14.10.2026

How an EMAS Bed Is Engineered: What Determines Its Length and Depth

Every EMAS bed looks the same from the runway. Underneath, no two are alike.

Length and depth aren’t standardized. They’re calculated. Three main variables drive the design: available space beyond the runway end, site topography, and the aircraft fleet mix the airport actually operates.

EMAS is designed to collapse under the weight of an aircraft’s landing gear. As an aircraft rolls onto the system, the engineered material crushes in a controlled manner, absorbing the aircraft’s kinetic energy and bringing it to a stop within a short, predictable distance.

Where a traditional Runway End Safety Area (RESA) requires up to 240 meters, an EMAS installation can reduce that need to 140 meters or less depending on the fleet mix. For airports constrained by terrain, water, roads, or other obstacles, that difference often determines whether full RESA compliance is achievable at all. In the USA, the FAA requires a 1000 feet long Runway Safety Area, which is almost identical to the 240 meters RESA plus 60 meter runway strip.

Fleet mix matters because the bed has to perform across the full range of aircraft using the runway, not just its heaviest or most frequent type. An EMAS designed for a narrow-body fleet won’t behave the same way under a wide-body aircraft overrun. Getting the fleet mix input right at the design stage is what makes the bed perform as intended when it’s needed.

Same engineering principles, every installation. Different bed, every time.

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About the author

Trip Thomas

Business Area manager, Runway Safe Group.
Trip works with airports and defense customers throughout the specification and procurement process, from initial technical questions to final system selection. He is part of the Runway Safe team.