The IFCMs have three modes of operation; electronic control, mechanical control, and what additional mode?

The additional mode of operation for the Integrated Flight Control Systems (IFCMs) is float. This mode allows for a specific form of control where the system can respond to external inputs and maintain stability without direct mechanical intervention. It is crucial for providing a level of aerodynamic efficiency and control responsiveness during flight, especially in various flight conditions. This mode plays a vital role in ensuring the aircraft can adapt to changes in the operational environment, promoting safety and performance.

The other options do not represent the correct third mode for IFCMs. Pneumatic control is not applicable to the IFCM functions in modern aircraft such as the C-17, and while computer-assisted methods are integral to modern aviation technology, they don’t refer specifically to a mode of operation within the context of IFCMs. Remote control, while relevant in other contexts, does not define a standard operational mode for the integrated flight control systems of the C-17.