Definition
EMASMAX is the brand name of the Engineered Material Arresting System manufactured by Runway Safe, installed at the end of certain runways to safely stop an aircraft that overruns the runway. It consists of a bed of crushable cellular cement blocks that collapse predictably under the weight of an aircraft's wheels, decelerating it without causing major structural damage to the airframe or injury to occupants.
Plain English
A patch of special crushable concrete blocks built at the end of a runway. If a plane runs off the end, its wheels sink into the blocks and the plane is brought to a stop without crashing.
Context Anchor
Seen in runway safety discussions, airport planning information, and pilot guidance about what may be located beyond the departure end of a runway.
Derivation
EMAS stands for Engineered Material Arresting System. 'Arresting' here means stopping or holding back, the same sense used in 'arresting cables' on aircraft carriers. MAX is part of the manufacturer's product name. The 'engineered material' is the specially designed crushable cement.
Why Pilots Care
Provides an engineered safety margin that can prevent runway excursion damage or injury when normal stopping distance is exceeded.
Grounding Statement
Picture a wide bed of crushable blocks past the runway end that gives way under the aircraft and helps bring it to a stop.
Intuition Check
Do not read EMASMAX as a runway extension. It is a stop-assist area for an overrun, not pavement to use during normal operations.
Example Sentence 1
The airport installed an EMASMAX bed at the end of Runway 4 because the runway safety area was shorter than the standard length.
Example Sentence 2
During the approach briefing the captain confirmed the runway had EMASMAX available if a long landing occurred.