Effected CPoA

The closest point of approach between two aircraft subject to a Compromised Separation event following intervention from ATC.

Emulated Recognitions

Emulated Recognitions are speech recognition events where the speech engine makes a guess at the correct phrase within probability bounds. The use of this function can lead to computer lockups.

Flight Level

The term used to describe aircraft altitudes above the Transition Layer. When operating on flight levels, the pressure setting used in the altimeter is set to a standard value, normally 1013.2 hectopascals.

Funnel

A training graphic aid used in Visual Vectoring training material to display graphically on the radar map the requirements that must be met when vectoring an aircraft for an ILS Approach.

Groundspeed

The speed at which an aircraft is actually moving over the earth’s surface. A vector addition of True Airspeed and the wind component at its current altitude results in the velocity of the aircraft. The velocity is a vector quantity, the norm (magnitude) of which is groundspeed and the direction of which is known as the aircraft's track.

Heading

The alignment of the front-to-rear axis of the aircraft, or, in other words, the direction the aircraft is ‘pointing’. It is usually measured and described in Degrees Magnetic. A Heading instruction from a Controller requires the pilot to steer the aircraft along the nominated heading.

History Dots

A visual display on the radar screen of an aircraft’s position at preceding radar sweeps. They appear as a trail behind the current position, and give important visual indications of the speed and direction of the aircraft’s movement.

HMI

Human Machine Interface: the interface with which the Radar/Surveillance System (or simulator) provides information to the controller, and with which the controller provides inputs to it.