See Indicated Airspeed


The International Civil Aviation Organisation; the body that regulates civil aviation throughout the world. Among its many functions, it defines standards by which Air Traffic Control services are provided.


See Instrument Landing System.

ILS Approach

An approach carried out by a pilot to land on a runway under the guidance of the Instrument Landing System.

ILS Intercept

The process of joining the radio signals provided by the ILS to carry out an ILS Approach. Controllers are required to vector aircraft for such intercepts on a routine basis.

Indicated Airspeed

An aircraft’s speed through the air, as measured as air pressure in a metal tube (pitot tube), the open end of which is exposed to the airflow. IAS is corrected for reducing air density as altitude increases to obtain the aircraft’s True Airspeed (TAS). Speed Control instructions are given in IAS.

Information Phrase

A part of a radio transmission to a pilot that is included only to keep him/her aware of the controller’s intentions during radar vectoring. It requires no control action of the pilot, and therefore of the simulator.

Instrument Landing System

The most common electronic landing aid in use today. It consists of individual components that provide a pilot with high-precision vertical and lateral guidance to a runway.

Wikipedia Entry