Evandro J. da Silva 1
                           55 11 3091 5488 evandro.jose@ymail.com

                                   Nicolau D. F. Gualda 1
                               55 11 3091 5731 ngualda@usp.br
                            Escola Politécnica da USP (POLI/USP)
                          Av. Prof. Almeida Prado, Travessa 2, n° 83
                         Cidade Universitária - São Paulo – SP, Brazil
              Received: September 20, 2012; Accepted: August 02, 2013


     An airside compatibility analysis of the São Paulo/Guarulhos Airport regarding the
operation of A380-800 and B747-8 aircraft is presented. The analysis is based upon ICAO and
FAA design standards and their possible flexibilizations. Needs for airside infrastructure
intervention are pointed out, along with flexibilizations that could alleviate those needs. Some
design criteria such as jet blast, fillet dimensions and curve radii are addressed by means of a
comparative approach, considering the new aircraft and others currently under operation at the
     Key words: São Paulo / Guarulhos Airport, Airside, New Large Airplane, International
Civil Aviation Organization, Federal Aviation Administration.

                                                      agency of the United Nations setting forth
1. INTRODUCTION                                       standards related to civil aviation, which must
                                                      be adopted by the signatory countries in their
The onset of A380-800 and B747-8 aircraft             international airports. So far, 191 countries are
families brings up the need for proper airport        ICAO members, including Brazil. On the other
infrastructure, given their size and weight,          hand, domestic airports obey country level
which overcome those of current commercial            established design standards. In this case, a
aircraft.                                             common pattern is the adoption of ICAO design
In this article, the implications of operating the    standards with no major modifications. The
A380-800 and the B747-8 aircraft at the São           alternative solution is the development of a
Paulo/Guarulhos Intl (SBGR) airside are               customized model, taking into account the
analyzed. The design criteria considered are: jet     peculiarities of the country rather than the wide
blast velocities; runway width; runway                standardization prioritized by ICAO. This is the
shoulders width; taxiway width; taxiway               case of the United States FAA (Federal Aviation
shoulders width; blast pad width and length;          Administration), which has a considerably
curve radius in a taxi route; fillet dimensions;      different model, as shown by Silva (2012).
parallel runway/taxiway separation; parallel          In Brazil, ANAC (Agência Nacional de Aviação
taxiway/taxiway separation; and the inner             Civil – National Civil Aviation Agency) is the
transitional OFZ (obstacle free zone).                agency in charge of civil aviation, basically
These analyses are performed according to             following the ICAO model for both domestic
design standards established by ICAO                  and international airports.
(International Civil Aviation Organization) and       The following sections present a concise
by FAA (Federal Aviation Administration),             description of the airside geometric design
taking into account the corresponding possible        standards related documents from ICAO, FAA
flexibilizations.                                     and ANAC.
The article structure is as follows: Section 2
presents a literature review, pinpointing the         2.1. ICAO
documents related to design standards under           ICAO main document concerning aerodrome
consideration; Section 3 discusses ARC                geometric design is the Annex 14 to the
(Aerodrome Reference Code); Section 4                 Convention on International Civil Aviation -
presents the accomplished analysis; and lastly,       ICAO Annex 14 (2004a). In this document, the
Section 5 presents the study conclusions.             design standards related to physical components
                                                      of an aerodrome and to the protection of
2. LITERATURE REVIEW                                  navigable airspace are set forth in chapters 3
                                                      and 4, respectively. ICAO Annex 14 (2004a) is
Design standards play an important role in
                                                      cross associated to several other ICAO
airside geometric design, not only for legal
                                                      documents which also tackle aerodrome
implications, but also for the conceptual gap in
                                                      geometric design, as presented in the following
the field. Textbooks such as Horonjeff &
McKelvey (1994) and Kazda & Caves (2008)
                                                      ICAO Doc 9157 Part 1 (2006a) is a manual that
focus on presenting design standards rather than
                                                      complements ICAO Annex 14 (2004a), by
developing concepts, or investigating the
                                                      addressing runway design. This manual adds
underlying ideas.
                                                      important information such as: i) adjustments
Ultimately, the institutions behind design
                                                      for slope, temperature and elevation for the
standards are government related bodies,
                                                      cases in which these factors are not considered
although other organisms of the air
                                                      in the APMs (Airport Planning Manuals); ii)
transportation industry also contribute. Among
                                                      examples of turn pad geometries; iii) a set of
the government and government related
                                                      aircraft and the corresponding ARC (Airport
institutions, two different branches are worth
                                                      Reference Code); and iv) a study about the
naming: ICAO and FAA. ICAO (International
                                                      relationship between runway slope and aircraft
Civil Aviation Organization) is a specialized

Similarly, ICAO Doc 9157 Part 2 (2005a) is an           the accommodation of NLAs (New Large
ICAO Annex 14 (2004a) complementary                     Airplanes) in existing aerodromes.
manual, concerning taxiways, holding and                Regarding the accommodation of NLAs, two
bypassing areas. In this manual, important              non ICAO documents deserve being mentioned:
methodologies are presented, especially for the         the AACG (A380 Airport Compatibility Group)
design of fillets and rapid exit taxiways, besides      and the BACG (Boeing 747-8 Airport
general considerations about design of taxi             Compatibility Group)2. These documents
routes.                                                 summarize a common position of the industry
PANS-OPS (Procedures for Air Navigation                 concerning the design standard flexibilizations
Services: Aircraft Operations) comprises two            to be accepted for the accommodation of the
documents: ICAO PANS-OPS Volume I                       two new aircraft at existing aerodromes. In
(2006b) and ICAO PANS-OPS Volume II                     addition to the possible flexibilizations, the
(2006c). In these documents, flight procedures          documents provide the associated justifications.
are described in conjunction with the associated
flight path deviations and the subsequent               2.2. ANAC
airspace required to be free of obstacles for the       The main Brazilian regulation aerodrome design
safety of operations.                                   related is the ANAC RBAC 154 (2009a), which
ICAO Doc 9137 (1983), in turn, concerns                 is fundamentally a Portuguese translation of the
airspace protection at a planning level, by             ICAO Annex 14 (2004a), although some
describing the function of airspace protection          recommendations were turned into required
surfaces presented in chapter 4 of the ICAO             standards.
Annex 14 (2004a). These protection surfaces
forbid both natural and manmade obstacles.              2.3. FAA
ICAO Doc 9137 (1983) also compares the
                                                        FAA main regulation concerning aerodrome
surfaces set forth in ICAO Annex 14 (2004a)
                                                        design is the FAA Advisory Circular 150/5300-
and those introduced in PANS-OPS.
                                                        13 (1989), which is complemented by other
Lastly, ICAO Procedures for Air Navigation
                                                        FAA regulations as discussed in the next
Services: Air Traffic Management - PANS-
ATM (2007) concerns air traffic control and
                                                        The EUA e-CFR Title 14 (2010) comprises a set
management. This matter is somehow related to
                                                        of US regulations for aeronautics and space,
the placement of runways in an aerodrome, as
                                                        electronically available from the US GPO
the document tackles in flight aircraft separation
                                                        (Government Printing Office). Specifically, in
                                                        Part 1 of this regulation, abbreviations are
As previously mentioned, design standards
                                                        shown, while Part 77 concerns navigable
flexibilizations are possible solutions when a
                                                        airspace protection, similarly to chapter 4 of
design standard is not deemed possible or
                                                        ICAO Annex 14 (2004a). However, Part 77
convenient. In this context, it is worth noting
                                                        does not present OFZ design standards, which
two ICAO documents, as underneath explained.
                                                        are shown in FAA Advisory Circular 150/5300-
ICAO Circular 301 (2005b) presents a set of
                                                        13 (1989).
studies regarding the utilization of a
                                                        Runway length considerations are presented in
nonstandard OFZ by an aircraft categorized as
                                                        FAA Advisory Circular 150/5325-4B (2005),
code letter F1, such as A380-800 and the B747-
                                                        which establishes a division of airplanes
8. The document presents aeronautical studies,
                                                        according to their approach speed, MTOW
simulations, data analyses and conclusions
                                                        (Maximum Take-Off Weight) and according to
intended to assist States interested in allowing
                                                        the fact of the airplane being or not a regional
flexibilizations in OFZ design standards.
                                                        jet. For regional jets and airplanes weighing
In turn, ICAO Circular 305 (2004b) presents a
                                                        27.200kg or more, the regulation sets the use of
risk assessment methodology to be utilized for
                                                        the APM (Airport Planning Manual). For the
the flexibilization of design standards related to

1                                                       2
   Section 3 may be consulted       for   code letter     Website: https://www.ecac-ceac.org/nla-forum/ Access
categorization.                                         on August, 2011.

other airplanes, a calculation methodology is                   turn, the second term is referred to as airplane
presented.                                                      design group and depends on the more
The flexibilizations of FAA standards aiming to                 demanding of two aircraft characteristics:
accommodate A380-800 and B747-8 in existing                     wingspan and tail height. This term is
airports are issued by the agency through EBs                   represented by Roman numbers from I to VI.
(Engineering Briefs).                                           For nomenclature standardizing purposes, the
                                                                expressions dynamic group and geometric
3. ARC (AERODROME REFERENCE CODE)                               group are herein adopted for reference to the
                                                                first and the second terms of the ARC,
Several design criteria standards rely on ARC                   respectively.
(Aerodrome Reference Code) as a simplified                      In order to establish the relationship between
and direct relationship between a given aircraft                ICAO and FAA ARC coding, Silva (2012)
and the required airport airside infrastructure.                compares a set of 31 aircraft. ICAO and FAA
ARC is a two-term code, in which the first term                 geometric groups are shown to be quite close,
stands for dynamic characteristics of the aircraft              whereas a consistent pattern was not found for
and the other one depends on geometry. ICAO                     dynamic groups. As a result, geometric group
and FAA ARC codifications are quite different,                  specified design criteria may be directly
as follows.                                                     compared, while a more detailed analysis is
According to ICAO Annex 14 (2004a, p. 1-8),                     required when dealing with dynamic group
the first term is referred to as code number and                based design criteria.
depends on the airplane reference field length3.                Concerning ARC, it is worth mentioning that
The codification is based on 4 classes                          both A380-800 and B747-8 fall into ICAO 4-F
represented by Arabic numbers from 1 to 4. The                  and FAA D-VI categories. However, as A380-
second term, in turn, is referred to as code letter,            800 presents larger height and wingspan than
and depends on the most demanding of two                        B747-8, the former may be expected to demand
aircraft features: wingspan4 and wheel span5.                   additional infrastructure, as well as a shallower
The codification is based on the Latin alphabet,                level of flexibilization for design standards. The
from A to F.                                                    largest airplanes currently operating at SBGR,
According to FAA Advisory Circular 150/5300-                    such as A340-600 and B747-400, fall into
13 (1989, p. 1), the first ARC term is referred to              ICAO 4-E and FAA D-V categories.
as aircraft approach category and depends on
the aircraft approach speed6. The representation                4. ANALYSIS
is based on the Latin alphabet from A to E7. In
                                                                This section presents a compatibility analysis
3                                                               according to the criteria listed in Section 1.
   The minimum field length required for take-off at
maximum certificated take-off mass, sea level, standard
atmospheric conditions, still air and zero runway slope, as     4.1. JET BLAST
shown in the appropriate aeroplane flight manual                Jet blast plays an important role on airside
prescribed by the certificating authority or equivalent data
                                                                design, given the risks arising from the high
from the aeroplane manufacturer. Field length means
balanced field length for aeroplanes, if applicable, or take-   speeds and temperatures of jet engines.
off distance in other cases. (ICAO Annex 14 2004a, p. 1-        Common mitigations for jet blast effects
2).                                                             include: separation between aircraft and other
  Wingtip to wingtip distance, measured perpendicularly         aircraft, vehicles and personnel/pax; operational
to aircraft longitudinal axis.
5                                                               procedures, such as limiting thrust level in given
  Distance between the outer edges of the outer wheels,
measured perpendicularly to aircraft longitudinal axis.         areas of the aerodrome; exclusion of non-
   A grouping of aircraft based on 1.3 times their stall        essential objects; erecting of blast fences;
speed in their landing configuration at the certificated        controlling the movement of people and
maximum flap setting and maximum landing weight at              vehicles inside and outside the aerodrome.
standard atmospheric conditions. (FAA AC 150/5300-13
                                                                Silva (2012, p.131-133) presents a classification
1989, p. 1).
  While ICAO establishes 4 categories, FAA codification         of jet blast effects, assessment techniques, and
is based on 5. The fifth was created for Concorde.              related design standards. A direct conclusion of

the study is the contrast between regulations                                                                                           centerline is the datum. It may be observed that
warning about jet blast risks and the lack of                                                                                           B747-8 increments are very slight, whereas
assessment techniques and design criteria.                                                                                              A380-800 calls for attention in this respect.
However, both ICAO and FAA set speed limits                                                                                             On the other hand, a longitudinal datum is not
to jet blast over people and vehicles. Such limit                                                                                       that clear. For this reason, two references are
is 35mph (when converted from 56km/h, from                                                                                              proposed: the nose wheel, which is a taxi
the original document) according to ICAO Doc                                                                                            maneuver reference, and the aircraft rear. Figure
9157 Part 2 (2005a, p. APP 2-1) and 30mph                                                                                               1 displays the related data.
according to FAA Advisory Circular 150/5300-                                                                                            It may be observed that, for take-off thrust level,
13 (1989, p. 77). For the scope of the present                                                                                          B747-8 is the critical airplane, overcoming the
study, the limit of 35mph over people and                                                                                               second in the rank, B747-400, in roughly 155m.
vehicles is chosen, as Brazil adopts ICAO                                                                                               Hence, runway vicinity inside and even outside
regulations.                                                                                                                            the aerodrome may be affected by B747-8
Jet blast analyses herein presented comprise                                                                                            operation. From another standpoint, A380-800
longitudinal and lateral dispersion of velocity                                                                                         operation does not incur additional concerns for
contours at different speed levels on a                                                                                                 runways serving B747-400. From Figure 1,
comparative basis. In this case, the comparison                                                                                         considering breakaway thrust, B747-400 is
involves the new aircraft (A380-800 and B747-                                                                                           found to be the critical airplane. And for idle
8) and two others (A340-600 and B747-400)                                                                                               thrust level, both A380-800 and B747-8 are
deemed as the most critical regarding jet blast,                                                                                        more demanding than B747-400, as shown in
currently under operation at SBGR. The                                                                                                  Figure 1. As a result, the new aircraft require
supporting velocity contours data may be found                                                                                          larger separations for people and vehicles on the
on the aircraft APMs (Airport Planning                                                                                                  apron.
Table 1 compares the lateral dispersion of
35mph velocity contours, in which the fuselage
                                    700                                                                                               800
                                                                                                                                627                                                                                              694
    maximum long. cont. disp. (m)

                                                                                                                                      600                                                                     539
                                    500                                                                     478                                        517               525
                                                    449               458
                                                                                         391                                          500                                                    458
                                                                                                                                      300                                                               243                232
                                                                                                      182                 165
                                    200                                                                                               200                                              141
                                                                                                                                                 103               120           103                                 107
                                    100                                             74                                                      65                74                                   83
                                                                 53                                                  41               100
                                               35                             36                 22
                                      0                                                                                                 0
                                            A340-600      A380-800 TRENT       A380-800           B747-400         B747-8 e B747-8F          A340-600        A380-800 TRENT       A380-800          B747-400        B747-8 e B747-8F
                                                               900              GP7200                                                                            900              GP7200

                                             Idle Thrust 35mph        Breakaway Thrust 35mph          Take-off Thrust 35mph                  Idle Thrust 35mph           Breakaway Thrust 35mph         Take-off Thrust 35mph

Figure 1: 35mph jet blast longitudinal contours dispersion: from aircraft rear (left) and from nose wheel (right)
SOURCE: Compiled from aircraft APMs.

                                                                            Table 1: Increments in 35mph lateral jet blast contours
                                          Thrust level                                         Idle Thrust                                  Breakaway Thrust                                       Take-off Thrust
                                           Aircraft                                A380-800|a                     B747-8                A380-800|a                 B747-8                     A380-800|a                   B747-8
                                           A340-600                                   5m                           -1m                     12m                      1m                           20m                        1m
            B747-400                   7m                                                                           1m                       8m                      -4m                           10m                           -9m
   |a: based on the critical power plant.
   SOURCE: Compiled from aircraft APMs.
Even though FAA and ICAO do not present                                                                                                 disposition of several components in the airside
specific standards for jet blast speeds in excess                                                                                       such as signs, lights, instruments and
of 30/35mph, a proper analysis is required, since                                                                                       pavements, to name a few.
higher speeds directly affect the design and

Once again, a comparative approach is adopted.             Regarding lateral dispersion, A380-800 shows
However, as a consequence of the lack of                   positive increments over A340-600 and B747-
standardization of APMs, it was not possible to            400, whereas B747-8 is even less demanding in
compare all APM presented levels of velocity               this respect at least for breakaway and take-off
contours. Nevertheless, some conclusions may               thrust levels. These results may be due to the
be outlined from Table 2 data.                             position of A380-800 outer engines.
       Table 2: Jet blast lateral and longitudinal increments: A380-800 and B747-8 X A340-600 and B747-400

                                                    Idle Thrust        Breakaway Thrust   Take-off Thrust
         Criterion     Aircraft
                                      (mph)                    A380-             A380-              A380-
                                                  B747-8               B747-8             B747-8
                                                                800               800                800
                                     68              -          5m         -      10m        -      15m
                                    100              -          5m       -0m      10m       0m      15m
                                     50              -           -       -5m        -      -5m        -
                    B747-400        100              -           -         -        -       0m      10m
                                    150              -           -         -        -       0m        -
                                     68              -          5m         -       5m        -      110m
     Longitudinal A340-600          100              -          5m       20m       0m     100m      90m
                                     50              -           -                  -     100m        -
     (from aircraft
          rear)     B747-400        100              -           -        -         -      20m       0m
                                    150              -           -        -         -     -40m        -
    SOURCE: Compiled from aircraft APMs.
      For longitudinal dispersion of jet blast             FOD (Foreign Object Damage) and protect
contours in excess of 35mph, it is found that              adjacent surfaces against erosion.
both A380-800 and B747-8 present augments                  SBGR runways 09L/27R and 09R/27L are 45m
up to 20m, considering idle and breakaway                  wide, thus complying with the ICAO 4-E ARC
thrust level. For take-off thrust level, it is found       established standard. However, the 4-F ARC
that the two new aircraft show augments up to              requires a runway width of 60m, as depicted in
110m over the A340-600. When compared to                   ICAO Annex 14 (2004a, p.3-2), which is a
B747-400, a pattern is not that clear, as the              stimulus to consider the related flexibilizations.
results diverge depending on which contour is              The AACG (A380 Airport Compatibility
being considered.                                          Group) and the BACG (B747-8 Airport
      As a conclusion, it was found that the two           Compatibility Group) present 45m as a common
new aircraft are not necessarily more                      position of the industry for the full bearing
demanding than B747-400 and A340-600 as the                capacity width of runways intended to serve
results vary across different criteria (i.e.,              A380-800 and B747-8.
longitudinal dispersion, lateral dispersion and            AACG position relies on the A380-800
velocity range). Nonetheless, A380-800 is found            certification, whereas BACG presents the
to be the critical airplane regarding lateral              following justifications8: i) planned FAA
dispersion of jet blast velocity contours below            operational approval on 45m wide runway; ii)
and above 35mph, for all addressed thrust                  outer main gear wheel span of 12.7m is similar
levels.                                                    to the 747-400 (12.6m) and well within the
                                                           ICAO geometric group E limit of 14m; iii)
4.2.      RUNWAY WIDTH                                     numerous design changes from the 747-400 to
The full bearing capacity width of runway must             improve lateral handling qualities during takeoff
be such as to accommodate airplane wheels                  or rejected takeoff; iv) otherwise, design
during landing and take-off, considering the
deviations expected to occur. An additional                8
                                                             BACG dates back to November, 2010 when B747-8 had
function of the pavement is to prevent against             not yet obtained certification approval. Hence, some
                                                           justifications may be outdated.

commonality with the 747-400; v) flight deck            this standard, flexibilizations may be
features that improve situational awareness; vi)        considered.
ICAO Circular 301 (2005b) shows maximum                 AACG advocates the use of the ICAO standard
lateral deviation (7.6m) is similar between             (75m wide pavements for runway + shoulders),
landing at sea level vs. 6,500ft (1,981m) altitude      claiming that A380-800 outer engine position
(higher approach speed) in autoland; and vii)           and jet blast contours so demand. The document
aborted take-off max lateral deviation                  also states that, in the case of substandard 45m
requirement for certification of 30 ft (9.1m)           wide runways, the shoulder should be split into
applies to all aircraft sizes9.                         inner shoulder and outer shoulder, each 7.5m
FAA Advisory Circular 150/5300-13 (1989, pg.            wide. As the inner shoulder is immediately
from 25 to 26-1) presents 60m as the standard           adjacent to the runway, its thickness should be
width of a D-VI ARC runway, but                         such as to support aircraft wheels passage with a
flexibilizations may be applied according to            higher incidence than the outer shoulder.
FAA EBs (Engineering Briefs): FAA EB 65A                Shoulder thickness is left to be decided by the
(2007c) allows A380-800 operations in runways           national civil aviation authority in charge.
as narrow as 45m, and FAA EB 74A (2011)                 BACG allows a reduction in the ICAO standard
states the same for B747-8.                             pavement width from 75m to 60m for B747-8.
As a conclusion, it is found that A380-800 and          Again, shoulder thickness of 45m wide runways
B747-8 could operate on 45m wide runways via            is left to be decided by the national civil
flexibilization of design standards, according to       aviation authority in charge. The justifications
both ICAO and FAA rules. This is exactly the            presented are: identical lateral position of B747-
current width of the two SBGR available                 8 engines when compared to B747-400; B747-8
runways.                                                35mph jet blast contour is restricted to a width
                                                        of 60m, which is the same case of B747-400ER.
4.3.   RUNWAY SHOULDERS WIDTH                           FAA Advisory Circular 150/5300-13 (1989,
Shoulders are paved or stabilized surfaces              pgs. from 25 to 26-1) establishes that D-VI
adjacent to both sides of runways. They serve           ARC aircraft be provided with 12m wide
the purpose of protecting aircraft engines              shoulders. Hence the total pavement results in a
against FOD, protecting adjacent surfaces               width of 84m.
against erosion, providing access for emergency         As a flexibilization of this standard, FAA EB
and service vehicles as well as accommodating           65A (2007c) allows A380-800 operations on
eventual passage of aircraft wheels without             paved areas (runway + shoulders) as narrow as
inducing damages to the aircraft. These                 66m. However, this situation must be mitigated
functions, although crucial, permit shoulders to        by means of runway inspection for the presence
be constructed in a more economic way than              of debris after each A380 take-off. So as to
runways.                                                attain a more expeditious operational
So far, SBGR two runways are 45m wide and               environment, a minimum width of 76m should
surrounded by 7.5m wide shoulders, totalizing           be provided.
60m of pavement width.                                  FAA EB 74A (2011), in turn, allows B747-8
 From the regulatory point of view, there is a          operations on paved areas (runway + shoulders)
slight difference whereby ICAO and FAA set              66m wide with no specific need for debris
shoulder width standards. While ICAO specifies          inspections.
the total width of the paved area, comprising the       As a conclusion, it is found that A380-800
runway and the two shoulders, FAA directly              requires a wider pavement (runway + shoulders)
specifies a shoulder width.                             than B747-8, as ICAO 4-F ARC standard must
ICAO Annex 14 (2004a, p.3-2 e 3-5) specifies a          be met, which incurs physical interventions at
pavement total width of 75m for 4-F ARC                 SBGR. On the other hand, B747-8 may be
aircraft, such as A380-800 and B747-8. As               accommodated on paved areas as narrow as
SBGR runways/shoulders do not comply with               60m, based on BACG, which is already met by
                                                        the current airport infrastructure.
  According to the ANAC RBAC 25.149 (2009b), which
is related to aircraft certification.

4.4.   BLAST PAD LENGTH AND WIDTH                     sections, a proper methodology is required to
Blast pads are rectangular surfaces situated          predict wheel deviation. This issue is further
beyond runway extremities. Such surfaces are          discussed in section 4.7.
intended to protect aircraft against FOD events       At SBGR, straight sections of taxiways are 23m
and adjacent areas from erosion, which could          wide, which is the ICAO standard for 4-E ARC
create potentially hazardous exposed edges.           aircraft.
At SBGR, the stopways serve as blast pads, as         As set in ICAO Annex 14 (2004a, p. 3-11), the
aircraft neither land nor take-off touching these     standard taxiway width for 4-F ARC aircraft is
pavements. Stopways are found at both ends of         25m and the standard wheel-to-edge clearance
the two runways, being 60m long and as wide as        is 4.5m.
runway and shoulders together (60m).                  As taxiway standard width is not met at SBGR,
Although blast pads are not mandatory                 the wheel-to-edge clearance should be analyzed.
according to ICAO standards, ICAO Doc 9157            A380-800 landing gear is 14.3m wide, therefore
Part 2 (2005a, pg. APP 2-5) recommends a              requiring a minimum taxiway width of 23.3m
length of 120m for blast pads serving aircraft        (                  ). In turn, B747-8 landing gear
such as A380 and B747. Hence, the current             has a width of 12.7m, hence requiring 21.7m
infrastructure     does     not      meet      this   (                  ) of taxiway width.
recommendation        for   B747-400      already     ICAO flexibilizations and FAA standards and
operating in the airport. Regarding width, the        flexibilizations are examined next.
combined runway and shoulders width should            Based on landing gear width, observed
be applied.                                           deviations, and visibility from cockpit, AACG
FAA Advisory Circular 150/5300-13 (1989,              allows A380 operations in 23m wide taxiways.
pgs. from 25 to 26-1) establishes a standard          BACG also allows B747-8 operation in 23m
length of 120m for D-VI ARC blast pads, while         wide taxiways, based on the fact that this width
the applicable width is the same as that totalized    is enough to attain the 4.5 wheel-to-edge
by runway and shoulders. FAA EB 74A (2011)            clearance.
authorizes B747-8 operation in 66m wide blast         FAA Advisory Circular 150/5300-13 (1989, p.
pads. This is in agreement with the existing          38) establishes a wheel-to-edge clearance of 6m
flexibilization for B747-8 operation in a             and a standard taxiway width of 30m for
runway/shoulder compound width of 66m.                geometric group VI aircraft.
From the standards and flexibilizations just          Nevertheless, FAA EB 80 (2010b) permits a
presented, it may be concluded that an                reduction in wheel-to-edge-clearance up to
expansion in length is recommendable for the          4.5m, which is enough for B747-8 operation in
paved areas beyond runway extremities, even           23m wide taxiways, as previously demonstrated.
for B747-400 operations. Besides, the width of        Additionally, FAA EB 73 (2007b) authorizes
these areas should keep pace with the adopted         B747-8 operation in 23m wide taxiways. In a
runway/shoulder combined width.                       similar fashion, A380 operation in 23m wide
                                                      taxiways is allowed by FAA EB 63B (2007a).
4.5.   TAXIWAY WIDTH                                  Considering the straight section of taxiways,
The width of the full bearing capacity portion of     A380 operation tends to be permitted at SBGR
a taxiway in straight routes must be such as to       current taxiways, via flexibilization of design
accommodate landing gear width and taxi               standards. On the other hand, B747-8 already
deviations expected to occur. Curved sections         complies with the standard wheel-to-edge
require additional width, as wheels further           clearance.
deviate.                                              4.6.   TAXIWAY SHOULDERS
Although ICAO and FAA specify standards for
taxiway width, wheel-to-edge clearance is             Taxiway shoulders basically serve the same
ultimately the design principle in both               purpose as runway shoulders, whilst thrust
regulations. Hence, minimum taxiway width             levels exerted differ.
will be the sum of landing gear width plus twice       At SBGR, taxiways are 23m wide in straight
the wheel-to-edge clearance. For curved               sections, and taxiway shoulders are such as to

complete a compound width of 44m, complying                    It can thus be concluded that B747-8 can be
with ICAO 4-E ARC standard.                                    authorized to operate in the current combination
However, ICAO Annex 14 (2004a, p. 3-11 e 3-                    of taxiway and shoulders, through the
15) specifies a compound width of 60m for                      flexibilization of design standards. A380-800,
taxiways and its shoulders, considering the 4-F                on the other hand, is expected to call for a 60m
ARC standard.                                                  wide pavement. This means expanding the
Examination of ICAO flexibilizations, as well                  current shoulders from 10.5m to 18.5m,
as FAA standards and flexibilizations are next                 assuming taxiway width is retained in 23m.
                                                               4.7.    CURVES AND FILLETS
AACG does not propose flexibilization for the
standard under consideration, mentioning that                  When taxiing on an aerodrome, aircraft perform
A380-800 engines position and jet blast                        curves through stands, aprons, taxilanes,
contours demand compliance with the standard.                  taxiways, bypasses, holding bays and turn pads.
However, BACG authorizes B747-8 operation                      As an aircraft negotiates a curve, wheels,
on a taxiway/shoulders compound width of                       wingtips, stabilizers and other parts will deviate
44m, considering that B747-8 has: the same                     from the guideline followed by a reference
outer engine span as B747-400; a 35mph jet                     point, which is usually the center of the cockpit.
blast lateral contour close to B747-400ER; and                 Accordingly, predicting the relationship
slight higher thrust center of outer engines as                between the reference point position and other
compared to B747-400.                                          aircraft parts is essential for the design of
FAA Advisory Circular 150/5300-13 (1989, p.                    several aerodrome components. Another
38) specifies 12m wide shoulders, causing the                  concern regards the maneuverability limitation
combined pavement width to be 54m for D-VI                     of airplanes in terms of the nose wheel
aircraft. Conversely, FAA EB 73 (2007b), based                 maximum steering angle. As set in appendix 10
on preliminary jet blast data, authorizes B747-8               of FAA Advisory Circular 150/5300-13 (1989),
to operate in a combined width of 44m (23m for                 nose wheel steering angle should not exceed
taxiway and 10.5m for each shoulder).                          50°. Silva (2012) may be consulted for further
                                                               discussion on ICAO and FAA methods and
                                                               standards related to curves and fillets.
                             Table 3: Wheel span, d and dnw data of selected aircraft
                                           Longitudinal distance from
        Aircraft         Wheel span        cockpit center to nose wheel         Aircraft reference length | ( ) |a
                                                      (    )
       A340-600             12.6m                       4.2m                                  37.4m
       B777-300             12.9m                       3.6m                                  34.2m
       B747-400             12.6m                       2.3m                                  26.4m
       A380-800             14.3m                       2.1m                                  31.9m
         B747-8             12.7m                       2.4m                                  30.5m
  |a: Longitudinal distance from cockpit centre to the centroid of fixed wheels (no steering capability).
  SOURCE: Aircraft APMs.
  The present approach to the matter is                         will be, where d is measured from the cockpit
  comparative, where the A340-600, the B777-                    centre (point N) to the landing gear geometric
  300 and the B747-400 are the reference                        centre, just considering fixed wheels (no
  aircraft. By comparing these airplanes to                     steering capability). Nose wheel steering angle
  A380-800 and to B747-8, fillet dimensions and                 (βnw), in turn, is directly proportional to β and
  the maximum nose wheel steering angle are                     to dnw1. Hence, βnw is directly proportional to d
  analyzed.                                                     and dnw. As a consequence, if a given aircraft
  The aircraft steering angle (β) is directly                   has both d and dnw larger than other, β and βnw
  proportional to the aircraft reference length (d)
  and inversely proportional to the curve radius                1
                                                                  Distance between nose wheel and the cockpit centre
  (r). It follows that the higher d is, the higher β            (point N).

will be higher. This means that the second            checked: OFZ (obstacle free zone)2, runway
aircraft can follow the same path than the first      holding position, runway and taxiway safety
one.                                                  areas, rapid exit taxiways and curve radius in
From the data in Table 3 it is easy to conclude       the runway/taxiway route.
that, regarding nose wheel steering angle,            Annex 14 (2004a, p.3-13) sets a standard
A340-600 and B777-300 are more demanding              separation of 190m between a runway and the
than A380-800 and B747-8.                             parallel taxiway, if the runway is an instrument
On the other hand, further analyses are               one and the aircraft expected to be
required to assure that design clearances are         accommodated is 4-F ARC classified. This
not violated, as the track of specific parts of an    separation standard is set to protect a runway
airplane depends upon both β and aircraft             safety area required by ICAO: the runway
geometry. For instance, wingspan is higher in         strip. This area is set to be 300m wide for
the two new aircraft, which requires a detailed       instrument runways serving aircraft belonging
analysis of the combinations between a lower          to the fourth dynamic group of ARC.
β and a higher wingspan. However, for the             (                             .
scope of the present study, only the wheel            For the scope of the present study, solely the
track is assessed.                                    distance between runway 09L/27R and
Again, from Table 3, B747-8 may be deemed             taxiway B is analyzed. Such separation is
as less demanding, as both figures of wheel           approximately of 184m, hence substandard.
span and d are lower as compared to B777-             If the runway strip width is considered, B747-8
300.                                                  almost fits the current separation, as its
However, A380-800 situation is a bit less             wingspan                  is              68.4m.
clear, given its larger wheel span. Hence, a          (                               ). On the other
detailed analysis was carried out, taking into        hand, A380-800, with a wingspan of 80m,
account the methodology depicted in ICAO              would infringe the standard by 6m. This is a
Doc 9157 Part 2 (2005a).                              reason to search for design standard
It was found that A380-800 wheels are                 flexibilizations.
confined inside the tracks drawn by A340-600          AACG claims that 190m is conservative, but
wheels. Hence, curves and fillets which are           does not present a specific flexibilization for
enough for A340-600 are also enough for               the A380-800. Conversely, BACG allows a
A380-800, as the same wheel-to-edge                   reduction of separation standard up to 182.5m
clearance applies.                                    for B747-8, even though the document
It may be concluded that B747-8 is easier to          recommends an in site ILS interference
accommodate than A340-600 and B777-300,               assessment.
which already operate at SBGR. Thus, the new          FAA Advisory Circular 150 5300-13 (1989,
Boeing airplane can, at least, taxi through the       pg. from 14 to 15) establishes a standard
same routes negotiated by the mentioned               separation of 168m plus OFZ adjustment in
airplanes. A380-800, in turn, is less demanding       higher than sea level locations. Considering
than A340-600.                                        FAA Advisory Circular 150 5300-13 (1989,
                                                      pg. 22) standards for OFZ, in CAT II/III
                                                      conditions, it was found that the current 184m
                                                      separation would allow a clearance of 0.3m for
Runway to parallel taxiway separation                 the A380-800 and a clearance of 6.6m for the
standard is such as to protect aircraft landing,      B747-83.
taking-off or taxiing. To protect airplanes
situated on the entrance taxiways between
runways and parallel taxiways, additional             2
separation may be necessary to protect                 Discussed on item 4.10.
                                                       Section 4.10 provides OFZ assessment information.
navigational    aids     from      interference.      Additionally, further data is required to assure that the
Additionally, other design items must be              mentioned clearances are enough to account for

For B747-8, according to EB 81 (2010a),                  less restrictive scenarios, flexibilizations may
geometric group V separation of 150m is                  be considered.
allowed. Such flexibilization relies on the fact         AACG allows a reduction in wingtip clearance
that B747-8 is inside the geometric group V              down to 11m. The justifications are: Air
tail height range.                                       Navigation Plan – ICAO European Region –
 From the information presented, it is found             Reduced Separation Distances for NLA
that the current separation between runway               operations (the same 11m buffer as 747-400);
09L/27R and taxiway B may be authorized via              Taxiway deviation statistics analysis (existing
flexibilization of design standards. Regarding           and ongoing analyses); A380 Cockpit
ILS interference, in favor of B747-8 is its tail         visibility. As a consequence, simultaneous
height that is the same as that of B747-400.             operation of an A380-800 and an aircraft with
On the other hand, for A380-800, there are no            a wingspan up to 78m could be allowed.
possible flexibilizations, with the exception of         (                                  )).
OFZ standards, as presented in ICAO Circular             BACG also allows reduction in wingtip
301 (2005b).                                             clearance to 11m, based on: Air Navigation
4.9. PARALLEL TAXIWAY TO TAXIWAY                         Plan – ICAO European Region recommended
SEPARATION                                               reduced separation distances for 747-400
                                                         operations with 11m wingtip clearance;
Taxiway separations are based on aircraft
                                                         Taxiway deviation statistics analysis; AACG
geometry and taxi expected deviations.
                                                         agreement of 11m for A380, if taxiway centre
Depending on what part of an aerodrome the
                                                         line lighting or equivalent guidance is
aircraft taxies, speed varies, as well as the
                                                         available. Considering these flexibilizations,
objects surrounding taxi route. Hence,
                                                         two B747-8s or even a B747-8 and a A380-800
associated risks and potential harms also differ.
                                                         may simultaneously operate on taxiways A and
It follows that taxi routes and required
standards are also different. Silva (2012)
                                                         FAA Advisory Circular 150/5300-13 (1989,
discusses     these   differences    and     the
                                                         pg. 16) sets 99m as the standard separation and
terminology used by ICAO, ANAC and FAA.
                                                         a wingtip clearance of 19m. No related EBs
For the purpose of this study, the separation
                                                         were found.
between parallel taxiways A and B is analyzed.
                                                         It may be concluded that A380-800 and B747-
Such separation is approximately 90m.
                                                         8 may operate on taxiways A and B, given
According to ICAO Doc 9157 Part 2 (2005a,
                                                         proper restriction is applied on the parallel
pg. 1-11), 97.5m is the standard separation
                                                         taxiway. Flexibilization of design standards
between parallel taxiways serving geometric
                                                         may alleviate such operational restrictions.
group F aircraft, and a wingtip clearance of
17.5m would allow an equivalent level of                 4.10.   OFZ (OBSTACLE FREE ZONE)
safety.                                                  So as to protect the airspace surrounding an
As easily perceived, the current separation is           aerodrome, ICAO and FAA establish a set of
substandard. However, the wingtip clearance              imaginary surfaces which should not be
principle allows simultaneous operation of               protruded by natural or manmade objects. Such
A380-800 and an aircraft with a wingspan not             surfaces start close to the runway and may
larger                than                 65m.          extend dozen of kilometers beyond airport
(                                  )). For the           limits. Different criteria may apply also
B747-8 case, an airplane with a wingspan up to           depending on the fact of the object being fixed
76.6m could operate concomitantly in the                 or movable.
parallel taxiway with no need of standard                Additionally, there are two ways for tackling
flexibilization                                          these surfaces and related criteria: while some
(                                        ). For          specifications are intended for operational
                                                         level, others are oriented to long term
                                                         planning, allowing the establishment of an
differences in ground level between the runway and the
taxiway under examination.                               ideal environment in terms of safety, capacity

and economics. For instance, an antenna,
depending on its position and height, may
cause aerodrome operating minima to be
increased, thus diminishing airport usage in
days of bad weather. ICAO Annex 14 (2004a),
in its chapter 4, presents related standards and
recommendations, whereas FAA standards
may be found in EUA e-CFR Title 14 (2010).            Figure 2: Example of an inner transitional OFZ as
As operations are allowed under lower                 seen in a frontal view of the associated runway
visibility conditions, airspace should be further     SOURCE: Prepared by the author from ICAO and FAA
                                                      OFZ descriptions.
protected in the very vicinity of the runway. In
this context, both ICAO and FAA specify a set
of surfaces together referred as OFZ (obstacle
                                                      Case i:
free zone). Beyond these imaginary surfaces,          According to ICAO criteria, the inner
no objects, fixed or movable, may be allowed,         transitional OFZ clearance is 75m for A380-
unless deemed as essential to operations and,         800 and 80m for B747-8. According to FAA
in this case, mounted on frangible structures.        criteria, these clearances would fall to 30m and
Silva (2012) presents a set of equations              35m, respectively. Hence, the presence of an
intended to assess a specific OFZ surface,            A380-800 or B747-8 on a runway would not
called inner transitional OFZ, which is a key         protrude the inner transitional OFZ of the
criterion     when      designing     aerodrome       parallel runway.
components situated sidewards the runway, as
parallel taxiways, holding positions and so           Case ii:
forth.                                                According to ICAO criteria, the inner
Inner transitional OFZ has its origin at a given      transitional OFZ clearance is of 11m for A380-
distance aside the runway, and extends                800 and 16m for B747-8. According to FAA
orthogonally to runway axis, possessing an            criteria, these clearances would fall to 0.3m
upward inclination. Figure 2 illustrates that         and 6.6m, respectively. Hence, if differences in
geometry 4.                                           elevation between runway 09L/27R and
For the scope of the present study, two cases         taxiway B are not unfavorable enough, the
are analyzed: i) an A380-800 or a B748-8 lies         presence of the new aircraft on the centerline
on a runway during a precision approach in the        of taxiway B would not affect parallel runway
parallel runway; and ii) an A380-800 or a             inner transitional OFZ.
B748-8 lies on the taxiway B during a                 It may be concluded that the presence of the
precision approach in the runway 09L/27R.             two new aircraft on runways 09L/27R,
It is worth mentioning that separation between        09R/27L or on taxiway B would not affect
runways is roughly 375m and separation                inner transitional OFZ of the parallel runway,
between runway 09L/27R and taxiway B is               unless the presented clearances are smaller
about 184m.                                           than possible unfavorable differences of
                                                      elevation between runways and the taxiway B.
                                                      5. CONCLUSIONS
                                                      As a general pattern, B747-8 is found to be
                                                      more easily accommodated at SBGR than
                                                      A380-800, due to its smaller wingspan and its
                                                      similarity to B747-400. Specific conclusions
 The depicted geometry is identical to the inner      regarding different design criteria are
transitional OFZ surface specified by ICAO, whereas
FAA specified surface is a bit more complex in
                                                      presented next:
geometry, as upward slope varies along the way from
the runway centreline.

    Current runway width of 45m may be                flexibilization of design standards may be
     acceptable for both new aircraft types via        utilized.
     design standard flexibilization;
                                                       6. ACKNOWLEDGEMENTS
    Runway shoulders, via flexibilization of
     design standards, may be considered               The authors would like to express their
     suitable for B747-8, but A380-800 does            gratitude to CNPq (Conselho Nacional de
     require widening the total pavement width,        Desenvolvimento Científico e Tecnológico –
     from the current 60m to 75m;                      National Council for Scientific and
    Current blast pads length does not even           Technological      Development),        CAPES
     meet ICAO recommendations for B747-               (Coordenação de Aperfeiçoamento de Pessoal
     400 aircraft. Compliance with ICAO                de Nível Superior – Coordination for the
     recommendations for B747-400 and the              Improvement of Higher Education Personnel)
     two new aircraft would require an                 and      LPT/EPUSP         (Laboratório    de
     augment in length from 60m to 120m;               Planejamento e Operação de Transportes da
    Taxiway current width of 23m could be             Escola Politécnica da Universidade de São
     accepted for both new aircraft if                 Paulo – Transportation Planning and
     flexibilization of design standards are           Operation Laboratory of the Polytechnic
     considered;                                       School of the University of São Paulo).
    Taxiway shoulders, via flexibilization of
     design standards, may be considered               7. REFERENCES
     suitable for B747-8, but A380-800 does            ANAC. Agência Nacional de Aviação Civil. Regulamento
                                                       Brasileiro de Aviação Civil -RBAC 154 – Emenda 00.
     require widening total pavement width,            Brasília, 2009a.
     from the current 44m to 60m;                      ______. Requisitos de Aeronavegabilidade: Aviões Categoria
                                                       Transporte – RBAC 25 - Emenda 128. Brasília, 2009b.
    Regarding fillet dimensions and curves            EUA. Electronic Code of Federal Regulations: Title 14-
     radii, B747-8 is easier to be                     Aeronautics and Space. GPO Access. Available at: <
     accommodated than A340-600 and B777-              http://ecfr.gpoaccess.gov/cgi/t/text/textidx?c=ecfretpl=/index.t
                                                       pl>. Access on February, 23, 2010.
     300 that already operate at SBGR. Hence,          FAA – Federal Aviation Administration. Airport Design:
     the new Boeing airplane can, at least, taxi       Advisory Circular 150/5300-13 – Incorporates changes 1 thru
     through the same routes negotiated by the         15. Washington, 1989.
     mentioned airplanes. A380-800, in turn, is        ______. Minimum Requirements to Widen Existing 150-Foot
                                                       Wide Runways for Boeing 747-8 Operations: Engineering
     also less demanding than A340-600.                Brief No 74A. Washington, 2011.
    Separation between runways and taxiway            ______. Runway Length Requirements for Airport Design:
     B is enough to avoid inner transitional           Advisory Circular 150/5325-4B. Washington, 2005.
                                                       ______. Taxiways for Airbus A380 Taxiing Operations:
     OFZ violation if an A380-800 or a B747-           Engineering Brief No 63B. Washington, 2007a.
     8 occupies a runway or the taxiway; and           ______. Use Of Guidance For Runway Centerline To Parallel
                                                       Taxiway/Taxilane Centerline Separation For Boeing 747-8:
    Separation between taxiways A and B is            Engineering Brief No 81. Washington, 2010a.
     sufficient to permit, at least, a 65m             ______. Use of Interim Taxiway Edge Safety Margin
     wingspan airplane to taxi simultaneously          Clearance for Airplane Design Group VI: Engineering Brief
     to a A380-800. Flexibilizations may be            No 80. Washington, 2010b.
                                                       ______. Use of Non-Standard 75-Foot Wide Straight Taxiway
     applied for less restrictive scenarios.           Sections for Boeing 747-8 Taxiing Operations: Engineering
                                                       Brief No 73. Washington, 2007b.
From the addressed airside design criteria, it is      ______. Use of 150-Foot-(45-M) Wide Runways for Airbus
shown that São Paulo/Guarulhos Airport needs           A380 Operations: Engineering Brief No 65A. Washington,
several interventions to comply with ICAO              2007c.
                                                       HORONJEFF, R.; MCKELVEY, F. X. Planning and Design
standards for aircraft such as A380-800 and            of Airports. 4th Edition. New York, 1994.
B747-8. For the same purpose, and only for             ICAO. International Civil Aviation Organization. Aerodrome
specific criteria, such as taxiway/taxiway             Design Manual: Part 1 – Runways - Doc 9157. 3rd Edition.
                                                       Montreal, 2006a.
separations, operational restrictions may be set,      _____. Aerodrome Design Manual: Part 2 – Taxiways, Aprons
but in exchange of capacity or expeditiousness.        and Holding Bays - Doc 9157. 4th Edition. Montreal, 2005a.
For a more reasonable, but still safe                  _____. Airport Services Manual: Part 6 – Control of Obstacles
                                                       - Doc 9137. 2nd Edition. Montreal, 1983.
accommodation of the new aircraft,

_____. Annex 14 to the Convention on International Civil
Aviation: Aerodromes, Volume I - Design and Operation.4th
Edition. Montreal, 2004a.
_____. New Larger Aeroplanes - Infringement of Obstacle
Free Zone: Operational Measures and Aeronautical Study -
Circular 301. Montreal, 2005b.
_____. Operation of New Larger Aeroplanes at Existing
Aerodromes - Circular 305. Montreal, 2004b.
_____. Procedures for Air Navigation Services: Aircraft
Operations – Volume I: Flight Procedures – Doc 8168. 5th
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_____. Procedures for Air Navigation Services: Aircraft
Operations – Volume II: Construction of Visual and
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_____. Procedures for Air Navigation Services: Air Traffic
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da FAA para o projeto geométrico de aeródromos. 2012.
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Universidade de São Paulo, São Paulo, 2012.
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