ENV01 — Continuous Descent Operations (CDO)

Continuous Descent Operations (CDO)(1) is an aircraft operating technique enabled by airspace design, procedure design and facilitated by ATC in which an arriving aircraft descends continuously, to the greatest extent possible, using minimum engine thrust and low drag.
CDO does not adversely affect safety and capacity and will produce environmental and cost benefits including reductions to fuel burn, gaseous emissions and noise impact. (2)

(1) Since the publication of ICAO Doc 9931, the term Continuous Descent Operations (CDO) has generally replaced the term CDA (Continuous Descent Approach).

(2) In principle, it is not required to implement CDO on a 24/7 basis, but is preferable, wherever possible. Depending on National legislation and/or National court decisions and/or local constraints at airports, a limited introduction, for example during night time, is considered equally valid.

FOR MILITARY AUTHORITIES: It is the responsibility of each Military Authority to review this ESSIP Objective IN ITS ENTIRETY and address each of the SloAs that the Military Authority considers RELEVANT for itself. This has to be done on top and above of the review of "MIL" SloAs which identify actions EXCLUSIVE to MIL Authorities.

Air Navigation Service Provider / Airport Operator / Airspace Users


Related Elements

Applicability Area(s) and Timescales

Applicability Area:
See list of Airports in ESSIP Plan - Annex D
Timescales From By Applicable to
Initial operational capability 01-07-2007 Applicability Area
Full operational capability 31-12-2013 Applicability Area

Links to SESAR Solutions

Links to PCP ATM Sub-Functionalities


Applicable legislation
Regulation (EU) 598/2014 of 16 April 2014 on the establishment of rules and procedures with regard to the introduction of noise-related operating restrictions at Union airports within a Balanced Approach and repealing Directive 2002/30/EC (as from 16/06/2016).
EC Directive 2002/30/EC, dated 20.03.2002 on the establishment of rules and procedures with regard to the introduction of noise-related operating restrictions at Community airports.
EC Directive 2002/49/EC, dated 25.06.2002 relating to the assessment and management of environmental noise.
EC Directive 2008/50/EC, dated 21.05.2008 on ambient air quality and cleaner air for Europe.
Applicable ICAO Annexes and other references
ICAO Annex 16 - Volume I - Aircraft Noise
Deployment Programme 2016
Operating Environments

Expected Performance Benefits

Operational efficiency
Cost efficiency
CDO is a low cost measure with no equipment upgrade needed.
Reduction of fuel, noise and atmospheric emissions due to lower drag and thrust facilitated by this initiative. Indications are a reduction of around 40% fuel for the segments for flights affected, and 5-6 dB for noise.
  Code Title From By Related Enablers
ASP01 Coordinate activities and implement rules and procedures for the application of CDO techniques whenever practicable in Approach Control Service in close co-operation with aircraft operators
  • 01-07-2007
  • 31-12-2013
ASP02 Train controllers in the application of CDO techniques whenever practicable
  • 01-07-2007
  • 31-12-2013
APO01 Support CDO measures, implement monitoring of performance and feedback to ANSP and users where equipment is available. Provide the main link with the local community
  • 01-07-2007
  • 31-12-2013
USE01 Include CDO techniques in the aircrew training manual and support its implementation wherever possible
  • 01-07-2007
  • 31-12-2013
Code Dates
1999 99
2000 00
2001 01
2002 02
2003 03
2004 04
2005 05
2006 06
2007 07
2008 08
2009 09
2010 10
2011 11
2012 12
2013 13
2014 14
2015 15
2016 16
2017 17
2018 18
2019 19
2020 20
2021 21
2022 22
2023 23
2024 24
2025 25

Supporting Material

Title Related SLoAs

EUROCONTROL - European Joint Industry CDA Action Plan


APO01, ASP01, ASP02, USE01

EUROCONTROL - IANS-ENV-INTRO - IANS-ENV-INTRO-Introduction to Environment -e-learning training course 12/2012


ASP02, USE01

ICAO - Doc 9931 - Continuous Descent Operations (CDO) Manual - Edition 1 / 12/2010


APO01, ASP01, ASP02, USE01

Consultation & Approval

Working Arrangement in charge
Airport Operations Team (AOT)
Outline description approved in
Latest objective review at expert level
Commitment Decision Body
Provisional Council (PC)
Objective approved/endorsed in
Latest change to objective approved/endorsed in