Body of Knowledge Module 4

7/27/2019 Body of Knowledge Module 4

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Body of Knowledge Module 4

Airport Capacity andDelay

Ph.D. Student Tukhtaev Dilshod

Department of Flight Operation and Management



Capacity and Delay

1. Capacity (throughput capacity) is a measure of the maximum number of

aircraft operations which can be accommodated on the airport or airport

component in an hour. Circe the capacity of an airport component is independent

of the capacity of other airport components, it can be calculated separately.

2. Delay. Delay is the difference between constrained and unconstrained

operating time



Capacity and Delay

Capacity refers to the ability of a portion of airspace or an airport to handle a

given volume of traffic (demand) within a specified time period. As a result of

airline deregulation and the general strength of the U. S. economy, more people

are using the system. The resulting increased activity affects not just the

capacity of the airfield and gate areas but also the terminal buildings, public

access routes, and parking facilities.



Capacity and Delay

Beginning with the 1987 Airport and Airway Safety and Capacity Expansion Act

(ACEA), funding priority was given to airport projects that focused on enhancing

and developing an airport’s overall capacity to handle aircraft and ground

operations.



AIP Priority System for Capacity

Enhancement

1. Electronic or visual guidance on each runway;

2. Grooving or friction treatment on each primary and secondary runway;

3. Distance-to-go signs for each primary and secondary runway;

4. A precision approach, vertical guidance, and full approach light system

for each primary runway;

5. A non-precision instrument approach for each secondary runway;

6. Runway end identifier lights on each runway that does not have an approachlight system;

7. A surface movement radar (SMR) system at each CAT-III airport;

8. Taxiway lighting and sign systems;

9. Runway edge lighting, marking; and

10. Radar approach coverage for each airport terminal area.



Impact of Capacity Restraints

To understand the impact of capacity restraints or improvements, airport

management must view the different areas of an airport as a set of interrelated

and interdependent physical facilities and components. For an airport to function

efficiently the capacity of each component must be matched to the others.

Improving or restricting one part of the system has an impact on the others.




The four distinct elements in a capacity analysis are

(1) airspace,

(2) airfield,

(3) terminal, and

(4) ground access.




Airfield capacity—the rate at which aircraft movements on

the runway/taxiway system result in a given level of delay




Throughput capacity and practical capacity define airfield capacity.

Throughput is the rate at which aircraft can operate into or out of the airfield

without regard to any delay.

Practical capacity, always less than throughput capacity, is the number of operations that can be expressed in terms of the maximum acceptable rate

incurring an average delay.

PHOCAP( practical hourly capacity)—the total combined capacity measure of the runway, taxiway, and gate areas.

PANCAP( practical annual capacity)—the level of operation that results in notmore than four minutes average delay per aircraft in a normal peak two-hour

operating period.




AAR (Airport Acceptance Rate)— used by airport radar traffic control centersto calculate the desired interval between successive arrival aircraft.

An airport is considered severely congested when average delays exceed nineminutes per operation.

Practical capacity is a subjective value judgment about how much delay is

tolerable.

Acceptable delay is a judgment that recognizes that some delays are

(1) unavoidable,

(2) too expensive to eliminate, and

(3) a few aircraft will encounter a higher level than normal.




ATOMS—Air Traffic Operations Management System

ASQP—Airline Service Quality Performance

The FAA now stipulates that AIP grants can be issued for capacity

enhancement projects only if airport certifies that all of its elements can

handle the increased traffic.



Managing Capacity

Factors that lower capacity or induce delay—airfield characteristics, airspace

characteristics, air traffic control, meteorological conditions, and demand

characteristics



Airfield Characteristics

The most critical capacity determinant— runway use configuration

Historically, the lateral distance for aircraft operations on parallel runways

has decreased in accordance with emerging technology. Currently, FAA Air

Traffic control procedures allow for simultaneous departure and arrival

operations under visual meteorological conditions (VMC) and instrument

meteorological conditions (IMC) when two parallel runways have a minimum

spacing of 2,500 feet.



Airspace and Air Traffic Characteristics

TMS (traffic management systems)— software packages that assist themanagement of a smooth flow of aircraft to and from airports with minimum

delay.

The mile-in-trail or minute-in-trail restrictions are both the least disruptive

traffic management initiatives and the least accurate.

Metering aims to match the arrival of aircraft to the ability of the airport to

handle the volume (known as acceptance rate). Wake vortex—an aerodynamic disturbance that originates at the wingtips of

an aircraft and trails in a corkscrew fashion behind the aircraft

Spacing standards between aircraft taking off require ATC to double departure

release times from 60 seconds to 120 seconds after a heavy jet.



Demand Management

Administrative or economic demand management methods promote moreeffective or economically efficient use of existing facilities rather than

adding true capacity.

Allocating or restricting airport access by setting quotas on passenger

enplanements or on the number and type of aircraft operations permitted isan administrative method of managing demand.

Rehubbing—using transfer hubs to redistribute operations to less busy airportsin other regions as a means to alleviate or reduce delays at busy Airports

Aviation economists favor allocating airport access by demand management,which relies on a pricing mechanism.



Demand Management

Differential pricing and the auctioning of landing rights or slots are the twomost commonly favored methods of reducing delay by including airport costs

and demand as determinants of user fees.

By applying a peak hour surcharge, which is one type of differential pricing,

three New York City metropolitan airports managed to reduce congestion.



Slot Management

A slot identifies a block of time allocated to an airport user to perform anaircraft operation, either a takeoff or a landing

Slot allocation rules, first proposed in 1968, designated five airports asexperiencing high-density operations. They were Chicago’s O’Hare (ORD),

New Jersey’s Newark (EWR), New York’s John F. Kennedy (JFK), New York’s

LaGuardia (LGA), and Washington’s National (DCA). The high-density rule was

implemented in 1969 and formalized under Federal Aviation Regulation Part

93.

When weather deteriorates to instrument meteorological conditions, the

airlines would be required to reroute or cancel flights that exceeded thecapacity limit.

The reservation system is used primarily for allocating general aviation and

charter slots on a first come-first serve basis.



Slot Management

The purpose for having slot allocations and auctions was to alleviate congestion at high-

demand or high-density airports.

Advocates of slot auctions have argued that access to an airport should be treated as a scarce

resource and priced accordingly.

Slot auctions allow peak-hour access for a market-determined price.

Slots—one of the most significant barriers to entry in the airline business

The FAA recalls any slot that is not used 80 percent of the time over a two-month period.

The FAA has modified FAR Part 93 and incorporated into it special rules that allowed slots tobe purchased, sold, traded or leased by any party.



Modeling Airport Capacity

SIMMOD is the name of a simulation model used by the FAA, airlines, airports,

architects, and engineers to design improvements, calculate travel times and

flow rate for an airport or an airport component, and/ or develop procedural

alternatives for domestic and international air traffic management.

The Airport Machine Model (AMM) is a general-purpose simulation product that

provides detailed landing deceleration modeling, as well as exit selection,

runway crossing spacing intervals, and controlled departure queuing. Another

simulation model is the Airfield Delay Simulation Model (ADSIM).



Technological and Weather Solutions

In the search for solutions to capacity and delay problems, the value of newtechnology is typically measured by its ability to achieve one or more of the

following results:

(1) increased capacity,

(2) higher efficiency or throughput,

(3) greater safety,

(4) improved reliability,

(5) greater accuracy,

(6) lower cost, and

(7) greater convenience.



National Airspace Architechure

The NAS architecture integrates services, procedures, facilities, and technologies

into a compatible network. It does so by enhancing safety through the component

areas of communication, navigation, surveillance, decision support systems,

weather, flight service, and oceanic routes.

GPS (Global Positioning System), coupled with the Wide Area Augmentation System

(WAAS) and the Local Area Augmentation System (LAAS), is intended to be the sole

means of future navigation and landing guidance.

DSS (Decision Support System)— provides more functions and information,

upgraded displays, and better data exchange capabilities for the air traffic

controllers and traffic management coordinators.



National Airspace Architechure

STARS (Standard Terminal Automation Replacement System)— supports current

radar, traffic and weather advisory, and navigational assistance services.

OASIS (the operational and supportability implementation system)—a

commercial- based DSS, incorporating functions currently provided by the

graphic weather display, flight service data processing equipment, aviation

weather processor, and direct user access terminal service.



Impact of Very Large Aircraft (VLA)

Aside from technological advances in navigation capabilities, the possibility of

future very large aircraft (VLA) or super large aircraft (SLA) will impact

airport capacity. VLA and SLA will affect airport components such as the

runways, taxiways, ramps, terminal bridges, baggage rooms, and security.

Factors, which must be considered, include weight, length and wingspan

(estimated at up to 265 feet in width).



Meteorological Effects and WeatherAids

Weather has significant influence on efficiency, capacity, and safety. The FAA

estimated in 1992 that 80 percent of all delays greater than 15 minutes were

caused by weather. Improved weather reporting systems can reduce the

occurrence of aviation accidents related to weather and improve the

economic operating conditions of the airlines and other users of the airport

system.



Wake Turbulence and Vortices

Wake vortex or turbulence is an aerodynamic disturbance that originates at

the wingtips of an aircraft and trails in a corkscrew fashion behind the

aircraft.

Previously, wake turbulence separation was based upon the aircraft’s design

classification of A, B, C, or D. The standard separation between two aircraft

approaching an airport required a two-minute wait, while three minutes of

wait were required for small aircraft departing behind large aircraft.



Wind Shear

A special type of weather phenomenon affecting airport capacity is wind

shear. Wind shear is defined as any sudden change in wind velocity or

direction. It is associated with weather conditions such as warm or cold

fronts, low-level jet streams, and mountainous terrain.

The LLWAS consists of Doppler radars positioned at different locations on and

around an airport for measuring wind velocity and direction.



Flight Service Stations

The Flight Service Station is an air traffic facility that provides pilot briefing,

aircraft enroute communication, and visual flight rule (VFR) search and

rescue services. In providing pilot briefings, the FSS broadcasts aviation

weather and National Airspace System (NAS) information, receives and

processes IFR flight plans, and relays ATC clearances. The FSS has

responsibility for originating and disseminating notices to airmen (NOTAMs)

and for monitoring various navaids around the country.



Flight Service Stations

Some aviation users have criticized the use of ASOS because

(1) it cannot replicate the observations of distant phenomena, such as

thunderstorms,

(2) it doesn’t provide a trend analysis of whether conditions are improving or

deteriorating, and

(3) sometimes the information transmitted is in error.



Future Weather Technologies

Through their ongoing modernization, the NWS and the FAA have collaboratedto develop plans for new and enhanced capabilities, which, if implemented,

will bring about a dramatic transformation in the accuracy, timeliness, andapplicability of aviation weather information. Focusing on aviation-impacted

variables and decision aids, the planned system offers the potential forachieving enhanced safety and efficiency. An example is the Integrated

Terminal Weather System (ITWS) display. It integrates information from theTerminal Doppler Weather Radar and the Low Level Wind Shear Alert System.

The ITWS provides detailed information and situational awareness fordeparting or arriving aircraft. It can also assists in the metering and spacing

of both inbound and outbound traffic at an airport as a means of improvingairfield capacity.



Summary

The ability of the national airspace system to serve the growing demands of the flying public and cargo operators is dependent upon the ability of airports

and the FAA air traffic control system to handle increased traffic. Efforts toimprove airport capacity are centered on the construction and development

of runways, taxiways, terminal facilities, roadway access, and navigationalaids. There are also a number of administrative processes available to airport

executives, which can help manage the demand.

Not all capacity problems exist at the airport. Aircraft operating in theairspace encounter restrictions as a result of other factors such as weatherand separation standards. Technological improvements in weather reporting,

instrument and global positioning systems, and automated decision support allaid in improving overall system capability.

Body of Knowledge Module 4

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