Continuous descent approach

Comparison of CDA and non-CDA-profile - In order to facilitate and harmonise implementation of CDA, an International Civil Aviation Organisation (ICAO) CDA implementation Manual is under development. As an intermediate step, for Europe, CDA guidance material has been published by EUROCONTROL: CDA Implementation Guidance Information

Continuous Descent Approach (CDA) is an aircraft operating technique where arriving aircraft descend from an optimal position with minimal thrust and avoid level flight, as much as possible, while complying with safe operations, published procedures, and air traffic control (ATC) instructions. The primary goal of CDA is to reduce noise, fuel consumption, and emissions by maintaining a continuous descent, intercepting the approach glidepath at an appropriate altitude for the distance to touchdown.

Key aspects of CDA

• Continuous Descent: Aircraft descend smoothly without leveling off, minimizing engine thrust.
• Reduced Noise: By maintaining higher altitudes for longer and operating at lower thrust, CDA reduces noise pollution.
• Fuel Efficiency: Continuous descent with minimal thrust results in reduced fuel consumption.
• Environmental Benefits: Lower fuel consumption translates to reduced emissions, contributing to a more sustainable aviation industry.
• Stabilized Approach: CDA can help pilots achieve a more stabilized approach profile on final approach.
• Non-Precision Approaches: CDA is particularly relevant to non-precision approaches (NPAs) where the aircraft maintains a constant rate of descent until the missed approach point or visual contact with the runway.

CDA vs. Conventional Approaches

In a conventional approach, aircraft often descend in a step-wise fashion with level flight segments in between. This results in more frequent changes in engine thrust and altitude, increasing noise and fuel consumption compared to a continuous descent.

In essence, CDA is a more efficient and environmentally friendly way of approaching an airport, reducing noise, fuel burn, and emissions while also contributing to a more stabilized approach for pilots, particularly in non-precision approach scenarios.