B.5.9 WP95 Review Continuous Descent Operations Manual Presented by: Bill Holtzman (USA) Roosevelt Pena (Dom Rep) on behalf of TOC B.5.9 CDO WP95 FAA Administrator Note: This video from February 8, 2011 was shown at the Amman Conference but is not available for distribution. B.5.9 CDO WP95 Current Operations B.5.9 CDO WP95 Continuous Descent B.5.9 CDO WP95 IATA B.5.9 CDO WP95 Doc 9931 B.5.9 CDO WP95 Doc 9931 Definition Continuous Descent Operations (CDO) is an aircraft operating technique aided by appropriate airspace and procedure design and appropriate air traffic control (ATC) clearances enabling the execution of a flight profile optimized to the operating capability of the aircraft, with low engine thrust settings and, where possible, a low drag configuration, thereby reducing fuel burn and emissions during descent. B.5.9 CDO WP95 Terminology • “Continuous Descent Operations” (CDO) is a class of procedures. • “Continuous Descent Approach” (CDA) is a procedure. • “Optimized Profile Descent” (OPD) is a procedure. This term is used in the USA. B.5.9 CDO WP95 CDAs in the UK B.5.9 CDO WP95 Los Angeles Intl (LAX) • First published OPD in the US, the River One STAR - 2007 • Average savings - 25 gallons a flight for 300-400 daily • Fifth busiest US airport with 545,000 operations in 2009 • 40+% of LAX approaches now OPDs B.5.9 CDO WP95 RIIVR2 B.5.9 CDO WP95 RIIVR2 Profile B.5.9 CDO WP95 RIIVR2 to ILS B.5.9 CDO WP95 The LA Way 1. 2. 3. 4. Use active controllers Obtain data on typical trajectories Apply the “90%” rule Build an initial CDA B.5.9 CDO WP95 The LA Way 5. 6. 7. 8. 9. Break trajectory into segments Use a trajectory simulation tool Redesign the associated sectors Perform simulation testing Begin implementation B.5.9 CDO WP95 US Lessons Learned Critical elements • Precisely spaced arrival flow • Automated wind information • “90% rule” • Design to hit merge points • Lots of simulation Not necessary • Dynamic resectorization B.5.9 CDO WP95 Doc 9931 - Predictability Manual identifies two goals: • Continuous descent • Increased flight predictability To the controller, predictability is: • Restricted trajectory - single 3D path • “Low tolerance” CDA To the pilot: • Unrestricted trajectory • “High tolerance” CDA B.5.9 CDO WP95 Trajectories B.5.9 CDO WP95 90% Envelope B.5.9 CDO WP95 Open Path 126.96.36.199.2 - The open path design is a design where a portion, or all, of the route consists of vectoring. The specific distance to runway threshold is not known prior to start of the CDA. Two procedures: • Vectored CDA • Open CDA to Downwind B.5.9 CDO WP95 Open CDA to Downwind B.5.9 CDO WP95 Closed Path 188.8.131.52.1.1 - The closed path design is a design where the route is fixed and the specific distance to the runway is known prior to start of the continuous descent operation. The procedure may be published with crossing levels, level windows and/or speed constraints. The design of the closed path may comprise the STAR and (initial) approach phases of flight until the FAF/FAP final approach point (FAP). B.5.9 CDO WP95 Path Stretching B.5.9 CDO WP95 Merge Points B.5.9 CDO WP95 Tailored Arrivals (TA) • On demand, individually constructed route and profile clearance • Transmitted via data link from Ocean21 system to FANS-1/A aircraft • 6 years of testing in Australia, Netherlands and US • Operational in San Francisco, Los Angeles, Miami this year • Fuel savings – 75-400 gallons per arrival (280-1500 L) B.5.9 CDO Conclusions 1. The CDO Manual incorrectly uses the term “CDO” to refer to a procedure. 2. The ICAO definition of CDO only considers the perspective of a single aircraft. 3. Flight predictability should be increased for both the aircraft and the ATM system. 4. Best practices for CDA design should be derived from successful implementations. 5. Open Path CDAs are a compromise between predictability and controller flexibility. 6. Restricting the controller’s ability to intervene reduces ATM capacity. B.5.9 CDO Conclusions 7. In CDA design, there is a trade-off between capacity and the aircraft’s optimal flight path. • “Low tolerance” CDA Higher predictability for controller Higher capacity for non-arrival traffic Inhibits ideal engine-idle trajectories • “High tolerance” CDA Lower predictability for controller Lower capacity for non-arrival traffic Pilots fly ideal descent trajectories B.5.9 CDO WP95 Debate B.5.9 CDO WP95 Recommendations 4.1 - IFATCA Policy is: 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. and is included in the IFATCA Technical and Professional Manual. B.5.9 CDO WP95 Recommendations 4.2 – IFATCA Policy is: 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. • • • • • and is included in the IFATCA Technical and Professional Manual. B.5.9 CDO WP95 Recommendations 4.3 - IFATCA Policy is: 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). and is included in the IFATCA Technical and Professional Manual.