This glossary is written for virtual airline and flight simulation use within Virtual Air Canada Airline. It is not intended as a real-world aviation reference.
CDA
Continuous Descent Approach
A Continuous Descent Approach (CDA), also known as Continuous Descent Final Approach (CDFA) in ICAO terminology, is an approach technique in which the aircraft descends continuously from the top of descent in the terminal area to the runway threshold, avoiding level flight segments at intermediate altitudes. Traditional step-down approaches involve periods of level flight at intermediate fixes while speed is reduced and configuration is adjusted, which requires intermittent use of thrust and drag devices and creates additional noise and fuel burn. In a CDA, the aircraft maintains a smooth, unbroken descent profile - typically at idle or near-idle thrust - which significantly reduces noise exposure for communities beneath the approach path and improves fuel efficiency.
CDA is actively promoted by ICAO, Eurocontrol, and national authorities as part of noise abatement procedure design. It is closely related to the concept of Required Navigation Performance (RNP) approaches, which use precise lateral and vertical guidance to define continuous curved or straight descent paths into airports. ATC sequencing plays a key role in enabling CDAs at busy airports - controllers must provide appropriate spacing to allow aircraft to remain at cruise altitude longer before beginning their descent, rather than issuing early step-downs for traffic separation. During peak traffic periods, CDAs may not always be possible at high-density airports.