Air Transport World

Airbus A320 cockpit: an electric experience.

Airbus A320 cockpit: an electric experience Toulouse--Airbus Industrie calls the cockpit of the A320 a "second generation" advanced cockpit. As far as the instrumentation is concerned, this is a correct label, the panel flowing directly from the solid foundation laid in the first Airbus glass cockpit shared by the A310 and A300-600.

But the flight control system, taken as a whole, is not based on any commercial product. It is based on years of extensive research and military use of similar systems, and parts of it have a commercial background. But the complete system, from its innovative side stick controller to its fly-by-wire technology to its electronic engine control, is a pioneering step for commercial transport aircraft. Airbus calls its electrical flight control system (EFCS) a "new concept of aircraft control," a statement that appears to be a fair appraisal. And while it may appear to a big leap in technology, the kind of leap that often is equated with risk, senior pilots tell ATW that Airbus has advanced cautiously.

The symbol of the EFCS revolution is, of course, the famous side stick controller, called "mini-stick" by Airbus, taking the place of the traditional control yoke. The yoke became expendable when it was decided to do away with a "mechanical" reversion mode in the majority of the aircraft's flight controls--the rudder and elevator trim retain mechanical links, but these controls are operated by the rudder pedals and trim control wheel respectively. The yoke has been needed in the past to provide the leverage, or mechanical advantage, necessary to move the elevator and aileron control surfaces in the event power assists failed.

FBW advantages

The A320 will be the first commercial transport to have digital fly-by-wire (FBW) on all roll and elevator controls without mechanical reversion capability. Concorde has been flying for years with analogue FBW, but with a mechanical backup, and the A310/A300-600 uses digital FBW for slats, flaps and upper wing surface devices. Of course, military aircraft such as the General Dynamics F-16 use FBW only.

The A320 side stick and autopilot inputs are processed by redundant, dissimilar computers loaded with dissimilar software. The computers activate the controls through hydraulic actuators. While the A320 hydraulic system is less extensive than a contemporary aircraft's, it is not shrunk to the tiny electro-hydrostatic actuators that Boeing is considering for its 7J7. …

Log in to your account to read this article – and millions more.