Article citation information:
Kwasiborska, A., Skorupski, J. Operational restrictions for reducing
noise and the safety of air operations. Scientific
Journal of Silesian University of Technology. Series Transport. 2017, 94,
89-98. ISSN: 0209-3324. DOI: https://doi.org/10.20858/sjsutst.2017.94.9.
Anna KWASIBORSKA[1],
Jacek SKORUPSKI[2]
OPERATIONAL
RESTRICTIONS FOR REDUCING NOISE AND THE SAFETY OF AIR OPERATIONS
Summary. Many European airports are located in close
proximity to residential or protected areas. Aircraft noise emissions caused by
the landing and taking off of aircraft are a big problem in these areas. From
an operational point of view, the method for reducing noise is to reduce
traffic volume or change its organization, especially during the night. Some
procedures and tools have been developed to support air traffic management in
the implementation of operational constraints necessary to maintain noise at an
acceptable level. The objective of this paper is to analyse the effectiveness
of these tools. For this purpose, we have analysed existing methods of
operational noise reduction, taking into account their influence on the
structure, smoothness, punctuality and, especially, the safety of air traffic.
As a result, existing risks have been identified, while methods have been
proposed to combine two important air traffic service tasks: ensuring safety,
while taking into account the environmental constraints, especially in relation
to the acoustic climate.
Keywords: aircraft noise, traffic management, safety of
air operations
1. INTRODUCTION
Aircraft noise generated by aircraft
engines during flight operations (mainly take-offs and landings) depends on
many factors [2, 21]. The most important is the volume of air traffic,
expressed in the number of daily flight operations. Another factor is the type
of aircraft. The noise level depends greatly on weather conditions, such as
wind direction and force, temperature and humidity (these are the parameters
conditioning the propagation of sound waves). An important factor determining
the nuisance of aircraft noise is the time of day in which airline operations
are performed. Night operations are perceived as much more onerous [3].
In recent years, the dynamic
development of air transport has been noteworthy. Airport expansions result in
higher throughput, as well as an increase in nuisance for the surrounding
environment. Indeed, noise is the main source of negative feelings and
reactions among the public towards air transport, which can even impede its development
in the future. In accordance with European regulations, aviation noise must be
continuously monitored [8]. In cases where the standards are exceeded, measures
to mitigate them must be introduced. The most commonly used operating
limitations are those that reduce the amount of traffic (as a whole or at
certain times of the day) or change its structure, for example, by altering the
approach direction or starting procedure.
This paper attempts to analyse how
implemented operational limitations, which are associated with noise, affect
the safety of flight operations. Depending on the planning horizon of changes
in traffic (well in advance or leaving the decision to the air traffic
controller until the last moment), the type of planned changes and the nature
of restrictions (e.g., a total ban on access or simply a suggestion to change
the procedure), the impact of these changes on traffic safety in airport areas
may be different.
The remainder of the article has the
following organization. Chapter 2 presents a review of the literature and legal
regulations limiting noise in airport areas. Chapter 3 presents an analysis of
the possible measures for reducing noise in terms of their scope and impact on
the structure of air traffic. As a result of this analysis, Chapter 4 proposes
the greater use of Quota Counts (QCs), as well as presenting measurements to
show how it is possible to obtain benefits, while highlighting their effects on
air traffic, including its security. Chapter 5 provides a summary and conclusions.
2. LITERATURE REVIEW
The general
framework for combating noise in the EU is set out in Directive 2002/49/EC of
the European Parliament and of the Council of 25 June 2002 [5]. This refers to
the assessment and management of environmental noise and the standardization of
noise measurements. Member countries, in turn, are obliged to draw up action
plans aimed at the prevention of noise in the environment and reducing its
levels.
Directive
2002/30/EC of the European Parliament and of the Council of 26 March 2002 [4]
on the establishment of rules and procedures with regard to restrictions
relating to noise levels at Community airports introduces the need for a
balanced approach to dealing with noise problems at airports. As part of these
activities, analyses should be conducted in order to predict the effects of the
reduction in aircraft noise at source, along with carrying out the spatial
planning and implementation of operational procedures to reduce noise, which is
the subject of this work.
The ICAO document, which contains
guidelines for a balanced approach in the management of aircraft noise, is
Document 9829 [17], which presents four basic methods for reducing noise:
1) reduction of noise and its source
2) spatial planning
3) operating procedures to minimize
noise
4) restrictions on operating activities
The relevant legislative acts
indication a range of different methods, the use of which contributes to noise
reduction. There is a noticeable emphasis in the normative documents on
operational activities that are believed to be the most “profitable” at
reducing noise levels. These are outlined in more detail in Chapter 3. That
said, these documents do not contain an analysis of the effects of introducing
these solutions on safety and liquidity, or the general quality of air traffic.
Methods that have been implemented
in the context of operating activities are the QCS and the “green” Continuous
Descent Approach (CDA). Analysis of the methods for reducing operational noise
levels can be found, for example, in [3], whose authors pointed out that the
QCS method is straightforward but effective, because it assumes the noise level
based on the structure of the aircraft. Other authors have attributed the
success of noise reduction in large part to the quantitative QCS, which allows
for a certain permissible limit on noise at any given time, with each aircraft
assigned a number of QC noise points, separately for take-off and for landing
[10]. Each further operation reduces the available limit by the appropriate
number of points. The first implementation of such a system took place in 1990
at several airports in the UK [11]. Analysis of the literature reveals the
benefits of the system’s implementation for night operations. This is confirmed
by the extensive use of the system at European airports, which indicates the
correctness and relevance of implementation. Although noise at night is the
most troublesome for the environment, the problem concerning the generation of
noise by air traffic also occurs in the daytime. In our work, we propose a
greater use of the QCS during daytime flight operations. For this purpose, we
propose the introduction of quantitative restrictions for QCS operations
performed during the day between 06:00 and 22:00. In the following part is an
analysis of the effects of such a solution in respect of the benefits to the
surroundings of an airport and the risks due to possible (necessary) traffic
diversion.
3. METHODS OF OPERATIONAL NOISE REDUCTION
The overarching objective of
operational noise reduction is to facilitate a change in the characteristics of
aircraft flow such that the noise level is consistent with the prescribed
standards, or, more generally, that flight operations do not cause a nuisance
to the environment. These standards are defined in [4] and presented in brief
in Table 1.
Operational activities related to
noise abatement can be divided into two main groups: soft and hard. The former
involves the use of economic incentives or various kinds of guidance that will
encourage aircraft operators to put operations planning into place that lead to
reducing noise-related nuisance. The latter involves the introduction of
obligatory action involving the redirection of traffic or its physical
limitation.
According to the Act of 3 July 2002
on Aviation Law [8], the airport operator may determine a noise-related airport
surcharge or a distinct a noise fee. In practice, this is a very effective
means of reducing noise, which can be classified as a soft measure.
Table 1. Acceptable environmental noise levels caused by aircraft take-offs,
landings and flights expressed using the indicators LAeq D
and LAeq N
|
Type of land |
LAeqD: |
LAeqN: |
|
a) Protection zone A (health resorts) b) Hospitals, care homes c) Residential areas permanently or temporarily inhabited by children and
young people |
55 |
45 |
|
a) Single and multifamily residential areas, homesteads and housing
estates b) Recreational and leisure areas c) Residential and service areas d) Central areas of cities with populations over |
60 |
50 |
Source:
[4]
The layout and orientation of
runways and taxiways at the airport are factors in the creation of noise
nuisance from flight operations. However, decisions in this area are taken at
the design phase, whereas, in the operating phase of the airport, you can, to
some extent, control the use of these infrastructure elements, for example, by
choosing which runway to use. In addition to purely motion-related criteria,
you can take into account the environmental aspect and minimize the number of
aircraft operations over critical areas or at a critical time (for example, at
night). There are, of course, further-reaching reduction measures available,
including the complete closure of the airport at night. These are hard
measures, as aircraft operators are essentially forced to apply them (except in
special situations, such as emergencies).
In addition to these activities,
noise reduction can be achieved by applying appropriate piloting techniques
combined with appropriate operating procedures, such as implementing the CDA to
landing operations [5]. CDA involves the steady reduction of altitude, while
maintaining the aircraft engines in idle mode (Fig. 1). As a result, the engines produce a noise of low intensity. At the
same time, throughout much of the approach procedure, the aircraft is at a
greater height above the ground, which also reduces noise nuisance on the
ground. It is estimated that, compared to the traditional approach, this method
allows for the reduction of noise by 2-5 dB, depending of course on the type of
airplane, the distance from the airport and weather conditions [13].
In addition,
compared to the traditional “stepped” approach, the aircraft performing the CDA
consumes less fuel, which means the emission of harmful substances is lower.
The above-mentioned anti-noise
operations cannot, however, impair the safe operation of airports. It is
therefore necessary to support ATM services in the form of consulting systems
or experts, which can facilitate traffic planning in both the long and the short
terms. An example of such a support system is the QCS, which facilitates the
coordination of night flights. The main aim of
operational activities using this system is to identify a certain point
limit (related to noise), which cannot be exceeded within a specified time
(e.g., within an hour, night, day etc.). These points (known as QCs) are
determined (allocated) for each flight operation, depending on the acoustic
parameters, on the basis of the certificates of airworthiness of the aircraft
in terms of noise [20]. According to the applied noise scale, the level of
points ranges from 0.25 to 16, which translates into individual operations and
types of aircrafts (see Table 2).
Fig. 1. Scheme of landing approach CDA
Source: [1]
Table 2.
Rule of determining QC points
|
Noise level in EPNdB |
Value of QC points |
|
Poniżej 87
EPNdB |
0.25 |
|
87-98.9
EPNdB |
0.5 |
|
90-92.9
EPNdB |
1 |
|
93-95.9
EPNdB |
2 |
|
96-98.9
EPNdB |
4 |
|
99-101.9
EPNdB |
8 |
|
101.9
EPNdB |
16 |
Source: [20]
Limits on QC points
are determined mostly for night-time air operations, according to the
respective scheduling season, while values can be changed depending on the
results of the monitoring of noise disturbance [19]. For example, at Warsaw
Chopin Airport during summer 2014, 32 QC points were adopted, while operational tactics involving the planning of
operations to the level of 29 points QC was used at the same time. The
remaining 10% limit was regarded as a provision for special operations,
excluded from the coordination process. The benefits of such an approach, as
well as its potential threat to air traffic safety, will be presented in
Chapter 4.
Table
3. Number of QC points depending on the aircraft type and type of operation
|
Type of aircraft |
Landing |
Take-off |
|
Airbus A310 |
1 |
2 |
|
Airbus A318 |
0.25 |
0.25 |
|
Airbus A330 |
0.5 |
2 |
|
Boeing 737-100 |
20 |
20 |
|
Boeing 737-600 |
0.25 |
0.25 |
|
Boeing 747 |
8 |
16 |
|
Antonov An-30 |
20 |
20 |
|
ATR 42/72 |
0.5 |
0.25 |
Source:
own elaboration based on [9]
4. NOISE LIMITATIONS AND SECURITY
OPERATIONS
This chapter
presents the noise measurements for the area around Warsaw Chopin Airport,
which has 10 measuring points located near the runways. The noise monitoring
system is called ANOMS and consists of a computerized network, workstations and
measuring points (Fig. 2).
Fig. 2. Measurement points at Warsaw Chopin Airport
The
measurements at these points are presented in Table 4, showing parameters
related to average acoustic value based
on the data acquired in January 2016.
Table 4. Average acoustic value –
January 2016
|
Measurement
points |
Average value of the sound level
exposition: [dB] |
Standard deviation σ: |
Confidence interval Δ |
Long-term average sound level for
the time of night [dB] |
|
1.
“Załuski” |
93.34 |
6.19 |
0.65 |
56.5 |
|
2.
“Piaseczno” |
78.2 |
3.24 |
0.67 |
43.2 |
|
3. “Mysiadło” |
82.31 |
2.49 |
0.1 |
56.1 |
|
4. “Onkologia” |
86.37 |
3.08 |
0.73 |
45.8 |
|
5. “Meral” |
84.59 |
5.33 |
0.64 |
56.8 |
|
6. “17 Stycznia” |
85.11 |
3.79 |
0.32 |
51.3 |
|
7. “Kossutha” |
79.55 |
3.0 |
0.55 |
48.9 |
|
8. “Ursus” |
83.18 |
3.01 |
0.1 |
56.8 |
|
9. “Zamienie” |
80.45 |
5.48 |
0.7 |
46.8 |
|
10. “Piastów” |
78.25 |
3.09 |
0.14 |
48.4 |
Source: own
elaboration based on [21]
As shown,
the best result and, at the same time, the lowest value in dB were recorded for
Measuring Point 2 (LAeq, LT = 43.2 dB),
while the highest value was recorded for Measuring Point 5 and Measuring Point
8 , both with the same value (LAeq, LT = 56.8 dB). At
all points, the noise limit was observed, so the standard was maintained.
Based on the
identification of aircraft at individual measurement points, the allocation of
QC points was made for flight operations performed during the night
(22:00-06:00) and during the day (06:00-22:00). The presented QC system is
currently deployed at night; but, to illustrate the level of the noise
nuisance, points for aircraft conducting take-off and landing were designated
between 6 and 22 (Table 5).
Table 5. Assigned QC points for
operations performed on 4 January 2016
|
Measurement
points |
Aircraft
operations (A:
landing, D: take off) |
Night 22:00-06:00
|
Day 06:00-22:00 |
|
1. “Załuski” |
A |
11 |
124.75 |
|
2. “Piaseczno” |
D |
2 |
9.75 |
|
3. “Mysiadło” |
D |
7.5 |
5 |
|
5. “Meral” |
A/D |
1 |
4.25 |
|
6. “17 stycznia” |
A/D |
2 |
5.25 |
|
8. “Ursus” |
A |
11 |
111.25 |
|
9. “Zamienie” |
D |
1.5 |
6.75 |
|
10. “Piastów” |
A |
9.25 |
70.25 |
Table 4 does
not include information on Measuring Points 4 and 7 because they did not
register any noise measurement on the reporting day of 4 January 2016. As indicated
in Table 4, the QC point limit was not exceeded on that reporting day at night.
Regarding operations performed during the day, the largest number of QC points
was recorded for Measuring Points 1 and 8.
By
introducing a QC limit for operations performed in the 06:00-22:00 time period
to 90 points, or three times that limit at night, it should be noted that, at
Measuring Points 1 and 8, these limits were exceeded.
If treating
the noise limit appears challenging, then try and think about what kinds of
changes in traffic organization should be made instead. It is noteworthy that
the two Measuring Points that exceed of the proposed QC limit was observed in
relation to the RWY11 runway of Warsaw Chopin Airport. Choosing the direction
of the runway used for landing is dependent on a number of elements, of which
the main one is wind direction. With this in mind, consideration could be given
to temporarily changing the runway used to RWY15 for a certain number of
aircraft. From a noise nuisance point of view, such a change is quite possible,
given that, at Measurement Point 5, there was only a very slight noise level,
while there was nothing recorded at all at Measurement Point 7. Both of these
points are located on the approach path for landing on RWY 15.
However, let
us consider the effects of such changes on the organization of air traffic in
the vicinity of airports from the safety point of view. Even a cursory analysis
indicates that this is disadvantageous. Firstly, in the RWY15 direction, there
is much worse navigation equipment. There are only SALS and PAPI lights. In the
RWY11 direction, as well as ALPA-ATA Category II and PAPI lights, there is
available Category II ILS/DME. Therefore, regarding an alternative direction,
landing can only be made by means of the VOR/DME lights and the approach light.
It seems
that an even greater operational issue, which is closely linked to security,
could occur in respect of the aerodrome traffic. Given that the direction of
RWY15 is not normally used for landing, it is not equipped with an exit
expressway. This is a problem that is mainly related to capacity. However, it
should be noted that the need to decelerate to a very low speed, in order to
exit at the T, H and B taxiways, is a potential threat for a tightly packed
queue of aircraft wishing to land, which is common during peak hours. In such a
situation, any disruption to the process of landing may result in the need to
perform a missed approach procedure, which can be regarded as an adverse
(dangerous) event as it causes a disturbance in planned traffic.
Another
safety problem concerning the use of RWY15 for landing procedures is associated
with taxiing, which most likely involves the taxiway exit marked H2. In this
case, the A7, A6, A5 and A4 taxiways could be used, or the A7, L, E3, E2 and E1
roads. In each of these cases, it is necessary to intersect the other runway,
on which you can expect to find start operations, since, at Warsaw Chopin
Airport, it is a standard rule to use one runway for landings and another for
take-offs. Intersecting a runway that is in use by taxiing aircraft is one of
the main factors contributing to the incidents of runway incursion, which can
have disastrous consequences. The described relationship is connected to the
shape of the network of taxiways and runways, as well as the location of the
passenger terminal.
The above
analysis of the need to reorganize the structure of air traffic, in cases where
the limit on noise nuisance (treated in hard way) is exceeded, shows that this
can have a negative impact on the overall level of aviation safety. Therefore,
how do we reconcile the two most important criteria: maximizing safety and
minimizing the negative environmental impacts? Undoubtedly, the simplest and
probably the cheapest solution is to plan ahead. Assuming that the restriction
imposed by the QCS remains active, the landing approach procedure should be
reorganized so that it takes place in the second direction on RWY 33 (provided
that weather conditions, specifically wind, allow it). In this case, all the
above disadvantages disappear. However, it requires the earlier application of
other procedures of “standard terminal arrival route” diversion. Performing
such an action “at the last minute” is impossible, however.
5. SUMMARY
In summary, the issue of aircraft noise and the policy
of mitigating its impact remain important issues in traffic and safety
modelling. Care for the environment is one of the priorities in terms of
sustainable transport. One of the elements of airport operations is the
reduction of noise disturbance through the use and implementation of systems
and procedures for changing the organization of traffic.
This
article has presented the concept of introducing a QCS during the day, as well
as shown that hard compliance with imposed limitations, without suitably
advanced methods for predicting QC points, will have a negative impact on
traffic safety. Thus, the need has been demonstrated for a more
comprehensive approach to the issue, in which the process of change in the
organization of air traffic, as a result of imposing noise limitations, must be
coordinated. Possible computer systems must include the appropriate module
forecasting of noise load, correlated with a module for supporting air traffic
controllers, while accepting the need to act in relation to a much longer time
horizon.
References
2.
Bartosiewicz
Jacek, Anna Stelmach. 2014. “General assumptions of mathematical modelling the
trajectory of the aircraft during flight and landing procedures on a ‘green
approach’”. Logistyka, Vol. 4.
3.
Directive
2002/30/EC of the European Parliament and of the Council of 26 March 2002 on
the Establishment of Rules and Procedures with Regard to Restrictions Relating
to Noise at Community Airports.
4.
Directive
2002/49/EC of the European Parliament and of the Council of 25 June 2002
Relating to the Assessment and Management of Environmental Noise.
5.
ICAO.
2013. ICAO Environmental Report 2013.
Reducing Aircraft Noise: Aviation and Climate Change. 2016. Available at: http://www.icao.int/oraz.
6.
Aircraft
noise as a local issue of European scale, Magazine Safety security. Peter
Hollingsworth, David Sulitzer. 2010. “Investigating the potential of using
quota count as a design metric”. Proceedings
of the 10th AIAA Aviation Technology, Integration, and Operations (ATIO)
Conference. 2016. https://arc.aiaa.org/doi/10.2514/6.2010-9289.
7.
Hollingsworth
Peter, Sulitzer David, Peter Hollingsworth, David Sulitzer. 2010.
“Investigating the potential of using quota count as a design metric”. Proceedings of the 10th AIAA Aviation
Technology, Integration, and Operations (ATIO) Conference. 2016.
https://arc.aiaa.org/doi/10.2514/6.2010-9289.
8.
Kwasiborska
Anna, Jacek Skorupski. 2014. “Scheduling methods as a tool for solving the
problem of sequencing aircraft”. Prace
Naukowe Politechniki Warszawskiej, Transport, Vol. 101.
9.
“London
Heathrow, London Gatwick and London Stansted Airports noise restrictions notice
2007”. 2016. Available at: https://web.archive.org/web/20110524125439/http://www.boeing.com/commercial/noise/notamfeb2007.pdf.
10.
Department
of Transport. 1993. Night Flights at
Heathrow, Gatwick and Stansted Airports: Proposals for Revised Restrictions
from 24 October 1993. Consultation Paper. London: Department of Transport.
11.
Ollerhead
J.B., H. Hopewell, 2002. Review of the
Quota Count (QC) System: Re-Analysis of the Difference between Arrivals and
Departures. ERCD Report 0204.
London: Environmental Research and Consultancy Department, Directorate of
Airspace Policy, Civil Aviation Authority.
12.
ICAO.
2013. ICAO Environmental Report 2013.
Reducing Aircraft Noise: Aviation and Climate Change. 2016. Available at: http://www.icao.int/oraz.
13.
Regulation
of the Minister of Environment of 14 June 2007 on Permissible Noise Levels in
the Environment (Dz. U. Nr 120 – 5 July 2007, Item 826).
14.
Skorupski
Jacek (ed.). 2014. Contemporary Problems
in Traffic Engineering – Models and Methods. Warsaw: Oficyna Wydawnicza
Politechniki Warszawskiej.
15.
Skorupski
Jacek, Artur Florowski. 2015. “Concept for a system implementation evaluation
process for scheduling aircraft landing”. Scientific
Journal of Silesian University of Technology. Series Transport, Vol. 87:
5-10. ISSN: 0209-3324.
16.
Tomaszewski
Franciszek, Wojciech Misztal. 2012. “The impact of aircraft noise on
the environment”. Mechanics, Vol. 14: 307-313. ISSN 1897-6328.
17.
Act
of 3 July 2002: Air Law. Annex to the Notice of the Marshal of the Polish Sejm
on 31 March 2016 (Item 605).
18.
Warsaw
Chopin Airport. 2016. Available at: http://www.lotnisko-chopina.pl/pl/monitoring-halasu.html.
19.
Warsaw
Chopin Airport. Available at:
http://www.lotnisko-chopina.pl/pl/quota-count-system.html.
20.
Warsaw
Chopin Airport Quota System Table. 2016. Available at: http://www.acl-uk.org/UserFiles/File/EPWA%20QCS%20TABLE%202.pdf.
21.
Kriel
Elmarie, Jackie Walters. 2016. “Passenger choice attributes in choosing a
secondary airport: A study of passenger attributes in using Lanseria
International Airport”. Journal of
Transport and Supply Chain Management, Vol 10, No 1: 1-10. DOI: http://doi.org/10.4102/jtscm.v10i1.256.
ISSN: 2310-8789.
Received 18.11.2016;
accepted in revised form 29.01.2017
Scientific Journal of Silesian University of
Technology. Series Transport is licensed under a Creative Commons
Attribution 4.0 International License