An Amazon cargo jet overran the runway at Miami International Airport on Sunday, killing five and injuring five, reigniting debate over Engineered Materials Arresting Systems (EMAS). These crushable concrete buffers, installed at over 70 U.S. airports since the 1990s, have successfully stopped 26 aircraft carrying 497 passengers, per the Federal Aviation Administration. The F.

A. A. has recommended EMAS for two decades but requires only a 1,000-foot by 500-foot paved safety area at runway ends. Miami International meets this standard but lacks EMAS.

National Transportation Safety Board Chair Jennifer Homendy said whether EMAS should be mandatory everywhere will be a key investigation focus. Aviation consultant Michael O’Donnell questioned if 1,000 feet was sufficient. EMAS costs several million dollars per runway, with federal grants aiding installation at space-constrained airports like Kennedy and La Guardia in New York.

The system recently stopped a Learjet 60 at Teterboro Airport. Miami-Dade Aviation Department spokesman Gregory Chin stated no U.S. airport has both a full 1,000-foot safety area and EMAS, as EMAS is considered an alternative, not an addition.