Draft ICAO Circular on NLA.pdf - Airports Council International

<strong>ICAO</strong> Version 4.1 — 15 March 2004
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c) Risk assessment and possible mitigation measures related to the specific infrastructure
item are given as a guideline. Information on risk assessment methods is contained in
paragraph 3.4.2 of this <strong>Circular</strong>.
4.1.1.4 A reference list of studies is provided in Appendix B. Subject to cautions and guidance
elsewhere in this <strong>Circular</strong>, these studies and results may assist authorities in developing their aeronautical
studies. Inclusion of references in this <strong>Circular</strong> to studies conducted outside of <strong>ICAO</strong> does not imply <strong>ICAO</strong>
endorsement. They are provided solely for the information of the reader. Any application of the results of
the studies listed in the references to any ongoing studies remains a matter for decision by the appropriate
authorities.
4.1.2 Runway and shoulders
4.1.2.1 Runway width
4.1.2.1.1 Annex 14, Volume I, paragraph 3.1.9 recommends that the width of a runway should not be
less than 45 m where the code letter is E, and 60 m where the code letter is F.
4.1.2.1.2 Guidance in the Aerodrome Design Manual (Doc 9157), Part 1, Runways, indicates that,
primarily the runway width is related to the outer main gear wheel span and the clearance required on either
side of the outer main gear wheels when the aeroplane is centred on the runway centre line, as shown in the
following formula:
Runway width = TM+2 x C
where TM = outer main gear wheel span and C= clearance between the outer main gear wheel and the
runway edge.
The guidance in Doc 9157, Part 1 states that other factors of operational significance indicate that it might
be advisable, for planning purposes, to consider a width of up to 60 m. The rationale for this was to have a
margin for factors such as wet or contaminated runway pavement, cross wind conditions, crab angle
approaches to landing and aircraft controllability during aborted take-off.
4.1.2.2 Hazard identification and analysis
4.1.2.2.1 The main hazard linked to available runway width is from structural damage associated with
an aircraft running off the runway, during take-off, rejected take-off, or landing phase.
4.1.2.2.2 The main causes and accident factors are:
a) for take-off:
1) Aircraft (asymmetric spin-up and/or reverse thrust, malfunctioning of control
surfaces, hydraulic system, tires, brakes, nose gear steering, aft CG);
2) Power plant (engine failure, foreign object ingestion);
3) Surface conditions (standing water, snow, runway friction coefficient);