Noise mitigation considerations when designing PBN departure and arrival

117 Pages·2016·3.34 MB·English

by  Symecko Anastasia

Safety & Airspace Regulation

Performance-based Navigation
Airspace Design Guidance: Noise mitigation
considerations when designing PBN departure
and arrival procedures

CAP 1378
CAP 1378 Contents

Published by the Civil Aviation Authority, 2016
Civil Aviation Authority,
Aviation House,
Gatwick Airport South,
West Sussex,
RH6 0YR.

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First published March 2016

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notification of amendments.

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CAP 1378 Contents
Contents
Contents ..................................................................................................................... 3
Background ................................................................................................................ 6
Introduction ................................................................................................................ 7
Airspace design and vectoring ............................................................................ 8
Chapter 1 ................................................................................................................. 10
Guidance to complement consultation ..................................................................... 10
How to use the guidance ................................................................................... 10
Chapter 2 ................................................................................................................. 12
Environmental impacts ............................................................................................. 12
Noise objectives ................................................................................................ 12
Altitude based priorities ..................................................................................... 14
Redistribution .................................................................................................... 15
Increases in the total number of people affected by noise ................................ 15
New populations exposed to noise .................................................................... 16
Reductions in fuel / CO efficiency .................................................................... 16
2
Chapter 3 ................................................................................................................. 18
Operational impacts ................................................................................................. 18
Applicability ....................................................................................................... 22
Chapter 4 ................................................................................................................. 23
Concepts, options and impacts ................................................................................ 23
Height bandings ................................................................................................ 23
Chapter 5 ................................................................................................................. 25
Departures ............................................................................................................... 25
Concept 1: Single PBN SIDs to Replace Conventional Routes ......................... 25

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CAP 1378 Contents
Departures concept 2 – Relief options for PBN SIDs not constrained by NPRs 33
Departures concept 3 – Relief options for PBN SIDs which are constrained by
NPRs ................................................................................................................. 40
Departures concept 4 – Relief options for dual runway operations ................... 42
Departures concept 5 – Alternating SID usage with offloads ............................ 49
Departures concept 6 – Multiple PBN routes to replicate conventional dispersal
.......................................................................................................................... 54
Departures concept 7 – Traffic dispersal into new / wide areas ........................ 60
Departures concept 8 – Increased climb gradients ........................................... 62
Departures concept 9 – Remove step climbs .................................................... 64
Chapter 6 ................................................................................................................. 66
Arrival options .......................................................................................................... 66
Arrivals definitions ............................................................................................. 66
Continuous descent approach (CDA) ................................................................ 67
Curved approaches ........................................................................................... 67
Network enablers for low altitude PBN noise solutions ..................................... 68
Arrival concept 1 – Single PBN routes for arrivals ............................................. 70
Arrival concept 2: Multiple routes for arrivals relief ............................................ 77
Arrival concept 3: Multiple PBN arrival routes for dispersal ............................... 88
Arrival concept 4: Options for final approach ..................................................... 90
Annex A ................................................................................................................... 97
Changes in on-track noise level due to lateral displacement .................................... 97
Annex B ................................................................................................................. 100
FAS Noise Task Force discussion paper: Definition of aircraft overflight for the
purposes of noise ................................................................................................... 100
Introduction ..................................................................................................... 100
Track density diagrams ................................................................................... 101
Lateral attenuation of aircraft noise ................................................................. 101

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CAP 1378 Contents
60° track density diagrams .............................................................................. 103
Annex C ................................................................................................................. 107
Fuel / CO opportunity costs calculation for noise mitigation solutions ................... 107
2
Annex D ................................................................................................................. 109
Noise abatement departure procedures (NADP) .................................................... 109
Annex E ................................................................................................................. 111
Network solutions for streaming arrivals ................................................................. 111
Holds or ‘stacks’ .............................................................................................. 111
Point merge ..................................................................................................... 112
Point merge (different sequencing legs for the runway in use) ........................ 114
Network trombones ......................................................................................... 114
Annex F ................................................................................................................. 116
List of acronyms ..................................................................................................... 116

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CAP 1378 Background
Background
1. The UK’s airspace infrastructure is currently based on ‘conventional’
navigation, using ground-based beacons. This system has been in place for
many decades and does not exploit the modern navigational capabilities
with which most commercial aircraft are already equipped. It is therefore
relatively inefficient, both operationally and environmentally.
2. Modernisation will enable UK aviation to reap the benefits of the latest
technologies including Performance-based Navigation (PBN). A route
system using PBN standards allows more flexible positioning of routes and
enables aircraft to fly them more accurately. This helps improve operational
performance in terms of safety and capacity, and also offers the flexibility to
attempt to design routes to mitigate the environmental impact of aviation.
Most aircraft are already navigating using PBN which has led to a gradual
greater concentration of aircraft on route centrelines over the years.
However, as the routes have not been originally designed to a PBN
specification, some operators have interpreted the conventional route
centrelines and created ‘overlays’. These are their individual interpretations
of the conventional route centreline which will vary slightly between airlines
and across aircraft fleets. Once a route is formally designed to a PBN
specification and published by the Civil Aviation Authority (CAA) for use, it
creates an identical standard for all operators to follow, thereby increasing
concentration of aircraft on that route centreline.
3. The move to a PBN environment is considered to be inevitable and beyond
the scope of this guidance; its focus is instead on providing a range of
options for consideration when applying PBN and how best to mitigate
noise impacts1. The Noise Task Force was established to consider the
issues associated with the negative impacts of PBN and create this
guidance.

1 For further details on PBN and why the UK must modernise its airspace see www.caa.co.uk/FAS

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CAP 1378 Introduction
Introduction
1. This document provides guidance on a range of design options for PBN
(Performance-based Navigation) procedures with the intention of offering
options for different kinds of noise mitigation guidance, including varying
degrees of relief and dispersal, and incorporates them into this guidance
which:
 outlines the potential benefits and impacts;
 outlines technical requirements and constraints;
 provides guidance on where solutions may be considered and where
they may be inappropriate.
2. This document explores the impacts and possibilities of using PBN routes
to mitigate noise impacts and does not make reference to the stand-alone
benefits of performance based versus conventional navigation.
3. The design solutions presented are drawn from existing designs, emerging
concepts generated by the aviation industry and solutions proposed by
environmental groups.
4. This guidance aims to provide a constant and transparent basis to the
design of PBN procedures in UK airspace. It aims to achieve this by listing
the key characteristics of all noise related PBN design solutions and
provide generic guidance on the circumstances where they should be
considered as options.
5. It is likely there will be no optimal solution that addresses all stakeholder
needs but a balance will be required in order to find the most acceptable
route positioning or operating concept. The optimal solution will be heavily
dependent on the local circumstances; establishing ‘what good looks like’
across the local collective of stakeholders will remain the key factor in
identifying which solution is most appropriate in any given circumstance.
For example, for some stakeholders, concentration on a single route
avoiding main population centres may be their preferred option, whereas

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CAP 1378 Introduction
others may seek multiple routes to disperse traffic or achieve periods of
relative relief from aircraft noise.
6. This guidance is intended to provide options for consideration by airspace
designers and sponsors. The guidance is intended to provide a common
reference when considering aircraft noise mitigation in the placement of
PBN routes.
Airspace design and vectoring
7. The scope of the guidance is on the design of route centrelines. This is a
key factor in determining traffic patterns. However, traffic patterns are also
dictated by vectoring2 practices. Vectoring is expected to reduce as the Air
Traffic Management (ATM) system becomes more systemised through the
introduction of PBN routes and other new technologies. However,
maintaining system safety and efficiency will mean that some vectoring is
always likely in certain circumstances. This will be in unpredictable
circumstances such as bad weather, and also in some more predictable
ways, such as where for safety and efficiency reasons the procedures are
planned to be available for use on a more or less permanent basis.
8. In a systemised ATM network the routes to/from different airports must be
interwoven. Consider a situation where there is a departure route that
interacts with an arrival hold. To ensure they are safely separated3 the
departure route may be designed to fly additional miles around the hold
and/or be capped at a low level beneath the hold. However if there
happens to be no arrivals in the system as the departure gets airborne,
ATC will have the opportunity to provide a more direct/efficient routeing
climbing directly through the holding area. This type of situation can lead to
vectored traffic patterns that deviate from the published route alignment.

2 Aircraft vectoring is a service provided to aircraft by ATC. The controller decides on a
particular direction for the aircraft to fly by issuing tactical instructions or ‘vectors’.
3 In a systemised airspace environment routes must be designed to be separated by a designated
amount to ensure that there no risk of the aircraft on each route coming too close to one another.
The safe separation depends on the route configuration in question.

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CAP 1378 Introduction
9. Where there are defined Noise Preferential Routes (NPRs) for departures,
vectoring is only allowed on departure routes once aircraft have climbed
through the NPR ceiling (typically 3,000 or 4,000ft).
10. It is important that the impact of vectoring is taken into account when
considering the PBN solutions presented here and in particular when
setting stakeholder expectations with regard to benefits. For example, a
design solution may aim to provide some noise relief from aircraft below
4,000ft by providing two routes, each with an associated NPR swathe;
route A and route B, each being activated at different times. When route A
is deactivated, all the flights below 4,000ft would be on route B. However,
aircraft may be vectored at 4,000ft and in most cases this will be before the
end of the NPR. The vectoring may therefore take the aircraft over the
geographic area covered by route A's NPR swathe even though it is during
the route A relief period. As these aircraft would be above 4,000ft they
would, in general, be quieter, however this may not meet stakeholder
expectations of an acceptable form of relief from aircraft noise.
11. It must therefore be made clear that in most cases relief will mean relief
from aircraft directly overhead at low altitude, but not will not mean relief
from all overflight/noise. Note also that relief routes may not be spaced
sufficiently to remove all noise impact – see Annex A for details.
12. Vectoring is expected to decrease in the future, as ATM systemisation
increases, and any PBN relief design that is implemented now would be
expected to become increasingly more effective over time. This will be a
gradual process and depends on the continued modernisation of the whole
route network to the PBN standard and on the development and
implementation of supporting tools to manage traffic flows. It is vital that
designers and stakeholders alike understand the limitations of the solutions
presented in this guidance.

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CAP 1378 Chapter 1: Guidance to complement consultation
Chapter 1
Guidance to complement consultation
1.1 All significant route changes will be subject to consultation. This guidance
is intended to complement the consultation process by providing a
common understanding of the options available and their pros and cons
across the wide community of stakeholders.
1.2 A common understanding and wide perspective is key to ensuring that
consultation is effective and focussed on design solutions that are optimal
in the long term. New routes may be in place for many decades and so it is
vital that the design and consultation process has a long-term focus.
1.3 The guidance is intended to be a living document which will be updated
periodically as new ideas, research and technology emerge.
How to use the guidance
1.4 The guidance is designed to be a practical reference document
highlighting the design solutions available and how each can mitigate
noise impacts in certain circumstances.
1.5 Design solutions are therefore described in turn and key characteristics
identified relating to:
 Noise objective,
 Environmental impacts,
 Operational impacts,
 Aircraft capability issues,
 Applicability.
1.6 Departure route options and arrival route option are considered in turn.
1.7 Whilst this document presents potential solutions for individual routes it
must be noted that routes can rarely be designed in isolation from one

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