The airport safety system that could have slowed the plane that left the runway in Miami, killing 5 people

When the Amazon Air cargo plane barreled off the runway at Miami International Airport this week going nearly 130 miles an hour, there was little to slow it down. The 156-foot-wide jet crushed vehicles, smashed concrete road barriers and tore through navigational equipment. Five people in vehicles were killed.

A concrete system designed to decelerate planes when they can’t stop at the end of the runway has been installed at some US airports — but not in Miami.

It’s called EMAS — which stands for engineered materials arresting system — and it is designed to bring an aircraft going about 80 miles an hour to a stop in just feet. It’s not clear it would have entirely stopped the plane in Miami, since the aircraft was going much faster, but it certainly would have kept the plane from going so far off the runway.

It’s a system being praised for saving as many as 250 lives in the last decade.

Steve Harrison was sitting next to his wife, Deborah Tatar, looking out the window of United Express Flight 4339 when he realized this landing wasn’t going to be normal.

The approach on September, 24 2025 into Virginia’s Roanoke-Blacksburg Regional Airport took the flight through a rainstorm, according to federal investigators. But what bothered Harrison most was that the plane sailed past the point where it would normally touch down.

“I thought, ‘This better stop pretty soon,’” he told CNN.

Seconds later, the Embraer 145 regional jet heaved into a bed of lightweight, crushable cement, bringing the 20-ton jet to a sudden stop just shy of an embankment that drops toward four lanes of a busy road.

Roanoke–Blacksburg Regional Airport

Harrison and his wife walked away uninjured.

They, along with 48 other passengers on board, were saved by EMAS. Deployed at 70 airports across the United States, the system has halted potentially deadly runway overruns 26 times. On September 3, 2025, the system scored two saves less than five hours apart.

“It’s like a runaway truck stop, but for airplanes,” said Nick Subbotin, the acting head of the team overseeing EMAS for the Federal Aviation Administration. Inside a hangar next to Atlantic City International Airport where the FAA initially tested EMAS by intentionally speeding a Boeing 727 into it, Subbotin has spread out a series of photographs detailing each incident where he says the material saved lives.

EMAS looks deceptively simple. Installed beyond the end of a runway, it is made from lightweight cellular cement engineered to collapse under the concentrated weight of an airplane’s landing gear. As the wheels break through the surface and sink into the material, the resistance rapidly slows the airplane.

The beds can contain hundreds of blocks laid out in a grid, growing progressively deeper so an aircraft slows without subjecting the landing gear — or the people aboard — to extreme deceleration forces that can be deadly in a crash.

“Lots of testing went into mathematical models of determining the material and how it crushes,” Subbotin said. Given aircraft with a certain weight, size and energy as it leaves the runway, this type of material will safely decelerate that aircraft coming to a stop, saving the airplane and saving lives.

EMAS is typically installed where geography or development makes it impossible for an airport to provide the full runway safety area normally required beyond the pavement. At some airports, the obstacle beyond the runway is a highway. At others, it is a hillside, water or homes. In Roanoke, it’s four lanes of traffic.

“If the available real estate is not there, EMAS becomes an alternative for the airport to safely stop aircraft in the event of an overrun,” Subbotin said.

Runway excursions remain one of aviation’s most prevalent accident risks.

A industry study by the Flight Safety Foundation found from 2005 through the first half of 2019, runway excursions accounted for 23 percent of accidents chronicled in an international crash database, more than any other accident type.

The report said the industry had reduced the rate of commercial aviation runway excursion accidents, but their absolute number and severity still represented a significant risk.

EMAS cannot prevent a pilot failing to abort a flawed descent to landing — a top training target for major airlines.

In Roanoke, the EMAS bed became the last layer of protection after a landing the National Transportation Safety Board says had already gone wrong.

According to the NTSB’s preliminary report, Flight 4339 was too high as it approached the runway. The first officer twice told the captain to abort the landing, investigators said.

“There were probably other things that should have happened differently before we got to that point,” Tatar told CNN. “All we know is that that was the last point.”

“And that’s what saved us,” Harrison added.

Roanoke-Blacksburg Regional Airport

The NTSB investigation remains ongoing.

Safety experts stress that EMAS is not a substitute for preventing runway excursions in the first place. The Flight Safety Foundation calls for layers of protection, including better training for pilots about when to abort flawed approaches to land.

But when those layers fail, EMAS is there to mitigate the consequences.

The recent string of saves comes as Boston Logan International Airport is making a major investment in the same technology.

Starting August 31, Logan closed Runway 9/27 for approximately 75 days as crews undertake the next phase of a multimillion-dollar runway safety project.

Part of that work involves installing more EMAS protection at the end of a runway extending toward Boston Harbor.

The project underscores the unusual tradeoff involved in building a system designed for an emergency that may never happen.

For roughly two and a half months, Logan will lose the use of an entire runway. Airport officials have warned the closure will reduce capacity under some configurations and could lead to flight delays and traffic-management measures.

Austin DeSisto/NurPhoto/Getty Images

Massport, which operates the airport, calls the work a critical safety upgrade, but Boston highlights why EMAS was developed in the first place.

Logan is hemmed in by water and dense urban development. At airports where extending a conventional runway safety area would mean filling in water, moving a road or acquiring developed land, EMAS can provide stopping distance within a much smaller footprint.

For Tatar, Boston’s investment carries a significance that goes well beyond construction schedules and flight delays.

As a teenager, she lost a friend aboard a commercial flight that crashed into a seawall at Boston Logan International Airport.

Only weeks after Tatar and Harrison walked away from the Roanoke overrun, their first grandson was born.

“We would not have seen him born,” Tatar said. “There’s a very good chance that we would not have survived.”

本周，一架亚马逊航空的货机在迈阿密国际机场冲出跑道，时速接近130英里，几乎没有任何阻挡。这架宽156英尺的喷气式飞机撞毁了车辆，撞碎了混凝土路障，并损毁了导航设备。事故造成五名车内人员死亡。

美国一些机场已经安装了用于在飞机无法在跑道尽头停下来时减速的混凝土系统——但迈阿密机场还没有安装。

它名为EMAS，全称为工程材料阻拦系统，其设计目的是使时速约80英里的飞机在短短几英尺内停下来。目前尚不清楚它是否能完全阻止迈阿密那架飞机，因为当时飞机的速度远高于此，但它肯定能防止飞机偏离跑道那么远。

该系统因在过去十年中挽救了多达 250 条生命而受到赞扬。

史蒂夫·哈里森当时正和妻子黛博拉·塔塔尔坐在美国联合航空快运 4339 号航班的舷窗边，看着窗外，这时他意识到这次着陆不会像往常一样。

据联邦调查人员称，2025年9月24日，这架飞机在弗吉尼亚州罗阿诺克-布莱克斯堡地区机场进近时遭遇暴雨。但最令哈里森担忧的是，飞机飞过了通常的着陆点。

“我当时想，‘这最好尽快结束，’”他告诉 CNN。

几秒钟后，巴西航空工业公司生产的 E145 支线喷气式飞机猛地撞进一层轻质可压碎的水泥层中，这架 20 吨重的飞机在即将撞上通往繁忙道路四车道的路堤前突然停了下来。

罗阿诺克-布莱克斯堡地区机场

哈里森和他的妻子毫发无损地离开了现场。

他们和机上其他48名乘客都因EMAS系统而获救。该系统已在美国70个机场部署，26次成功阻止了可能致命的冲出跑道事故。2025年9月3日，该系统在不到5小时内两次成功挽救了乘客的生命。

“这就像一个失控卡车停靠站，只不过是为飞机准备的，”美国联邦航空管理局 (FAA) 负责 EMAS 项目的代理负责人尼克·苏博廷 (Nick Subbotin) 说。在大西洋城国际机场旁的一个机库里，FAA 最初测试 EMAS 时，故意让一架波音 727 高速撞向机库。苏博廷在这里展示了一系列照片，详细记录了每次 EMAS 材料挽救生命的事件。FAA 最初就是在这里测试 EMAS 的，他们故意让一架波音 727 高速撞向机库。

EMAS系统外观看似简单，实则不然。它安装在跑道末端，由轻质泡沫水泥制成，这种水泥经过特殊设计，能在飞机起落架的集中重量下坍塌。当轮子压穿表面并陷入水泥中时，产生的阻力会迅速降低飞机速度。

这些床可以容纳数百个呈网格状排列的模块，逐渐加深，这样飞机就能减速，而不会使起落架或机上人员承受在坠机时可能致命的极端减速力。

“我们进行了大量的测试，建立了数学模型来确定这种材料的特性以及它的压溃方式，”苏博廷说道。对于具有特定重量、尺寸和离地能量的飞机，这种材料能够安全地减缓飞机的减速，使其最终停止，从而保护飞机并挽救生命。

EMAS（跑道安全区域系统）通常安装在因地理环境或城市发展而导致机场无法提供跑道外完整安全区域（通常要求）的机场。在一些机场，跑道外的障碍物是公路；在另一些机场，则是山坡、水域或住宅区；而在罗阿诺克机场，则是四车道的公路。

“如果没有足够的可用土地，EMAS 就成为机场在飞机冲出跑道时安全停下飞机的替代方案，”苏博廷说。

跑道偏离仍然是航空事故中最普遍的风险之一。

飞行安全基金会的一项行业研究发现，从 2005 年到 2019 年上半年，跑道偏离事故占国际事故数据库记录事故的 23%，超过任何其他类型的事故。

报告称，航空业已降低了商业航空跑道偏离事故的发生率，但事故的绝对数量和严重程度仍然构成重大风险。

EMAS 无法阻止飞行员在着陆过程中出现故障而未能中止下降——这是各大航空公司最重要的训练目标之一。

在罗阿诺克，EMAS 安全床成为最后一道防护屏障，此前美国国家运输安全委员会称，飞机着陆时已经出现了问题。

根据美国国家运输安全委员会（NTSB）的初步报告，4339号航班在接近跑道时高度过高。调查人员称，副驾驶曾两次指示机长中止着陆。

塔塔尔告诉CNN：“在我们走到那一步之前，可能还有其他事情本该以不同的方式发生。我们只知道那是最后一步。”

“正是这一点救了我们，”哈里森补充道。

罗阿诺克-布莱克斯堡地区机场

美国国家运输安全委员会的调查仍在进行中。

安全专家强调，EMAS并不能替代从源头上预防跑道偏离。飞行安全基金会呼吁采取多重保护措施，包括加强对飞行员的培训，使其了解何时应该中止错误的进近着陆操作。

但当这些防护措施失效时，EMAS 可以减轻其后果。

最近一系列的成功挽救行动发生之际，波士顿洛根国际机场也正在对这项技术进行重大投资。

从 8 月 31 日起，洛根机场关闭了 9/27 号跑道约 75 天，以便工作人员开展一项耗资数百万美元的跑道安全项目的下一阶段工作。

这项工作的一部分是在通往波士顿港的跑道末端安装更多的EMAS防护装置。

该项目凸显了构建一个为应对可能永远不会发生的紧急情况而设计的系统所涉及的不寻常的权衡。

在接下来的大约两个半月里，洛根机场将无法使用一条完整的跑道。机场官员警告称，跑道关闭将降低部分航班的运力，并可能导致航班延误和交通管制措施。

奥斯汀·德西斯托/NurPhoto/Getty Images

运营该机场的马萨诸塞州港务局称这项工程是一项至关重要的安全升级，但波士顿强调了当初开发 EMAS 的原因。

洛根机场被水域和密集的城市开发区包围。在那些需要填海造地、改道或征用已开发土地才能延长传统跑道安全区的机场，EMAS 系统可以在更小的占地面积内提供更长的制动距离。

对塔塔尔来说，波士顿的投资意义远不止于施工进度和航班延误。

十几岁时，她的一位朋友在一架商业航班上丧生，该航班在波士顿洛根国际机场撞上了海堤。

塔塔尔和哈里森离开罗阿诺克被占领的地区仅仅几周后，他们的第一个孙子就出生了。

“我们可能就看不到他出生了，”塔塔尔说。“我们很可能也活不到今天。”