Air International 1984-02
M.Hirst - Safety in Numbers /Avionics analysed/ (6)
The General Dynamics F-16 is a highly-manoeuvrable fighter, the key to its high performance being a quadruplex analogue fully-FBW flight control system.
This specially modified Sepecat Jaguar has a fully fly-by-wire flight control system, and has no mechanical back-up.
A hybrid (digital/analogue) flight control system is used in the Dassault-Breguet Mirage 2000. Control activities are handled by analogue components, while digital functions provide precise control computation.
Modern strike aircraft often have a high-integrity flight control system that allows the aircraft to be flown automatically at low level. The Panavia Tornado has an automatic terrain-following system linked to a radar mounted in the nose.
There are prominent attitude-displays at both the pilot and co-pilot positions on this Boeing 747 and a smaller attitude indicator is incorporated alongside the engine instruments. This is part ofa triplex system configuration where the crew is left to conduct a "majority vote" of displayed information to assure attitude-information integrity.
One of the earliest applications of a high-integrity flight control system was in the Trident airliner, which used a system developed by Smiths Industries to make automatic landings in thick fog.
The Airbus A310 has a flap-slat control system developed by Marconi Avionics which uses dissimilarly-redundant channels to ensure that a single component failure cannot cause an asymmetric deflection of the control surfaces.
Airliner automatic flight-control systems began to use digital electronics in earnest when the McDonnell Douglas MD-80 entered service with a Sperry-developed flight-guidance system.