1. Study Continuous Climb Operations
B WP85
Study Continuous Climb Operations
Presented by:
Bill Holtzman (USA)
Member of TOC

2. Why Continuous Climb?

3. Current Operations

4. Continuous Climb

5. Sample RNAV SID

6. Vertical Profile

7. How does it affect ATC? Complexity is Bad! Complexity is Good!
Goodbye K-I-S-S
Monitoring compliance is difficult
Intervention difficult
Situational awareness can suffer
Complexity is Good!
Multiple restrictions in one clearance
Reduced transmissions
Potential de-confliction of airspace
Less chances for readback errors

8. MITRE Study, 2008

9. MITRE Conclusion
For 35 US Airports, savings of 380 million USD in fuel:
90% from savings during arrival
10% during departure
Reduction of 850,000 metric tons CO2
Reduction of 216 metric tons SOX

10. Dallas Study, 2010 3800 departures studied over 9 days:
20% leveled off at 10,000 ft
Average level-off lasted 1.7 minutes
Average fuel savings for all departure aircraft with continuous descent was 7 gallons out of 450
For continuous descent, savings was 50 gallons out of 300

11. IFATCA CDO Policy (1) IFATCA defines Continuous Descent Operations as:
Continuous Descent Operations (CDO) are aircraft operating techniques facilitated by appropriate airspace and procedure design which meet all ATM requirements, allowing the execution of an optimized descent profile.

12. IFATCA CDO Policy (2)
IFATCA supports the development and implementation of Continuous Descent Operations provided that:
Controllers are involved in the design.
Airspace is suited to the design.
The design meets the desired ATM capacity.
Tactical ATC interventions are allowed.
Flight predictability is increased for both pilots and controllers.
Controller workload is not increased beyond an acceptable level.

13. IFATCA CDO Policy (3) Doc 9931 should be amended as follows:
Incorporate CDA design practices learned by the pioneers of continuous descent, including the 90% rule, the use of extensive simulation and the need for automated wind data and advanced sequencing tools.
More precisely refer to those procedures it aims to regulate as either Continuous Descent Arrivals (CDAs) or Optimized Profile Descents (OPDs).

14. De-confliction of Airspace
Build routes whose vertical profiles remain clear of each other
Aircraft are “route separated” or “sterile” – conflictions impossible!
Wasteful and inefficient
Daily demands change
Much airspace unused
Degrades benefits of continuous ops
De-confliction useful as starting point.

15. Procedure Design Need to balance:
Aircraft need for altitude range to adjust trajectory
Controller need to limit altitude range to make room for other aircraft
Daily traffic cycle, seasonal changes and varying trends over time
Competition between routes for larger vertical envelopes

16. Dual departure operations

17. ICAO Manual Need to balance:
Aircraft need for altitude range to adjust trajectory
Controller need to limit altitude range to make room for other aircraft
Daily traffic cycle, seasonal changes and varying trends over time

18. Conclusions
Continuous climb departures are considered by the industry as an important element of future ATM.
Continuous climb operations do not represent the same potential benefits as continuous descent because departure procedures are generally fairly efficient.
For the same route, continuous climb can provide the following benefits in comparison to step climbs:
Reduced fuel burn
Shorter flight times
Reduced emissions
Reduced noise
Reduced number of ATC clearances

19. Conclusions
Generally, there will be a tradeoff between optimizing continuous climb operations and optimizing continuous descent operations. However, in some cases continuous climb operations can enable the implementation of continuous descent operations.
Continuous climb operations can provide controllers with an important advantage. They can be used to issue complex, multi-restriction clearances easily and quickly.
There are potential problems with the use of continuous climb:
Complexity of procedures generally increases risk.
Compliance with the vertical profile of a CCO is more difficult to monitor.
Distinguishing which aircraft have been cleared to fly the vertical profile or not could be difficult.

20. Conclusions
Effective design of continuous climb procedures provides some level of de-confliction with other traffic flows.
The “90% Rule” recommended for use in design of continuous descent procedures is not appropriate for continuous climb because of the wide range of climb performance.
IFATCA policy on continuous descent operations is also relevant on continuous climb operations.

21. Questions?

22. Recommendations 4.1 - IFATCA Policy is:
IFATCA defines Continuous Climb Operations as:
Continuous Climb Operations (CCO) are aircraft operating techniques facilitated by appropriate airspace and procedure design which meet all ATM requirements, allowing the execution of an optimized climb profile.
and is included in the IFATCA Technical and Professional Manual.

23. Recommendations 4.2 - IFATCA Policy is:
IFATCA supports the development and implementation of Continuous Descent Operations and Continuous Climb Operations provided that:
Controllers are involved in the design.
Airspace is suited to the design.
The design meets the desired ATM capacity.
Tactical interventions are always possible.
Flight predictability is increased for both pilots and controllers.
Controller workload is not increased beyond an acceptable level.
It increases the overall performance of the ATM system without reducing safety.
and is included in the IFATCA Technical and Professional Manual.

24. NATCA Comments on Draft ICAO CCO Manual
CCO designs should not require intervention under routine conditions.
Mixed mode operations - undesirable.
Procedures should encourage users to invest in advanced avionics.
Dual departure route concept has potential but is unproven.
CCO Manual should not encourage use of shortcuts.