Stopway and Related Airport Infrastructure: A Comprehensive Guide

Introduction

Modern airport design incorporates a range of features to maximize safety, efficiency, and regulatory compliance. Among these, the stopway is a critical yet often misunderstood element. This guide provides an in-depth exploration of stopways, their relationship to other runway infrastructure (such as clearways, blast pads, EMAS, and RESA), and their role in ensuring safe and effective aircraft operations. It also delves into relevant standards, markings, performance calculations, and best practices for construction and maintenance.

What is a Stopway?

A stopway is a specially constructed, load-bearing area located immediately beyond the end of a runway. Its purpose is to provide additional distance for an aircraft to stop safely if a takeoff is aborted past the point of no return (decision speed, or V1). Unlike the main runway, the stopway is not intended for routine takeoff, landing, or taxiing operations. Instead, it acts as a passive safety feature, increasing the overall Accelerate-Stop Distance Available (ASDA).

Key Characteristics

• Location: Beyond the runway end, aligned with its centerline.
• Surface: Paved and strong enough to support the heaviest aircraft using the runway.
• Markings: Distinctive yellow chevrons or diagonal stripes.
• Use: Only in emergencies, specifically for aborted takeoffs.
• Regulation: Defined by ICAO Annex 14 and FAA Advisory Circulars.

The Role of Stopway in Runway Declared Distances

Understanding where the stopway fits within declared distances is essential for flight crews and airport operators:

Stopway vs. Clearway vs. Blast Pad vs. EMAS

Understanding the differences is vital for both pilots and airport planners:

• Stopway: Load-bearing, for rejected takeoff stops only; marked with yellow chevrons.
• Clearway: Obstacle-free area for initial climb, not paved or load-bearing; not for stopping.
• Blast Pad: Paved to resist jet blast erosion, not meant for aircraft weight during overrun.
• EMAS (Engineered Material Arresting System): Specially engineered material to safely arrest overrunning aircraft, often used where space is limited.

Markings and Lighting

Stopway Markings

• Yellow chevrons: Standard marking indicating an area not suitable for takeoff, landing, or taxiing.
• Location: Directly adjacent to the runway end, extending the full width of the runway.

Lighting

• Stopway edge lights: May be installed for visibility in low-light conditions.
• Distinct from runway edge lights: Prevents pilot confusion during critical operations.

Performance Calculations Involving Stopways

ASDA (Accelerate-Stop Distance Available)

The ASDA is the sum of the TORA and the stopway. It is the maximum distance available for an aircraft to accelerate to V1 and, in the event of an aborted takeoff, come to a complete stop using the runway and the stopway.

Example:
If a runway is 2,500 meters long and has a 300-meter stopway, then:

• ASDA = 2,800 meters
• TORA = 2,500 meters
• LDA = 2,500 meters (stopway not included)

No Impact on TORA, TODA, or LDA

The stopway does not increase the distances available for normal takeoff, landing, or clearway calculations.

Construction and Maintenance Standards

• Surface strength: Must support the heaviest aircraft using the associated runway.
• Width: At least equal to the runway width for seamless transition.
• Friction and smoothness: Not held to the same standards as runway surfaces, but must not pose hazards (e.g., FOD).
• Drainage: Essential to prevent standing water and hydroplaning risks.
• Regular inspections: To ensure ongoing compliance and operational readiness.

Related Safety Areas

Runway Safety Area (RSA)

A graded area surrounding the runway, designed to reduce the risk of damage during an undershoot, overrun, or veer-off.

Runway End Safety Area (RESA)

A defined area beyond the runway, typically at least 90 meters long as per ICAO, designed to minimize aircraft damage in overruns or undershoots.

Engineered Material Arresting System (EMAS)

An alternative to long RESAs or stopways, made from crushable concrete or cellular materials, engineered to arrest overrunning aircraft safely in constrained environments.

Displaced Thresholds

A displaced threshold is a designated point on the runway set back from the physical end, used to provide obstacle clearance or pavement protection. The area before a displaced threshold may be used for takeoff or rollout, but not for landing touchdown.

Information Sources and Standards

• ICAO Annex 14, Volume I: International standards for runway and stopway design, markings, and safety areas.
• FAA Advisory Circulars (e.g., AC 150/5300-13, AC 150/5340-1): US standards for runway and stopway design, markings, and lighting.
• Aeronautical Information Publications (AIP): Official airport data on declared distances, including stopways.

Best Practices for Airport Operators

• Publish accurate declared distances: Ensure all stopways are included only in ASDA.
• Regularly inspect and maintain: Surface strength, markings, and drainage.
• Educate staff: Pilots, airfield maintenance, and ground personnel on stopway function and markings.
• Plan for growth: Design stopways to accommodate future increases in aircraft size and weight.

Conclusion

Stopways are a vital component of runway safety and performance planning. By providing a structurally sound area for emergency stops, they enhance operational flexibility and reduce risk in critical takeoff scenarios. Proper design, marking, and maintenance of stopways, alongside clear distinction from clearways, blast pads, and EMAS, are essential for safe airport operations and regulatory compliance.

For airports seeking to improve safety margins and operational flexibility, investing in well-designed stopways and related infrastructure remains a best practice in global aviation.

Further Reading

• ICAO Annex 14 – Aerodromes
• FAA AC 150/5300-13 – Airport Design
• FAA Runway Safety Area Program

For further advice or consultation on airport safety infrastructure, please contact our team or schedule a demonstration .