Glossary: ICAO Doc 9157 – Aerodrome Design Manual – Standards

Introduction

The ICAO Doc 9157, known as the Aerodrome Design Manual, forms the backbone of global airport design and operational standards. Published and maintained by the International Civil Aviation Organization (ICAO), this manual provides the technical details for implementing the Standards and Recommended Practices (SARPs) outlined in Annex 14 — Aerodromes. Its guidance ensures uniform safety, efficiency, and interoperability across international airports, from runway geometry and lighting to obstacle management and visual aids. Regulatory authorities, airport operators, planners, and engineers worldwide rely on Doc 9157 as the authoritative source for aerodrome infrastructure design, certification, and modernization.

Abbreviations

Glossary of Key Terms and Concepts

Aerodrome

An aerodrome is a defined area on land or water—including all buildings, installations, and equipment—intended for the arrival, departure, and surface movement of aircraft. The term encompasses airports, airfields, and heliports, regardless of size or type of operation. The aerodrome boundary marks where ICAO design standards apply, ensuring consistent safety and infrastructure. Aerodrome design factors include anticipated aircraft, traffic density, meteorology, and local geography. Facilities range from runways and taxiways to terminal buildings, lighting, and emergency services. Certification depends on compliance with ICAO Annex 14 and national regulations, covering everything from geometry to obstacle and wildlife management.

Aerodrome Design Manual (Doc 9157)

The Aerodrome Design Manual (Doc 9157) is ICAO’s principal technical guide for the planning, design, and operation of aerodromes. It is published in several parts, each focusing on specific areas—Part 1 (runways), Part 2 (taxiways, aprons, holding bays), Part 3 (pavements), and Part 4 (visual aids). The manual sets out geometric, structural, and operational standards, ensuring alignment with Annex 14 SARPs. Used by airport authorities, engineers, planners, and regulators, Doc 9157 supports every stage of aerodrome development and modernization, and is updated regularly to reflect innovations and operational experience.

Standards

Standards are specifications for physical characteristics, performance, procedures, or configurations, the uniform application of which is recognized as necessary for safety and regularity in international air navigation. In aerodrome design, these standards are mandatory for ICAO Contracting States unless a difference is filed. They determine runway dimensions, lighting, obstacle clearance, and more, ensuring consistent safety and interoperability. Standards are periodically reviewed and updated to reflect advances in technology and operational requirements.

Recommended Practices

Recommended Practices are specifications considered desirable for safety, regularity, or efficiency in air navigation. While not mandatory, they provide guidance for States to achieve or exceed minimum safety and operational objectives. In aerodrome design, recommended practices supplement standards, offering alternatives or enhancements (e.g., wider runway strips or advanced lighting) that support innovation and continuous improvement.

Annex 14 — Aerodromes

Annex 14 — Aerodromes is the foundational ICAO document specifying SARPs for aerodrome design, construction, and operations. It covers runways, taxiways, aprons, obstacle limitation surfaces, visual aids, fire and rescue services, and operational procedures. Published in two volumes (Volume I: Aerodrome Design & Operations; Volume II: Heliports), Annex 14 is essential for international aerodrome certification. Doc 9157 provides the technical guidance needed to implement Annex 14’s requirements in practice.

Runway

A runway is a defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft. Runways are classified by intended use (instrument or non-instrument) and designed according to code, with standards for length, width, orientation, pavement strength, friction, markings, and lighting. For precision approach runways, additional infrastructure (e.g., centerline and touchdown zone lighting) and advanced guidance systems are required.

Runway Strip

A runway strip includes the runway and stopway, intended to reduce the risk of damage to aircraft running off the runway and protect overflying aircraft. Strips provide an obstacle-free, graded zone and must meet minimum width and length standards. All objects within the strip must be frangible or essential for air navigation, with regular maintenance to ensure safety.

Runway End Safety Area (RESA)

A RESA is a graded area beyond the end of the runway strip, designed to minimize damage to aircraft in the event of an overrun or undershoot. ICAO requires a minimum RESA of 90 meters for runways serving international operations, with longer dimensions recommended for larger or faster aircraft. RESAs must be obstacle-free and strong enough for rescue vehicles.

Clearway

A clearway is a defined area under the authority’s control, selected or prepared so an aircraft may make part of its initial climb over it after take-off. Clearways must be obstacle-free and may be included in declared take-off distances. Their dimensions are based on aircraft performance requirements.

Stopway

A stopway is a defined area at the end of the take-off run, suitable for stopping an aircraft in case of an aborted take-off. It must have the same load-bearing strength as the runway, be obstacle-free, and is factored into declared distances (TORA, TODA, ASDA) published in the AIP.

Aerodrome Reference Code

The Aerodrome Reference Code classifies aerodromes by a two-part code: a number (1–4) based on reference field length, and a letter (A–F) based on wingspan and main gear span. This code determines the design of runways, taxiways, aprons, and obstacle clearances.

Visual Aids

Visual aids include lighting, markings, and signage that provide pilots with essential navigation and situational awareness on the aerodrome surface and during approach. Categories include:

• Lighting Systems: Approach lighting, runway/taxiway lights, stop bars, apron floodlights.
• Markings: Painted indications (alignment, thresholds, touch-down zones, taxi routes).
• Signs: Mandatory instruction signs, direction signs, information signs.

All visual aids must meet ICAO requirements for color, configuration, intensity, and placement, with regular inspection and maintenance.

Surface Movement Guidance and Control System (SMGC / A-SMGCS)

A Surface Movement Guidance and Control System integrates visual aids, lighting, signage, surveillance, and automated controls to ensure safe and efficient aircraft and vehicle movement on the aerodrome surface—especially in low visibility. Components include stop bars, runway status lights, ground radar, and automated conflict alerts. SMGCS enhances situational awareness, reduces runway incursions, and supports complex operations.

Runway Visual Range (RVR)

Runway Visual Range (RVR) is the distance a pilot can see runway markings or lights along the centerline. Measured by transmissometers or scatter meters, RVR is critical for determining approach and take-off minima and for specifying lighting system requirements.

Visual Meteorological Conditions (VMC) / Instrument Meteorological Conditions (IMC)

VMC are conditions where pilots can navigate visually, meeting prescribed visibility and cloud clearance minima. IMC occur when weather prevents visual navigation, requiring instrument flight rules and specialized visual aids and procedures.

Frangibility

Frangibility is the property of objects designed to yield or break upon impact, minimizing danger to aircraft. ICAO mandates frangibility for all objects in safety-critical areas (e.g., lighting supports, signs), with standards for material, design, and maintenance.

Obstacle

An obstacle is any fixed or mobile object on or near aerodrome surfaces, or extending above defined protective surfaces (obstacle limitation surfaces, OLS). ICAO prescribes maximum heights and locations for obstacles, requiring marking, lighting, or removal to maintain safety.

Markings and Markers

Markings are painted indications on aerodrome surfaces, conveying information about alignment, thresholds, and operational restrictions. Markers are physical devices used when paint is unsuitable, such as on grass strips. Both must conform to ICAO standards for color, dimension, and placement.

Light Characteristics

Light characteristics describe aerodrome lighting in terms of configuration, color, intensity (candela), and coverage. ICAO’s “Four Cs”:

• Configuration: Arrangement and spacing of lights.
• Color: Standardized for function (e.g., white for runway edges, red for stop bars).
• Candelas: Required luminous intensity.
• Coverage: Visibility area and angles.

Correct characteristics ensure visual aids are effective in all conditions.

Candelas

A candela is the SI unit of luminous intensity. ICAO standards specify minimum and maximum candela values for aerodrome lights, with variable settings for different weather and operational needs. Regular calibration is required.

Taxiway

A taxiway is a defined path for aircraft taxiing, linking runways, aprons, hangars, and maintenance areas. Design factors include aircraft size, turning radii, surface strength, lighting, marking, and signage, all specified by ICAO.

Further Reading

• ICAO Annex 14 — Aerodromes
• ICAO Doc 9157 – Aerodrome Design Manual
• ICAO Safety Management Manual

Summary

ICAO Doc 9157, the Aerodrome Design Manual, is the international standard for airport planning, design, and operation. Its glossary of terms, standards, and best practices ensures the safety, efficiency, and interoperability of aerodrome infrastructure worldwide. Adherence to these provisions is essential for regulatory compliance, operational excellence, and the ongoing modernization of global aviation infrastructure.

For more information or expert guidance on implementing ICAO standards at your aerodrome, contact our aviation specialists.