Continuous Climb and Descent Operations

Continuous Climb and Descent Operations (CCO and CDO) are aircraft operating techniques enabled by airspace design, instrument procedure design and facilitated by Air Traffic Control (ATC).

CCO and CDO allow aircraft to follow a flexible and optimum flight path that delivers major environmental and economic benefits - reduced fuel burn, gaseous emissions, noise and fuel costs - without any adverse effect on safety (see ICAO Doc 9993 and ICAO Doc 9931).

CCO and CDO operations allow arriving or departing aircraft to descend or climb continuously, to the greatest extent possible. Aircraft applying CCO use optimum climb engine thrust and climb speeds until they reach their cruising levels. With CDO, aircraft use minimum engine thrust, ideally in a low drag configuration, prior to the final approach fix. These techniques result in more time being spent at more fuel efficient higher cruising levels, hence significantly reducing fuel burn and lowering emissions and fuel costs.


Deployment of optimised CCO and CDO throughout Europe will benefit all European ATM system stakeholders and will help the network to address the environmental challenges it faces.

A single CCO or CDO compared to a non-optimised climb or descent profile can result in fuel savings of 50 - 200 kilograms of fuel per flight. ICAO estimated that savings from the planned implementation of CCO and CDO in Europe could save as much as 500 kilotons of fuel per year. Using CDO can reduce noise by 1-5dB compared to a non-CDO operation. (Source: European Joint Industry CDA Action Plan).

Implementation Support

EUROCONTROL supports CCO and CDO deployment. A dedicated team works with stakeholders (ANSPs, aircraft manufacturers and aviation industry associations such as IATA, ERA, ACI and CANSO) to measure and maximise the achievable benefits in the current ATM framework. The team also supports the facilitation of a more advanced CCO and CDO concept that will result from deploying future ATM tools and procedures. A guide to implementing Continuous Descent is available.

Download guide

Are you ready to save fuel and reduce both emissions and noise? We will help you to implement CCO and CDO.

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The European CCO and CDO Task Force

Historically in Europe, the implementation of CCO and CDO operations has been encouraged on an ‘as much as you can’ basis. Until recently, there was no harmonised definition of CCO and CDO operations, or of their potential network-wide benefits.

In 2015, a task force European ATM stakeholders was created with the objective to agree on harmonised definitions, metrics and parameters to measure CCO and CDO operations in Europe.

The resulting harmonised definitions, metrics and parameters agreed by the Task Force are recommended to be used by any European ATM stakeholder for the measurement of CCO, CDO or vertical flight efficiency performance in order to enable harmonisation at the international level.

Watch the video below to learn more.

In 2017, EUROCONTROL will be conducting a European-wide CCO and CDO analysis based on the outcomes of the Task Force in order to identify the real benefits of vertical flight efficiency in Europe in terms of fuel savings, emissions reduction and fuel costs.

Continuous Climb and Descent Operations (CCO/CDO)

Support Team

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