Aviation Week & Space Technology - January 15, 2015

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ATM+1

Domain-Focused

Enhanced System

ATM+2

Integrated Airspace

System

ATM+3

System-wide

Autonomous

Optimized Airspace

NextGen Full

NextGen Beyond

NextGen

Known methods,

mostly ongoing

research

Extends methods,

begins signifcantly

new research

activities

Encompasses new

complexity and

autonomy sciences

and innovative ATM

concepts

2010 2020 2030

ATM-Generations Timeline

Source: NASA Ames Research Center

Robinson. ATD-1, originally launched in 2011, explored tech-
nologies to increase the efciency of arrivals, from just prior
to top-of-descent down to the runway, using a suite of existing
controller technologies, including trafc management advi-
sor with terminal metering and controller-managed spacing
tools. NASA will integrate those technologies and others,
including the efcient descent advisor and dynamic weather
routes, into a broader suite of controller tools to simulate
over the next two years the holism of linking together the ar-
rival, departure and surface operations tools into a combined
scheduler as part of the ATD-2 project. Leighton Quon, the
ATD project manager, says NASA will focus its eforts on
certain key areas of the broader arrival-departure-surface
domain. “We’re going to address some aspects that we think
are sticking points up front,” he says. “The team is nailing
down the details of what we’re going to do in the next five
years.”
Individually, the component pieces of ATD-2 are already
making a diference. TSS, which NASA Ames transferred
to the FAA last year, is expected to save airlines $200-400
million per year when rolled out at 35 major U.S. airports in
2018 and beyond. The tool gives terminal radar approach
controllers a “slot
marker” visual cue
onscreen to keep air-
craft centered on op-
timal descent profiles
from cruise to the
terminal area, with
speed advisories to be
radioed to the crew as
opposed to the tradi-
tional fuel-inefcient
method of vectoring.
NASA Ames com-
pleted 20 high-fidelity
human-in-the-loop
simulations in the
past 2.5-year, multi-
week activities with
dozens of pilots and
controllers partici-
pating. Quon says NASA continues to work with the FAA “to
further define requirements for implementation” to roll out
the tools at the first radar facilities in 2018. “They’ve been very
happy and categorically stated that these eforts will be an un-
precedented contribution to NextGen technology,” says Quon.
Another likely component of the ATD-2 toolbox will be the
Spot and Runway Departure Advisor (Sarda), a ramp control
tool that manages the departure queue to predetermined
levels by modeling all the activity at the airport. US Airways,
now American Airlines, signed a Space Act Agreement with
NASA in April 2013 to use the application at its Charlotte,
North Carolina, hub where the carrier represents nearly 90%
of the daily operations, in order to keep the runway queue
size to a maximum of five or six aircraft to minimize idling
time and passenger annoyance. Running on a set of four ter-
minals in the ramp control tower, one for each departure sec-
tor (North, South, East and West), the application provides
ramp controllers with a wait time in minutes when the pilot
calls in asking for pushback to depart. The software takes in-
put from the sequence of runways in use, taxi routes, arrivals
and departures (in part to factor in taxi time when crossing

active runways) and other constraints to “come up with the

best scenario and best schedule for every individual aircraft

movement,” says Yoon Jung, technical lead for Airport Sur-

face Research at NASA Ames. Jung says the team plans to

install Sarda in the ramp control tower in July and run the

system in “shadow mode” with the carrier’s existing ramp

control software through September 2016.

Another possible addition to the integrated arrival depar-

ture scheduler is the en route descent advisor, a tool that

gives controllers at air route trafc control centers strategic

speed and course modification guidance to help pilots fly an

optimal descent profile from the enroute segment to the ter-

minal area boundary (about 50 nm from the airport).

ATD-3 demonstrations will feature technologies to opti-

mize the en route portion of a flight, a program that NASA

is formulating in parallel with ATD-2. Quon says the idea is

to remove barriers to domestic and ocean flight through “ap-

plied” trafc flow management that takes into account better

weather planning and avoidance. “On the domestic side, many

times [the barrier] is the weather,” says Quon. “How do you

get an efcient route around that?” For oceanic routes in the

North Atlantic, there is a need to optimize the track system

with wind-optimal

user-preferred rout-

ing for best efcien-

cies. Included in the

demonstrations will

likely be an evolved

version of NASA’s

dynamic weather

routes (DWR) pro-

gram, which today

can give airline dis-

patchers a proposed

rerouting around

weather to save time

and fuel.

Dave McNally, a

NASA ATM engi-

neer, says American

Airlines has been

using DWR in trial

mode since July 2012 and has saved 3,200 min. of flight time

by 520 aircraft over a 21-month period. The ground-based

system computes new routes around weather every 12 sec.,

taking into consideration air trafc congestion, radar-track

and flight-plan information and hourly weather updates from

the National Oceanic and Atmospheric Administration. The

software alerts American’s ATC desk coordinator with a “ka-

ching” sound every time a new flight can save 5 min. or more

flight time with a reroute. The desk coordinator sends the

request to dispatchers who, if they accept the request, send

the crew a message over the Aircraft Communications Ad-

dressing and Reporting System, better known as ACARS.

The crew then has to ask ATC for the changes over the radio.

McNally says NASA estimates that 40% of reroutes “accept-

ed” by dispatchers will then get approval for course changes.

For ATD-3, McNally says, researchers would like to iden-

tify common routes around weather for groups of flights, an

option the FAA could use to determine “playbook” routings

around bad weather, and methods for using the software for

merging and arrival metering, a process that is generally

discontinued. c