How to Design Taxiways, Aprons and Holding Bays According to Aerodrome Design Manual Doc 9157 Part 2
Aerodrome Design Manual Doc 9157 Part 2: A Guide for Taxiways, Aprons and Holding Bays
Introduction
If you are involved in the planning, design, construction, operation or maintenance of an aerodrome, you may have heard of the Aerodrome Design Manual Doc 9157 Part 2. This document, published by the International Civil Aviation Organization (ICAO), provides guidance on the design of taxiways, aprons and holding bays at aerodromes. But what exactly is this document, why is it important for aerodrome design, and how can you use it effectively? In this article, we will answer these questions and give you an overview of the main topics covered by the manual.
Aerodrome Design Manual Doc 9157 Part 2
What is Aerodrome Design Manual Doc 9157 Part 2?
The Aerodrome Design Manual Doc 9157 Part 2 is one of the six parts of the Aerodrome Design Manual, which complements the Annex 14 to the Convention on International Civil Aviation. The Annex 14 sets out the standards and recommended practices (SARPs) for aerodromes, while the Aerodrome Design Manual provides more detailed guidance on how to apply them. The Part 2 of the manual focuses on taxiways, aprons and holding bays, which are essential components of an aerodrome's infrastructure. The manual aims to help aerodrome designers, operators, regulators and users to ensure that these components are safe, efficient, compatible and environmentally sustainable.
Why is it important for aerodrome design?
The design of taxiways, aprons and holding bays has a significant impact on the capacity, efficiency, safety and environmental performance of an aerodrome. Well-designed taxiways can reduce taxiing distances, times and fuel consumption, as well as minimize conflicts between aircraft movements. Well-designed aprons can facilitate aircraft parking, servicing and boarding, as well as optimize the use of space and resources. Well-designed holding bays can enhance runway throughput, reduce delays and emissions, as well as improve safety margins. Therefore, following the guidance provided by the manual can help aerodrome designers to meet the operational requirements and expectations of various stakeholders, such as airlines, passengers, air traffic controllers, ground handlers, service providers and regulators.
How is it structured and what does it cover?
Taxiways
Taxiways are the paths that connect the runway with the apron, the terminal and other facilities at an aerodrome. They allow aircraft to move from one point to another without interfering with other aircraft operations. Taxiways are designed to accommodate different types and sizes of aircraft, as well as different weather and visibility conditions. In this chapter, we will discuss the general layout and design criteria for taxiways, as well as some specific aspects such as taxiway width and shoulder, taxiway edge and centerline markings, taxiway lighting and signage, taxiway intersections and exits, and jet blast considerations.
General layout and design criteria
The general layout and design criteria for taxiways are based on the following principles:
The taxiway system should provide safe, efficient and direct routes for aircraft movements.
The taxiway system should minimize the number and complexity of intersections and exits.
The taxiway system should avoid sharp turns and changes in gradient.
The taxiway system should be compatible with the runway system and the apron layout.
The taxiway system should consider the operational characteristics and performance of the aircraft using the aerodrome.
The taxiway system should take into account the environmental impacts such as noise, emissions and land use.
The design criteria for taxiways include the following elements:
Taxiway width and shoulder: The width of a taxiway is determined by the wingspan and the wheel track of the aircraft using it. The shoulder is an area adjacent to the taxiway edge that provides additional clearance for wingtips, engines and landing gear. The width of the shoulder depends on the type of pavement, the drainage requirements and the jet blast effects.
Taxiway edge and centerline markings: The edge markings indicate the limits of the taxiway pavement that can be used by aircraft. The centerline markings indicate the center of the taxiway and help aircraft to maintain alignment. The markings are usually yellow and can be solid or dashed depending on whether the taxiway is continuous or discontinuous.
Taxiway lighting and signage: The lighting and signage provide visual guidance for pilots during low visibility conditions. The lighting includes edge lights, centerline lights, stop bars, runway guard lights and clearance bars. The signage includes direction signs, location signs, destination signs, runway distance remaining signs and information signs. The lighting and signage are usually color-coded according to their function and location.
Jet blast considerations
Jet blast is the high-velocity stream of air that is generated by jet engines during take-off, landing and taxiing. Jet blast can cause damage to buildings, vehicles, equipment and personnel in the vicinity of the taxiways and aprons. Jet blast can also affect the stability and control of other aircraft on the ground or in the air. Therefore, jet blast considerations are an important aspect of taxiway and apron design. In this section, we will discuss the effects of jet blast and the mitigation measures that can be taken to reduce its impact.
Jet blast effects and mitigation measures
The effects of jet blast depend on several factors, such as the type and size of the aircraft, the engine thrust and configuration, the distance and angle from the jet nozzle, the wind direction and speed, and the presence of obstacles or terrain features. Some of the possible effects of jet blast are:
Damage to buildings, vehicles, equipment and personnel: Jet blast can cause structural damage, break windows, dent metal surfaces, overturn light vehicles, dislodge loose objects, injure or kill people etc.
Interference with other aircraft operations: Jet blast can create turbulence, crosswinds, wake vortices and reduced visibility that can affect the stability and control of other aircraft on the ground or in the air.
Environmental impacts: Jet blast can increase noise levels, fuel consumption and emissions that can affect the quality of life and health of people living near the aerodrome.
The mitigation measures that can be taken to reduce the effects of jet blast include:
Designing taxiways and aprons to avoid or minimize jet blast exposure: This can be done by increasing the separation distance between aircraft and other objects, aligning taxiways and aprons parallel to or away from prevailing winds, avoiding sharp turns or changes in elevation etc.
Installing jet blast fences or barriers: These are structures that are designed to deflect or dissipate jet blast away from sensitive areas. They can be made of various materials such as concrete, steel, wood or plastic. They can be fixed or movable depending on the operational needs.
Implementing operational procedures and regulations: These include restricting aircraft movements or engine power settings in certain areas, coordinating aircraft departures and arrivals with air traffic control, informing pilots and ground personnel about jet blast hazards etc.
Jet blast fences design and location
Jet blast fences are one of the most common and effective ways to mitigate jet blast effects. They are usually installed at the end of runways, along taxiways or around aprons to protect buildings, vehicles, equipment and personnel from jet blast exposure. The design and location of jet blast fences depend on several factors, such as:
the jet blast loads and pressures without deformation or failure.
The engine thrust and configuration of the aircraft using the aerodrome: Different engine types and configurations have different jet blast patterns and intensities. The jet blast fence should be able to deflect or dissipate the jet blast effectively without creating adverse effects such as turbulence, noise or reflections.
The distance and angle from the jet nozzle to the jet blast fence: The distance and angle affect the jet blast velocity and direction at the jet blast fence. The jet blast fence should be located as far as possible from the jet nozzle to reduce the jet blast impact. The jet blast fence should also be oriented perpendicular or slightly inclined to the jet blast direction to maximize the deflection or dissipation effect.
The wind direction and speed at the aerodrome: The wind can influence the jet blast dispersion and direction at the jet blast fence. The jet blast fence should be designed to account for the prevailing and extreme wind conditions at the aerodrome. The jet blast fence should also be able to withstand the wind loads and pressures without damage or instability.
The presence of obstacles or terrain features near the jet blast fence: Obstacles or terrain features can affect the jet blast flow and distribution at the jet blast fence. They can also create secondary effects such as reflections, turbulence or noise. The jet blast fence should be designed to avoid or minimize interference with obstacles or terrain features. The jet blast fence should also be compatible with the aesthetic and functional aspects of the surrounding environment.
The design of jet blast fences should follow the guidance provided by the manual, which includes formulas, charts, tables and examples for calculating the jet blast loads, pressures, velocities and directions at different distances and angles from the jet nozzle. The manual also provides recommendations on the materials, dimensions, shapes and locations of jet blast fences for different types of aircraft and aerodromes.
Aprons
the general layout and design criteria for aprons, as well as some specific aspects such as apron size and geometry, apron markings and lighting, apron service roads and equipment parking areas, and aircraft stand allocation and management.
General layout and design criteria
The general layout and design criteria for aprons are based on the following principles:
The apron should provide adequate space and facilities for aircraft parking, loading, unloading, refueling, servicing and boarding.
The apron should minimize the distance and time required for aircraft to move between the runway and the terminal or other facilities.
The apron should avoid or reduce conflicts between aircraft movements and ground service vehicles or equipment.
The apron should be compatible with the taxiway system and the terminal layout.
The apron should consider the operational characteristics and requirements of the aircraft using the aerodrome.
The apron should take into account the environmental impacts such as noise, emissions and land use.
The design criteria for aprons include the following elements:
Apron size and geometry: The size of an apron is determined by the number and type of aircraft stands required to meet the peak demand. The geometry of an apron is determined by the shape and orientation of the aircraft stands, as well as the clearance distances between them. The size and geometry of an apron should also consider factors such as aircraft maneuverability, wingtip clearance, jet blast protection, passenger access etc.
Apron markings and lighting: The markings indicate the boundaries of the apron pavement, the location and dimensions of the aircraft stands, the taxiing routes and guidance lines, the safety zones and restricted areas etc. The lighting provides visual guidance for pilots and ground personnel during low visibility conditions. The markings are usually white and can be solid or dashed depending on their function. The lighting includes edge lights, stand lights, floodlights, stop bars etc. The markings and lighting are usually color-coded according to their function and location.
and lit appropriately to avoid confusion or collision.
Aircraft stand allocation and management
Aircraft stands are the designated areas on the apron where aircraft are parked and serviced. Aircraft stands can be classified into different types according to their layout and configuration, such as contact stands, remote stands, nose-in stands, angled stands, parallel stands etc. Aircraft stand allocation and management are the processes of assigning and coordinating aircraft stands to meet the operational needs and demands of airlines, passengers and service providers. In this section, we will discuss the factors that affect aircraft stand allocation and management, such as stand types and dimensions, stand guidance systems and docking aids, stand occupancy monitoring and coordination.
Stand types and dimensions: The type and dimension of a stand depend on the type and size of the aircraft using it, as well as the type and level of service required. The type of a stand determines the orientation and position of the aircraft relative to the terminal or other facilities. The dimension of a stand determines the clearance distance between the aircraft and other objects. The type and dimension of a stand should also consider factors such as passenger access, ground service vehicle access, jet blast protection, noise abatement etc.
Stand guidance systems and docking aids: The stand guidance systems and docking aids are devices that provide visual or electronic guidance for pilots to park their aircraft accurately and safely on the stand. They can be classified into different types according to their function and technology, such as visual docking guidance systems (VDGS), stop bars, lead-in lights, laser docking systems etc. The stand guidance systems and docking aids should be compatible with the aircraft types and systems using them. They should also be reliable, visible and easy to use.
and methods such as software, databases, sensors, cameras etc.
Holding Bays
Holding bays are the areas where aircraft are held or queued before entering or after exiting the runway. They are usually located near the runway ends or at strategic points along the taxiway system. They allow aircraft to wait for their turn to take-off or land without blocking other aircraft movements or occupying valuable runway time. Holding bays are designed to accommodate different types and sizes of aircraft, as well as different traffic and weather conditions. In this chapter, we will discuss the general layout and design criteria for holding bays, as well as some specific aspects such as holding bay size and geometry, holding bay markings and lighting, holding bay location and access, and holding bay operations and procedures.
General layout and design criteria
The general layout and design criteria for holding bays are based on the following principles:
The holding bay should provide adequate space and facilities for aircraft to hold or queue safely and comfortably.
The holding bay should minimize the distance and time required for aircraft to enter or exit the runway.
The holding bay should avoid or reduce conflicts between aircraft movements on the taxiway system or on the runway.
The holding bay should be compatible with the taxiway system and the runway system.
The holding bay should consider the operational characteristics and requirements of the aircraft using the aerodrome.
The holding bay should take into account the environmental impacts such as noise, emissions and land use.
The design criteria for holding bays include the following elements:
Holding bay size and geometry: The size of a holding bay is determined by the number and type of aircraft that can be accommodated at any given time. The geometry of a holding bay is determined by the shape and orientation of the aircraft positions, as well as the clearance distances between them. The size and geometry of a holding bay should also consider factors such as aircraft maneuverability, wingtip clearance, jet blast protection, noise abatement etc.
Holding bay markings and lighting: The markings indicate the boundaries of the holding bay pavement, the location and dimensions of the aircraft positions, the taxiing routes and guidance lines, the safety zones and restricted areas etc. The lighting provides visual guidance for pilots and ground personnel during low visibility conditions. The markings are usually yellow and can be solid or dashed depending on their function. The lighting includes edge lights, centerline lights, stop bars etc. The markings and lighting are usually color-coded according to their function and location.
the runway and the taxiway system. The access of a holding bay is determined by its connection and alignment with the taxiway system and the runway. The location and access of a holding bay should also consider factors such as aircraft speed, turning radius, sight distance, separation distance, holding position etc.
Holding bay operations and procedures: The operations and procedures of a holding bay are determined by its function and purpose. The function of a holding bay can be classified into different types according to its role in the runway operation, such as departure holding bays, arrival holding bays, intermediate holding bays etc. The purpose of a holding bay can be classified into different types according to its objective, such as capacity enhancement, delay reduction, noise abatement etc. The operations and procedures of a holding bay should also consider factors such as holding bay capacity and utilization, holding bay sequencing and clearance, holding bay safety and security measures etc.
Conclusion
In this article, we have given you an overview of the Aerodrome Design Manual Doc 9157 Part 2, which provides guidance on the design of taxiways, aprons and holding bays at aerodromes. We have discussed the main topics covered by the manual, such as general layout and design criteria, specific aspects and examples for each component, and appendices with additional information. We hope that this article has helped you to understand the importance and usefulness of this document for aerodrome design. If you want to learn more about this document or other related documents, you can visit the ICAO website or contact your local civil aviation authority.
FAQs
Here are some frequently asked questions about the Aerodrome Design Manual Doc 9157 Part 2:
Q: Who is the target audience of this document?
A: The target audience of this document are aerodrome designers, operators, regulators and users who are involved in the planning, design, construction, operation or maintenance of taxiways, aprons and holding bays at aerodromes.
Q: What is the difference between standards and recommended practices (SARPs) and guidance material?
A: SARPs are the minimum requirements that States must comply with or exceed in order to ensure safety, regularity and efficiency of international civil aviation. Guidance material are additional information or advice that States may use to implement or supplement SARPs.
Q: How often is this document updated or revised?
A: This document is updated or revised periodically to reflect the latest technolo