Todd Farley

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Time-Based Metering and the Multi-Center
Traffic Management Advisor (McTMA)

• Todd Farley
• todd.c.farley_at_nasa.gov
• [phone]

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Agenda

• McTMA training, part 1
• Time-based metering
• Why the push for metering? Why here? Why now?
• Autopsy of failed metering programs
• Metering then and now
• The transition to time-based metering
• It can be done. Heres how its going at ZLA
• Introduction to McTMA
• McTMA system architecture
• Whats next?
• The game plan and your role in it

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Time-Based Metering

• The M word

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Time-based metering
We tried that already. It didnt work. You
can leave now. - Boston Center controller
This is the best feed of aircraft I have seen
from ZLA ever. - SoCal Tracon controller
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Time-based metering

• Why the push to go to metering?
• Theoretically proven to be more efficient
• Throughput
• Arrival delay
• Airborne holding
• but what about workload?

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TMA Single-Center vs. Multi-Center

• In practice so far, so good
• At every TMA site so far, results from
  operational use have validated the benefits that
  theory suggests
• including workload

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Time-based metering

• Why the push to go to metering here?
• Weve tried the obvious places and its worked
• ZFW, ZMP, ZLA, etc.
• ZLA is the first facility to transition from
  miles-in-trail to time-based metering, and the
  results have been positive(more on that later)
• This is the Northeast Corridor theres more
  demand and tighter constraints here than
  anywhere
• The Northeast is the ultimate test
• Why Philly?
• RTCA recommendation
• Its location makes it interesting from a research
  perspective

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Time-based metering

• timebased metering (tim based met r-ing) n.
  1. A traffic management alternative to
  miles-in-trail spacing to de-peak the arrival
  demand to meet a downstream restriction. 2. A
  sector control technique by which aircraft are
  vectored (speed, heading, and/or altitude) to
  meet a crossing-time restriction at a
  coordination fix.

e
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Time-based metering

• In theory, a more efficient way of spacing
  traffic flows to spread out the demand to meet
  capacity.

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Time-based metering

• In practice, works very well in airspace with
  large, open sectors that have been metering for
  years.
• for example, ZFW ZMP

of course, thats not the case here.
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Arrival airspace comparison

• ZNY characteristics
• Small, complex sectors
• Heavy crossing traffic
• Flights in transition

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Time-based metering

• Heres the basic questionIs there a way to
  implement time-based meteringin complex airspace
  that makes sense in terms of efficiency and
  workload?

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McTMA cadre
Traffic management Jay Conroy, Jack White NATCA
CPC Mike Dowd
Traffic management Mark Evans, Doug
Davis NATCA CPCs Jim Bartel, Bob Weaver
Traffic management Boucher, Kurz,
Rosenberg NATCA CPCs Golder, Kohler, Cummings
Traffic management John Kelley NATCA CPC
Patrick Rodden
NASA Tom Davis, Todd Farley, Ty Hoang, Steve
Landry, Kathy LeeMITRE Kerry Levin, Dennis Rowe
Traffic managementMike Klinker, Barry
Constant NATCA CPC Bob Padgett
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We tried that already. It didnt
work.Metering Then and Now

• This is not your fathers metering system

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Time-based metering predecessors

• En-Route Metering (ERM)
• 1970s-80s R.I.P.

• Arrival Spacing Program (ASP)
• 1980s-today

• Both failed to work in complex airspace

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Time-based metering predecessors

• Shortcomings are well understood, and
  surmountable
• ERM and ASP are Host-resident programs
• Subject to processing limitations of the Host
• Inaccurate trajectory estimates
• No wind data
• Inaccurate trajectory estimates
• Host-resident programs unable to interface with
  other Centers
• Unable to develop a common metering plan across
  Centers
• Adjacent Centers worked with uncoordinated
  arrival metering plans

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Time-based metering with McTMA

• McTMA is a completely different approach
• Not a Host-resident programMcTMA is a brand
  new, independent infrastructure of
  state-of-the-art computer equipment
• Superior computational resources make possible
  the use of far more sophisticated trajectory
  modeling and scheduling algorithms
• More accurate trajectory estimates

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Time-based metering with McTMA

• McTMA is a completely different approach
• McTMA has access to hourly wind updates (RUC
  forecasts)
• More accurate trajectory estimates
• The inherent advantages of the TMA approach over
  that of ERM or ASP have resulted in significant
  operational improvements at every facility that
  has upgraded from ASP to TMA
• Land more aircraft per hour
• 5-8 throughput increase
• Less metering

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Time-based metering with McTMA

• McTMA is a completely different approach
• McTMA is fully integrated between Centers
• Access to all relevant flightplan and track data
• Able to exchange metering data across Centers
• Adjacent Centers synchronized to a common arrival
  metering plan

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The transition to time-based metering

• It can be done. Heres how its going at ZLA

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LAX transition to metering

• Traffic management before metering
• Adjacent Center MIT initiatives or GDP or both
• MIT-based initiatives (jets)
• Call for release on satellite departures (ZLA and
  SCT TMU)
• Internal holding at SLI, DARTS, LAHAB
• No-notice holding by ZLA at SCT boundary
• Occasional unfilled gaps on finals
• Arrival numbers often below advertised AAR
• TMS delays common on IFR days

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LAX transition to metering

• Benefits for LAX arrival operations
• ZLA
• Vectoring occurs in High Altitude sectors
• Less coordination necessary (speeds/vectors)
  between SCT feeder sectors and ZLA sectors
• No-notice holding greatly reduced
• SCT
• Arrival flow to SCT based on all traffic and the
  runway availability
• Aircraft are staggered on merging routes (East
  gate)
• Speeds faster transitioning to finals
• Less space wasted on finals

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LAX transition to metering

• Traffic management initiatives for initial
  time-based metering trials
• Implemented to allow for safe transition to new
  procedures associated with time-based metering
• May 14 - TMIs (regardless of AAR at LAX)
• 30 MIT from East Adjacent ARTCCs - ZAB, ZDV, ZLC
• 20 MIT from ZOA
• SAN arrivals (from the East) routed south O/IPL
  (Sector 39)
• 10 MIT - VTU Departures (from SCT)
• Altitude capping for arrivals to LA Basin/San
  Diego area airports (i.e. BUR/VNY, SNA/LGB,
  SAN/CRQ)
• June 4 - TMIs back to normal operations.
• Dynamic application based on sector demand and
  workload

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May 30 metering trial results

• May 30 (1700-1850Z)
• WX VIS 3 MI, BKN 006, OVC 008. VIS North 2 MI
• No VAPs
• LAX advertised AAR 64 due to heavy mix and 3 mile
  separation at THD
• East Winds at altitude
• Actual arrivals 1710-1810z 69
• Heavy/757 mix 38

38 Heavy/757
38 Heavy/757
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June 7 metering trial results

• June 7 (1615-1900Z)
• WX IFR OVC 008
• No VAPs
• LAX advertised AAR 68
• Actual arrivals 1740-1840z 69
  (Heavy/757 mix 43)
• Actual arrivals 1800-1900z 71
  (Heavy/757 mix 34)

43 Heavy/757
34 Heavy/757
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June 10 no metering

• June 10 (1700-1900)
• WX BKN/OVC 020 (IFR)
• No VAPs
• LAX advertised AAR 68
• Actual arrivals 1700-1800z 59
  (Heavy/757 mix 32)
• Actual arrivals 1800-1900z 61
  (Heavy/757 mix 36)
• 3 A/C held _at_ VTU/DARTS for 10
• SAN 27 (Ground Delay)

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Transition to metering at LAX

• SCT statement regarding June 10

• It is difficult to compare metering vs.
  non-metering arrival numbers however, I believe
  that if metering had been used (on June 10), the
  arrival numbers would have been higher, without
  the delays incurred today.
• Gary Hobbs, STMC, Southern California TRACON

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June 21 metering trial results

• June 21 (1630-1830Z)
• WX IFR OVC 020
• No VAPs
• LAX advertised AAR 64 - 68
• Actual arrivals - 10 minute running totals
  1630-1830z
• 67-66-68-67-68-68
• Heavy/757 Mix - 10 minute
• running totals 1630-1830z
• 31-34-35-39-38-41
• Metering has provided a more consistent flow of
  traffic over long periods of time

41 Heavy/757
38 Heavy/757
35 Heavy/757
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June 27 metering trial results

• June 27 (1630-1850Z)
• WX IFR OVC 020
• No VAPs until 1815z
• AAR 72 _at_ 1815z
• LAX advertised AAR 68 - 72
• Actual arrivals - 10 minute running totals
  1730-1900z
• 66-68-69-69
• Heavy/757 mix correlates to net hourly arrivals

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Traffic flow from the East is staggered reducing
the incidence of vectoring within TRACON airspace.
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Internal traffic fits into overall scheduling
plan as a result of TBM.
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ZLA transition to metering

• SCT testimonials for time-based metering
• This is the best feed of aircraft I have seen
  from ZLA (to LAX) ever.
• Doug Voelpel, SCT LA Area
• We were busy (during rush on June 7), but we
  were never out of control and we consistently
  had enough aircraft to fill both of the finals.
• Dan Boyle, SCT LA Area
• Do you have to stop metering?
• SCT TM (daily)

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The bottom line

• Improved awareness results in
• Fewer surprises
• Earlier knowledge of traffic and delay spikes
• Improved quality of information to controller
• More consistent flows reduce
• No-notice holding
• Incidence of excessive ground delays
• Frequency of sudden need to create a hole in
  sequence, e.g., for aircraft in a low sector
• Fluctuation in flow rates into approach airspace
• Coordination with TRACON, TMCs, supervisors

• Allows flexible traffic options
• Spacing is based on runway availability
• Delays can be effectively managed according to
  sector workload
• Enhanced credibility with airspace users
• Improved accuracy of delays and holding
  predictions
• Equitable distribution of delays counters
  perception of favoritism

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Introduction to Multi-Center TMA

• Officially TMA-MC
• NASA Jive McTMA

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What is TMA?

• Traffic Management Advisor
• TMU planning tool for arrival rush operations
• Tool for passive communication/coordination
  between ARTCC(s) and TRACON
• Time-based metering tool
• Purpose Help generate and implement a more
  efficient arrival plan for the adapted TRACON
  airport
• Seeks to manage these arrival flows while the
  aircraft are still in Center airspace
• Goal improve throughput, ease workload, reduce
  delay, increase capacity, improve coordination
  between facilities
• TMA is being deployed nationally as part of the
  FAAs Free Flight Program.

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What is TMA in practical terms

• Predicts arrival demand
• TMA provides fresh (12-second update), accurate
  prediction of the arrival demand
• Matches demand to capacity
• Based on constraints entered by the TMC (e.g.,
  AAR, meter fix closures, etc.), TMA computes a
  time-based schedule by which arrival demand will
  meet (and not exceed) the capacity of the airport
  TRACON
• Provides metering targets
• Sector controllers implement the schedule by
  vectoring aircraft to meet crossing times posted
  on their radar displays

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What is TMA-MC?

• TMA Multi-Center is an extension of the TMA
  Single-Center to regions where more than one
  facility is significantly involved in arrival
  traffic flow management
• TMA-MC creates a network of TMAs at adjacent
  Centers
• Enables transition to time-based metering in
  complex airspace
• Provides scheduling information at adapted
  runways, approach fixes, and upstream Center
  boundaries
• Facilitates regional collaboration
• TMA-MC is a priority research project for the
  FAAs Free Flight Program, with a goal of
  providing capability in the field in the
  2004-2005 timeframe.

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TMA basic system description
Atmospheric data
TMC Flow Visualization
Controller advisories
System control communication
Arrival time prediction
Flight plan data Radar Track Speed Controller
commands
Constraint Scheduling
Operational ATC Computer
TMA Workstations
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TMA functions

• TMA (single-center, multi-center, whatever)
  essentially does three things
• Predict arrival demand more accurately
• than anything available today
• Help TMU develop a better plan for the arrival
  rush
• via Timeline display (see next slide) and a
  much, much smarter scheduling algorithm than has
  ever been available with ASP
• Produce metering lists to implement the overall
  arrival plan.
• The advisories are designed to distribute the
  metering delay (i.e., workload) upstream and/or
  downstream across different sectors, areas, and
  even facilities. The result is that separate
  flows into a common destination (PHL TRACON, for
  example) are synchronized to the overall master
  arrival plan generated in the TMUs.

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TMU timeline display
41
DSR sector controller meter list
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Field test phases

• Round 1 Multi-Facility Collaboration (March -
  June)
• TMA to provide TMCs in multiple facilities with
  consistent, accurate arrival information
• Each TMU to use TMA to help develop a coordinated
  arrival plan
• Develop the ops concept
• Determine hierarchy for decision-making between
  facilities
• Round 2 Metering (Fall 03 - Spring 04)
• Use TMA time-based scheduling
• Enable free-flow of heavily saturated sectors
  while metering others
• Transition to time-based metering in all McTMA
  facilities
• Develop operational procedures for metering in
  multiple facilities
• Determine costs/benefits of metering in complex
  airspace

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Challenges for McTMA in NE Corridor

• Complex airspace
• Involves multiple facilities (TMUs, sectors, and
  TRACONs)
• Small sectors, restricted controllability
• Tower enroute control (TEC) traffic
• Crossing traffic flows
• Streams of metered traffic with unmetered traffic
• Transition to metering control techniques
• Potential benefits
• Accurate prediction a reliable window on the
  next 90 minutes
• Smoother traffic flow fewer ties, less airborne
  holding, more advance notice when holding is
  required
• Redistributed, more balanced workload

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Whos involved
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McTMA System Architecture

• The plumbing

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Airspace Schematic
ZBW
ZNY
PHL
ZOB
ZDC
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Track flight plan data sources
HOST
ZBW
HOST
ZNY
HOST
PHL
ZOB
HOST
ZDC
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Individual ARTCC TMA processors
ZBW
ZNY
PHL
ZOB
ZDC
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McTMA scheduler
ZBW
ZNY
PHL
ZOB
ZDC
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McTMA scheduler
ZBW
ZNY
PHL
ZOB
ETAs
STAs
ZDC
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McTMA Timeline graphical user interface
ZBW
ZNY
PHL
ZOB
ETAs
STAs
ZDC
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McTMA Timeline displays control
ZBW
ZNY
PHL
ZOB
ETAs
STAs
ZDC
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Whats next?

• The Game Plan

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Field trials 1 and 2
January 2003

• Evaluate each TMA instance in standalone mode
• Objectives
• Confirm McTMA installations and network are
  stable
• Verify internal flight data processing
• Refine internal ETA computations
• Collect baseline data
• Expected result
• Each TMA node operating stably
• Reliable flight data processing within each TMA
  and between TMA pairs
• Accurate partial ETAs

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Field trial 3

• Transition to full McTMA network
• Objectives
• Connect and operate full McTMA network
• Verify flight data processing
• Refine end-to-end ETA computations
• Collect baseline data
• Expected results
• McTMA network operating stably
• Reliable flight data processing throughout the
  McTMA network
• Accurate end-to-end ETAs
• TMCs familiar with timeline display, load graph
  display, and basic scheduling panels

March 2003
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Field trials 4 and 5

• Round 1 operational evaluations
• Objectives
• Evaluate candidate operational concepts for
  coordinated arrival planning
• Conduct human factors assessments
• Usability, suitability, acceptability
• Collect baseline data
• Expected results
• Accurate demand forecasts
• Critical review of operational concept candidates
• User interface design requirements
• Scheduling performance data collected

April 2003
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June 2003
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Simulation at WJHTC

• Objectives
• Meter competing arrival flows with overflight
  traffic
• Training
• Provide cadre with exposure to metering
  operations and techniques in the presence of
  competing arrival flows prior to the start of
  metering trials in the field
• Illustrate the workload benefits of regulating
  arrival flows using McTMA Illustrate the
  workload costs of poor metering conformance
• Demonstrate how TMUs at different facilities can
  coordinate their decisions (e.g., departure
  releases) with respect to competing, external
  flows, and thereby avoid holding at their meter
  fix(es)
• Research
• Identify the need for requirements changes in the
  McTMA scheduling and/or delay distribution
  algorithms
• Assess the impact of unscheduled TEC flights

August 2003
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Field trials 6 and 7

• Round 2 operational evaluations
• Shadowing
• Objective
• Assess McTMA metering performance
• Activate McTMA advisories for shadowing
• TMCs use Timeline display to coordinate
  acceptance rates and restrictions
• Output fed into McTMA for shadowing exercises
• Controllers shadow the advisories for one
  rush,then debrief
• Shadow use of departure release tool by TMCs
• Assess metering advisories and human factors
  issues
• Collect data for performance metrics

September 2003
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November 2003
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Field trials 8 and 9

• Round 2 operational evaluations
• Active metering
• Objective
• Assess McTMA performance and TFM operations in
  live traffic situations
• Activate McTMA advisories for live metering of
  PHL arrivals
• TMCs coordinate acceptance rates and restrictions
• Controllers use advisories for one rush, then
  debrief
• TMCs use advisories to issue departure releases
• Assess McTMA performance and human factors issues
• Expected results
• Coordinated, efficient, workable arrival rush
  planning and control

January 2004
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Enough already

• Thanks for your time and interest
• For more informationask_mctma_at_osprey.arc.nasa.go
  v
• better yet, just gimme a call or drop me a
  lineTodd Farley(650) 604-0596todd.c.farley_at_na
  sa.gov
• See you March 4th