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Air Traffic Control & Airline Flight Operations

190116 – Week 3

Semester 1, 2013

(c) J.Murrie, School of Aviation, Massey University 1

Lecture overview

• Relevant course objective: – Discuss airline flight operations and air traffic

control procedures.

• Topics explored this week: – Aviation terminology.

– Provision and purpose of ATC.

– Barriers to effective ATC.

– Generic elements & structure of an ATC system.

(c) J.Murrie, School of Aviation, Massey University 2

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Aviation terminology

• Flight Plan: – Description of route an aircraft will take from origin to

destination; must be filed for most flights.

• Airspace: – Region of fixed dimensions within the atmosphere

with its own rules governing flight operations.

• Controlled airspace: – Airspace within which ATC is responsible management

of aircraft separation.

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Aviation terminology (cont.)

• Uncontrolled airspace:

– Airspace within which aircraft not ATC are responsible for maintenance of separation & flight rules.

• Separation:

– Term given to minimum distances (vertical & horizontal) required between aircraft and other aircraft, terrain & other hazards.

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Aviation terminology (cont.)

• Clearance:

– Formal permission from relevant ATC authority for an aircraft to enter an airspace region and/or perform some function e.g. take off, descend.

• Air transport operations:

– Legal designation usually given to flights of a commercial nature involving carriage of passengers.

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Air traffic control/management

• Traditionally provided by state provided and run by government agencies in each nation.

• Becoming increasingly complex due to: – Infrastructure & human development.

– Technological change & industry growth.

– Staffing costs & other human resource issues.

• Many such services are being privatised, or run as private organisations or ANSP’s. – Air Navigation Service Providers.

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Airways Corporation NZ

• Controls all air movement within NZ’s airspace.

• Develops & maintains ASNP infrastructure.

• Manages ATC facilities. • Provides technical &

engineering facilities. • Develops/designs airspace,

maps & charts. • Trains air traffic controllers. • Provides flight inspection

services for airports. (c) J.Murrie, School of Aviation, Massey University 7

Basics of flight operations

• All flights from A to B conducted under either:

– Visual (VFR) or Instrument flight rules (IFR), and in

– Visual (VMC) or Instrument meteorological conditions (IMC).

• Airspace through which aircraft transit divided into zones with different rules.

• Zones mix of controlled & uncontrolled airspace allowing different types of flight operation.

• Rules intended to ensure safe separation of aircraft, terrain & weather, and efficient operations.

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Basics of separation

• Maintained by Air Traffic Control & pilots.

• Separation puts a bubble around an aircraft that is not supposed to be breached. – Size determined by a/c & flight characteristics.

• Other factors considered by ATC are: – Runway characteristics.

– Mixture of aircraft types using those runways.

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The separation bubble

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What does airspace look like?

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Standard navigation chart showing airspace around Auckland

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ATC Functions (Provide safe & efficient traffic flow)

• Aircraft separation assurance:

– Aircraft from each other and other hazards.

• Traffic congestion management.

– Particularly significant in developed regions.

• Flight information:

– For pilots, flight planning and scheduling activities.

• Search and Rescue:

– Responsible for coordination & communication.

Size of the problem Comparison of aircraft movements 2011/12

Worlds Top 5 busiest airports

Airport Total movements

Atlanta 923,996

Chicago 878,798

Los Angeles 702,895

Dallas/Fort Worth

646,803

Denver 628,796

New Zealand’s Busiest

Airport Total Movements

Auckland 158,993

Hamilton 132,210

Christchurch 124,368

Wellington 106,148

Tauranga 73,926

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The total number of aircraft movements

at ALL of New Zealand’s airports in

2012 totalled 1,098,081

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Factors determining ATC capacity

• Demand: – Peak demand, hub & spoke networks.

• Airspace capacity: – Airspace design, controller workload,

balkanization.

• Airport capacity: – Runways, gates, landside limits, weather.

• Environmental limits: – Noise, emissions

Barriers to effective ATM & ATM

• Technology: – A significant proportion of ATC equipment in many

countries is 40+ years old and obsolete. – Lack of commonality between many countries ATC

systems. – Key navigation aids based on 30-40 year old

technology and not 100% reliable.

• Industry growth: – Industry growing 5% annually, airspace size as defined

by separation rules has not increased.

• Lack of investment in infrastructure & training. • Capacity of existing controllers.

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ATC Roles

Air Traffic Service

Air Traffic Control Unit

Aerodrome Controller

TWR

Approach Controller

APP

Area Controller

ACC or UAC

Flight Information

Service Alerting System

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Aerodrome Control (TWR)

• Services provided to all flights within vicinity of an operating control tower, typically through visual observation.

• Zone of control depends upon volume and type of traffic using aerodrome – typically 5nm & 1500/2500’.

• Control all ground movements at aerodrome, along with traffic entering and leaving control zone and aerodrome traffic circuit. – Issuing of clearances.

Approach Controller

• Based at radar equipped aerodromes they control airspace immediately above (and around) aerodrome zones.

• Key role is management of IFR traffic flow into and out of specific aerodromes via defined IFR tracks: – Includes clearances to enter, transit, climb and

descend within controlled airspace. – Also provide clearance/directions to enter other zones. – Responsibility for aircraft passed to Aerodrome

Controller (TWR) once aircraft on final approach.

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Area Controller

• Two basic types:

– High altitude areas used by IFR traffic and commercial operators.

– Uncontrolled airspace used by general aviation VFR traffic.

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Generic elements of an ATC system

• Communication systems: – Primarily radio based, mixture of VHF & HF. – Limited use of SATCOM. – Some data uploads/connections, but also limited.

• Navigation systems: – En-route systems VOR, DME, GPS, INS – Approach systems some runways provide precision ILS,

non-precision systems are VOR,NDB.

• Surveillance systems: – Methods by which ATC monitors traffic locations i.e. RADAR,

direct observation, transponders

Next Generation ATC

• Initiative to modernise the US ATC system to:

– Increase capacity and reliability.

– Improve safety and security.

– Minimise the environmental impact of aviation.

• Vision behind Next Gen:

– A system that is based on satellite navigation and control, digital non-voice communication, automated ATM, and advanced networking, and a sharing of decision making between the ground and the cockpit.

• Aiming for completion 2018-2025.

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Next Gen & weather

• Weather accounts for 70% of all air traffic delays within the US: – FAA determined that 2/3 of these are preventable with

better weather information.

• Average annual cost of delays is US$50b.

• Next Gen requires integration of improved weather information into decision systems: – Provides multiple users with common data.

– Aims to increase consistency & reliability of data.

– Improved data storage and dissemination processes.

More Aviation terminology

• Load factor: – Measure of % of seats on an aircraft are occupied.

• City-pair: – Two cities (origin & destination) that define a given route

flown by commercial aircraft on scheduled operations.

• Scheduled operations: – Typically refers to operations of commercial airlines

promulgated ahead of time between defined city-pairs.

– Usually conducted under supervision of ATC.

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Airline terminology (cont.)

• Hub: – A hub is an airport that forms the principle base of

operations of a particular airline. Possible for airlines to have multiple hubs in different regions.

• Route network: – Set of city-pairs served by an airline.

• Frequency: – Number of flights offered by an airline per city-pair as

part of its route network.

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Airline terminology (cont.)

• Hub and spoke network: – Network where a central hub acts as focal point to smaller

spoke airports with all flights moving via the hub.

• Point to point network: – Route network where aircraft fly from A B without

transiting through an intervening hub location.

• Slot – Specific date & time during which an aircraft can take off

and/or land at a given airport. Subject to allocation and management by relevant authority.

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Weekly Reading

• Textbook Chapter 8 – Sections 8.1 to 8.4 (inclusive)

• Really only for interest for students not familiar with basic airline operations

• Textbook Chapter 13 – Sections 13.1 to 13.4 (inclusive).

• The important reading for the week, review the rest of the chapter briefly if you wish but it is not necessary

• STREAM Reading: – The Next Generation Air Transport System

• Also a video relating to this and one on airline flight operations.

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