A continuous descent operation (CDO) (1) is an aircraft operating technique, enabled by airspace design, procedure design and ATC clearances in which arriving aircraft descend without interruption, to the greatest possible extent, by employing minimum thrust in order to optimise the descent profile in terms of fuel burn. The optimum vertical profile takes the form of a continuously descending path.
Operating at optimum flight levels is a key driver to improving fuel efficiency and minimise carbon emissions as a large proportion of fuel burn occurs during the climb phase.
Many major airports now employ PBN procedures which can enable both CDO and continuous climb operations (CCO) and, in a large number of cases, judicious airspace and procedure design has resulted in significant reductions in environmental impacts. This is particularly the case where the airspace design has supported CCO and CDO.
CDO does not adversely affect safety and capacity and will produce environmental and operational benefits including reductions to fuel burn, gaseous emissions and noise impact.
It is important that monitoring and measuring of CDO execution is defined across ECAC using harmonised definitions to avoid misleading interpretations of performance measurement. It is equally important that CDO execution is measured across ECAC, as far as practicable, using a harmonised methodology and parameters. Whilst reporting can be undertaken at the local level according to local legislation and requirements, when CDO execution is reported on an international basis, this measurement should always be based upon a harmonised method, parameters and metric. The proposed methodology (4) identified by the European TF on CCO/CDO is detailed at http://www.eurocontrol.int/articles/continuous-climb-and-descent-operations.
Notes:
(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 it should be facilitated to the extent possible, according to local conditions.
(3) The methodology is detailed in the European CCO / CDO Action Plan, see https://www.eurocontrol.int/publication/european-cco-cdo-action-plan.
NOTE FOR MILITARY AUTHORITIES: It is the responsibility of each military authority to review this 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 military authorities.
Code | Title | IOC | FOC | Related Elements |
---|---|---|---|---|
AOM-0701 | Continuous Descent Approach (CDA) | — | — | |
AOM-0702-A | Continuous Descent Operations (CDO) | 01-07-2017 | 01-07-2021 |
Code | Title | Program | Related Elements | Analysis |
---|---|---|---|---|
#11 | Continuous Descent Operations (CDO) | SESAR1 | Analysis |
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
|
||
|
||
ENV01 | 20070701_20231231 | |
ASP01 |
88%
|
20070701_20231231 |
ASP02 |
61%
|
20180101_20231231 |
ASP03 |
86%
|
20070701_20231231 |
ASP04 |
65%
|
20180323_20231231 |
APO01 |
73%
|
20180101_20231231 |
USE01 | 20070701_20231231 |
Title | Related SLoAs |
---|---|
EUROCONTROL - CCO / CDO Performance dashboard |
APO01, ASP01, ASP03, ASP04, USE01 |
EUROCONTROL - CCO, CDO harmonised definitions, metrics and parameters |
APO01, ASP04, USE01 |
EUROCONTROL - CDO refresher course for ATCs |
APO01, ASP03, ASP04, USE01 |
EUROCONTROL - EUROCONTROL CDO/CCO Supporting Material https://www.eurocontrol.int/concept/continuous-climb-and-descent-operations |
APO01, ASP01, ASP02, ASP03, ASP04, USE01 |
EUROCONTROL - European CCO/CDO Action Plan https://www.eurocontrol.int/publication/european-continuous-climb-and-descent-operations-action-plan |
APO01, ASP01, ASP02, ASP03, ASP04, USE01 |
EUROCONTROL - IANS-ENV-INTRO - Introduction to Environment -e-learning training course 12/2012 |
ASP03, USE01 |
ICAO - Doc 4444 - Air Traffic Management - Edition 16 / 11/2016 |
ASP01, ASP02 |
ICAO - Doc 9426 - Air Traffic Services Planning Manual - Edition 1 / 12/1992 |
ASP01, ASP02 |
ICAO - Doc 9613 - Performance-based Navigation (PBN) Manual - Edition 4 / 03/2013 https://store.icao.int/en/performance-based-navigation-pbn-manual-doc-9613 |
ASP01, ASP02 |
ICAO - Doc 9931 - Continuous Descent Operations (CDO) Manual - Edition 1 / 12/2010 https://cfapp.icao.int/tools/ATMiKIT/story_content/external_files/102600063919931_en.pdf |
ASP01, ASP02, ASP03, USE01 |