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Old 5th Jul 2020, 11:59
  #129 (permalink)  
pitchlink1
 
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There is substantial difference between analog and digital FBW.

Originally Posted by CTR
From Aviation Today:

”The principal flight control stick will be in the cyclic position, in front of the pilot, but it will function more like a joystick. Officially called the "right-hand controller," it is comparable to the Comanche's sidearm controller, and it controls pitch, roll and yaw.

The right-hand controller doesn't give the pilot the exact feedback of a conventional cyclic stick, but Mayo believes helicopter pilots will find operating the FBW-equipped S-92 "to be an easy transition because the automatic features simplify the job of flying."

(Link deleted)

And yes, I am familiar with the differences between analog and digital flight control systems. But in all other FBW production helicopters and Tiltrotors (Comanche does not count) the cyclic is back driven in response to AP inputs. In the CH-148 it does not, unless changes to the architecture have been made late in development I am not aware of.
While you comment on analog and digital flight control systems, my point is there is difference between analog and digital FBW. While the analog FBW transmit signals at different voltages a digital FBW transmit signals by binary values (0 and 1). The first could be exposed the disturbance from outside while the latter is non effected by external sources as packages of information would have control logarithm established.

My understanding is that it was the A320 in 1987 and B777 in 1994 thar where the first commercial aircraft to utilize a digital FBW.

The NH90 for example has a FBW system, although it has two digital lanes and two analog lanes, so it can only do what an analog computer can do (basic damping and such), as Nick Lappos mentioned in an earlier post.

And further:

“2nd Aug 2006, 02:56
(...) The basic architecture of the NH 90's FBW is that all computations are made in a pair of analog computers that match the outputs of a pair of digital computers. Any miscompare shuts down that lane. This means that the FBW on the NH90 is incapable of doing anything that can't be done with resisters and capacitors. It is therefore relegated to damping and making normal helo flight controls, basically 1975 flight controls, in spite of the fact that it is a FBW.”

So FBW is divided into Analog FBW and Digital FBW. It is not the same and represents two very different ways of FBW.

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