Flight Test Preparations of the Ground Collition Avoidence System (GCAS) on the Saab Gripen Fighter

Björn Rubensson, Flight Test Engineer, Saab, Linköping, Sweden

Abstract

An automatic Ground Collision Avoidance System (GCAS) is being integrated on the Saab Gripen Fighter. Now, the final stage of testing, the flight test, awaits.
The GCAS has been designed to warn the pilot if there is an imminent risk for ground collision. Such situations can for example arise due to g-induced loss of consciousness or target fascination. If the pilot fails to take the appropriate actions to avoid a ground collision, the system will do so automatically.

The question is: how do we safely test a system designed to only intervene at the very last moment before ground impact? Which preparations will be required and how do we identify and handle identified risks? Maybe even more importantly. how do we prepare for the non-identified risks. i.e. the unexpected?

Since parts of the GCAS have been operational for years, the last part of the implementation in the Flight Control System (FCS) was considered to be a quite standard FCS update. However, more time and effort than anticipated were required. Nevertheless, the integration of GC’AS on the Saab Gripen Fighter is now coming up to the final stage of testing. the flight test.

This paper will briefly describe the GCAS and the design goal. The focus will however be on describing the preparations made for the flight test of the GCAS. Furthermore, key elements to the preparations and risk identification, both expected and unexpected. will be highlighted. The nature of these elements will be the small everyday thing that easily can be applied to most flight test preparations. Unfortunately, these elements can also just as easily be overlooked.