Document

Author
Donough WILSON
Abstract
When flying in instrument meteorological conditions (IMC) – conditions where all visual reference to the earth’s surface and horizon is removed – pilots are taught to construct a 3D mental model of the attitudinal position of the aircraft in 3D space, including their current position along the intended flight path, using information and data which has been extracted from the flight instruments and factored to include any additional operational parameters. Theoretically, it is a straightforward process, and the flight instruments are specifically designed to enable safe, effective control of the aircraft in IMC. Yet, how often following a serious aviation accident do media reports state ‘Weather conditions at the time were reported as poor’? As accident records confirm, 98% of all fatal CFIT and LoC accidents involving commercial aircraft operations occur whilst the crew are flying on instruments in IMC (source: BAAA, 2015). But how can professional pilots lose control of a fully functional aircraft in IMC; or CFIT an aircraft in IMC, whilst flying on the instruments which were specifically designed to enable safe flight in IMC? This paper proposes that there are five distinct, but intrinsically linked issues, which, when events conspire, align to enable a LoC or CFIT trajectory to progress unchallenged, to a fatal outcome.