1. travel
2. transports
3. air travel
4. airports

MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
CASA MANUAL OF
STANDARDS (MOS) 139
A review by the Australian Airports Association with the assistance of Aerodrome Design
and the AAA Standards Working Group.
May 2014
1
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
TABLE OF CONTENTS
27
Type C Charts.................................................... 10
28
Viability............................................................. 10
CHAPTER 8.............................................................10
AUSTRALIAN AIRPORTS ASSOCIATION.................4
29Markers............................................................. 11
30
Runway Centreline Width................................. 11
31
Temporarily Displaced Threshold Markings...... 11
32
Passenger Path Markings.................................. 11
33
Wind Indicators................................................. 11
34
Taxiway Edge..................................................... 12
35
Helicopter Standards......................................... 12
CHAPTER 5.............................................................5
36
Use of Gable Markers........................................ 12
3
Aircraft Classification Number (ACN)................ 5
37
Use of Gable Markers........................................ 12
CHAPTER 6.............................................................5
38
Runway Holding Position Markings................... 13
4
Non-Instrument and Instrument Runways....... 5
39
Equipment Clearance Line................................ 13
5
Runway Slope.................................................... 6
40
Equipment Storage Markings............................ 13
6
Runway Line of Sight......................................... 6
41
Apron Road Crossing Taxiway Marking............. 14
7
Characteristics of Runway Shoulders................ 6
42
Apron Road Adjacent Taxiway Marking............ 14
8
Surface of Graded Area of Runway Strip........... 6
43
Airside Road Marking........................................ 14
9
RESA.................................................................. 7
44
Secondary Lead In Line..................................... 14
10
RESA.................................................................. 7
45
Keyhole Marking............................................... 14
11
Surface of Stopway........................................... 7
46
Stopbar Marking............................................... 15
12
Taxiway Edge Clearance.................................... 7
47
Marshaller Stop Line and Pilot Stop Line.......... 15
13
Surface of Taxiway Shoulders............................ 8
48
Alignment Lines................................................. 15
14
Width of Taxiway Strip...................................... 8
49
Secondary Position Marking............................. 15
15
Taxiway Separation Requirement...................... 8
50
Tow Bar Disconnect Marking............................ 15
16Aprons............................................................... 8
51
Push Back Limit Marking................................... 16
17
Helicopter Taxilane............................................ 8
52
Runway Designation Signs................................ 16
18
Separation Distances on Aprons....................... 8
53
Tug Parking Position Lines................................. 16
19
Procedures for Aerodrome Operators to deal
with Obstacles................................................... 9
54
Primary Source of Electricity Supply................. 16
20
Objects that could become Obstacles............... 9
21
Tall Structures................................................... 9
22
Additional Obstacle Assessment for an Existing
Non-Instrument Runway to be Upgraded to a
Non-Precision Instrument Runway................... 9
EXECUTIVE SUMMARY..........................................4
CHAPTER 1.............................................................5
1
Definitions......................................................... 5
CHAPTER 2.............................................................5
2
Transverse Slope on Runway Strip.................... 5
CHAPTER 9.............................................................16
55
Portable Lighting............................................... 17
56
Taxiway Lights................................................... 17
57
Elevated vs Insert Runway Edge Lights............. 17
58
Lighting Colour.................................................. 17
23
Curved Takeoff.................................................. 9
59
Obstacle Lighting............................................... 18
24
PANS OPS.......................................................... 9
60
Visual IWDI Lighting.......................................... 18
CHAPTER 7.............................................................9
61
Approach Lighting............................................. 18
25
Runway Strip Width.......................................... 10
62
Visual Lighting................................................... 18
26
2
Type B Charts.................................................... 10
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
63
General (Visual Approach Slope Indicator
Systems)............................................................ 18
64
Low Intensity Lighting....................................... 19
65
Taxiway Centreline Lighting............................... 19
66
Location of Taxiway Centreline Lights............... 19
67
Location of Taxiway Centreline Lights on Exist
Taxiways............................................................ 19
68
Runway Guard Lights........................................ 20
69
Illustrations of Taxiway Lighting........................ 20
70
Apron Flood Lighting......................................... 20
71
Vehicle Warning Lights...................................... 20
72
Lighting In Vicinity of Aerodromes.................... 20
73
Chances to Reported Australian NOTAM
Office ................................................................ 21
74
NOTAM Request Form....................................... 21
75
Nomination of ARO’s to NOF and CASA............ 21
76
Emergency Planning.......................................... 21
77
Emergency Exercise Exemption......................... 21
78
Frequency of Emergency Exercises................... 21
96
Area Marking.................................................... 26
97
Aerobridge Home and Preselect Positions........ 26
98
Engine Start Designation................................... 26
99
Low Strength Pavement Marking...................... 26
100 Hold Safe Markings .......................................... 26
101 MAGS Size and Location.................................... 26
102 Lighting LEDs..................................................... 27
103 Lighting SMGCS................................................. 27
104 Demand for Track Changes in Aerodrome
Manual.............................................................. 27
105 Use of Displaced Threshold............................... 27
106 Apron Line Marking........................................... 27
107 Side Transitions................................................. 28
108 Apron Markings Needing Clarification ............. 28
109 Wind Socks........................................................ 28
CHAPTER 10...........................................................21
79
Vehicle Lights.................................................... 22
80
Aircraft Parking.................................................. 22
81
Aircraft Parking.................................................. 22
82
Friction Test Standards...................................... 22
83
Navaid Signage and Maintenance..................... 22
84
Light Aircraft Tie-Down Facilities....................... 23
85
Siting of Equipment in Operational Areas......... 23
86
Airservices Australia Navaid Standards............. 23
87
Requirement of NCN......................................... 23
CHAPTER 11...........................................................23
MISCELLANEOUS ITEMS........................................23
88
Definition of Instrument – Non Instrument
Runway............................................................. 24
89
Aircraft Classification Number ......................... 24
90
PANS OPS.......................................................... 24
91
Manual Update RDS.......................................... 24
92
Line Marking..................................................... 24
93
Runway Strip Marking 150 vs 90....................... 25
94
Apron Line Marking........................................... 25
95
Fuel Hydrant Marking....................................... 25
3
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
AUSTRALIAN AIRPORTS
ASSOCIATION
The Australian Airports Association (AAA) is the
national industry voice for airports in Australia. The
AAA represents the interests of more than 260 airports
and aerodromes Australia wide – from local country
community landing strips to major international gateway
airports. The AAA’s members include Adelaide, Brisbane,
Cairns, Canberra, Darwin, Gold Coast, Hobart, Perth,
Melbourne and Sydney airports.
The AAA serves airports across the entire national
aviation infrastructure network. This includes:
• Tier 1 Capital City Airports
• Tier 2 Non-Capital International Gateway Airports
• Tier 3 Major Regional Airports with direct interstate
services
• Tier 4 Major Regional RPT airports without direct
interstate services (with more than 20,000 passengers)
• Tier 5 Regional Airports without direct interstate
services (with less than 20,000 passengers)
• Tier 6 Regional Airports without Regular Passenger
Transport services (general aviation operations only)
• Tier 7 Remote Community Aerodromes (exist for
community service aviation: medical, emergency
flights)
There are a further 100 corporate members who provide
goods and services to airports. The Charter of the AAA is
to facilitate co-operation among all member airports and
their many and varied partners in Australian aviation,
whilst maintaining an air transport system that is safe,
secure, environmentally responsible and efficient for the
benefit of all Australians.
If you have any questions regarding this document please
contact the AAA National Office.
Australian Airports Association
9/23 Brindabella Circuit
Brindabella Park ACT 2609
T: 02 6230 1110
F: 02 6230 1367
E: [email protected]
EXECUTIVE SUMMARY
The primary focus of all involved in the aviation industry
across Australia is to deliver aviation safety to the
Australian public and it is recognised that there are
many elements to ensuring this level of safety. The AAA
recognises the wide scope of responsibilities that CASA
has in establishing a regulatory framework, securing
compliance from the regulations, issuing certificates and
licences and assessing safety-related decisions taken by
industry that impact on aviation safety. The resourcing of
the regulator to perform all these responsibilities is a key
aspect of ensuring that Australia remains at the forefront
of aviation safety.
The Manual of Standards (MOS) Part 139 - Aerodromes
is the set of regulations established and maintained
by CASA which covers all aspects of the operation of
aerodromes. Such an important document, dealing with
highly technical and complex issues, requires regular and
dynamic review.
A major concern for industry is the amount of time
it is taking for CASA to undertake a review and
make the required amendments to the MOS Part
139 – Aerodromes. Some chapters of the MOS 139 –
Aerodromes have been in the process of being reviewed
for over five years.
MOS Part 139 - Aerodromes contains many conflicting
rules and definitions. Even at the most basic level,
differing definitions of what an “aircraft” is exist. As can
be expected, legacy issues have been accruing over the
years, such as new rules that are in stark conflict with
existing rules.
Industry believes a lack of clarity in the MOS Part 139
- Aerodromes has the potential to cause safety risks at
aerodromes and as such, these amendments must be
considered as a priority. The AAA understands a review
was started on certain chapters some years ago, but
no further information has been received from CASA
regarding the outcomes of these reviews.
The AAA has established a Standards Working Group
which brings together the highest skilled, most
knowledgeable individuals in the industry around the
matter of regulation of aerodromes. The purpose of
this Working Group is to review existing standards and,
where appropriate, recommend the development of new
aerodrome standards. This Working Group’s focus is on
the regulations prescribed by CASA.
A priority exercise for this Working Group and the AAA
has been the establishment of the following Issues
Register.
4
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
This exercise provided members of the AAA with a
mechanism to raise issues they have noted with the MOS
Part 139 – Aerodromes, with a view to informing future
discussions between the AAA and CASA regarding the
review and amendment of the standards.
This document outlines all the issues to date that have
been raised with the AAA from across our membership
(both aerodrome operators and consultants to the
industry). Where possible, detailed comments and
recommendations for amendments have been provided
by our members for consideration by CASA.
AAA’s goal is that this document can be used to assist
CASA in a broad review of MOS 139 and serve as a
starting point for further discussions with industry. It is
vital that this cornerstone document be updated and
amended to maintain pace with the evolving aviation
industry to ensure aerodromes continue to operate in a
safe and efficient manner.
CHAPTER 1
1 Definitions
Aerodrome Operator
CHAPTER 5
3 Aircraft Classification Number (ACN)
Aerodrome Operator
Section 5.1.3.9 (Table 5.1-1) – Aircraft ACNs.
Comment
Not all the current aircraft ACN’s are detailed in this table
e.g. Embraer EMB 175, EMB 190.
Recommendation
That the table be updated to include current operating
aircraft ACN’s.
CHAPTER 6
4 Non-Instrument and Instrument
Runways
Section 1.2: Definitions.
Aerodrome Operator
Recommendation
A NCN was issued at an aerodrome in relation to excess
transverse slope on the runway strip, adjacent to a
runway that does not have shoulders.
That Taxiway and Taxilane are to be defined separately,
as the separation distances differ (see section 6.5.2).
CHAPTER 2
Section 6.2.22.2 - The transverse slope of the graded
runway strip adjacent to the runway shoulder, for the
first 3m outwards, must be negative and may be as great
as 5%.
MOS 139 does not cover the case where no shoulder is
provided. In this case, the maximum transverse slope
permitted for Code 3 or 4 runways is 2.5%.
2 Transverse Slope on Runway Strip
Comment
Aerodrome Operator
The 5% allowance is to facilitate drainage away from the
pavement. Over a small width of 3m the 5% slope would
have no impact on aircraft safety, regardless of whether
it was from the shoulder or runway. MOS 139 6.2.23.1
allows a step down from the edge of the runway or
shoulder of 25mm.
Section 2.1.8 and 2.1.9 – lack of definitions.
Comment
Whilst the information is available on what constitutes a
non-instrument or instrument, it is across a number or
sections e.g. definitions 1-8, 2.1.8, 2.1.9 etc.
Recommendation
That definitions be included in 2.1.8/2.1.9.
Recommendation
That Section 6.2.22.2 be reworded to read: “The
transverse slope of the graded runway strip adjacent to
the runway shoulder (or runway edge in the case where
5
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
there is no shoulder), for the first 3m outwards, must be
negative and may be as great as 5%”.
Consideration should also be given to including
a statement similar to “the determination of
transverse slopes results from balancing two opposing
requirements. On one hand there is an advantage in
providing relatively steep runway cross slopes for runway
pavement drainage”. Such a statement would assist
an aerodrome subject to seasonal periods of heavy
precipitation.
5 Runway Slope
Consultant
Section 6.2.6.2 – refers to “large Jet Aircraft” (lack of
definition).
Uniform slope – unclear whether this is to be measured
from the start of the runway or any displaced threshold
location.
Comment
9.1.16.1.1 states “For the purpose of this Section,
aeroplanes bigger than code 3C are treated as larger
aeroplanes. Code 3C aeroplanes and aeroplanes smaller
are treated as smaller aeroplanes”
It appears that the MOS is not clear on a definition of
large jet aircraft, nor where the prescribed distance of
runway with a uniform slope commences i.e. end of
runway, threshold, or the start of the runway.
Recommendation
That clarification/definition for ‘large jet aircraft’ be
provided, as well as clarification on where it is intended
the uniform slope required distance be measured from.
6 Runway Line of Sight
Consultant
Table 6.2-3 - if a Code C, E or F runway is used by Code A
or B aircraft, smaller aircraft are likely to be more critical
with lower eye height (1.5m versus 3m).
Comment
A runway suitable for Code C, D, E or F aircraft can be
unsuitable, in some instances, for small Code A or B in
terms of line of sight. The problem is twofold - a large
aircraft has a much higher pilot eye height, so the pilot
can see for a far greater distance than the pilot of a light
aircraft. A light aircraft only requires in the order of 1000
to 1500m of runway, whereas a pilot of a large aircraft
typically requires 3000m.
6
Applying the requirement for the stricter line of sight
criteria to a large runway construction may impose
prohibitive costs particularly in the case where the
runway will be rarely used by light aircraft. Conversely,
the pilot of a small aircraft will not see a significant part
of the runway designed specifically for large aircraft use.
Recommendation
Consideration be given to amendments that allow for
runway designers to take into account the line of sight
requirements (including where there are intersecting
runways) of all aircraft expected to use the facility.
Consideration may also be given to the following extract
form ICAO Annex 14: “Consideration will have to be
given to providing an unobstructed line of sight over
the entire length of a single runway where a full-length
parallel taxiway is not available. Where an aerodrome
has intersecting runways, additional criteria on the
line of sight of the intersection area would need to be
considered for operational safety”.
7 Characteristics of Runway Shoulders
Aerodrome Operator
Section 6.2.12 - Characteristics of Runway Shoulders
Comment
6.2.12.1 (d) states “… be constructed so as to be capable
of supporting an aeroplane, running off the runway,
without causing structural damage to the aeroplane;
and…”
Recommendation
That clarification be provided to the extent of the
structural pavement required (i.e. 75m wide structural
pavement would have significant implications).
8 Surface of Graded Area of Runway
Strip
Consultant
Section 6.2.23.1 – Any step down to the abutting surface
of a runway strip from a runway, runway shoulder or
stopway must not be more than 25 mm.
Comment
The allowable step down from the runway edge or
shoulder to the grassed graded section only refers for a
downward step tolerance and not an upward step. The
problem is when grass, silt, etc. builds up on the edge of
a runway it creates an earthed step upwards.
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
Without a tolerance, most airports would likely have
no conforming steps on the runway edges. It could
also be construed that every tough of grass is a nonconformance.
the end of the runway. The part abutting the runway
cannot be RESA by CASA’s definition. It could be called
undershoot which is often constructed and sealed
pavement.
Recommendation
Recommendation
That the clause be amended to read: “Any step to the
abutting surface of a runway strip from a runway edge,
runway shoulder or stopway must not be more than 25
mm downwards or XXmm (TBD) upwards”.
That the RESA section and associated clauses be
amended so that when referring to areas abutting the
runway, those areas are clearly identified as undershoot
or something other than RESA.
9 RESA
11 Surface of Stopway
Consultant
Aerodrome Operator
Section 6.2.26 Dimension of RESA – Ambiguity in the
wording
Section 6.2.37- Surface of Stopway
Comment
Section 6.2.25.2 states: “Where it is not practicable to
provide the full length of RESA, the provision may include
an engineering solution to achieve the objective of RESA,
which is to enhance aeroplane deceleration. In the latter
case, aerodrome operators will need to liaise with the
relevant CASA office”. Therefore this section does not
allow a reduction in length, but rather requires measures
in place that would need to provide an equivalent degree
of protection as provided by the full length.
There is no issue with specifying a minimum length
of 90m for Code 3 or 4 air transport jet, however
consideration should be given to the issues in specifying
240m for Code 3 or 4 international airports. Given
the RESA standard was changed some time ago, a lot
of airports would have a problem reaching the 240m
requirement. If it became mandatory, those noncompliant airports would need to seek an exemption.
Recommendation
That amendments be considered allowing for new
runway developments to include the full RESA
dimensions in the design.
10 RESA
Consultant
Section 6.2.29 – Bearing strength of RESA
Consultant
RESA commences at the end of the runway strip, yet it is
called a runway end safety area. More confusing is the
note under Section 6.2.29.1 that provides instruction
on constructing the RESA to half pavement strength at
Comment
Consideration needs to be given to the wording of this
section, as it is difficult to friction test stopways due
to the length and required speed to undertake friction
testing.
12 Taxiway Edge Clearance
Aerodrome Operator
Section 6.3.2 - Taxiway Edge Clearance
Comment
Section 6.3.2.1 states: “Subject to paragraph 6.3.2.1A,
the width of any section of a taxiway must be such that,
with the nose wheel of the aircraft remaining on the
taxiway, the clearance between the outer main gear
wheels and the edge of the taxiway, at any point, must
not be less than the distance determined using Table
6.3-2”.
There may be issues with application of this section to
old/original sections of taxiway versus new/extended
taxiways. Consideration may be given to creating an
allowance for older existing Code E taxiways to be used
for Code F without an exemption requirement – this
would be consistent with clause 6.3.1.1B
Recommendation
That consideration be given for making allowance for
new Taxiway construction (Code F Taxiway) to tie into
existing Taxiway (Code E), with the fillet not meeting the
4.5m Taxiway edge clearance.
7
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
13 Surface of Taxiway Shoulders
16 Aprons
Aerodrome Operator
Consultant
Section 6.3.10 - Surface of Taxiway Shoulders
Section 6.5 - Aprons (it may be useful to cross reference
requirements with CAO 20.9)
Comment
Clarification be provided that the ‘sealed’ section does
not mean structural pavement capable of supporting an
aircraft.
14 Width of Taxiway Strip
Aerodrome Operator
Section 6.3.12 - Width of Taxiway Strip
Comment
Clarification be provided that the Taxiway strip is to be
determined by critical aircraft not the code of aircraft e.g.
B744 = 47.5m or A333 = 45.2m.
15 Taxiway Separation Requirement
Consultant
For Code 3C and 4C, non-precision runway centreline
distances for both codes is shown at 93m. If a 300m
runway strip is required for an airport with a 45m wide
runway, 93m would fall within 150m of the runway
centreline
Comment
Table 6.3-5 allows parallel taxiway serving NPA Code
4C to be clear of the 150m runway strip but within the
flyover area of a 300m runway strip. Table 6.2.18.2
requires a 300m runway strip for Code 3 and 4 aircraft
where the runway width is 45m or more.
The allowance in 6.5-2 appears to be a legacy issue
from when Code 4C aircraft could operate from a 30m
runway under instrument 235A, which has now changed.
Changing the table to require a separation clear of 300m
and would place a number of airports in a position where
they would need to apply for an exemption. This may
also imply an expectation of compliance at some future
time, where compliance may not be possible.
Additionally, Annex 14 does not list a separation for Code
4C in Table 3.1.
Comment
CAO 20.9 provides clearance requirements during aircraft
refuelling from buildings, other aircraft exposed public
areas etc.
Recommendation
Consideration be given to amending Section 6.5 to
include a cross reference to CAO 20.9
17 Helicopter Taxilane
Aerodrome Operator
Example - A taxi lane between the lit Helicopter
Landing Site (HLS) and a set of hangers was observed
by CASA to have an uneven surface that may permit
the accumulation of water, an NCN was issued. This
particular taxi lane is only utilised via air taxi and thus
the accumulation of water would not pose a threat
to helicopter safety. It should be recommended that
taxiways provided for helicopter operations and available
only via air taxi be exempt be from para 6.3.5.1 of MOS
part 139 (Aerodromes).
This standard also applies to aircraft taxiways only with
no mention of helicopter requirements. ICAO Annex
14 Heliport standards should be applied to helicopter
taxiway strips. The new draft CAAP 92-2(2) for Helicopter
landing Sites does not give any guidance on helicopter
taxiway clearances and surface standards.
Comment
It is unclear why, in this particular instance, CASA applied
a fixed wing taxiway standard to a facility solely for air
taxi. There is a general lack of information in MOS 139 on
helicopters.
Recommendation
That MOS 139 be amended to adopt the standards for
helicopters contained in ICAO Annex 14 Volume 2.
18 Separation Distances on Aprons
Aerodrome Operator
Section 6.5.2 - Separation Distances on Aprons
8
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
Recommendation
6.5.2.1 – Amend this clause so that the taxilane strip is
to be determined by critical aircraft, not code of aircraft.
Clarification is also required regarding delineation
between taxiway and taxilane.
6.5.2.2 - Amend this clause to include the standard for
aerobridge clearance IATA 1.5m
6.5.2.3 – Amend this clause to define reduced separation
distance.
CHAPTER 7
19 Procedures for Aerodrome Operators
to deal with Obstacles
Airport Operator
Section 7.1.4.1 - The aerodrome operator must monitor
the OLS applicable to the aerodrome and report to CASA
any infringement or potential infringement of the OLS.
21 Tall Structures
Consultant
Section 7.1.8.3 – Tall Structures Data base is not easily
accessible.
Comment
The Tall Structure Data Bank, under the custodianship
of the RAAF, should be made available to airports and
consultants.
22 Additional Obstacle Assessment for
an Existing Non-Instrument Runway
to be Upgraded to a Non-Precision
Instrument Runway
Airport Operator
Section 7.1.8.5.
Recommendation
That this section be amended to include a statement
that no object is to be allowed to penetrate the Pans Ops
surface (refer to Airspace Regulations).
Recommendation
That this section be amended to remove the requirement
of potential infringements, as aerodrome operators are
governed by protection of airspace regulations.
20 Objects that could become Obstacles
Airport Operator
Section 7.1.6.4 - Temporary and transient obstacles.
Temporary obstacles and transient (mobile) obstacles,
such as road vehicles, rail carriages or ships, in close
proximity to the aerodrome and which penetrate the
OLS for a short duration, must be referred to CASA to
determine whether they will be a hazard to aircraft
operations.
Recommendation
That this section be reviewed, particularly in relation to
re-defining non-aerodrome road vehicles, such as grass
mowers or airfield operations vehicles. Such vehicles
driving outside the 300m runway strip are currently
classified as transient obstacles and the requirement to
refer to CASA is very onerous.
23 Curved Takeoff
Consultant
Section 7.1.9.1 - Curved approach, Section 7.3.2.5 (g)
Curved take off, and Section 7.3.2.11 – it is not clear how
these are defined, nor how to survey and draw.
Comment
It is likely that these assessments need to be performed
on a case by case basis as the requirement is rare.
24 PANS OPS
Consultant
Chapter 7 concentrates on OLS but is short on
information for the more important protection of PANS
OPS surfaces. There may be benefit in considering cross
references to MOS 173.
Comment
This is a very significant item. All aerodromes with an
RPT service plus many others have published instrument
procedures. Very few, other than capital city airports
have PANS OPS plans. Nearly all have OLS plans.
9
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
Also MOS 173 6.1.5.1 states: “Prior to the effective
publication date of a procedure, the certified designer
must forward to the aerodrome operator for which a
procedure has been designed, diagrams and obstacle
data sufficient to enable the aerodrome operator to fulfil
obligations to report and monitor obstacles in the vicinity
of an aerodrome as required under CASR Part 139”.
While this occurs, very few aerodrome operators have
an understanding of the data supplied as it lists obstacles
but does not provide guidance on what is or is not likely
to impact on the procedure design. If details are given of
existing Object A B C etc. both at different locations and
elevations, it is unclear how this assists the aerodrome
operator to determine what new object height and
location would be suitable or unsuitable in terms of PANS
OPS.
Recommendation
Consideration be given to amend MOS 139 to provide
reference material on the construction of PANS OPS
surfaces. This could involve procedure designers working
collaboratively with CASA so that the data provided for
monitoring is clear and easily understood.
25 Runway Strip Width
Aerodrome Operator
Clarification is required in relation to the applicability of
300m wide RWS for Code 4C operations where there is a
45m wide RWY.
Note the interrelationship to Table 7.1-1 OLS
specification for Code 4 Instrument Non-precision
approaches, which provides for a 150m inner edge
where the RWY width is 30m. It is unclear whether this
means, for example, B737 ops approved for narrow
runway (i.e. 30m) do/do not require the full 300m inner
edge and associated transitional surface protection.
However, if the aerodrome happens to have a 45m wide
RWY does it trigger the full 300m inner edge.
Comment
CASA have consistently stated that approval to operate
off a narrow runway width does not flow to other
standards.
The situation works in reverse in the case of aerodromes
having a 45m runway but only catering for a Code 3C
aircraft. In this case the aerodrome exceeds the standard
and it should not be required to have a 300m runway
strip to match the runway as stated in NCNs.
10
Recommendation
That this section be amended so that the width
standards for runway, runway strip, and approach takeoff
inner edge are related to the aircraft type rather than
runway width, where it is appropriate to do so.
26 Type B Charts
Airport Operator
Section 7.2.2.3 - The decision to prepare a Type B chart
must be made in consultation with CASA.
Recommendation
Consideration be given to reviewing the requirement for
a Type B Chart.
27 Type C Charts
Airport Operator
Section 7.2.3.2 - For aerodromes regularly used by
aircraft engaged in international aviation, the decision
to prepare a Type C chart must be made in consultation
with the international aircraft operators and CASA.
Recommendation
Consideration be given to reviewing the requirement for
a Type C Chart.
CHAPTER 8
28 Viability
Aerodrome Operator
Section 8.1.4.1 - Markings must be clearly visible against
the background upon which they are placed. Where
required, on a surface of light colour, a contrasting
black surround must be provided: on a black surface, a
contrasting white surround must be provided
Comment
Consider amending this clause to “may be clearly
visible”, as red staging/storage areas are in contrast to
black background, however the standards require white
surround.
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
29 Markers
Aerodrome Operator
Figure 8.2-1: Cone markers
Comment
Consider the use of other marking for Works limited
markers. In certain locations these markings can be the
cause of safety concerns due jet blast.
Subject to the duration and type of works, The Limit of
Works markers may comprise or be a combination of:
witches hats; yellow lights at night or in poor visibility;
900mm high red/white water barriers; 300mm high red/
white water barriers; Concrete barriers; and or Flagging
tape/rope.
The proposed Limit of Work marking will be stated in the
Method of Working Plan.
30 Runway Centreline Width
Aerodrome Operator
Section 8.3.3.3 states that the required runway
centreline width is 0.45m for Code 3 or 4 NPA runways
and Cat 1 precision approach runways, and 0.9m for Cat
II and III precision approach runways.
It is unclear how this clause would apply to a Cat 1
approach with departures in RVR 350 metres. In such a
case a risk assessment would show 0.9m is needed.
and the use of CASA approved Runway Threshold
Identification Lights (RTILs).
Comment
There are various areas in the standards where markings
are required for runway works, including to identify
a displaced threshold (V Bars etc.) and to mark the
closed portion (crosses) and in some cases to remove
permanent markings. The standards don’t differentiate in
day or night.
Recommendation
That the requirements for markings in this section be
reviewed to take into account situations where the works
are only conducted at night.
32 Passenger Path Markings
Aerodrome Operator
Section 8.5.32.1 - This clause states passenger paths
must be provided in accordance with relevant State
Road Authority marking standards. The traditional zebra
crossing markings cannot always be utilised at a gate and
simpler markings may be more effective.
Comment
Comment
Use of zebra crossing on extended walkways raises
concerns as they are: slippery when wet; an overly
dominant marking on an apron at the expense of aircraft
guidelines; and provide no visual difference if a road
crossing is encountered.
Rather than Section 8.3.3.3 stating the runway centreline
width ‘must be’, a better wording would be the
‘minimum width should be’, giving airports the option of
providing an increased width where a risk assessment
suggests a width wider than the standard is appropriate.
Walkways defined by 2 parallel white lines and a
walking man pictogram are simpler and have been used
effectively at some airports. Zebra crossing markings
could be applied at vehicle intersection points to
highlight risk
Recommendation
Recommendation
That section 8.3.3.3 be amended to read: “the minimum
runway centreline marking width shall be …” with a
recommendation of 0.9m width in the case of runways
allowing departures in RVR of 350m.
That this section be reviewed and amended to allow for
a simple walkway marking combined with zebra crossings
at vehicle intersections points.
31 Temporarily Displaced Threshold
Markings
Aerodrome Operator
Section 8.3.9.1 - Whenever a permanent threshold
is temporarily displaced, a new system of visual cues
must be provided, which may include provision of new
markings, obscuring and alteration of existing markings,
33 Wind Indicators
Aerodrome Operator
Section 8.7.1.2 – NPA approach runways are to have a
wind direction indicator except 8.7.1.2 does not apply
if the surface wind information is provided through an
AWIS. Section 8.7.2.3 – Wind Sock must be yellow if not
intended to be lit at night. Section 9.6.1.2 – If a wind
indicator is provided for straight in approaches at night,
then the wind indicator is to be lit.
11
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
There are examples of airport with an unlit secondary
yellow wind indicator and an operational AWIS.
According to Section 8.7.1.3, a secondary sock is not
required as the AWIS is operational. However, 9.6.1.2
states that if one is provided, then it must be lit and
white.
Comment
This is a case where a secondary sock is provided in
excess of the minimum CASA standard and serves
to assist safety. In such cases MOS 139 should allow
provision of facilities in excess of the minimum without
the operator being exposed to a NCN issue.
Similar issues have occurred at airports with no
shoulders but runway edge lines. Where these are not to
the prescribed width (i.e. 450mm in the case of a NPA),
a NCN has been issued. The removal of a secondary sock
would meet compliance but it reduces safety for small
aircraft operating by day.
Recommendation
That this section be amended to allow provision of
facilities in excess of the minimum standard in cases
where their use enhances safety and does not cause
conflict.
34 Taxiway Edge
Consultant
Section 8.4.5.1 - Taxiway edge markings “must be
provided for paved taxiways where the edges of full
strength pavement are not otherwise visually clear.
Markings must consist of two continuous 0.15 m wide
yellow lines, spaced 0.15 m apart and located at the
taxiway edge, as shown below.” It is not explicitly clear
which part of the marking constitutes the actual edge
of the taxiway. One interpretation is that the outer edge
of the outer yellow line is constituting the edge of the
taxiway.
Comment
The outer edge of the line defines the edge of the
taxiway as formally accepted by CASA standards,
however it has been noted that some CASA inspection
staff have a different interpretation.
Recommendation
That clarification be provided that the outer edge of the
line is the taxiway edge, which is the same interpretation
as used for runway side stripe markings in 8.3.6.3.
12
35 Helicopter Standards
Aerodrome Operator
With the exception of 8.11 helicopters are covered under
two CAAPs rather than MOS 139.
Comment
There is very little useful information on helicopter
standards available within MOS 139. Designers generally
refer to ICAO Annex 14 Volume 2 or material from other
countries.
Recommendation
That consideration be given to adopting ICAO Annex 14
Volume 2 or similar for inclusion in MOS139.
36 Use of Gable Markers
Aerodrome Operator
Section 8.2.2.2 - Runway strip markers must be white,
and may be gable, cone or flush. Gable markers are
preferred, and flush markers must only be used where
runway strips overlap.
Comment
There was an example provided where a CASA audit
has required existing flush markers to be replaced with
gables.
This may be an example of where strictly following the
standard may actually reduce safety, in this instance the
potential for an increased risk of a glider wing strike. In
this example the flush markers are clear and have been
used for many years without incident. Pilots landing
on the sealed runway will concentrate on the painted
runway markings rather than strip markers, regardless of
type, and as such clear makers should be allowed.
Recommendation
That consideration be given to reviewing this section
to allow discretionary application of the clause in
circumstances where rigid compliance results in a
demonstrated reduction in safety.
37 Use of Gable Markers
Aerodrome Operator
There was an example provided where a CASA audit
required existing flush markers to be replaced with
gables.
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
Comment
In this particular example it was recommended that
the Final Approach and Take Off area around HLS be
marked with white gable markers. The intention was
that to enter the area a clearance should be sought from
ATC, similar to entering a graded runway strip. CASA
Surveillance subsequently made the observation ‘white
gable markers delineate the Helicopter Landing Site
adjacent to Taxiway Uniform. The Manual of Standards
(MOS) – Part 139 Aerodromes Sub-Section 8.2.2 states
that the use of the white gable marker is to mark the
graded portion of the runway strip’. Gable markers on
this and another HLS were then changed to blue in
colour although this marking is not recognized in MOS
139.
Recommendation
That this section be amended to include information
on markings for Helicopter Final Approach and Take-Off
Area (FATO).
38 Runway Holding Position Markings
Aerodrome Operator
Figure 8.4-2: Pattern A and Pattern B runway-holding
position markings.
Comment
Clarification is sought on the distance from the runway
centreline to the holding point and whether this includes
markings. It is unclear where the three yellow holding
point lights need to be in relation to the markings (two
broken, two continuous). MOS 139 simply says ‘located
not more than 0.3 m before the intermediate holding
position marking’.
For the figure in question, it is unclear whether half the
runway strip width measurement includes the two solid
and two broken lines (bottom arrow pointing up) or if it
stops at the top arrow pointing down.
Recommendation
That an amendment be made to the diagram to clearly
show measurement points.
39 Equipment Clearance Line
Aerodrome Operator
Section 8.5.8.1 - Equipment clearance lines must be used
on congested aprons to assist service vehicles to keep
clear of manoeuvring aircraft. This marking must consist
of red stripes, 1 m long and 0.15 m wide, separated by
1 m gaps.
The designation ‘EQUIPMENT CLEARANCE’ must
be painted on the side of the line occupied by the
equipment and readable from that side. The designation
must be repeated along the line at intervals of not more
than 30 m. Letters must be 0.3 m high, 0.15 m from the
line, painted red.
Comment
This clause is designed to safely facilitate the prepositioning of GSE service equipment for an operational
turn-around of an aircraft on an apron manoeuvring
area.
The current wording is not clear and therefore it can’t
be determined whether this area can be used to store
GSE. The equipment limit area, when not in use should
be clear with all GSE returned to the Equipment Storage
area.
Unattended GSE parked within the Equipment Clearance
areas after an aircraft departure causes unnecessary
congestion to aprons. As the MOS does not state
GSE must be removed immediately after an aircraft’s
departure, the MOS interpretation is ambiguous in that
GSE can be left within this area indefinitely.
Recommendation
That section 8.5.8.1 be amended to read “Equipment
clearance lines must be used on congested aprons to
assist with the pre-positioning of service vehicles to keep
clear of manoeuvring aircraft. This Equipment Clearance
area is not for storage of GSE. This marking must… etc.”
40 Equipment Storage Markings
Aerodrome Operator
Section 8.5.9.2 - The words ‘EQUIPMENT STORAGE‘ must
be painted in red on the side where equipment is stored,
and readable from that side. Letters must be 0.3 m high
and 0.15 m from the line, as shown below. This marking
must be repeated at intervals not exceeding 50 m along
the boundary.
Comment
There is no guidance marking/dividing the equipment
storage area internally.
Recommendation
That this section be amended to include provisions
permitting airports to divide the storage areas
(internally) and identify vehicle types by markings on
the ground, markings should be white and text size not
greater than the labels marking the storage area.
13
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
41 Apron Road Crossing Taxiway Marking
Aerodrome Operator
Section 8.5.10.1 - Apron service roads to keep vehicles
clear of aircraft and taxiways.
Comment
Recommendation
Consideration be given for this section to include
additional recommended markings for airside
roads etc. preferably in line with the ACI handbook
where appropriate, or alternatively, include a new
Manoeuvrability Limit Area Line marking.
It is unclear how to address airside service roads that fall
within Taxiway/Taxilane strips and whether they should
be zipper patterned or some other new marking.
43 Airside Road Marking
Where airside roads fall within taxiway / taxilane strips
due to lack of space at legacy airports MOS 139 must
provide guidance on how those roads should be marked.
Section 8.5.10.5 - Service road crosses taxiway or apron
taxilane road edge, marking to be zipper patter.
Recommendation
Similar to previous comments in differentiating between
taxiway and taxilane from a driver’s perspective. This
could become complex and the intent of the marking
is to warn drivers of adjacent taxying, rather than use
for control of vehicles. The zipper crossing marking as
developed by the ACI would appear preferable as it
would be internationally recognised, rather than a local
marking.
That this section be amended to provide clearer
guidance on markings for apron road crossing taxiway/
taxilane strips.
42 Apron Road Adjacent Taxiway Marking
Aerodrome Operator
Aerodrome Operator
Comment
Section 8.5.10.4 - Service road adjacent taxying aircraft
side marking must be a continuous double white line.
Consideration should be given to developing a limit line
marking to distinguish/define between apron area and
manoeuvring area or a new Manoeuvrability Limit Area
Line marking which is separate to road markings. This
would assistance in vehicle control on taxiway systems,
ATC radio communication requirements and proposed
future Apron security screening requirements.
44 Secondary Lead In Line
Comment
It has been suggested that this marking is impractical as
it is difficult to paint, difficult to see, appears subservient
to a lead out line and importantly it is not understood by
pilots.
Lime is a difficult colour to paint and may not contrast
well with white. The issue appears to be about vehicle
control adjacent taxiways as opposed to adjacent apron
taxilanes.
The ACI handbook shows a double white line to provide
clearance from adjacent taxying aircraft, irrespective
of taxiway taxilane. The simpler ACI version appears
preferable.
Alternatively - a new Manoeuvrability Limit Area Line
marking that delineates the apron area from the
manoeuvrability area which acts as a boundary from
where radio permission is required with the tower if you
wish to cross the line and also delineates where a higher
level of driver authority is required if you wish to cross
the Manoeuvrability Limit Area Line. This allows only
those with the required additional training to cross the
line managing the greater risks of the Manoeuvrability
Area with higher degrees of training for drivers.
14
Aerodrome Operator
Section 8.5.12.3 - requires lead in at a secondary
parking position to be marked by yellow circles 150mm
in diameter. It is sometimes unclear to pilots what the
purpose of this line is for.
Comment
Recommendation
That this section be amended to remove the
requirement for dots on secondary lead in lines, to be
replaced with a continuous solid yellow line.
45 Keyhole Marking
Aerodrome Operator
Figure 8.5-14: Keyhole marking.
Comment
There is no dimensions provided for the alignment line in
this diagram.
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
Recommendation
Comment
That amendments be made to include dimensions for
the alignment line in Figure 8.5-14: Keyhole marking.
The principle of the 18 m length of the alignment line
forward of the most forward nose wheel is to aid the
pilot of an aircraft to correctly steer the aircraft onto the
relevant Bay. This appears to be an unnecessary length
for the alignment line where there is a positive guidance
aid, either marshalled in or under guidance by a Nose in
Guidance System (NIGS). Both of these guide the pilot as
to their positioning in relation to the alignment lines.
46 Stopbar Marking
Aerodrome Operator
Section 8.15.16.1- Consideration may be given to
including this stopbar for VGDS visual docking guidance
system (NIG) stopbar or other marking.
Comment
Stop bars can be installed to compliment NIGs.
Consideration should also be given to including provision
for another marking (in addition to marshaller and pilot
stop bars) for use at bays with NIGS, particularly fixed
aerobridges.
Recommendation
That this section be amended to either remove the
need for an alignment line forward of the most forward
nose wheel or decrease the required length from 18
m to a maximum of 10 m where marshalling or NIGS
are provided. This will provide flexible options (in Table
8.5.3) where positive guidance is provided to pilots then
a reduced alignment line length can be allowed.
47 Marshaller Stop Line and Pilot Stop
Line
49 Secondary Position Marking
Aerodrome Operator
Section 8.5.20.1 - Secondary markings for 15m wingspan
or greater must be identified by keyhole marking. Where
multiple aircraft stopbars exist on a secondary lead in
line consider adopting marshaller stopbar marking.
Section 8.5.16 and 8.5.17 - Under these clauses there is
no provision for a marking for bays equipped with NIGS.
Comment
It can be assumed that a marshaller stop line should
be used, however with fixed aerobridges this proves
difficult. Stop positions can be less than 300mm which
results in overlapping stop bars. The standards should
permit an abbreviated stop bar for NIGS bays.
There is also no provision for standoff parking positions
where the aircraft is towed on and towed off, the full 6m
x 300mm marking is not required. Both situations can
be achieved with a 100mm wide line approximately 1m
long.
48 Alignment Lines
Aerodrome Operator
Section 8.5.18 - The alignment line must extend from
the location of the nose wheel in the parked position,
backwards under the body of the aircraft for a distance
of ‘X’ in Table 8.5-3. The line must also extend forward,
commencing at a point 3 m past the most forward nose
wheel position and extending for a distance ‘Y’, in the
table. A 1 m long section of the alignment line must be
placed in the centre of the 3 m gap, as shown in Figure
8.5-13.
Aerodrome Operator
Comment
The keyhole works well and has been used with a pilot
stop bar at remote areas. Where marshalling is provided
and it is not practical to stop all aircraft on the same
position, the idea is perfectly sensible. The idea of a key
hole is to show where the nose wheel must be placed.
If there are multiple stop locations then a key hole is no
longer appropriate and standard stop bars should be
installed. Another consideration would be permitting a
combination of keyhole and pilot stops.
50 Tow Bar Disconnect Marking
Aerodrome Operator
Section 8.5.29 and figure 8.2.25 provide details of tow
bar disconnect markings. In addition to the MOS 139
requirements for Tow Bar Disconnect Points, each point
on a common Taxiway and/or Taxilane is numbered
sequentially and annotated with the words “TOW BAR
DISCONNECT”
Tow Bar Disconnect Points are marked along straight
centrelines of a Taxiway, Taxilane or Pushback Line.
The designation marking will be orientated to face the
pushback engineer where practicable.
15
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
Comment
It has been suggested that there is not necessarily a
need to identify tow bar disconnect points, as all tug
operators are trained and understand the marking. But
at a complex layout if there is a risk of confusion it may
be appropriate to give a Bay number associated with a
particular tug released point. The airport should be able
to add additional information as needed.
Recommendation
That consideration be given to amending this section to
allow some flexibility in determining risks and the need
for additional information in the form of line marking,
without the risk of potential non-compliance.
51 Push Back Limit Marking
Aerodrome Operator
Section 8.5.30.1 - Push-back limit markings must
comprise of two parallel white lines at right angles to and
symmetrical about the push back line. The marking must
be 1 m long, 0.15 m wide and lines 0.15 m apart.
Where it is necessary to disconnect a tow bar at a
location where a Pushback Limit marking is also required,
a Pushback Limit marking will be provided combined
with the sequential number for the Tow Bar Disconnect
Point and annotated with the words “TOW BAR
DISCONNECT
Comment
The less line marking the better in terms of avoiding
confusion but where required identification of the push
back limit marking pertinent to a particular bay may be
appropriate in some cases.
53 Tug Parking Position Lines
Aerodrome Operator
Section 8.5.28 -The tug parking position line marking
must be provided at aerobridges and other power-in/
push-out aircraft parking positions, to ensure parked tugs
are clear of incoming aircraft.
Comment
The standards require tug position markings. There have
been examples where some aircraft positions with a
head of stand road, providing tug parking position that
conflicts with the road. As the tug position is intended
to allow for tugs to be on the bay when an aircraft taxies
on, the provision of markings should be on a case by case
basis, such as for locations where a building or other
fixed objects make it difficult to position the tug after the
aircraft arrives. With a head of stand road there is easy
access for a tug to get to the nose. Providing tug position
markings permits the operators to park there and in
some cases the airport operator may not want to allow
this.
CHAPTER 9
54 Primary Source of Electricity Supply
Aerodrome Operator
Aerodrome Operator
Section 9.1.5.3 - where power cannot be supplied by
normal reticulated power, this section allows use of solar
power for use by aircraft with less than 10 passenger
seats. Solar power supplies, coupled with storage, are
arguably becoming increasingly reliable and should
be able to be used at aerodromes intended for use by
aircraft with 10 passengers or more, without the need of
a secondary power supply.
Figure 8.6-8: Runway designation signs with taxiway
location sign.
Comment
52 Runway Designation Signs
Comment
There is no example figure provide for a runway
designation sign placed on the right-hand side of the
taxiway.
Recommendation
That this section be amended to include an example
figure under 8.6-8 of a right-hand side designation sign.
16
The issue is whether solar power, without a backup
generator, is reliable in all conditions – this could be
considered through a risk-based assessment. Concerns
would occur during extended periods of overcast
days. The standard appears to allow solar but requires
a backup generator for air transport aircraft with 10
passenger seats or more.
Recommendation
Consideration should be given to allow solar lighting
systems to be used for registered aerodromes regardless
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
of number of passengers, providing there is adequate
redundancy in place.
minimum distance offset from the taxiway centreline can
be specified if needed.
55 Portable Lighting
It should also be noted that in the case of cone markers,
these must be 500mm yellow cones (MOS 8.2.1.2) and
must be placed on the edge of the taxiway pavement
MOS 8.2.4.2. There is a clear contradiction here.
Aerodrome Operator
Section 9.1.10 - ambiguity exists in the case of solar
portable lights. According to this chapter because of
the variable technology permitted, no light intensity is
specified. Operators have been instructed to conform
with the lighting standards for unserviceability lights
specifying minimum intensity of 10cd, and minimum
taxiway intensity of 5cd, even though the portable solar
lighting according to chapter 9.1.10 does not require
these intensities. This has resulted in considerable extra
cost to the airport.
Comment
The use of portable lights described in 9.1.10 at RPT
aerodromes is to replace unserviceable lights until
permanent lights are urgently repaired. There is no
reference to their use during airside works, which is
where for example portable taxiway and unserviceability
lighting would be needed during airside works. If this was
the case and CASA required the intensities of 10cd and
5cd, there is a good case for clarification as it is a severe
demand to insist on normal lighting intensity outputs
from temporary portable lights during short-term works,
and are covered by WSO supervision and NOATM.
Recommendation
That clarification be provided on what is expected of
temporary lighting used during temporary works. The
expectation that such lighting meets permanent lighting
outputs is unnecessary and unrealistic given the shortterm use and Works Safety Officer surveillance.
56 Taxiway Lights
Aerodrome Operator
Section 9.1.12.1 - Elevated lights must be frangible and
sufficiently low to preserve clearance for propellers and
the engine pods of jet aircraft. In general, they should
not be more than 360 mm above the ground.
Comment
There was an example of an operator that installed lights
clear of the taxiway edge that were below 360mm. This
was not accepted by CASA who stated the lights must be
low enough to be clear of the critical aircraft propellers.
It is not possible to purchase edge lights of different
heights. If there is a risk of propeller damage, then a
Recommendation
That section 9.1.12.1 be amended to remove ambiguity
and confirm 360mm is the allowable height of elevated
edge lights and lights to be placed clear of propeller of
aircraft at the minimum taxiway wheel to edge spacing.
Section 8.2.4.2 is also to be amended state the cones
to mark the edge of the graded taxiway strip, or at least
a suitable distance clear of the apron edge top, remain
clear of aircraft using the taxiway.
57 Elevated vs Insert Runway Edge Lights
Aerodrome Operator
Section 9.1.12.2 - Elevated lights, in general, are
preferable to inset lights, because they provide a larger
aperture from which light signals can be seen. Elevated
lights must be used in all cases except: (a) where the use
of inset lights is specified in this Chapter, or (b) where it
is not practicable to use elevated lights. Technically this is
incorrect as the outputs of elevated and inset lights are
the same.
Comment
Clause (b) allows use of inset lights where elevated lights
are impractical. So in the case of operations by very large
aircraft where there is a risk of jet blast damage, there
should be provision for use of inset lights. At locations
not served by large jets where there is no risk of damage,
elevated lights are probably preferred for the reason
stated in MOS 139.
Recommendation
That this section be amended to allow use of inset
runway edge lights at locations where the aircraft,
through either wheel contact or excessive jet blast,
would cause damage to elevated light fittings.
58 Lighting Colour
Aerodrome Operator
Section 9.2 - The definition of green is different to that
of ICAO. This requires special product development for
a small market, and results in higher RandD costs being
passed on to the airport. It has been argued that the
ICAO standard is better for the reason that it allows for
17
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
easier distinguishing of the colour green, as the green
lies closer to the blue spectrum.
Recommendation
Recommendation
That the IWDI standard be reviewed to become
commensurate with pilot needs rather than a technical
value that is not supported internationally. The method
of testing also needs to be clarified. If a device has been
tested by the manufacturer to show compliance then the
requirement for additional field testing of each installed
unit should be removed.
That the section be reviewed to align with the lighting
colour requirements outlined in ICAO.
61 Approach Lighting
Comment
There is no reason why Australian airport lighting should
differ to that approved by ICAO.
59 Obstacle Lighting
Aerodrome Operator
Section 9.4 - The divergences from ICAO in this instance
are advantageous as they allow for better illumination of
obstacles that may pose a hazard to aircraft
Comment
Although there are differences on this section when
compared to ICAO requirement, there is general support
to retain this section as it currently stands.
60 Visual IWDI Lighting
Aerodrome Operator
Section 9.6 - Clarification is required as to what testing
is required on windsock fittings. All fittings require NATA
approval under chapter 9.1.15.2A
Currently the MOS 139 states that an acceptable
method of testing for illumination compliance is to
measure illumination levels on the horizontal plane
passing through the top of the sleeve at the pole end.
It is ambiguous as to whether the lab or in-situ testing
or both is needed to ensure compliance. This apparent
contradiction has resulted in confusion for both airports
and suppliers.
Comment
The requirement for IWDI is a standard copied from
CAA UK who have since abandoned the requirement
and reverted to a far simpler option. One problem
is the standard differentiates between pre and post
2011 construction. So in essence, if an aerodrome
has a primary IWDI installed pre 2011 it will have less
light output than a secondary installed after 2011. The
method of testing is overlay complex and unwarranted.
18
Aerodrome Operator
Section 9.7 - This section lacks necessary detail. In
a number of areas, this section refers to the ICAO
standard. There is no obvious reason as to why this
section is not simply standardised to the ICAO standards.
Comment
It has been noted that MOS 139 appears to be trending
towards ICAO Annex 14 but sometimes in a piecemeal
fashion. Where the ICAO standard is more practical it
should be adopted.
62 Visual Lighting
Aerodrome Operator
Section 9.9.1.6 – “Where a T-VASIS is to be replaced by a
PAPI, a double-sided PAPI must be provided”. This section
needs to be clarified as it is now implemented on an adhoc basis.
Comment
The requirement for a TVASIS vs a AT VASIS is spelled
out in 9.9.1.5. The T VASIS is required at international
airports hence if replaced it will require a double sided
PAPI (where it is installed at an international airport)
or where CASA have determined that additional roll
guidance is necessary 9.9.1.5 (c).
63 General (Visual Approach Slope
Indicator Systems)
Aerodrome Operator
Section 9.9.1.9 - The choice of T-VASIS or PAPI is a matter
between the Aerodrome Operator and airline operators
using the runway. For capital city runways used by a
range of medium and large jet aeroplanes, T-VASIS would
be a better visual aid.
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
Comment
“T-VASIS would be a better visual aid”, this is a subjective
statement and is outdated, in so far as PAPI being the
standard install across the world.
64 Low Intensity Lighting
Aerodrome Operator
Section 9.10 - Validity of Low Intensity Runway Lighting
systems needs to be reviewed.
Comment
Medium intensity systems are able to be installed at
minimal additional cost, and result in a much more
flexible and energy efficient system. As lamps become
obsolete under government legislation and LED
technology is implemented, the cost of Low Intensity
systems will rise. The RandD cost/benefit will be difficult
to justify.
If low intensity runway lights are upgraded to medium
intensity at a rural aerodrome, there may be a case
where the lights are too bright in the case of an
aerodrome with low-level surrounding light. At some
locations MIRL may be preferable (e.g. places exposed to
regular poor weather), at other locations (i.e. inland arid
regions) the LIRL may still be preferred.
65 Taxiway Centreline Lighting
Aerodrome Operator
Section 9.13.7 - Location of Taxiway Centreline Lights.
Airport have experienced issues over whether curves
or straight lines are acceptable for lead-on taxiway
centreline lights. This requires clarification in the MOS
139.
Comment
66 Location of Taxiway Centreline Lights
Consultant
Section 9.13.7.1 - Taxiway centreline lights must be
located on the centreline of the taxiway or uniformly
offset from the taxiway centreline by not more than 0.3
m.
Recommendation
That this section be amended to read: “Taxiway
centreline lights must be located on the centreline of the
taxiway (within a 100mm tolerance) or uniformly offset
from the taxiway centreline by not more than 0.3m”.
67 Location of Taxiway Centreline Lights
on Exist Taxiways
Consultant
Section 9.13.9.1b - Taxiway centreline lights on exit
taxiways, other than rapid exit taxiways, must have the
first light offset 1.2 m from the runway centreline on the
taxiway side.
Comment
Referring to 9.13.9.1b, the first lead off Taxiway light
needs to be offset by 1.2m in case the Airport operator
decides to install runway centreline lights. The problem
is, the MOS 139 doesn’t require the second light to be
at 1.2m (but in fact, on the line which is at 0.9m). If the
Airport Operator wishes to keep unity with the lights and
the line they will technically be non-compliant.
Exit Taxiway Guidelines in MOS 139, section 9.13.9.1
b) “have the first light offset 1.2m from the runway
centreline on the taxiway side” because the line is at
0.9m O/S from the CL, this first light is the only light not
on the line, which appears incorrect on the ground and it
is not clear why only the first light requires to be offset.
More information is required to determine whether the
issue is a safety concern or a source of pilot confusion.
Better guidance is also required on what constitutes
a “runway entry” taxiway as it is currently open to
interpretation by various Airport Inspectors. If a taxiway
is an “entry” taxiway there are about 30 less light fittings
required when compared to one that is a part of a taxi
route.
It is noted that MOS 139 also allows lights to be offset
from the centreline by 0.3m. Given that the line is at
0.9m (offset from the CL) and a 0.3m offset is allowed
from the line, this would account for the 1.2m. It is also
noted that ICAO only requires a light to be O/S by 1.2m
when the runway has runway centreline lights (if the
Airport does not intend to have Runway Centreline lights,
this in pointless).
Recommendation
Recommendation
That more clarification and guidance be provided around
the requirements for this clause.
That this section be clarified so that it can be determined
if the first light can in fact be placed on the Exit Taxiway
line to match all the other taxiway lights.
19
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
68 Runway Guard Lights
during vertical testing.
Aerodrome Operator
Comment
Section 9.13.16 – Provision of Runway Guard Lights
More information is required in this section, specifically
on how the testing is done (i.e. height of meter, aiming
of meter etc.). There is a need for a practical outcome
so that the end result is lighting that provides clear
illumination around the parked aircraft and does not
dazzle pilots using the apron.
Comment
More specific detail is required in regards to where RGL’s
require installation (i.e. what defines ‘heavy’ traffic). The
flash rate requires the same clarification as provided in
ICAO (flashes per lamp per minute).
Recommendation
That this section be amended to provide a clear
definition of the terms used such as ‘heavy traffic’,
‘congested aprons’, etc. Standards on items used
internationally should preferably align with ICAO where
appropriate.
Recommendation
That this section be amended to review the apron
lighting requirements and provide clear guidance on
how illumination testing is performed and a practical
approach to obtaining the required outcomes in terms of
illumination and limited glare.
71 Vehicle Warning Lights
69 Illustrations of Taxiway Lighting
Aerodrome Operator
Consultant
Section 9.19.1 - Vehicle Warning Lights
Figure 9.15-1(a) - Typical Taxiway Centreline Lights
Layout.
Comment
Comment
Figure 9.15-1(a) is an illustration showing two details,
‘Detail A’ and ‘Detail B’. Detail A appears to show an
example of a Taxiway Intersection with a Runway, at
the Runway End. ‘Detail B’ appears to show an example
of a Taxiway Intersection with a Runway, at Runway
intersections. It is noted that MOS 139 Section 9.13.8.3
does not state which part of the runway/taxiway
intersections each of the detail should apply and within
the industry these are considered as illustrated examples
only. It also does not represent all scenarios for Taxiways
entering a runway.
The spacing of lead on lights shown in “Detail B” is
typical of low visibility requirements.
Recommendation
That clarification be provided for this section on when
and where certain “details” are applicable. These details
should include all information relating to a particular
scenario and not be vague.
70 Apron Flood Lighting
Aerodrome Operator
Section 9.16 - Apron Floodlighting Clarification required
for acceptable method of testing vertical luminance.
Specifically in relation to the orientation of the lux meter
20
Consider including a logical and enforceable requirement
e.g. a flashing light clearly visible in normal daylight from
a distance of not less than 200m.
72 Lighting In Vicinity of Aerodromes
Aerodrome Operator
Section 9.21 -Lighting in the Vicinity of Aerodromes.
There is an exemption required in this section to prevent
contradiction with other sections of MOS Chapter 9 (e.g.
no light allowed above horizontal)
Comment
Section 9.21 provides advice intended for persons
installing lights within a 6km radius of the aerodrome.
Therefore there would not be a requirement to exempt
situations where the airport operator was installing
airport lighting lights in accordance with the mandatory
standards contained in Chapter.
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
Comment
CHAPTER 10
9.
73 Chances to Reported Australian
NOTAM Office
Aerodrome Operator
Section 10.3.2.1 - Where a change in the aerodrome
condition requires a NOTAM to be issued, the nominated
reporting officer must send the notification to the
NOTAM Office (NOF) by FAX or by telephone. Telephone
advice must be confirmed in writing as soon as possible.
Recommendation
That this section be amended to include email
notification, which is ASA’s preference for receiving
NOTAM’s.
74 NOTAM Request Form
Aerodrome Operator
Section 10.4 - there is a need to change the NOTAM
request form outlined in this section, it is obsolete.
Recommendation
That this section be amended to show the current
NOTAM form or provide a current web link to the form.
75 Nomination of ARO’s to NOF and CASA
Aerodrome Operator
Section 10.6.1.1 - requires nomination of ARO’s to NOF
and CASA.
Comment
It is unclear why notification to CASA is still a
requirement, clarification on this section is required.
76 Emergency Planning
Aerodrome Operator
Section 10.7.1 - emergency planning should have a
focus on the emergency response team familiarising
themselves with aircraft cut points.
It has been questioned whether this issue is more of a
matter for the airlines and the combat agencies to work
through, rather than an item for inclusion in MOS 139.
77 Emergency Exercise Exemption
Aerodrome Operator
Section 10.7.1.3 - states if you have an incident it may be
assessed by CASA to replace your exercise. It should also
state that you must apply for exemption.
Comment
Section 10.7.1.3 does not expand on what level of
emergency would replace the requirement to hold an
exercise. It is left to the CASA aerodrome inspector
who may have differing views on what qualifies. An
explanation of what is needed and also the level of
debrief and review following the incident should be
made clearer. There is a level of detail provided in AC 139
07 Aerodrome Emergency Planning.
Recommendation
That this section be reviewed with consideration given to
better alignment with MOS 139 to AC139 07 Aerodrome
Planning.
78 Frequency of Emergency Exercises
Aerodrome Operator
Section 10.8.4.1 – minimum frequency of full-scale
aerodrome emergency exercises.
Comment
Section 10.8.4.1 states the minimum frequency of fullscale aerodrome emergency exercises of two years has
been set after considering international practice and the
cost of mounting such exercises. However, such exercises
should be held annually. This also differs to AC139 07.
Recommendation
That this section be amended to remove the ambiguity
on frequency of AEP exercises. There also needs to be
consideration given to take into account the size of
aircraft and density of aircraft traffic.
21
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
79 Vehicle Lights
Aerodrome Operator
Under MOS Part 139 (Aerodromes) there is no
requirement for the Aerodrome Operator to enforce
the requirement outlined in 10.9.2.6. There have been
suggestions that vehicle warning light requirements
become the responsibility of ground operators and
not the responsibility of the Aerodrome Operator, as
breaches of this requirement are often directly related to
staff disciplinary issues, or 10.9.2.6 be changed to note
the requirement for enforcement. The requirement for
360 degree lighting can also be a glare issue at night and
blind drivers especially on tugs or other equipment with
low mounted warning beacons.
airports have been assessed under the crowded apron
application when in fact the parking bays are rarely at
capacity.
Recommendation
That this section be amended to include clear guidance
on what constitutes a crowded apron.
82 Friction Test Standards
Aerodrome Operator
Section 10.15.2.3 - “designated international
aerodromes” are required to undertake friction testing of
the runway.
Comment
Comment
Section 9.19.1 requires amber yellow or orange warning
lights mounted on the top of the vehicle. Section 10.9.2.6
states vehicles operating on the movement area must be
lit with vehicle warning lights in accordance with 9.19.1,
unless accompanied by a vehicle that is so equipped.
MOS 139 10.15.2.3 states ‘from January 2006,
designated international aerodromes with runways
serving code 4 jet aeroplanes, conducting international
air transport operations, will be required to use an ICAO
accepted continuous friction measuring device with
self-wetting features to measure the friction level of the
runway’. The intent is therefore to capture international
air transport flights regardless of whether there are
customs facilities at the airport. The issue then becomes
what is an international air transport flight. It is unclear
whether this applies to RPT or regular charter. There is
definition of air transport.
Excess beacons can create a hazard and discretionary use
on aprons in some circumstances may be preferred.
80 Aircraft Parking
Aerodrome Operator
Section 10.12.1.1 – “Only applicable at aerodromes
where apron congestion is a problem”. No definition on
‘apron congestion’.
Comment
The lack of definition has left the determination of
what standards apply to the discretion of the CASA
inspectors, which often leads to differences of opinion
and unsatisfactory outcomes.
Recommendation
That this section be amended to include clear guidance
as to the definition of a congested apron.
81 Aircraft Parking
Aerodrome Operator
Section 10.13.1 - This Section is applicable only at
aerodromes where apron congestion is a problem.
Comment
The wording is unclear and needs more direction
on what constitutes a crowded apron. A number of
22
MOS 139 1.1.2 states ‘at this time CASR 121A and
CASR 121B have not been made. In the interim, for the
purpose of this MOS, air transport operations means
either regular public transport operations or charter
operations’. This ‘definition’ covers virtually everything. A
more precise definition is needed (e.g. RPT or charter at
least one per week).
Recommendation
That this section be amended to clearly define the
meaning of air transport and the intent of section
10.15.2.3.
83 Navaid Signage and Maintenance
Aerodrome Operator
Section 10.16 – It has been noted that clearer definition
on this section is required.
Recommendation
That confirmation be sought from Airservices Australia
that the clauses in MOS 139 referring to their specific
requirements are in fact up to date and accurate.
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
(a) 240 m from the end of the runway strip;
CHAPTER 11
84 Light Aircraft Tie-Down Facilities
Aerodrome Operator
Section 11.1.22.2 - This clause states that the tie-down
facilities ‘must be of adequate strength’ for the aircraft
type being secured. There have been examples of CASA
inspectors stating that tie-downs / cables need to be
tested regularly to ensure they can handle the load. This
is not in MOS 139 and airports find it difficult to find
appropriate testers.
Comment
This is another example where discretionary decisions by
the CASA inspector can lead to unsatisfactory outcomes.
The former DCA Airport Technical Instructions gave
details of tie downs including layout, detailed design and
a strength requirement to be capable of resisting a force
of 15KN or 1530 kg. To require operators to check the
load capacity is an unreasonable and costly expectation,
given the lack of evidence of tie downs breaking under
load. The term ‘must be of adequate strength’ cannot
be defined due to variances in wind loads and what
structural load the tie down points on the aircraft can
withstand. If the clause is to remain, MOS 139 should
only recommend that tie downs be suitable for the
intended aircraft use determined through a risk-based
approach by the airport operator.
(b) 60 m from the extended centreline — where the
runway code number is 3 or 4; or
(c) 45 m from the extended centreline — where the code
number is 1 or 2.
It has been questioned why this section is included in
Chapter 11. The purpose of this clause appears unclear
and the dimensions would appear to represent the
dimensions of an ICAO compliant RESA (but without the
requirement for surface preparation).
Comment
The above is part of a suite of sitting requirements for
navigational equipment that are set out in MOS 139.
Depending on frangibility, runway code number and
type of instrument approach, the dimensions vary. The
dimensions are similar but not the same as per the
RESA standard, which does not apply specifically to
navigational equipment.
86 Airservices Australia Navaid Standards
Aerodrome Operator
Section 11.1.7 – DME Facilities.
Comment
Details of sitting requirements restrictions of VOR
and DME are provided under MOS 11.1.6 and 11.1.7
respectively. It is unclear whether these details are
current.
Recommendation
Recommendation
That this section be removed from the MOS 139 or
amended to read: “tie-down facilities ‘are recommended
to be of adequate strength as determined through a riskbased approach by the airport operator’ for the aircraft
type being secured”. Consideration may also be given to
providing the former DCA Airport Technical Instructions
as an Advisory Circular.
That section 11.1.7 be referred to Airservices Australia to
seek confirmation that the requirements are current.
85 Siting of Equipment in Operational
Areas
87 Requirement of NCN
Aerodrome Operator
Section 11.1.4A.3 - Unless its function requires it to
be there for air navigation purposes, for a precision
approach runway Category I, II or III, equipment or an
installation must not be located within the following
distances:
MISCELLANEOUS ITEMS
Aerodrome Operator
There was an example provided where an NCN issued
in relation to contact numbers as advised by Airservices
Australia were out-of-date.
Comment
In the case where no safety issue is involved, it would
be preferred that an observation be made in regards to
23
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
editorial matters in the manual rather than issuing NCNs,
which are time consuming for both the Aerodrome
Operator and CASA.
Recommendation
That the issue of NCNs be applied only where there is a
material safety issue involved. NCNs should not be issued
for minor editorial matters in documentation such as
Aerodrome Manuals.
88 Definition of Instrument – Non
Instrument Runway
90 PANS OPS
Aerodrome Operator
Other than minor references PANS-OPS are not generally
dealt with under MOS 139. It has been suggested that
there would be value in including an information section
(responsibilities, etc.) on PANS-OPS within MOS 139.
Comment
This is a very significant item. All aerodromes with an
RPT service plus many others have published instrument
procedures. Very few, other than capital city airports,
have PANS OPS plans, however nearly all have OLS plans.
Aerodrome Operator
Whilst the information is available on what constitutes
a non-instrument or instrument, it is across a number of
sections (e.g. definitions 1-8, 2.1.8, 2.1.9 etc.).
Comment
To determine if a runway is an instrument runway,
Airservices Australia DAP must show a runway heading
for a procedure. Where no runway heading is shown it
is generally a circling approach (i.e. the runway is non
instrument).
Recommendation
That further clarification be provided in MOS 139 on
what defines an instrument runway.
89 Aircraft Classification Number
Aerodrome Operator
Not all the current aircraft ACN’s are detailed in the MOS
139 (e.g. Embraer EMB 175, EMB 190, and helicopters
(EC225, AW139, Supa Puma)).
Comment
This is true also in terms of aircraft reference codes such
as Pilatus PC12, which is the aircraft used throughout
Australia by the RFDS. The B787 and A380 are also not
mentioned.
91 Manual Update RDS
Aerodrome Operator
There was an example provided of an NCN being issued
as Runway Distance Supplement information in the
Aerodrome Manual was out of date.
Comment
At aerodromes, where trees and vegetation are the
critical object, the gradient information changes with
each annual survey due to growth. In this instance, CASA
required the Aerodrome Operator to update the manual
and to show the revised data. The revision was then
sent to CASA and all recipients who then must update
their records. This is questionable and time consuming
process, particularly when the aerodrome manual is not
considered a likely place for anyone to source this data. It
would be much simpler to allow the addition of a note in
the Manual to refer the reader to the current edition of
ERSA and NOTAMs for all the latest information.
Recommendation
That the requirement for constant update of runway data
in the Aerodrome Manual be reviewed, particularly when
in fact the Manual simply replicates data already issued
in ERSA FAC and NOTAMs. The information is driven by
the survey and published by NOTAM etc. The Manual is
not the source of this information; it is only a copy and
therefore should not be a requirement to include.
Recommendation
That CASA update the list of Aircraft Reference Codes
and Aircraft Classification Number details for all aircraft
models flying in Australia.
92 Line Marking
Aerodrome Operator
Aprons with reverse position bays utilise the exit
line from the primary as the entry line to the reverse
position. Designs such as this have received a NCN.
24
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
Comment
Use of reverse position occurs where requested by the
airlines to enable the aircraft to always park into wind.
Such layouts have never caused any problem with the
airlines. There is nothing unambiguous, unclear or unsafe
for a pilot to follow a designated exit line to a reverse
position. The alternative is to install 2 separate entry and
2 separate exit lines to the one reversible position. This
becomes overly complex and confusing.
South Australia airports universally adopted a simplified
apron marking for the Saab comprising an entry line, Bay
number, pilot stop bar and keyhole nose wheel position.
The exit turn point commenced 1m from the park
position as opposed to the standard 3m. Alignment lines
were omitted where they caused confusion or reduced
in length to avoid conflict with other lines. The modified
layout as originally developed for Kendell (Airlines) at
Adelaide and received widespread acceptance as a far
more practical alternative to the standard marking which
is more suited to larger aircraft i.e. B737.
For example the Saab 340 which due to the Outer Main
Wheel Span is listed as Code C, the same as B737 etc.
when in fact the OMGS has no influence on how the
aircraft turns. Main problems are (a) the mandated
length of the alignment bar of 18m which is so dominant
it can be confused as an exit line and (b) the requirement
to move forward 3m before commencing a turn. In
practice aircraft turn within 1m. The requirement to use
the 3m creates clearance problems on the apron.
Recommendation
That a review be conducted of standard bay markings
with a view to allow simplification in the case of small to
medium sized aircraft to be based on wing tip clearance
rather than Outer Main Wheel Span. There is also a need
to review the function and requirement for alignment
bars.
93 Runway Strip Marking 150 vs 90
Aerodrome Operator
An example of an NCN issued Runway 01/19 is marked
and published in ERSA as 150 m wide runway strip. The
full 150 m wide graded portion of the runway strip is not
available to aeroplanes to traffic due to the presence of
open unlined drains.
allow vegetation to increase in height as the area will
become flyover. The side transitions will be at risk of
becoming lost as there were be no reference markers
to determine the commencement of the 1 in 7. The
improvement in safety following change is questionable.
Recommendation
That the runway strip slope standards be reviewed
to allow some increase in the outer areas where, for
example, an increase transverse slope back towards the
runway actually assist aircraft in staying within the strip
and or returning to the runway
94 Apron Line Marking
Aerodrome Operator
There are no benefits to implementing alignment lines
on bays where aircraft are utilising Nose In Guidance
Systems nor does it seem to present any risks by
mitigating such lines.
The APIS++ NIGS provides the pilot all information to
safely park the aircraft including; aircraft type, and the
aircraft’s lateral and longitudinal position in relation to
the stand’s centreline.
Furthermore, the current alignment line dimensions
outlined in MOS 139 sees the Y distance for codes C, D
and E extending forward 18m commencing at a point 3m
forward of the most forward nose wheel position thus
seeing the alignment lines extending beneath a Terminal
or through a storage area and not within the pilot’s line
of sight or visible to the pilot.
Alignment lines can cause pilot confusion by giving the
false impression that the pilot is required to continue
straight even if the pilot is required to turn earlier on a
curved lead out line.
Recommendation
That the requirement for the alignment line be reviewed
where pilot guidance is provided. The requirement for
alignment lines in general should also be reviewed as
they are known to be a cause of confusion and are a
dominant line compared to the broken exit line in a lot of
cases.
95 Fuel Hydrant Marking
Comment
Aerodrome Operator
The runway strip has been marked at a width of 150m
for at least 30 years and has never drawn comment
from CASA. The outer edge in one area on one side
does not meet gradient criteria (i.e. excess cross fall).
The requirement is to relocate markers to 90m. This will
There have been suggestion for a continuous white
box marking to surround the hydrant to highlight the
location, which can be a raised feature and as such is a
hazard.
25
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
Comment
MOS 139 is silent on hydrant marking, whereas overseas
airports highlight them with a red box, for example.
Recommendation
That CASA, in consultation with airports, develop a
standard to highlight fuel hydrant locations taking note
of ICAO, ACI existing recommendations.
96 Area Marking
Aerodrome Operator
There has been suggestions that Safety Area Marking
is needed to highlight to drivers and pedestrians where
a safety area (i.e. fuel pit, evacuation points, terminal
concourse safety zones or apron drive aerobridge operational area) is located.
There has been a suggestions pf a red line of width
90mm spaced at 600mm intervals on an angle of 45
degrees. Note: Line could be highlighted in white.
Recommendation
That CASA in consultation with airports, develop a
recommendation for marking apron safety areas
preferably similar to the ACI handbook (150mm red with
0.5 – 1.0m).
impact on an adjacent bay or area, a specific engine
start marking designated on the pull forward line is
to be used. This marking is provided to indicate the
aircraft engine start position to engineering staff during
pushback. The designation is to be painted with a black
triangle of width 1.2 metres and height of 1.65 metres.
The letter ‘E’ is to be painted in white within the triangle
to a height of 1.0 metre.
Comment
While there is merit in this concept, care would be
needed to avoid proliferation of markings. It would be
suitable for discretionary use and only where blast has
been identified as a risk.
99 Low Strength Pavement Marking
Aerodrome Operator
The Low Strength Pavement Marking is used to designate
an area which is not designed to withstand the weight
of an aircraft or heavy vehicle. Markings are 8.0m long,
1.0m wide and are spaced at 15.0m centres on straight
sections and 10.0m centres on curved sections.
Recommendation
That CASA in consultation with airports, develop a
recommendation for Low Strength Pavement Marking.
97 Aerobridge Home and Preselect
Positions
100 Hold Safe Markings
Aerodrome Operator
The “HOLD SAFE” marking has been installed to
communicate to drivers that holding short at this
marking will provide adequate separation between a
vehicle and any aircraft using the intersecting taxiway or
taxilane.
These markings are provided to highlight to aerobridge
operators where the Aerobridge and Preselect Positions
are located within the Aerobridge Safety Area.
Comment
MOS 139 does not currently provide guidance on this.
ACI provides a recommended layout with a white painted
circle nose wheel position added.
Aerodrome Operator
Recommendation
That CASA in consultation with airports, develop a
recommendation for airside road Hold Safe Markings
preferably similar to the ACI handbook.
Recommendation
That CASA in consultation with airports, develop a
recommendation for aerobridge preselect position
markings preferably similar to the ACI handbook.
98 Engine Start Designation
Aerodrome Operator
Where a push-back/pull forward operation has a blast
26
101 MAGS Size and Location
Aerodrome Operator
It has been suggested to review the suitability of MAGS
size and location, taking into account new large aircraft
such as the A380 and resultant engine overhang and jet
blast.
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
Comment
The position of MAGS has been cause of concern at
several airports due to potential damage from jet blast
etc. The MOS 139 standard needs urgent review in line
with increasing aircraft size.
Recommendation
That the MAG location requirements be reviewed in
view of the growth in aircraft size, such as the A380, and
potential for jet blast damage.
102 Lighting LEDs
Aerodrome Operator
It has been suggested that MOS 139 needs to be updated
to allow for LED lighting. Low Current Systems are now
able to drive LED lighting at required intensities, though
no mention of them is made in MOS 139. There are
different intensity requirements of LEDs as compared to
halogen lamps.
Comment
This an ongoing issue for standards trying to keep pace
with the introduction of new technology. LED measured
outputs are lower than similar visual output from
halogen lamps.
Recommendation
That the lighting standards be reviewed to take into
account recent advances in technology (i.e. LED). It is
recommended that close alignment occur with ICAO
developments on these and similar issues.
103 Lighting SMGCS
Aerodrome Operator
There is no standard in the MOS 139 relating to A-SMGCS
(Advanced Surface Movement Guidance and Control
System).
Recommendation
That the lighting standards be reviewed with a view to
including A-SMGCS as appropriate. It is recommended
that close alignment occur with ICAO developments on
these and similar issues.
104 Demand for Track Changes in
Aerodrome Manual
Consultant
Various aerodromes have received a NCN for not
showing track changes in the Aerodrome Manual.
Regulation 139.100 states the manual must show (a)
when changes have been made to the information in the
manual; and (b) whether the manual is up to date. In one
case the Aerodrome Operator argued the manual clearly
showed the reader when the changes were made and
when the manual was updated by way of information
contained in the footers of the various parts and sections
of the Manual.
The Reply from CASA stated advised NCN has been
checked by legal advisor and the intent is clear, a method
of track change is required. This appears to contradict
the CASRs and not particularly helpful as access to the
legal opinion was denied.
Recommendation
That CASA review the method of evaluating objections
to NCNs. There is a need for national standardisation on
what constitutes a NCN, as this is currently determined
by individual CASA inspectors.
105 Use of Displaced Threshold
Consultant
Concerns have been raised on variance in CASA
directives when the approach slope exceeds the standard
in Table 7.1-1. In one example a Code 3 NPA runway
with a tree on the extreme edge of the splay gave an
approach gradient of 3.75% compared to MOS 3.3%. In
this instance CASA required a displaced the threshold.
This was questionable as (a) Vee Bar markers are almost
invisible to pilots on a straight in approach and (b) it
cancelled the option for night landing (presumably there
were no spare lights), forcing pilots to land on a single
runway end which may result in a downwind landing at
an increased risks.
In the other similar cases CASA inspectors have allowed
use of MOS 6.2.1, which allows the gradient to increase
to 5%
106 Apron Line Marking
Consultant
Consider reviewing the use of line marking for reference
Code C aircraft irrespective of the size of the aircraft. For
example using the same markings for a 36m wingspan
B737 as for a 22m wingspan Saab causes crowding and
27
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
clashing of the lines. The Saab is a Code B sized aircraft in
every aspect except main gear wheel span.
There is no apparent reason as to why the main gear
wheel span should dictate clearances and size/ extent of
parking position marking.
Recommendation
That CASA review the requirement for aircraft code for
apron line marking to be based on aircraft outer main
gear spacing.
107 Side Transitions
Comment
The demand for compliance with 1 in 7 side transition
clearance from a 300m runway strip at aerodromes with
only 4C aircraft operations for items of small mass (e.g.
floodlight towers) is inconsistent with what is permitted
elsewhere. For example, ILS towers of much greater
mass are constructed within the 300 runway strip at one
major airport and just outside the strip at other majors.
In addition, all aircraft hold for other aircraft using the
runway only 105m from the runway centreline. Section
1.1.1.8 states “In some circumstances, the uniform
application of a particular standard or procedure may not
be possible or necessary”. This appears to be the case
for items of small mass penetrating by small amounts
the side transitions, particularly in the case of a 300m
runway strip.
108 Apron Markings Needing Clarification
Comment
Major airports have identified numerous situations
where they consider line marking detail is absent in
MOS 139. The older major airports have evolved from
an original layout conceived at a time when the planners
would have no knowledge of how modern aircraft were
to develop in size. The resultant changes and need to
adapt leaves the Melbourne apron as an example where
complex lines are required.
Compare Australian major airports to a state of the art
facility such as Kansai Osaka in Japan. The straight linear
apron in comparison is almost devoid of markings. The
layout is so good it does not need many lines to guide
aircraft and other users. So in the case of new additional
line marking standards, it would be preferred that they
be developed as an advisory marking where discretion
to use can be with the Aerodrome Operator. Installation
of additional lines can take place where necessary as
identified in consultation with apron user’s ramp safety
committee etc.
28
109 Wind Socks
Consultant
The wording regarding windsocks is vague – must
be located so as to be free from the effects of air
disturbance caused by buildings or other structures.
Note the reference from MOS 173: “For runway aligned
approaches where a windsock is not located adjacent
to the runway threshold, it must be confirmed that a
windsock is visible when the aircraft is at the MDA, in
accordance with CAO 92.2.”.
A better definition is needed in MOS 139 for clearance
requirements to buildings etc. (e.g. 120 times height) and
a reference to MOS 173 section 7.1.19 and CAO 92.2.
Comment
Consideration to be given on amending MOS 139 to be
clear on what constitutes wind effect and to also cross
reference to the requirement of MOS 173 for windsocks.
MOS 139 - A REVIEW BY THE AUSTRALIAN AIRPORTS ASSOCIATION
This page is left intentionally blank.
29