In short, an instrument flight procedure is the description of a series of predetermined flight manoeuvres by reference to flight instruments, published by electronic and/or printed means (Eurocontrol, 2016).

It is a published procedure used by aircraft flying in accordance with the instrument flight rules which is designed to achieve and maintain an acceptable level of safety in operations and includes one or more of the following: an instrument approach procedure, a standard instrument departure (SID), a planned departure route and a standard instrument arrival (STAR) (IAA, 2020).

Instrument approach procedures provides the horizontal and sometimes vertical path(s), depending on the procedure, to the Decision Altitude/Height (DA/DH) or Minimum Descent Altitude/Height (MDA/MDH). If visual contact has not been acquired at that point, a Missed Approach Procedure (MAP) is initiated. These approaches are of two main types: 2D and 3D approaches. 2D approaches only provide lateral guidance, leaving the pilot with the decision regarding a suitable Rate of Descent (ROD) to achieve a Continuous Descent Final Approach (CDFA). 3D approaches provide both lateral and vertical guidance so the pilots can compare their flight path to a Course Deviation Indicator (CDI) and a Glide Path (GP) indicator (OSM Aviation Academy, 2020).