Emmett Lindner 美国联邦航空管理局（FAA）本世纪仅第三次发布全国性停飞令，导致超过8200个美国航班取消，造成严重的旅行中断。
Emmett Lindner The FAA ordered only its third nationwide ground stop this century, and more than 8,200 US flights were cancelled, causing major travel disruption.
部分国际航班、美国西海岸飞往夏威夷的航班以及飞往阿拉斯加的航线仍在飞行，因为它们使用独立的空中交通管制中心和洋面空域。
Some international flights, West Coast flights to Hawaii, and routes to Alaska still flew because they used separate air traffic centres and oceanic airspace.
医疗和应急飞机仍获豁免，飞行员和管制员使用备用系统和协调机制维持部分航班运行。
Medical and emergency aircraft stayed exempt, while pilots and controllers used backup systems and coordination to keep some traffic moving.
AI生成 纽约——随着空中交通于11月13日全国性停飞令后在11月14日缓慢恢复，成千上万乘客争相更改行程，但部分旅客已乘坐未受停飞令影响的航班抵达目的地。
AI generated NEW YORK - Thousands of passengers scrambled to update their travel plans on Nov 14 as air traffic slowly unsnarled after a nationwide ground stop on Nov 13, but a number of travellers had already arrived at their destinations on flights left unaffected by the order.
即使全美各地机场应对本世纪联邦航空管理局仅发布的第三次全国性停飞令，数十个国际航班仍升空飞行。西海岸飞往夏威夷的部分航班在停飞期间也获准起飞。以下是空中交通系统受阻时，部分航空旅行仍获准进行的原因。
Dozens of international flights took to the skies even as airports across the United States coped with only the third nationwide ground stop issued by the Federal Aviation Administration this century. Certain flights were also permitted to depart from the West Coast to Hawaii during the stoppage. Here’s why some air travel was allowed to proceed even as flight systems were hampered.
部分国际航班得以起飞 据航空数据公司Cirium统计，11月13日全美有超过8200个航班取消，占计划航班的31%以上。
Some international flights were able to depart More than 8,200 flights were cancelled nationwide on Nov 13 – over 31% of those scheduled – according to Cirium, an aviation data firm.
但据航空追踪网站Flightradar24数据，停飞期间有超过60个飞往海外的航班从美国起飞。
But more than 60 flights bound for overseas left the United States during the stoppage, according to Flightradar24, an aviation tracking site.
据联邦航空管理局称，美国共有21个空中交通管制设施，其中20个位于美国本土，1个位于阿拉斯加，负责管辖全国各大区域的空域。
There are 21 air traffic control facilities, 20 in the contiguous United States and one in Alaska, that oversee swaths of regions throughout the country, according to the FAA.
联邦航空管理局在停飞令发布不到两小时后发布的一份通告中表示，随着部分中心恢复运行，航班“获准在与空中交通管制系统指挥中心协调后起飞”。
As some of those centres recovered, flights were “allowed to depart through coordination with the Air Traffic Control System Command Center”, the FAA said in an advisory less than two hours after the ground stop was ordered.
从中西部或东海岸飞往欧洲的航班可以与加拿大当局通联，前商业飞行员、内华达大学拉斯维加斯分校航空史教授丹·巴布说。
Flights departing for Europe from the Midwest or the East Coast can communicate with the Canadian authorities, said Dan Bubb, a former commercial pilot and an aviation history professor at the University of Las Vegas, Nevada.
此外，他说，公海上空的空中交通比美国本土48州的空中交通拥挤程度低。
Additionally, air traffic over the open ocean is less congested compared with that of the contiguous United States, he said.
全美空管协会主席尼克·丹尼尔斯说，对于飞越如此遥远洋面领空的飞机，“它们有程序化流程，有不同的间隔标准，不同于我们在本土48州为应对大量空中交通所采用的标准”。国内飞往夏威夷或阿拉斯加的航班情况如何？
Nick Daniels, the president of the National Air Traffic Controllers Association, said that for planes travelling such a large distance over oceanic airspace, “they have process procedures, different standards of separations, than what we do to run the volume of air traffic” in the lower 48 states. What about domestic flights to Hawaii or Alaska?
太平洋标准时间11月13日下午3点，即全国性停飞令解除前约两小时，旧金山国际机场表示，飞往太平洋方向的航班，包括飞往夏威夷和亚洲的航班，已获准起飞。为什么飞往西方的乘客如此幸运？
At 3pm Pacific Standard Time on Nov 13, about two hours before the nationwide ground stop was lifted, San Francisco International Airport said that Pacific-bound flights, including to Hawaii and Asia, had been cleared for departure. Why were passengers flying west so fortunate?
巴布说，这些飞行员通常会与某个区域管制中心通联，直到达到巡航高度。
Those pilots generally will talk to one of the regional centres until reaching cruising altitude, Bubb said.
他说，处理飞往夏威夷或亚洲航班空中交通的管制中心位于美国本土48州之外，因此能避免因停飞令造成的长时间延误。他补充说，在一定高度，飞行员可以将与加州管制员的通联切换为与夏威夷或阿拉斯加管制员的通联。
Centres handling air traffic headed to Hawaii or Asia are outside the contiguous United States, and therefore could avoid long delays from the ground stop, he said. At a certain altitude, a pilot could swap communications with California controllers for those in Hawaii or Alaska, he added.
阿拉斯加航空公司在一份声明中说，阿拉斯加州内航班、从西海岸飞往夏威夷的航班以及从檀香山出发的国际航班也豁免于停飞令之外。
Flights within Alaska, those from the West Coast to Hawaii and international flights from Honolulu were also exempt from the ground stop, Alaska Airlines said in statement.
丹尼尔斯说，阿拉斯加、关岛和夏威夷等地区距离足够远，即使本土48州的系统受到影响，它们也能保持稳定。
Areas like Alaska, Guam and Hawaii are far enough removed that they can remain stable even as systems are affected in the contiguous United States, Daniels said.
他补充说：“如果他们在那里也看到系统存在任何风险，他们也会采取同样的反应来减少运力。”医疗飞机在停飞期间可以飞行吗？一般来说，可以。在地面停飞和延误期间，应急和医疗飞机获准起飞。
“If they would have seen any kind of risk in the system there as well, then they would have reacted the same to reduce the capacity,” he added. Can medical aircraft fly during a ground stop? Generally, yes. During ground stops and delays, emergency and medical aircraft are given clearance to take off.
医疗运输服务商“生命飞行网络”在11月13日的社交媒体帖文中表示：“急救医疗服务飞机不受此限制影响”，其服务正常运行。
Life Flight Network, a medical transport service, said in a social media post on Nov 13 that “EMS aircraft are exempt from this restriction”, and its services were operating normally.
“医疗撤离和执法任务优先级最高，”丹尼尔斯说。“它们在整个系统中享有优先调动权，我们会为它们让路，而不是让它们像其他飞机一样排队等候。” 尽管停飞，通讯仍在继续 飞行员和管制员拥有多种通讯工具，巴布说。
“Above all is medevac and law enforcement,” Daniels said. “They get a priority movement throughout the system, and we move other aircraft out of their way, versus, they need to get in line with everyone else.”Communications continued despite the stoppage Pilots and controllers have many tools to communicate, Bubb said.
即使某一系统失效，飞行员仍可通过不同的通讯系统与其他飞行员、所属公司和地面管制进行联络。
Pilots can talk to one another, their companies and ground control through different messaging systems even if one fails.
“存在冗余系统，飞行员可以互相通话，我们也能自行排序，但我们遵循空中交通管制给出的指令，”巴布说。 纽约时报 本文最初刊登于《纽约时报》。
“There are redundant systems where pilots can talk to each other, and we can sequence ourselves, but we follow the instructions that we were given by air traffic control,” Bubb said. NYTIMES This article originally appeared in The New York Times.