导致全国航空旅行瘫痪的核心是一团乱麻般的线缆。周五让航空旅行陷入停摆的系统，是一个由电线、电缆和网络设备组成的过时网络。
The tangle of wires at the heart of a nationwide air-travel meltdown The system that brought air travel to a standstill Friday is an outdated network of wires, cables and network gear.
该系统被称为 FTI，它承载着无线电传输、雷达数据和文本消息流，帮助成千上万名空中交通管制员指引飞行员穿越全国不可见的空域切片。
FTI, as the system is called, carries streams of radio transmissions, radar data and text messages that help thousands of air-traffic controllers guide pilots flying through invisible slices of the nation’s airspace.
交通部和联邦航空管理局（FAA）的官员周六表示，该通信骨干网内部出现的问题是导致全国几乎所有航班起飞停飞四个多小时的原因。国防承包商 L3Harris Technologies 负责监管 FTI。
Officials from the Transportation Department and Federal Aviation Administration on Saturday blamed problems that emerged within that communications backbone as the reason for halting nearly all departures across the country for more than four hours. Defense contractor L3Harris Technologies oversees FTI.
联邦官员表示，目前尚不清楚是新安装的路由器出现故障，还是 L3Harris 的操作失误触发了周五的空中交通大瘫痪。
Federal officials said it wasn’t yet clear whether problems with a newly installed router or errors by L3Harris triggered Friday’s air-traffic meltdown.
L3Harris 一位女发言人表示，该承包商迄今已升级了 FAA 约 70% 的老旧铜基网络，并正在配合该机构调查周五发生了什么问题。
An L3Harris spokeswoman said the contractor has so far upgraded about 70% of the FAA’s aging copper-based network and is supporting the agency’s probe into what went wrong Friday.
“L3Harris 高度重视全国性的停飞令及其对旅客、航空公司和空中交通运行的影响，”该公司在一份声明中表示。FTI 存在什么问题？
“L3Harris takes the nationwide ground stop and its impact on travelers, airlines and air traffic operations seriously,” the company said in a statement. What’s the issue with FTI?
联邦航空管理局电信基础设施（FTI）近年来屡次发生故障，而官员们在用基于光纤电缆和更新型路由硬件的现代化网络替换它的过程中举步维艰。但维护和更换这一任务关键型网络的工作已耗时多年，且成本不断上升。
The FAA Telecommunications Infrastructure, or FTI, has suffered repeated failures in recent years as officials struggle to replace it with a modernized network based on fiber-optic cables and newer routing hardware. But efforts to maintain and replace the mission-critical network have taken years and become more expensive over time.
老旧的铜线系统数据承载能力有限，而新的光纤链路传输信息更快。业内人士表示，如果来自新系统的数据使老旧系统过载，会导致传输不同步并引发中断。
The older copper-wire system has a limited capacity to carry data, while the new fiber links move information more quickly. If data from the newer system overloads the older system, it can throw transmissions out of sync and cause disruptions, industry officials said.
FTI 故障对美国联邦航空管理局（FAA）空中交通管制系统构成的风险早已为人所知。2023 年的一份外部评估警告称，由于网络中断增多、大修资金不足，“系统风险可能迅速达到不可接受的水平”。
The risks that FTI failures posed to the FAA’s air-traffic system are well known. A 2023 outside review warned that “system risk could quickly reach unacceptable levels” due to increased network outages and inadequate funding for overhauls.
近年来通信故障频发且严重。9 月，一条备用光纤线路被意外切断，加上主电路失效，导致美国东北部空中交通陷入瘫痪。L3Harris 扮演什么角色？
Communications failures have been severe in recent years. In September, the accidental cut of a backup fiber-optic line, along with the failure of a primary circuit, snarled air traffic throughout the Northeast. What is the role of L3Harris?
L3Harris 自 2002 年起担任 FTI 的主承包商。该专用网络的部分连接了全国空域系统约 1000 个地点。根据 2022 年的一份合同公告，其合同要求公司在发生中断后三小时内恢复部分站点的关键通信服务。
L3Harris has served as a prime contractor on the FTI since 2002. Part of the dedicated network connects about 1,000 locations across the nation’s airspace system. Its contract requires the company to restore vital communications services to some sites within three hours of an outage, according to a 2022 contract notice.
“L3Harris 做了什么？”交通部长肖恩·达菲在新闻发布会上说。“他们昨天犯错了吗？这网络归他们管。他们是我们的主承包商。我没法另找别家。网络在他们手里。还是路由器出了故障？我们会查明真相。坦白说，我们会追究责任。” FAA 多年来更换老旧网络的工作进展如何？
“What did L3Harris do?”Transportation Secretary Sean Duffy said at a press conference. “Did they make mistakes yesterday? They own this network. They’re our prime contractor. I can’t go somewhere else. They own it. Or was it a faulty router? And we’re going to find that out. And frankly, we’re going to hold people accountable.”Where is the FAA on its yearslong replacement of the aging network?
部分网络升级工作通过一个名为 FENS（FAA 企业网络服务）的多年项目进行。美国政府于 2023 年授予威瑞森一份价值 24 亿美元的合同，支持该大修项目。随后 AT&T 接手成为升级项目的主承包商。
Some of the network upgrade work runs through a yearslong project known as FENS, or FAA Enterprise Network Services. The U.S. government awarded Verizon a $2.4 billion contract in 2023 to support the overhaul. AT&T later took over as lead contractor on the upgrade project.
威瑞森发言人表示，该公司仍是 FAA 的合作伙伴，但其原合同下的大部分工作现由其他服务提供商承担。AT&T 发言人称，该公司网络运行正常。
A Verizon spokesman said it remains an FAA partner, but much of its former contract work is undertaken by other service providers. An AT&T spokeswoman said that the company’s network was working normally.
达菲周五呼吁国会拨款约 500 亿美元，用于升级国家空管通信系统和基础设施，以避免类似问题再次发生。
Duffy on Friday made a plea for Congress to provide around $50 billion for upgrades to the nation’s air-traffic control communications systems and infrastructure to avoid similar issues from happening in the future.
请致信 Drew FitzGerald，邮箱 andrew.fitzgerald@wsj.com；或致信 Andrew Tangel，邮箱 andrew.tangel@wsj.com。本解释性文章可能会定期更新。
Write to Drew FitzGerald at andrew.fitzgerald@wsj.com and Andrew Tangel at andrew.tangel@wsj.com This explanatory article may be periodically updated.