Component-Based Development of Aeronautical Software

Introduction

Modern Air Transportation demands a great amount of software, with a wide variety of purposes, from airline ticket reservation to aircraft engine control. Higher levels of system integration on transport aircraft systems and equipment have created new safety and certification challenges, making the aviation industry and the regulatory authorities elaborate technical guidance, gathering their mutual objectives and responsibilities in the system safety area. A great part of the software systems in aviation is considered safety-critical, as is the case of many aircraft control systems, in which failures can lead to catastrophic events, as happened to the Airbus A320 in Habsheim, France, 1988, just to mention a classical example. This accident was attributed to a software design error related to the complexity introduced by the once innovative computerized flight control. The failure showed the crew that the plane was flying at 100 ft above ground. When the captain increased throttle to level off at 100 ft, the engines and the completely computerized throttle control did not respond. The gear was only 30 ft above ground when the aircraft was passing over the runway (Walters, 2000), and a few seconds later the aircraft crashed into the bush. Due to the high social impact related to flight safety, there is a paramount need of requiring strict verification processes and tests on critical aeronautical software, defined and supervised by governmental authorities.