be illegal...................and we all know our government neveeeeeeeeeer does ANYTHING that's illegal