Transcript Airport Capacity and Delay

Modeling Airport
Capacity
Presented by
Newton G. Talley
Overview
The FAA’s William J. Hughes Technical Center is the premiere
aviation research, development, engineering, test and
evaluation facility.
Within the center are Aviation R&D Programs, under which falls
NAS Engineering and Analysis
Airport and Airspace Capacity -- This section has been intimately
involved in the FAA’s airport capacity program since 1976,
beginning with a prototype study of Chicago O'Hare using and
validating the Airfield Delay Simulation Model (ADSIM).
Graphical display for ADSIM is currently under development.
Overview (cont.)
Twelve initial studies were accomplished, then further studies were
delayed by the controllers strike in 1981.
During that time the Runway Delay Simulation Model (RDSIM) was
developed and the study of the top 40 delayed airports resumed
in 1985.
The Airport and Airspace Simulation Model (SIMMOD) was
procured for airspace studies in 1987.
Overview (cont.)
Recognizing the problems posed by congestion and delay within
the National Airspace System, the FAA, airport operators, and
aviation industry groups have initiated joint Airport Capacity
Design Teams at various major air carrier airports throughout the
U.S.
Each Capacity Design Team identifies and evaluates alternative
means to enhance existing airport capacity, to handle future
demand, to decrease delays, and to improve airport efficiency.
They also develop a coordinated action plan for reducing aircraft
delay.
Airport Capacity Design Teams
I Typical design teams consist of representatives from the FAA,
Military, Airport Consultants, Airline representatives, ATA, Airport
operators, ALPA, AOPA, and other concerned organizations
I Recommendations deal with airfield, facilities and equipment,
and operational improvements
Airport Capacity Design Teams (cont.)
I Over 48 Airport Capacity Design Teams have either completed
studies or have work in progress since inception of the program
I A typical Capacity Design Team makes twenty or more
recommendations for capacity improvements at specific airports
I Capacity Design Team improvement recommendations become
part of the airport master plan and are implemented when
needed to meet demand
Airport Capacity Design Team Flow
Simulation Models
The FAA has procured and developed different computer models
for airport analysis which are used to determine the capacity
and delay of airports and to study the sensitivity of capacity and
delay to various airport conditions. The results include:
I Hourly runway, taxiway, and gate capacity
I Hourly and daily delays, travel times, flow rates, and queuing
data
I Annual delay and annual delay costs
I Annual delay savings computed from annual delay costs
Simulation Models (cont.)
The models fall into two categories:
I Analytic models - a series of equations which compute hourly
capacity, daily delay, and annual delay from fixed input
parameters
I Simulation models - fast time, critical event, random order or
event-step models that emulate the movement of aircraft using
special sampling techniques
Simulation Models (cont.)
The different models include:
I
Runway Capacity Model
I
The Runway Delay Simulation Model (RDSIM)
I
Airfield Delay Simulation Model (ADSIM)
I
Airport and Airspace Delay Simulation Model (SIMMOD)
Model Usage
Runway Capacity Model
I An analytic model consisting of a series of equations to compute
airport capacity
I Assumes an infinite queue of arrivals and departures, and provides a
theoretical maximum throughput for the runways
I Capacity is computed by determining the minimum sustainable time
between successive arrivals and by inverting this time to find the
maximum number of arrivals per hour
Runway Capacity Model (cont.)
I The maximum number of departures which can be inserted
between the arrivals is then calculated, to give the arrival-priority
capacity
I The inputs to the model are the airfield's geometry and operating
strategy
I Each execution consists of a geometry/strategy combination
coupled with other variables such as aircraft mix, average
runway occupancy times (ROTs), and average separations
Runway Capacity Model (cont.)
I The principal output of the model is the total capacity per hour
for a specified arrival percentage
I The model prints out both arrival-priority and departure-priority
capacity figures. In addition, the output includes messages
containing operating strategies for reaching given percentages
of arrivals
Runway Delay Simulation Model (RDSIM)
I Primarily developed to perform runway capacity/delay analysis
I Simulates runway operations and provides both capacity and
delay information
I Critical event random order model employing special sampling
techniques
I Capacity simulations are made by varying the demand to
compute capacity at an acceptable level of delay and maximum
throughput
RDSIM (cont.)
I Results are calculated for a single traffic hour using many
replications
I Capable of operating with arrival-priority, departure-priority, or
balanced arrivals and departures
I Can be used to compute capacity at an acceptable level of delay
and maximum throughput
I Delay simulations utilize daily demand to provide by runway,
hourly and daily delay, flow rates and queuing data for arrivals
and departures
RDSIM (cont.)
I Inputs include runway usage, runway occupancy times, exit
probabilities, aircraft demand and mix, aircraft approach
velocities, aircraft separations and ATC rules and procedures
I Runway delay statistics are similar to those produced by ADSIM
I Can readily be used to capture the main benefits of a given
improvement, also to compare savings of various improvements
Review of past Design Team problems indicates that at least 95
percent of airport delays are runway-related and at least twothirds of the airport improvements studied are runway-related.
Airfield Delay Simulation Model (ADSIM)
I One of the most detailed models available for evaluating the
operations and sources of delay on the airport's surface using a
demand profile that contains meticulous definitions of the
characteristics of the airfield surface, ATC procedures, and aircraft
utilizing the airport
I Models the movement of aircraft throughout the airport system,
producing estimates of delays (pinpointing sources) and hourly flow
rates
ADSIM (cont.)
I Inputs include aircraft routings developed from a link-node
diagram of the airport, runway and taxiway usage, runway
occupancy times and exit probabilities, aircraft approach and
taxiing velocities, aircraft separations, gate service times,
aircraft demand and mix, and ATC rules and procedures
I Outputs are hourly arrival and departure flow rates, travel times,
arrival and departure delays for each runway, total delays for
each link on the airfield, departure queue lengths, and individual
aircraft delays
Airport and Airspace Delay
Simulation Model (SIMMOD)
I Address delays, capacity, and fuel consumption resulting from
changes in airspace utilization and operational procedures beyond
an airport's immediate airspace
I An event-step simulation model which traces the movement of
individual aircraft and simulated ATC actions required to ensure
aircraft operate within procedural rules
I Computes the impact on aircraft delay and fuel consumption using
a wide variety of parameters
SIMMOD (cont.)
I Inputs include traffic demand and fleet mix, route structures,
runway use configurations, separation rules and control
procedures, aircraft performance characteristics, airspace
sectorization, interactions among multiple airports, and weather
conditions
I Input parameters include: permissible airborne speed ranges for
use by ATC, runway occupancy times, safety separations, landing
roll and declaration characteristics, taxi speeds, and runway/taxiway
utilization
SIMMOD (cont.)
I Users control the timing of the simulation and the desired output
reports and provide data regarding the occurrence of various
simulation events
I Output consists of reports providing statistics describing aircraft
delay, travel time, and fuel consumption
I A post-processing animation system shows the movement of
aircraft on the airfield and in the airspace
Program Requirements Continue
I
Twenty-five airports each exceeded 20,000 hours of airline
flight delays in 1995
I The number of airports exceeding 20,000 hours of annual airline
flight delays is projected to grow from 25 to 29 by 2004 if no
capacity improvements are made
I The challenge for the air transportation industry is to enhance
existing airport and airspace capacity and to develop new
facilities to handle future demand
I Greater emphasis has been put on the redevelopment and
expansion of existing airport facilities as environmental,
financial, and other constraints continue to restrict the
development of new airport facilities in the U.S.
Information Source
The preceding information may
be accessed by going to
The FAA's
William J. Hughes Technical
Center Homepage at
http://www.tc.faa.gov/act500/capacity/index.htm