Workflow Structure of ATC in Non-nominal Conditions - Introduction and Initial Conceptual Approach

This document describes an approach to define and categorize non-nominal situations and possible impacts on air traffic controller tasks based on literature research. Further countermeasures are discussed on how to handle these situations. After describing the definitions and differences between non-nominal conditions and non-nominal situations, the EUROCONTROLs ASSIST processing model for controller in emergencies is introduced along with published procedures for air traffic control. After that the workflow structure between pilots and controllers in these situations is illustrated. A workflow model to handle non-nominal situations is introduced and applied for one use case. To give an example for the workflow model, the use case bird strike into one engine of a two engine aircraft during take-off is described. For this example, some possible assistance functionalities for air traffic controllers and for pilots are listed and shortly discussed.