What is an engineered materials arresting system (EMAS)?

An engineered materials arresting system (EMAS) is a passive, purpose-built bed of crushable, energy-absorbing material beyond a runway end. If an aircraft overruns, its wheels sink into and crush the bed, creating controlled resistance that slows it where the airport cannot provide a full-length conventional runway safety area.

In our Aviation & Real-World Flying reference, we use the formal plural expansion Engineered Materials Arresting System. “Engineered material arresting system” is a common singular search and procurement variant. “EMAS system” is widely understood, although the final word repeats “system”.

No pilot or controller activates EMAS. It is a final layer of protection after aircraft braking, runway design, operating procedures and overrun prevention have failed.

How does airport EMAS work?

Airport EMAS absorbs an aircraft's kinetic energy through the controlled crushing and displacement of calibrated, low-strength material beneath its landing gear.

As the wheels enter the bed, they break through its protective surface and sink into the crushable material. Resistance builds around the tyres and landing gear, progressively decelerating the aircraft. The stopping effect comes mainly from deforming the engineered material, not from ordinary tyre friction on a rough surface.

Many installations use manufactured cellular cementitious blocks beneath a weather-resistant covering. Approved systems may use other engineered crushable media. EMAS is not loose gravel, ordinary soft ground or a layer of foam: its material strength, bed dimensions, foundation, drainage, surface protection and quality controls form one designed installation.

The airport-specific design considers the selected aircraft or fleet mix, aircraft mass, landing-gear geometry, tyre loading, likely runway-exit speed, available length and width, slope, climate and nearby obstacles. Some beds become progressively deeper, but the construction profile depends on the approved product and site design.

In United States FAA design practice, 70 knots is the familiar runway-exit-speed reference for a standard installation. A space-constrained site may receive approval for a system with lower stopping capability. That number is an engineering criterion—not an operating limit, guaranteed stopping speed or distance credit for flight planning.

What can an EMAS arresting system not do?

EMAS cannot guarantee a safe stop in every runway excursion.

• An aircraft may miss the bed during a lateral excursion or enter it at a large angle.
• An aircraft that remains airborne may pass over some or all of the crushable section.
• An entry speed outside the installation's design assumptions may leave insufficient bed length.
• Collapsed or missing landing gear changes how loads reach the material, so predicted wheel-arresting performance no longer applies directly.
• EMAS cannot prevent the rejected take-off, unstable landing, brake failure, fire or structural damage that caused the overrun.
• A bed at one runway end does not protect an overrun towards the opposite end.

EMAS airport installation and runway layout

An EMAS runway bed sits beyond the physical runway end, normally centred on the extended centreline and occupying part of the runway-end safety area.

An airport may install EMAS at one end, both ends or only on selected runways. A bed protects aircraft moving towards that physical end, including landing overruns and rejected take-offs in that direction. It does not protect traffic moving towards the other end unless a separate installation is provided there.

A setback or blast-resistant lead-in may separate the usable runway from the crushable bed. This protects the arresting material from routine jet blast and is not necessarily part of the energy-absorbing section. Roads, railways, water, steep ground, buildings and airport boundaries are common reasons an airport chooses EMAS instead of trying to construct a full-length conventional safety area.

EMAS is never extra runway. It does not increase take-off run available, take-off distance available, accelerate-stop distance available or landing distance available. Only officially declared distances may enter performance calculations; our guide to using runway length and declared distances for take-off and landing explains that distinction.

How can pilots verify an EMAS installation?

Pilots should identify EMAS from effective airport information, not from its colour or an airport-scene texture.

1. Check the airport diagram. Look for an outlined or labelled bed beyond the runway end, sometimes accompanied by published dimensions.
2. Read the airport remarks. Aerodrome publications may describe the system, its location, usable dimensions or special restrictions more clearly than the drawing.
3. Review applicable NOTAMs. A bed may be unavailable, damaged, shortened by repair work or affected by construction even though it remains on the chart.
4. Confirm declared distances. Do not add the bed, its setback or adjacent pavement to a published distance. If a stopway is declared, use only the resulting published accelerate-stop distance.
5. Treat visual markings only as supporting evidence. Yellow chevrons identify unusable areas in some jurisdictions, but they do not by themselves prove that EMAS is present.

The KGMU airport chart collection and KSUA airport chart collection provide real examples of how an engineered materials arresting system and its dimensions may be presented. For an actual operation, verify the chart's effective status and associated notices rather than measuring an unscaled drawing or relying on simulator scenery.

EMAS vs blast pad, stopway, runway safety area and engineered arresting systems

Engineered arresting systems is the wider category for purpose-designed equipment that decelerates an aircraft during an overrun or emergency recovery. It can include civil EMAS beds and aircraft-specific cable, net or barrier systems; the terms are not interchangeable.

The practical blast pad versus EMAS distinction is simple: a blast pad protects the ground from engine exhaust, while EMAS sacrifices its crushable material to slow an aircraft. A paved area can also have more than one published function, so its official designation and declared distances—not appearance—control how it may be used.

A mistake we see regularly is calling every marked area beyond a runway a stopway. Our explanation of runway safety areas, stopways, blast pads and other airport features provides the broader layout context.

When do airports choose an engineered materials arresting system?

Airports choose EMAS when straight-ahead overrun protection is required but constructing a compliant conventional runway safety area is impractical.

A full cleared and graded safety area is generally the simpler solution because it accommodates more excursion paths and facilitates emergency access. At a constrained airport, however, extending it may require land acquisition, relocation of a road or railway, major earthworks, obstacle removal or construction over water.

Planners and regulators normally compare several approaches:

• Extend or regrade the safety area when suitable land and obstacle clearance are available.
• Relocate the runway end or reduce declared distances when the resulting aircraft-performance and airport-capacity penalties are acceptable.
• Install EMAS when limited ground remains beyond the runway and a compact wheel-arresting bed offers the most practical straight-ahead protection.

The assessment also covers the critical aircraft, likely fleet changes, rescue access, drainage, snow and ice procedures, jet-blast exposure, inspection requirements and post-engagement restoration. EMAS does not remove every runway safety-area requirement and is not an effective substitute for protection against lateral excursions.

Engineered Material Arresting System market: reviewed October 2026

The engineered material arresting system market is a specialised, project-based airport safety sector rather than a commodity market for generic crushable blocks.

A procurement package can include feasibility studies, aircraft and overrun modelling, bed design, approved energy-absorbing material, foundations, drainage, site preparation, utility relocation, installation, surface protection, regulatory acceptance work, inspections, maintenance and post-engagement repair. Civil works can represent a substantial part of a contract even when a market report classifies the entire award as EMAS revenue.

The eligible supplier field is limited because an airport needs a complete system accepted through the applicable aviation authority's process. Material blocks are not normally interchangeable solely because they look similar. Qualification evidence, manufacturing quality control, modelled stopping performance, climate suitability, installation controls and long-term replacement support all affect selection. A vendor's previous installation in one jurisdiction does not automatically establish approval in another.

Demand is driven by airports that cannot provide the required runway-end safety space, safety-standard upgrades, replacement of ageing beds, repairs after an engagement, runway reconfiguration and changes in the critical aircraft or fleet mix. A heavier aircraft, different landing-gear geometry or revised operating profile can trigger a new engineering assessment even when the existing bed remains physically intact.

Published market-size figures vary because reports often measure different products. Some count only civil EMAS; others combine it with military arresting cables, barriers, nets and related runway-safety equipment. Reports may also include or exclude civil engineering, inspections, replacement modules, repairs and maintenance, while using different geographies, currencies and base years.

There is therefore no single universal market total that can be quoted without defining the category. Any figure should identify its named publisher, publication date, base year, geography, currency, treatment of civil works and whether it covers new installations, refurbishment or the wider engineered arresting systems category. We do not present an unsourced worldwide value as if these scopes were equivalent.

What should a pilot do if an overrun into EMAS is unavoidable?

If entry into EMAS is unavoidable, the crew should continue the approved aircraft and operator stopping procedure, maintain directional control where possible and enter the bed aligned rather than treating it as manoeuvring space.

1. Continue approved stopping actions. Follow the applicable rejected-take-off, landing-overrun and aircraft checklist procedures. Use wheel braking, aerodynamic braking and reverse thrust only as authorised for that aircraft and situation; do not abandon approved stopping action merely because EMAS is ahead.
2. Maintain directional control where possible. Keep the aircraft near the runway centreline and avoid a last-second swerve towards obstacles or unsuitable ground. Aircraft-specific procedures and the immediate emergency still take priority.
3. Allow the aircraft to stop. Avoid unnecessary steering once in the bed, because uneven penetration can produce asymmetric loads. Continue the approved stopping procedure until the aircraft is stationary.
4. Request assistance. Inform air traffic control or the appropriate airport service, state the aircraft's condition and request emergency and recovery support. Do not attempt to taxi out under engine power.
5. Secure and assess the aircraft. Complete the applicable shutdown or securing checklist and monitor for fire, smoke, fuel leakage, brake overheating, structural damage or evacuation hazards.
6. Follow emergency, evacuation and reporting procedures. Evacuate when required by the emergency, checklist or command decision. Once people and aircraft are secure, complete the operator, airport and authority notifications and occurrence reports that apply.

EMAS must never be treated as performance credit or a planned extension of the stopping surface. Its presence does not justify accepting an unstable approach, continuing a take-off outside limits or reducing normal runway margins.

Does EMAS damage the aircraft?

EMAS is designed to reduce injuries and aircraft damage, but an engagement is not expected to be damage-free.

The bed is deliberately sacrificial. Crushed blocks or sections must be removed and replaced, while the foundation, joints, drainage and protective covering require inspection before the system returns to full service.

The aircraft normally needs inspection of its tyres, wheels, brakes, landing gear, lower fuselage and engines. Material ingestion and further embedding are possible if thrust or wheel movement is attempted after stopping. Recovery may require temporary ramps, lifting equipment and specialised towing rather than ordinary taxi power.

Weathering, water ingress, damaged seals, jet blast and unauthorised vehicle entry can degrade a bed without an aircraft overrun. Airports therefore inspect and maintain EMAS as an active safety asset, not as ordinary pavement beyond the runway.

Is EMAS modelled in flight simulators?

In most flight simulators, a visible EMAS bed is scenery rather than a physically accurate energy-absorbing system.

Microsoft Flight Simulator 2024 and 2020, FSX, Prepar3D and X-Plane can display blocks, markings and the bed while assigning the area a generic concrete, rough-ground, soft-ground or collision surface. Some detailed airport add-ons attempt custom drag or stopping behaviour, but that feature is package-specific and should not be assumed from appearance.

A convincing yellow-chevron rectangle does not prove that functional EMAS has been modelled. An invisible wall that stops the aircraft instantly is not realistic EMAS behaviour; neither is a generic soft surface that immediately flips the aircraft or collapses its landing gear.

• Confirm from airport data that the object represents EMAS rather than a blast pad or stopway.
• Check the scenery documentation for an explicit description of custom arresting behaviour.
• When testing scenery, keep aircraft mass, entry speed, braking, weather and surface condition consistent.
• Treat the result only as a test of that simulator and scenery package, never as evidence of real-world stopping performance.