Final answer:
The control linkage in modern airplanes such as the Boeing 777 is part of a fly-by-wire system that uses electrical signals to control the aircraft's control surfaces, relying on sophisticated computer technology instead of mechanical cables.
Step-by-step explanation:
The part of a control linkage for an airplane is a component of its fly-by-wire system, which is an aircraft control system where the setting of control surfaces like the rudder and ailerons is governed by electrical signals rather than mechanical linkages. This technology represents a significant advancement in aircraft design. In systems like the one used in the Boeing 777, the pilots' control inputs are fed into a computer system that translates them into electrical signals, which are then sent to control surface actuators.
Compared to older hydraulic actuator systems connected by cables, a fly-by-wire system is much lighter and can save costs. However, fly-by-wire systems depend on sophisticated and reliable computer technology to ensure accurate control in response to pilot inputs. The development of such systems, like the 777 fly-by-wire system, involves writing and debugging millions of lines of computer code.