The evolution from mechanical to Fly-By-Wire (FBW) designs of Flight Control Systems (FCS, the system that controls the aircraft trajectory) in both airplanes and helicopters has been a crucial step offering a variety of benefits such as easing the pilot mission and reducing the mechanical complexity of the aircraft. Yet, all these advantages have limited improvement unless the required safety level is met. In fact, for such systems, a very high safety level is imposed by both the safety-critical property of the system and certification standards (e.g., ARP4754A and ARP4761 standard). Now, industrials such as Airbus Helicopters aim at installing fully digital FBW architectures on future helicopters. This step raises new challenges particularly to comply with certification standards requirements. We present, in this paper, the architecture of future fully digital Airbus Helicopters FCS considered at the end of feasibility study. We focus particularly on the communication integrity issue of future digital architectures. In such systems, the non-detection of corrupted messages could lead to catastrophic consequences. To enhance communication integrity, we propose an end-to-end communication integrity approach based on the black channel concept, it is to be implemented in the application layer. This approach uses error detection codes. Given the constraints of targeted systems namely " embedded " and " safety-critical " features, the selection strategy of error detection codes consists in a trade-off between the computational cost and the error detection capability.