What do those letters mean?

Air Traffic Control

Community Aviation Consultation Group

Community Engagement Plan

A roadmap detailing how we will consult local communities regarding proposed changes to local flight paths or airspace

Community Engagement Report

A summary of public consultation activities, community feedback, and recommendations regarding proposed changes to local airspace or flight paths

Community Engagement Standard

Decibel

A measurement of absolute or relative raw physical sound energy

A-weighted decibels

A measurement of sound pressure level that reflects how the human ear perceives loudness, adjusting for the ear’s sensitivity to different sound frequencies. 

Environmental Impact Assessment

Instrument Landing System

An approach that can be conducted by all aircraft and is effectively an extension of the runway centreline, enabling the aircraft to fly a straight-in approach. 

An ILS approach guides aircraft to the runway by two ground-based radio signals, one providing horizontal guidance and the other providing vertical navigational guidance. 

These two radio signals are called: 

• Localiser (LOC) which is used for horizontal guidance 
• Glideslope (GS) which is used for vertical guidance.

When an aircraft intersects the LOC beam, it commences a straight-in approach towards the runway. When it intersects with the GS beam, the aircraft can safely descend. 

ILS approaches are often used in poor weather or low visibility conditions.

Noise Complaints and Information Service

Required Navigation Performance

This is a type of approach which uses a satellite-based system that allows aircraft to navigate along a precise path with on-board performance monitoring. It offers both lateral and vertical guidance, similar to ILS, but uses GPS and other on-board systems. 

This type of approach allows for more precise and efficient flight paths compared to ILS.

Required Navigation Performance – Authorisation Required

An advanced version of RNP which enables more complex manoeuvres, tighter and curved flight paths, allowing for more direct and efficient routes to the runway. 

Only authorised aircraft flown by suitably qualified pilots may be assigned RNP-AR approaches by ATC. 

Aircraft types typically authorised to use RNP-AR approaches include newer generation and generally more advanced aircraft such as the Boeing 737, Airbus A320, Airbus A380 and Boeing 787. However, aircraft operators may choose to retrofit this technology to other aircraft types. 

RNP-AR approaches can benefit the environment by reducing aircraft noise, emissions and fuel usage, while at the same time helping to maintain reliable all-weather operations.