Airbus A380 operations
at alternate airports
AACG
November-2004
Version 2
DRAFT
1.
Introduction
Within the next 2 years the Airbus A380 will enter commercial service. This aircraft will have a larger
wingspan and weight than the largest aircraft currently in scheduled use on world air routes. However, other
dimensions, for example fuselage length and gear dimensions are not as large as other aircraft already in
service, such as the A340-600 and B777-300.
Many airports need to adapt their airside infrastructure. Upgrading runways, and taxiways, relocating
taxiways and even relocating aircraft stands and buildings to provide sufficient wingtip clearance, are
examples of the works that several airports may need to carry out before the A380 enters service.
For airports which will see the A380 frequently such changes to the infrastructure may be reasonable. When
an airport operates close to its full capacity, efficiency of operations is a prime factor as well as safety.
Examples of airports, where large scale infrastructure changes could be economical, include the large
continental gateways, and those airports whose home-carriers have ordered the A380 aircraft: for example,
London-LHR, Paris-CDG, Frankfurt, New York-JFK, Los Angeles, Singapore, Hong Kong, Sydney, Dubai
etc.
Besides these large hub and main base airports, there are other airports around the world that will
experience A380 operations. The operating frequency could be either on regular basis, such as one or two
scheduled arrivals a day, but also may be a much lower frequency such as for a flight diversion. Such
diversions could be either due to the unavailability of the destination airport (because of weather or
operational issues) or because of an in-flight emergency. It is in the interest of in-flight safety to have a
reasonable number of alternate airports and runways available in addition to the scheduled ones.
For those alternate airports, large scale changes to their existing airside infrastructure would be financially
excessive and never be economical. On the other hand, especially in the case of a filed alternate, a
minimum should be done to properly handle the aircraft and its passengers.
The occurrences of flight diversions are relatively low and many alternate airports will see only a few
diversions a year or, in the case of emergency alternates, may never see one. It may therefore be
reasonable and admissible to maintain the level of operational safety by use of alternative measures,
operational procedures and operating restrictions. The two cases of alternates (flight diversion or emergency
alternate) require different consideration. Those nominated regularly for use as a destination or takeoff
alternate must meet a defined standard, which many states require to be similar to that of the scheduled
destination. Those used very infrequently, such as for an unexpected in flight diversion could alternatively
achieve an acceptable level of safety by establishing significant operational restrictions to cater for the lack
of airport infrastructure, instead of fully complying with the ICAO Annex 14 Airport requirements to cater for
code F aircraft (as defined by ICAO in Annex 14 for an aircraft of the A380 geometric size) or even AACG 1
A380 specifications.
This is not substantially different than what is regularly done at airports who receive the occasional visit of an
airplane bigger than their design aircraft: An 124, or even B 747 in many “old” airports.
1
The A380 Airport Compatibility Group is an informal group, consisting of a number of European Aviation Authorities,
Airport and Industry representatives. It was formed to agree and promote a common position among the group
members on the application of ICAO requirements, with respect to the A380 aircraft, for infrastructure and operations at
existing major European airports that currently do not meet the requirements.
1
This document aims to provide guidance for operators and States on the use of alternate measures,
operational procedures or operating restrictions, in combination with the minimum level of infrastructure
requirements at possible alternate and even lower frequency use airports. States and airport operators are
encouraged to review the guidance in this document, but as with the AACG Common Agreement Document
(destination airports), it must be clearly understood that the final safety based decision at a particular airport
remains the responsibility of the State and the airport operator.
The proposed procedures are based on the current state of knowledge, as used for the December 2002
AACG recommendations. Several Aeronautical studies are on-going at this time and they could result in
lower requirements than those proposed by the AACG (most noticeably for points which the AACG had left
open in December 2002, such as OFZs, holding point position and runway to taxiway separation). Use of
possible outcomes from the uncompleted studies would be premature.
However it is possible that the outcome of some of these studies, expected within the next year, could
render several proposed operational procedures unnecessary.
2.
Infrastructure requirements
The airside infrastructure requirements for aircraft with a wingspan up to 80 meters (Code F) are given by
ICAO in Annex 14, Volume 1. These requirements are a sound basis for new airport design or future airport
expansion but in most cases impractical for determining changes to existing infrastructure.
While ICAO member states are encouraged to fully implement the new code F requirements for the
development of their airports, it has also become clear that many states will have difficulties in complying
with these specifications for the upgrade of their currently existing facilities. For this reason ICAO developed
a circular for New Larger Aeroplane Operations at Existing Aerodromes. This circular identifies all issues
which are of relevance to the operations of NLAs and proposes possible mitigation measures for
accommodation of NLAs at those airports that are unable to comply with annex 14, code F provisions. The
circular does not specify what is acceptable and what is not: the responsibility remains with the local
authority. The State should decide on the suitability of lower requirements than those given by Annex 14,
based on aeronautical studies. The principle is that safety requirements must be met, however efficiency of
operations should also be considered, especially for airports which have a very low number of A380
movements and therefore whose infrastructure is unlikely to be code F (or AACG)-compliant.
The ICAO circular for New Larger Aeroplane Operations at Existing Aerodromes also gives guidance on
how to conduct aeronautical studies2. Several European Aviation authorities have, in close co-operation with
their airport organizations and industry, initiated a working group (A380 Airport Compatibility Group, AACG)
which performed several studies resulting in a number of recommendations for handling the A380 at existing
airports. The Common Agreement Document (version 2.1, December 2002) of this working group contains
all these recommendations.
Together with ICAO Annex 14 the AACG recommendations form a basis for the infrastructure requirements
at existing airports.
For many airports, especially those airports that in the near future will only see the A380 in case of diversion,
even the AACG requirements may be hard to comply with. Deviations from these requirements are only
sanctioned when aeronautical studies are performed. Even conducting aeronautical studies at these airports
can be an excessive burden in the context of the low number of A380 movements. A better solution in most
cases is to implement operational procedures to overcome the non compliances. In chapter 3 of this
document, such possible operational procedures are given. The basic assumption for these procedures
is that the airport complies with the ICAO code E requirements.
Reference documents:

ICAO, Annex 14,
Volume I, Aerodrome design and operations, fourth edition, July 2004.

ICAO, Circular on New Larger Aeroplane Operations at Existing Aerodromes,
Cir 305 – AN/177, June 2004

Common Agreement Document of the A380 Airport Compatibility Group,
Version 2.1, December 2002
2
Additional material of relevance for the production of an aeronautical study is available on the ECAC website
(http://www.ecac-ceac.org/nla-forum/index.php), where several states and authorities have decided to make their
aeronautical studies available as a reference.
2
3.
Alternative measures,
restrictions
operational
procedures
and
operating
In assessing the suitability of a given airport as an A380 alternate, two situations can be distinguished:

The case of a planned alternate, where the airport is regularly declared in the flight plans of an airline as
the alternate in the case of unavailability (most of the time for weather conditions) of the destination
airport. In this case, the conditions of accommodation can – and should – be negotiated in advance by
the airport with the airline and the ATC services. There may be some restrictions to “normal” operations,
but they should not be disruptive – if only because, in the case of bad weather, the A380 is unlikely to
be the only diverted aircraft and the alternate airport also has to handle its own traffic.

The case of an unplanned diversion airport, most likely to be used for an aircraft emergency. In such a
(rare) case, temporary disruption of operations at the alternate airport is to some extent tolerable.
The level of the operating restrictions that can be tolerated will be higher in the second case.
3.1
Runways
Runway width
Annex 14 prescribes a runway width of 60m for Code F aircraft. Many long-range traffic airports however,
and certainly those that will be filed as an alternate, have runways which are expected to comply with ICAO
Code E requirements, i.e. a width of 45m.
Subject to the A380 being certified on 45m wide runways, the AACG recommendations state that a 45 meter
wide runway can be used for Airbus A380 operations.
No specific alternative measures, operational procedures and operating restrictions are proposed
for operations of an A380 on a 45 meters wide runway.
Runway strength
The runway need only support the reduced operating weight at an alternate (airlines have quoted maximum
MLW and two hours fuel) and the infrequent use would allow pavement concession action for the
appropriate bearing strength.
Runway shoulders
For destination airports, AACG recommendations state that a 45 meter wide runway with 7.5 meter
shoulders on both sides can be used for Airbus A380 operations if the runway is also provided with
additional “outer” shoulders. These outer shoulders should be prepared for jet blast protection, engine
ingestion protection, and for supporting ground vehicles and their width should be at least 2x7.5m.
The use of 2* 7.5 meter shoulders in Code E alternate airports instead of 2*15 meter wide shoulders
(including the AACG “outer” shoulders) could therefore be an issue.
For an alternate airport, upgrading the total runway + shoulder width to 75m is mostly not viable. To find
whether, and under what conditions, the A380 can be operated on code E runways and shoulders, the focus
should be put on the intended use of the “outer” shoulder.
1. Jet blast and engine ingestion protection.
The outboard engine of the A380 is located inside the shoulder of a code E runway (see picture below), so
there is still some protection (4.3m margin) against any blast, erosion and A380 outer engine ingestion that
could be generated by its thrust.
On landing, blast, erosion and A380 engine ingestion protection is not critical for the A380 on such a
runway, as the outboard engines are not fitted with thrust reversers.
Take-offs however may require the blast and erosion protection capabilities of the outer shoulders, beyond
the 4.3m margin offered by the inner shoulder. Absence of the “outer” shoulder could result in an ingestion
risk for the A380 on takeoff, or FOD on the runway or inner shoulders which could be hazardous for the
following movement.
3
Use of a runway at a landing alternate is likely to happen on short notice. Specific preparation of the runway
and runway shoulders is not necessarily possible within the available time frame. However the landing does
not present a specific risk and therefore special procedures are not necessary (although runway inspection
is advisable).
In the take-off case more time is available and the departure of an A380 can be coordinated with other traffic
and the need to inspect the runway,(if a 75m wide runway area is not already inspected on a regular basis).
Runway inspection must be carried out immediately after take off to check that no loose objects have been
blown onto the runway. In addition, a de-rated thrust may be used for takeoff at alternate airports, further
reducing the engine hazard. It should be noted that the ingestion risk occurs in the very early part of the
takeoff roll, below about 35 knots. A special procedure would be required for A380 operations on 45m
runway without inner shoulders
2. Supporting ground vehicles
The other function of the outer shoulder is to allow the passage of ground, mainly emergency, vehicles. The
wingspan of a Boeing B747-400 already exceeds the runway and shoulder width of a code E runway. For
code E runways, the emergency vehicles already must be capable to make use of the strip part outside the
runway shoulder.
Rescue and Fire Fighting vehicles are designed for operating over short distances on the natural soil of the
runway strip. The lack of 7.5 meters of “outer” shoulder does therefore make no difference between code E
and A380 operations.
3. Bearing strength
The inner shoulder must be capable of withstanding the occasional passage of the aircraft without incurring
structural damage to the aircraft. A380 alternate airport operations would result in a pavement loading below
or comparable to the most critical code E aircraft at Maximum Take-Off Weight (B777-300ER). If the
shoulder is for example designed for the critical B777-300ER at MTOW, it should cater for an A380 at
alternate airport weights.
4
Future A380 operators have indicated that a take-off weight limitation, based on MLW + 2 hours fuel, is
acceptable.
The suitability of the runway and shoulder pavement for an A380 take-off is therefore a matter of comparing
it with the critical aircraft used for the design of the airport pavement.
The outer shoulder does not have to be designed for the occasional passage of an aircraft. Some states /
airports are studying the possibility of having the outer shoulder functions performed either by a stabilized
surface (which is a possibility also mentioned by the ICAO NLA circular) or even by a well tended grass
surface.
As stated in the AACG Common Agreement Document, the decision on the bearing suitability of the
shoulder (composition and thickness) is the responsibility of the airport or national authority. The authority is
able to declare a limiting takeoff weight for the A380, based on the gear layout, in the AIP or pavement
concession documentation
Proposed alternative measures, operational procedures and operating restrictions for airports that
cannot comply with ICAO requirements or AACG recommendations related to shoulder width (in
combination with at least 45 meter wide runway).

Runway and shoulder FOD inspection must take place before each A380 take-off if a 75 meters wide
runway area is not inspected on regular basis.

Runway and shoulder FOD inspection must take place after each A380 take-off.

Restrictions on actual take-off weight if the airport pavement PCN is not sufficient to handle an A380 at
MTOW; airlines will judge whether the published PCNs are appropriate for their outbound flights. MLW
plus two hours fuel would appear to be a good measure for the majority of cases
[Comment: When possible it is advised to have runway and shoulder FOD inspection before and after each A380
landing]
4. Runway edge lights
Runway edge lights are provided along both sides of the runway. They are located on the edge of the
runway or a maximum of three meters to the outside of the edge. In most cases elevated (and frangible)
constructions are used that could be subject to engine blast as the edge lights are almost in line with the
outer engines of the A380.
Tests have been carried out to see if light fittings, currently available on the market, can withstand blast
profiles comparable with an A380 engine. The results of these tests will soon become available 3.
Alternatively, the airport or local authority can perform runway edge light inspection after each A380
departure (which may well by required for FOD reasons). As the outer engines of an A380 are not fitted with
thrust reverse systems, it is not required to perform a runway edge light inspection after the landing of an
A380.
Proposed alternative measures, operational procedures and operating restrictions for airports with
non blast resistant elevated runway edge lights on a 45 meters wide runway.

Runway edge lights inspection after each A380 departure.
3.2
Taxiways
Taxiway width
The ICAO Annex 14 Code F taxiway width is 25m, or 2m more than Code E. The A380 has a wheel track
0.3m larger than the Code E limit.
Extensive deviation studies, carried out at several airports around the world, have shown that the deviation
of large aircraft (code E) is much less than the 4.5 meters margin used in the formula to determine the
taxiway width. Results show that a deviation of less than 2.5 meters is a very realistic value under the
condition that proper guidance such as centre line lights and markings or equivalent guidance is provided for
night or low visibility operations.
Additional to the above, it can be stated that the outer main gear wheel span of the A380 is such that the
actual wheel to edge clearance (4.3m) is more than the 2.5 meters if the aircraft is taxiing on a code E
taxiway.
3
Studies are in progress to assess the adequacy of current runway edge light fittings. The ECAC NLA website is
intended to reference those studies when available
5
It can be concluded that on a 23 meter code E taxiway the A380 can taxi safely under the condition that this
taxiway is provided with proper guidance. Under these conditions no specific operational procedures is
required.
If the taxiways are not provided with proper guidance or if the airport / local authority does no feel
comfortable with the use of 23 meter wide taxiways, the use of “follow me” guidance can be a solution.
No specific alternative measures, operational procedures and operating restrictions are proposed
for operations of an A380 on a 23 meters wide straight taxiway.
Width of curved taxiway
To facilitate the movement of an A380 on curved taxiways and on junctions / intersections of taxiways with
runways, aprons and other taxiways, fillets should be provided. The design of the fillet should ensure that a
minimum wheel to edge clearance is maintained, based on Cockpit over Centre Line (COCL) steering
technique. ICAO requires a minimum wheel to edge clearance of 4.5 meters for curved taxiway segments
Also the AACG recommendations mentions a 4.5 meters wheel to edge clearance for curved taxiways,
however in some states the use of smaller wheel to edge clearances (i.e. 2.5 meters) for the design of
taxiway fillets is under certain conditions accepted.
If the required wheel to edge clearance can not be guaranteed when using COCL steering technique,
judgemental over steering is required. The use of judgemental over steering must be published in the
appropriate aeronautical publications. If even judgemental over steering is not sufficient or if the airport /
local authority does not feel comfortable with this, additional markings (for over steering guidance) could be
a practical solution
Proposed alternative measures, operational procedures and operating restrictions for airports that
can not comply with ICAO requirements or AACG recommendations related to width of curved
taxiway.

Reduced wheel to edge clearance

Use of judgemental over steering

Additional markings for over steering guidance.

Publication in the appropriate aeronautical documentation is required.
Taxiway shoulder width
Both ICAO Annex 14 and the AACG Common Agreement Document recommend a 60 meters wide strip to
be protected against shoulder erosion and engine ingestion risk. The shoulders could build up of a paved, a
stabilized or a natural surface (experienced at CDG for many years). The A380 engine ground clearance is a
factor. The inner engines are 0.5m higher and the outer engines 1.2m higher than the 747-400 ones, which
would decrease the ingestion and jet blast risks. If the airport / local authorities does not feel comfortable
with the shoulder surface in combination with A380 operations, the possibility remains to taxi with both
outboard engines idle or even shut-off. The feasibility of this must first be confirmed by the manufacturer.
Taxiing on two engines is not unusual but is mainly a practice after landing. Taxiing on two engines before
take-off requires the outboard engines to be started up near or even at the runway which can result in a long
blockage of the runway and consequently disturbing other traffic flow.
If it is required that the outer engines being shut of, special attention should be given to tight curves where
normally asymmetric power is used to move the aircraft through the curve.
Proposed alternative measures, operational procedures and operating restrictions for airports that
can not comply with ICAO requirements or AACG recommendations related to shoulder width.

Taxing with outboard engines on idle thrust.

In the extreme case the airport authority could require taxiing with outboard engines shut-off (feasibility
to be confirmed by manufacturer) or the aircraft could be towed.

Publication in the appropriate aeronautical documentation is required.
6
3.3
Runway - taxiway separations
Separation between runway and parallel taxiway is given by ICAO as 115 meters for a non instrument
runway and 190 meters for an instrument runway. Both are applicable to code F. For code E these
separation distances are 107.5 and 182.5 meters.
Although AACG agreed with the 115 meters some members have the opinion that the 115 meters for noninstrument runways is at the very lower boundary of what could be acceptable. On the other hand AACG
also have the opinion that the 190 meters for instrument runways may be conservative4.
Within the frame of ICAO rules, if the runway-taxiway separation at an alternate airport with few (if any)
foreseeable A380 movements does not comply with code F SARPs, restrictions on the simultaneous use of
the runway and taxiway can be considered.
For this several cases can be distinguished, based on code E separation distances:
Landing of an A380 on an non instrument runway, Runway – taxiway separation is 107.5 meters,
The runway – taxiway separation is based on a half runway-strip width of 75 meters plus half the
wingspan of the aircraft on the parallel taxiway. The half runway strip width of 75 meters is equal for
both ICAO code E and code F. Landing (under VFR) of an A380 in this case may not restrict the
use of the parallel taxiway for aircraft with a wingspan of less than 65 meters. No specific
procedures are required.
Landing of an A380 on an instrument runway, Runway – taxiway separation is 182.5 meters,
The runway – taxiway separation is based on a half runway strip width of 150 meters plus half the
wingspan of the aircraft on the parallel taxiway. The half runway strip width of 150 meters is equal
for both ICAO code E and code F. Landing of an A380 in this case will not restrict the use of the
parallel taxiway for aircraft with a wingspan of less than 65 meters. No specific procedures are
required
Take-off of an A380, runway – taxiway separation is 107.5 meters,
For the take-off case the half runway strip width equals 75 meters plus half the wingspan of the
aircraft on the parallel taxiway. The half runway strip width of 75 meters is equal for both ICAO
code E and code F. Take-off of an A380 may not restrict the use of the parallel taxiway for aircraft
with a wingspan of less than 65 meters. No specific procedures are required
Take-off of an A380, runway – taxiway separation is 182.5 meters,
For the take-off case the half runway strip is 75 meters plus half the wingspan of the aircraft on the
parallel taxiway. The half runway strip half-width of 75 meters is equal for both ICAO code E and
code F. Take-off of an A380 will not restrict the use of the parallel taxiway even not for A380
aircraft. No specific procedures are required.
Taxiing of an A380 on a parallel taxiway, runway – taxiway separation is 107.5 meters,
The A380 wingtip will infringe the runway strip with a distance of 7.5 meters. Operations on the
runway should therefore temporarily be halted until the A380 has left the parallel taxiway.
Taxiing of an A380 on a parallel taxiway, runway – taxiway separation is 182.5 meters,
The A380 wingtip will infringe the runway strip with a distance of 7.5 meters 5. Take-off operations
can be operated as normal but instrument landings may temporarily be halted until the A380 has
left the parallel taxiway. Non instrument landings however could be operated normally
a)
b)
c)
d)
e)
f)
From the above it can be concluded that the critical point is not the operation of an A380 on the runway, but
rather the operation of an A380 on the parallel taxiway.
4
The FAA specifies a 600ft (182 m) separation in the US for FAA ADG VI category (equivalent to ICAO Code F). Other
states are studying the issue of allowing lower separations than those of ICAO, code F. The ECAC NLA website is
intended to reference those studies when available.
5
For an A380 taxiing on a code E parallel taxiway, the distance from runway centerline to the A380 wingtip is 142.5m.
With respect to FAA requirements, for a 747-400 taxiing on a Group V parallel taxiway, the distance from runway
centerline to the 747 wingtip is only 122m.
7
Recommended alternative measures, operational procedures and operating restrictions for airports
that can not comply with ICAO requirements or AACG recommendations related to runway – taxiway
separation.

When an A380 uses the parallel taxiway next to a runway, operations on that runway should be
restricted or even halted if the runway – taxiway separation is less than 115 meters (under visual
conditions).
[Comment: in annex 14, the width of the runway strip is a permanent characteristic attached to the runway, not to the
type of operations and the aircraft size. It may be necessary to note that proposals b, d, and f consist in saying that an
instrument runway in visual conditions can be operated with the clearances of a non-instrument runway, with an
acceptable level of safety. In practice, this may need to be validated by ATC services]
3.4
Obstacle Free Zone
The Obstacle Free Zone protects the airspace above the inner approach surface, the inner transitional
surfaces, the balked landing surface and that portion of the strip bounded by these surfaces. The OFZ may
not be penetrated by any fixed obstacle other than a low-mass and frangible mounted one required.
The width of the lower surface of the OFZ is 120 meters for code E (and lower) aircraft. For code F aircraft
the width of the lower surface is specified by ICAO to be 155 meters. The justification used is that not only
the wingspan is 20 meters larger (on initial code E 60 meters) but also the runway width is 15 meters larger
(60 meters code E).
The ICAO OCP Balked Landing Study is expected to reduce this value6. It should be noted that France has
already made an Aeronautical Study showing that an inner approach surface width of 133m for A380
operations will provide the same level of safety than for current B747-400 operations at existing Code E
runways.
3.5
Runway Holding Positions
Runway holding positions have two purposes, collision prevention and protection of the ILS signal.
a) For collision risks, the distance between runway holding point and runway centre line will be
determined by the biggest aircraft that can use the runway as well as the geometry of the aircraft at the
holding position.
b) The other purpose is to prevent unacceptable interference with the ILS signal. During ILS CAT II/III
operations, the runway holding positions needs to be positioned in such a way that the critical and the
sensitive areas are free of any aircraft movement on the ground
For code E the minimum distance for the runway holding position is 90 meters, for code F this distance is
107.5 meters. These distances are based on
“an assumed aircraft with a tail specific height (code E; 20 meters, code F; 24 meters), a distance from
nose to the highest part of the tail (code E; 52.7 meters, code F; 62.2 meters) and a nose height (both
code E and F ; 10 meters) holding at an angle of 45º or more with respect to the runway centre line,
being clear of the obstacle free zone (OFZ)” .
As can be concluded from above the Runway Holding Position is not only a function of the size of the
Holding aircraft, but also of the dimensions of the Obstacle Free Zone (OFZ) 7.
6
Final result is expected to be reached shortly by the international bodies studying the issue. The OCP 14 meeting in
March 2005 should validate an Annex 14 amendment, including a reference to guidance contained in a balked landing
circular (to be finalized in February 2005).
7
Studies are in progress to assess the adequacy of current holding points (90m) for normal A380 operations. The
ECAC NLA website is intended to reference those studies when available.
8
As an interim solution, operational procedures can be implemented which prevent aircraft coming near the
runway in case of the occasional A380 landing. If the airport is equipped with ILS CAT II/III holding positions,
these could be used for this purpose. Similar restrictions are already published on airport charts.
Proposed alternative measures, operational procedures and operating restrictions for airports that
can not comply with ICAO requirements or AACG recommendations related runway holding
positions.

Holding aircraft further from the runway in case of an A380 landing may be required (i.e. the ILS CAT
II/III holding positions).

Holding aircraft at the parallel taxiway, away from the runway entry taxiway.

Establish the appropriate ATC procedure.
3.6
ILS Category II / III operations
Operations during low visibility conditions require special attention to avoid unacceptable interference with
the ILS glide path and localizer facilities. For ILS Cat II / III operations this could result in additional runway
holding positions. On most airports with Cat II / III capability additional runway holding positions are located
150 meters from the runway centre line to prevent aircraft penetrating the ILS sensitive area during low
visibility operations.
Unacceptable interference to the ILS signal, due to the presence of an A380, could result in larger
dimensions of the ILS sensitive area.
Studies and simulations8 are being performed to find out if an A380 on a parallel taxiway and at holding
positions gives more interference to the ILS signal than the current large aircraft. The size of the tail fin is
under special consideration.
Preliminary results shows that the effect on the ILS signal is strongly related to local conditions and therefore
a standard and uniform solution can not yet be provided. Also the acceptable level of disturbance is not the
same at all airports and in all states.
If an alternate airport expects to handle diverted A380 operations during low visibility conditions, special
attention should be given to this kind of operations. An operational plan must be set up to guarantee that the
ILS signal is not disturbed or alternatively that operations at the runway are temporarily restricted.
3.7
Taxiway minimum separation distances
To reduce wingtip collision risk to an acceptable level, minimum separation distances for taxiways and
taxilanes are implemented. For this, ICAO has specified separation distances for the different aircraft
categories and taxiway / taxilane situations. For code F, these minimum separation distances are based on
extrapolation of the distances given for code E. However, risk assessment, as well as operational
experience with code E aircraft, has shown that large aircraft can be operated safely on taxiways with
smaller separation distances than those given by ICAO.
AACG recommendations for minimum separation distances are based on these risk assessment and
operational experiences. The results of the taxiway deviation studies carried out by London-LHR, Frankfurt,
Amsterdam and Paris-CDG were used for these recommendations.
Different type of taxiway separation distances can be considered:
1. Parallel taxiways (Taxiway centre line to taxiway centre line)
2. Taxiway centre line to object
3. Aircraft stand taxilane to object
Parallel taxiways (Taxiway centre line to taxiway centre line)
In ICAO Annex 14, the minimum distance between two parallel taxiways is given as 97.5 meters for code F
aircraft. AACG recommend a distance of 91 meters if proper guidance, such as centre line lights or
equivalent guidance, is provided for night or low visibility operations.
8
Studies are in progress to assess the effect of A380 operations on the ILS signal. The ECAC NLA website is intended
to reference those studies when available
9
Many alternate airports will have parallel taxiways which are designed for code E aircraft. A separation
distance of 80 meters will in those cases normally be available. This does not mean that the A380 cannot
make use of one of the two parallel taxiways. If an A380 operates on one of the taxiways, the other taxiway
will be restricted for use by aircraft smaller than code E.
The ICAO requirement for parallel taxiways to be separated by 97.5m gives a margin of 17.5 meters when
two A380 aircraft taxi on parallel taxiways. The AACG recommends 91 meter which results in a margin of
11m.
The maximum wingspan for the other aircraft in the case that an A380 taxies on parallel taxiways separated
by only 80 meters can easily be calculated: taxiway separation minus half wingspan of A380 minus margin
equals half wingspan of the aircraft on the other taxiway.
ICAO annex 14 requirements:
80 meters – 40 meters – 17.5 meters = 22.5 meters or a maximum wingspan of 45 meters (i.e. aircraft like
A310, A300 and B757).
AACG requirements:
80 meters – 40 meters – 11 meters = 29 meters or a maximum wingspan of 58 meters (i.e. aircraft like B767
and MD11).
Special attention must be given to curved taxiways or turning manoeuvres on taxiways. At all times a
minimum margin of 17.5 meters, or 11 meters if proper guidance is available, must be guaranteed. If this
minimum margin can not be provided or the local authority does not feel comfortable with the actual margin
additional procedural separation must be provided.
Proposed alternative measures, operational procedures and operating restrictions for airports that
can not comply with ICAO requirements or AACG recommendations related parallel taxiways

Restrict aircraft operations on the taxiway not used by the A380, to aircraft with a maximum wingspan of
45 meters.

If proper guidance is given, this restriction can be lifted to a maximum wingspan of 58 meters.

If necessary, procedural separation must be provided.

Publication in the appropriate aeronautical documentation is required.

Establish appropriate ATC operational procedures.
Taxiway centre line to object
For taxiway to object clearance, ICAO requires 57.5 meters while AACG recommend 49 meters if proper
guidance is available. However both accept lower separations distances for taxilanes based on the fact that
taxiing is more accurate on taxilanes. Although recent taxiway deviation studies have not found any relation
between taxi speed and deviations from the taxiway centre line, it is still one of the reasons why ICAO allows
smaller clearances on taxilanes. Extra caution on the more congested apron area could also be a factor in
better taxilane accuracy.
The local authority could allow taxilane to object clearances on taxiways, if necessary with measures such
as taxi speed reduction. If these measures can be ensured on the taxiway, e.g. by “follow me” guidance
and/or clear publication in the aeronautical documents, it may be acceptable to taxi an A380 on taxiways
with less than the required clearances.
If proper guidance, like for example taxiway centreline lights, is available, an A380 could be operated on a
code E taxiway (47.5 meters separation distance to object).
Special attention must be given to curved taxiways or turning manoeuvres. At all times a minimum margin of
10.5 meters, or 7.5 meters if proper guidance is available, must be guaranteed.
Proposed alternative measures, operational procedures and operating restrictions for airports that
can not comply with ICAO requirements or AACG recommendations related to taxiway – object
clearance

Use of code E taxiways with warnings to exercise caution, and possibly reduction of taxi speed (taxiway
to object clearance = 47.5 meters)

“Follow me” guidance or marshalling can be used.

In an ultimate step, towing the aircraft can be an option (if taxiway to object clearance less than 47.5
meters)

Publication in the appropriate aeronautical documentation is required.
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Aircraft stand taxilane to object
For aircraft stand taxilanes ICAO requires 50.5 meters clearance to any object while AACG recommend 47.5
meters if proper guidance is provided. Further reduction of the separations distances is difficult and will
result in higher and probably unacceptable risk of wingtip collision.
If separations of 50.5 (ICAO) or 47.5 meters (AACG) can not be guaranteed, the use of “Follow me”
guidance or marshalling but also towing the aircraft are possible solutions.
Proposed alternative measures, operational procedures and operating restrictions for airports that
can not comply with ICAO requirements or AACG recommendations related to aircraft stand taxilane
– object clearance

“Follow me” guidance or marshalling can be used.

Towing the aircraft on the taxilane.

Publication in the appropriate aeronautical documentation is required.
3.8
Aprons and aircraft stands
It is unlikely that an airport that does not meet Code F requirements will have an aircraft stand on which an
Airbus A380 can be parked without difficulties. It can be expected that the maximum aircraft that can be
parked on the stand is a Boeing 747-400 or equivalent.
The length of an A380 is similar to that of a B747-400. The depth of an aircraft stand will in most case not be
an issue. As the A380 semi span is 7.5m more than a B747-400 the entire 7.5 metre margin is used and
safety would be compromised, unless adjacent stands are downgraded to smaller aircraft size.
On aircraft stands along concourses, the above can sometimes be difficult as the stands can be equipped
with fixed installations like passenger bridges and light poles. It is sometimes easier to park the A380 on a
remote apron or even the cargo apron as these aprons have fewer restrictions on aircraft size.
When parking an A380 on stands where it is not designed for, marshalling is recommended and towing the
aircraft on to the stand is an option.
“Nose-in” parking requires suitable tow trucks and tow bars for push-back on departure. If an airport does
not have capable equipment, the A380 should be parked on a remote (or cargo) stand in such a way that
taxi-in and taxi-out on own power is possible. Attention should be given to blast issues, especially during non
standard taxi-out manoeuvre.
Proposed alternative measures, operational procedures and operating restrictions for airports that
can not provide aircraft stands for an A380 that complies with ICAO requirements or AACG
recommendations.

Temporary downgrading adjacent aircraft stands.

Towing the aircraft on to the stand.

Use of remote / cargo stands or “roll-through” parking positions for handling the A380.

Publication in the appropriate aeronautical documentation is required.
[Comment: In the case of an airport regularly filed as an alternate, it may be advisable to have a few marked remote
A380-capable stands (possibly downgrading adjacent stands), accessible by A380s under their own power]
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3.9
Taxiway bridges
For taxiway bridges, the following aspects are relevant;

Bridge width,

Blast protection,

Accessibility for rescue and fire fighting vehicles and

Structural maximum load, also applicable to tunnels underneath taxiways (and runways)
Bridge width
For the width of a taxiway bridge, AACG recommends a minimum of 49 meters (ICAO requirement 60
meters minimum). Smaller bridges are acceptable if a proven method of lateral constraint is provided. If the
taxiway bridge is designed for code E aircraft, the width of the bridge will be 44 meters minimum. In that
case, an A380 can only use that taxiway bridge if lateral constraint is provided. If not, the A380 may not use
that taxiway bridge, under its own power. Towing the aircraft over the bridge is a possibility. Connecting and
disconnecting time requires consideration. As the number of A380 movements is very low, the operational
disturbance may be acceptable.
Proposed alternative measures, operational procedures and operating restrictions for airports that
can not comply with ICAO requirements or AACG recommendations related to taxiway bridge width.

Towing the A380 over the taxiway bridge

Publication in the appropriate aeronautical documents that the A380 may not taxi under own power over
the bridge is required.
Blast protection
If the width of the taxiway bridge is such that the outboard engines overhang the bridge structure, blast
protection of areas below the bridge may be necessary. In case jet blast protection can’t be provided over a
width of 60m, taxiing with the outboard engines on idle thrust or even shut-off is a possibility.
Proposed alternative measures, operational procedures and operating restrictions for airports that
can not comply with ICAO requirements or AACG recommendations related to blast protection on
taxiway bridges.

Taxing with outboard engines on idle thrust.

In the extreme case the airport authority could require taxiing with outboard engines shut-off (feasibility
to be confirmed by manufacturer).

Publication in the appropriate aeronautical documentation is required.
Rescue and fire fighting vehicles
Access should be provided to allow rescue and fire fighting vehicles to intervene in both directions. This is
however not a specific A380 issue. The wingspan of code E aircraft also exceeds the width of a code E
taxiway bridge.
If the width of the bridge is not enough to provide vehicle passage on the bridge, when occupied by an A380
or any other large aircraft, an alternative path for RFF vehicles must be provided. This path could be a
service road with separate service road bridge. On large airports, more than one RFF station is mostly
provided. In most cases, a solution could be to intervene from both sides of the taxiway bridge if the RFF
stations are not located on the same side of the bridge. Specified response times should be taken into
account.
If an alternative path for RFF vehicles or response times from one of the RFF stations can not be
guaranteed the solution could be to strategically position RFF vehicles on both sides of the taxiway bridge
for an A380 passage. As the A380 passage is only occasional, the disturbance of this procedure should be
acceptable.
Proposed alternative measures, operational procedures and operating restrictions for airports that
can not comply with ICAO requirements or AACG recommendations related to accessibility of
rescue and fire fighting vehicles.

Strategically position RFF vehicles on both side of the taxiway bridge.
Structural maximum load
The maximum load of the bridge or tunnel is a prime factor in determining the capability for A380 aircraft.
Taxiway bridges and tunnels designed to be capable of supporting a B747-400 at MTOW, are in any case
capable of supporting a A380 on arrival. The Maximum Landing Weight (MLW) is less than the MTOW of a
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B747-400. The bridge should also be capable to support an A380 on departure as the airlines have quoted
that the actual take-off weight in practice will be limited to maximum MLW + 2 hours fuel (comparable to a
B747-400 at MTOW). In that case no special procedures are required.
The actual take-off weight should be based on the bearing strength of the bridge / tunnel9, using concession
procedures if appropriate. For the alternate airport, it is necessary that the actual bearing strength of taxiway
bridges and tunnels be published in the appropriate aeronautical publications.
Proposed alternative measures, operational procedures and operating restrictions for airports that
can not comply with ICAO requirements or AACG recommendations related bearing strength of
taxiway bridges or tunnels.

Publish the weight limitations on A380 taxi routes
3.10
Taxi routing
Specific taxi routes and procedures for diverted A380 aircraft may be necessary to permit A380 operations
with the existing airport infrastructure. This may for example involve extra runway occupancy and the
provision of turn pads. To specify a taxi route between the runway and the aircraft stand, all the items
mentioned in the previous paragraphs should be addressed.
As the A380 movement is occasional, the operational disturbance could well be acceptable in relation to the
enormous investment for upgrading the infrastructure. As these investments cost will be reflected into the
operational charges of the airport, the other airlines will probably accept the occasional disturbance a
diversion will cause.
To specify a taxi route between the runway and the aircraft stand, all the items mentioned in the previous
paragraphs should be addressed.
Taxiways
If an A380 can not operate on the taxiway parallel to the runway, taxiing on the runway becomes necessary.
Turning pads at the end of the runway must then be available.
Back tracking on the runway after landing or before take-off is not uncommon and normal practice on many
airports around the world. It is uncommon on airports where parallel taxiways next to runways are provided
and where normally traffic volume is high. Back tracking on the runway could in that case not only cause
operational disturbance (runway is blocked for a longer time), but could also be source of additional runway
incursion risk. Caution should be made for alternate airports where in practice only the occasional A380
movement needs taxing on (part of) the runway.
Taxiway bridges
The taxi route between an aircraft stand and the runway can contain taxiway bridges or tunnels. As
mentioned in paragraph 3.7, taxiway bridges can be critical not only in width but certainly also in bearing
strength. If that is the case, it is wise to define taxi routings that bypasses the taxiway bridge or tunnel.
Sometimes this will not be possible as the only route between runway and terminal area will be over the
taxiway bridge / tunnel. In that case, it is advisable to look for a parking position somewhere between the
runway and the Taxiway Bridge / tunnel. In the extreme situation this could be part of the taxiway system or
even a non used runway.
Fortunately, flight diversions are rare. Therefore, the pilot is likely to be less familiar with the airport, its layout and special procedures. Disorientation is more likely to occur. To prevent mishaps during taxiing,
especially when specific taxi routing have to be followed, guidance by “follow me” may be advisable,
especially in cases other than diversion to a planned alternate.
The design of taxi routes needs to be defined and validated in advance. Co-ordination with the ATC services
and the airlines who intend to regularly file the airport as an alternate is a requirement. The taxi routing,
together with all the other special procedures for the A380, must be published in the appropriate
aeronautical documentation.
9
If the bridge load is severely limited, the airlines involved would have to plan for means of limiting the take-off payload.
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3.11
Other items
Besides the mentioned infrastructure items, iother ssues related to A380 operations at an alternate airport
require resolution.
The following items are a relevant but not exhaustive list.
a) Rescue and Fire Fighting services
The need to upgrade the RFF equipment should be assessed with regard to the national and international
regulations. ICAO, FAA as well as JAA have requirements on RFF services on alternate airports. It is the
responsibility of the local authority to determine acceptability of the available RFF services and equipment.
b) Snow removal
The blast issues raised in the “runway” paragraph are also valid for snow removal. It is therefore necessary
that airports, which can be filled as an alternate, prepare a plan for runway snow removal based on the
characteristics of the A380.
c) Ground servicing
Normally, ground servicing can be achieved with GSE commonly used by other wide body jets (main deck
service). Attention must be given for ground service equipment which can be specific for A380 operations.
This could be:

a capable tow truck and suitable tow bar at alternate airports where towing the aircraft is unavoidable

Suitable de-icing equipment
In the case of a filed alternate, the servicing of the aircraft, its passengers, cargo and baggage should be
prepared in advance; the airline should ensure the availability of the relevant handling equipment.
Suggest adding charts on A380 servicing and door locations (very similar to 747)
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4.
Conclusion
For airports that will be an A380 alternate or even have a low number of A380 movements it is clear that
financially it will be difficult to fulfil the ICAO requirements and, in most cases, even the AACG
recommendations.
This document provides a number of alternative measures, operational procedures and operating
restrictions that can be implemented to cope with the occasional movement of the A380 aircraft without the
burden of high investment cost and infrastructure changes.
This is not substantially different than what is already common practice at many airports who accommodate
the occasional visit of an airplane bigger than their design aircraft: for example, an An-124, or even B 747 at
many existing airports.
Implementing the proposed procedures will have an impact on the airport /airside operations and therefore
should be analysed carefully. Close cooperation between airport / local authority, ATC services and the
airlines that could file the airport as an alternate is therefore a requirement. All necessary routings,
operational minimums, restrictions, procedures and requirements for ground equipment should be
determined, approved and published before the first A380 can be expected.
As the use of alternate airports is a rare occasion, it is also the responsibility of the airlines to train their crew
and provide them with the appropriate documentation to safely operate the aircraft at the alternate airport.
References

ICAO, Annex 14,
Volume I, Aerodrome design and operations, fourth edition, July 2004.

ICAO, Circular on New Larger Aeroplane Operations at Existing Aerodromes,
Cir 305 – AN/177, June 2004

Common Agreement Document of the A380 Airport Compatibility Group,
Version 2.1, December 2002
Additional material of relevance with respect to the A380 operations is available on the ECAC website (
http://www.ecac-ceac.org/nla-forum/index.php ), where several states and authorities have decided to make
their aeronautical studies available as a reference
Information on A380 Airport Characteristics for Airport Planning manual can be found on the AIRBUS
website
http://www.content.airbusworld.com/SITES/Technical_Data/docs/AC/DATA_CONSULT/AC_A380.pdf
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