Richard Riley opined

I've been working with a conventionally configured helicopter for a
few months and this suddenly started eating my brain.

In a 2 rotor helicopter you are countering the torque of one rotor
with the other rotor. But how do you do a pedal turn? In a coaxial
I'd think you'd increase the pitch of once set of blades and decrease
the other. But what do you do in a tandem, like a CH-46? Increase
the pitch, you get more torque, but you also get more lift, so the
aircraft would move forward or backward -

Any helo pilots out there that can set me straight?

Differential roll .

You tilt (say) the front rotor disk to the left, and the other to the right. The
helo then pivots counter-clockwise.

-ash
Cthulhu in 2007!
Why wait for nature?