I tried really hard to find the concept for its flying!
as my dad works in the R&D of the Helicopters he too couldn't get an answer for it.
how does the couple get cancelled with out a tail rotor  or a coaxial rotor?
and it attains a top speed of 430km/h.
   

if you have a closer look there are two horizontal propellers and a vertical rotor..!

the horizontal props are solely responsible for the torqure ( which wags the tail) getting cancelles.

changes to the RPM or pitch of one of the props ca help in yawing or keeping it stable..!

if the two horizontal  propellers are responsible ,then how does it gain lift from the ground?

if the main rotor starts rotating then, the  propellers should also start rotating to cancel the couple in this case the helicopter moves forward ,rite?   

wrong they both have different speed controls for them .one for prop , other for vertical rotors

for vertical lift the main rotors act. to take the heli forward the horizontal props act.

for the yawing or the tail waging( as i said earlier) change in thrust in any one of the two props causes  yawing .

just a schematic representation below. hope u understand.

sir
if both thrust props and lifting blades act at a time ,then i think hovering is not possible.
how can it be possible?

vineet
both thrust propellers and main blade are automatically connected..
it is not like" first of all ,main blades start rotating and then thrust blades".
although , speed of thrust propellers can be varied with respect to each other.

correct me if i am wrong..

while howering the thrust props only use to keep the tail fixed,

and when thrust is required they have the tendency to produce it to a very good extent.

the thrust producing props and the rotors have different controls..

sir
no , it is not possible to counter the torque produced by main rotor at low thrust..
untill and unless , both the thrust propellers are rotating in opposite direction.
and although thrust controlling props and main rotor are operated by different engines , but these must have to start at a time so connected with each other .

We can do that with variable pitch propellers on both the forward thrust propellers.

The Main rotor will be used to lift and the rpm of it is coupled to the two propellers in front. There would be speed difference in the speeds of them to couter the main rotor torque.

The speed differnce is changed to make the helicopter yaw.
 
The Pitch in the main allows the lift and along with the pitch changes in the forward propellers allows the helicopter to move forward or backward. 

It is the next level after NOTAR concept which is already proven and running in as commercial and police helicopters.

Cheers

exactly my point...!

all i would request is go through basics ! watch X3 video correctly , they say side propellers act as a anti torque while hovering and takeoff and in forward flight main rotor is disengaged from gear box and full power is given to propellers! and more over this concept is very old !

how can a variable pitch can solve the problem?
if prop pitch is zero during hovering, then no thrust will be produced...
then how can these counter with the main rotor torque?

@VISHVESH-okay got it! thanks.
can X3  roll as its other cousins do? doesn't that effect the trust propellers ?

the thrust props only give a forward thrust and act as a tail rotor(effects like one) in some cases.. rest all it has the same function.!

also check this.!