Continuous climb and descent operations

Continuous Climb and Descent Operations (CCOs and CDOs) 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, 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.

CCO and CDO operations allow arriving or departing aircraft to descend or climb continuously, to the greatest extent possible. Aircraft applying CCO employ optimum climb engine thrust and climb speeds until reaching their cruising levels. With CDO, aircraft employ minimum engine thrust, ideally from top of descent and in a low drag configuration, prior to the final approach fix. Employment of these techniques reduces intermediate level-offs and results in time being spent at more fuel-efficient higher cruising levels, hence significantly reducing fuel burn and lowering emissions and fuel costs (see ICAO Doc 9993 and ICAO Doc 9931).

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

In 2015, a task force of European ATM stakeholders was created with the objective of agreeing 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 (VFE) performance in order to enable harmonisation at international level.

The task force has developed the CCO / CDO Tool Kit to support CCO / CDO implementation in Europe, consisting of the European CCO / CDO Action Plan, the CCO / CDO performance dashboard and the resources available on this webpage.

Following the TF#10 meeting in November 2020, the European CCO / CDO Task Force completed its mandate. CCO and CDO, together with VFE, are now a permanent agenda item of RNDSG (the Route Network Development Sub Group of NETOPS, the NETwork OPerationS Team).

RNDSG meetings take place 3x per year with a calendar of meetings and full meeting documentations available at OneSky Teams. For membership of RNDSG, please register to OneSky Teams and request to join the RNDSG Team.

At each RNDSG meeting, EUROCONTROL will report on current CCO / CDO performance and activities to work with stakeholders to optimise CCO, CDO and VFE across the network.

For any requests for support on CCO / CDO / VFE or any further information, feel free to contact us via the button at the bottom of the page.

At EUROCONTROL, we support the deployment of CCO/CDO. Our experts, in strong collaboration with stakeholders including air navigation service providers, aircraft manufacturers and aviation industry associations such as IATA, A4E, AIRE, EBAA, ERA, ACI and CANSO, measure and maximise the benefits achievable in the current ATM framework.

We look to support the aviation industry by making our wealth of knowledge and expertise available to the aviation industry in the form of our action plan, guides and list of reputable additional sources of information provided by stakeholders.

We also supports the creation of a more advanced CCO and CDO concept that will result from deploying future ATM tools and procedures. 

We worked closely with our partners throughout the aviation industry to create a new action plan describing how potential constraints influence the ability to fly CCO / CDO together with key information on the mitigation proposals addressing these constraints in order to optimise the vertical flight efficiency of the climb and descent phases of flight.

The CCO/CDO performance dashboard measures:

• Noise - for that part of the climb / descent profile where, according to SESAR, noise is considered the primary environmental impact;
• Fuel - to measure the fuel burn / CO₂ performance of the whole climb / descent profile, to Top of Climb (ToC) and from Top of Descent (ToD).

We have gathered guidance material and supporting documentation to help our stakeholders' efforts to implement CCO/CDO and improve their operational efficiency. Below you will find a collection of documentation from across the industry. Some documents provided by our partners may require a subscription to access.

Our EUROCONTROL Aviation Learning Centre provides a variety of CCO/CDO-related training courses and opportunities for career improvements. These include two related trainings:

• an ATCO refresher training on CCO / CDO, which includes inputs from the Flight Crew side on what considerations have to be made within the aircraft to optimise the climb / descent profile; and,
• a Flight Crew CBT on CCO / CDO, which includes inputs from the ATCO side on what factors must be taken into consideration to provide a safe and optimised descent profile to all arrivals.

Explore our latest courses on our Learning Zone - we have something for everyone.

At EUROCONTROL, we know that there is no one-size-fits-all solution. Thus, we take our implementation support one step further by providing our stakeholders with a direct line to our experts. If you have any questions, or need on-site support for your project, just reach out - we are here to help you optimise your efficiency.