An engine fire sparked by plastic packaging wrap, a tire lost shortly after takeoff and a plane veering off the runway: These are among the eight incidents that have occurred over the past two weeks on flights operated by United Airlines. While no injuries — or worse — have been reported, the mishaps have generated headlines and stoked rising anxiety about aviation safety among federal officials and passengers alike.
塑料包装膜导致发动机起火、起飞后不久轮胎脱落、飞机偏离跑道：这些都是过去两周美国联合航空运营的航班发生的事故，这样的事故共有八起。虽然没有报告人员受伤或更严重的事故，但这些事故已经得到广泛报道，令联邦官员和乘客对航空安全日益担忧。
All of the incidents happened in the United States, and five involved airplanes made by Boeing, a manufacturer already under intense scrutiny. In January, a door plug blew out of an Alaska Airlines Boeing 737 Max 9 jetliner in mid-flight, forcing the plane to make an emergency landing.
所有这些事故都发生在美国，其中五起涉及已经受到严密审视的波音公司制造的飞机。今年1月，阿拉斯加航空公司的一架波音737 Max 9喷气式客机在飞行途中嵌门板飞脱，导致飞机紧急迫降。
United, one of the world’s largest airlines, flies aircraft manufactured mainly by Boeing and Airbus. In an email United began sending to customers on Monday, the company’s chief executive, Scott Kirby, wrote that while the recent incidents were unrelated, they were “reminders of the importance of safety.”
美联航是世界上最大的航空公司之一，其飞机主要由波音和空客制造。美联航首席执行官斯科特·柯比在周一开始向客户发送的电子邮件中写道，虽然最近的事件彼此不相关，但它们“提醒了安全的重要性”。
“I want you to know that these incidents have our attention and have sharpened our focus,” he continued, adding that every case was being reviewed by the airline and would influence its safety training and procedures.
“我想让你们知道，这些事件引起了我们的关注，使得我们更加明确重点，”他接着说，另外航空公司正在审查每一起事件，并将影响其安全培训和程序。
Here’s what travelers should know about the latest in airplane woes. 以下是旅客应该了解的最新飞机事故情况。
What exactly happened on or to the planes?
飞机上到底发生了什么？这些飞机出了什么问题？
Most of the incidents reported in the last two weeks required emergency landings or diversions.
过去两周报告的大多数事故都需要紧急迫降或备降。
• March 4: A Boeing 737-900 departing from George Bush Intercontinental Airport in Houston returned to the airport to make an emergency landing after one of the plane engines ingested and burned plastic wrap.
· 3月4日：一架从休斯顿乔治·布什洲际机场起飞的波音737-900飞机在一个引擎吸入并导致塑料包装膜燃烧后返回机场紧急降落。
• March 7: A Boeing 777 leaving San Francisco for Osaka, Japan, made an emergency landing at Los Angeles International Airport after the aircraft lost a tire.
· 3月7日：一架从旧金山飞往日本大阪的波音777飞机在失去一个轮胎后紧急降落在洛杉矶国际机场。
• March 8: A Boeing 737 Max 8 veered off the runway upon landing at George Bush Airport in Houston and tilted onto the grass. · 3月8日：一架波音737 Max 8在休斯顿乔治·布什机场降落时偏离跑道，倾斜着停在草坪上。
• Later that day, a flight leaving San Francisco for Mexico City was diverted to Los Angeles after the Airbus A320 experienced issues with its hydraulic system.
· 当天晚些时候，一架从旧金山飞往墨西哥城的空客A320在液压系统出现问题后，被迫转飞洛杉矶。
• March 9: An Airbus A320 heading to Salt Lake City turned back to Chicago O’Hare International Airport after it reported maintenance issues.
· 3月9日：一架飞往盐湖城的空客A320飞机在报告维修问题后返回芝加哥奥黑尔国际机场。
• March 11: A Boeing 777, flying from Sydney, Australia, to San Francisco, turned back after takeoff because the plane had a hydraulic leak.
· 3月11日：一架从澳大利亚悉尼飞往旧金山的波音777飞机在起飞后因液压油泄漏而返航。
• March 14: An Airbus A320 that departed from Dallas Fort Worth International Airport had a hydraulic leak shortly before it landed in its scheduled destination, San Francisco.
· 3月14日：一架从达拉斯沃斯堡国际机场起飞的空客A320飞机出现液压油泄漏，不久后降落在预定目的地旧金山。
• Later that day, a Boeing 737-800 that took off from San Francisco landed at Rogue Valley International Medford Airport in Oregon missing an external panel.
· 当天晚些时候，一架从旧金山起飞的波音737-800飞机降落在俄勒冈州的罗格谷国际梅德福机场时，一块外部面板丢失。
Are the recent issues typical, or cause for concern?
最近发生的这些是常见问题，还是值得忧虑的问题？
The mishaps were not the result of “systemic problems,” said Robert Sumwalt, a former chairman of the National Transportation Safety Board who now heads a new aviation safety center at Embry-Riddle Aeronautical University.
前美国国家运输安全委员会主席、现任安柏瑞德航空大学一个新成立的航空安全中心负责人的罗伯特·萨姆沃特说，这些事故不是“系统性问题”的结果。
“Some of these issues are things that happen occasionally, but often don’t get reported in media,” Mr. Sumwalt said, though he emphasized that none were acceptable.
“其中一些问题是偶尔发生的，但通常不会被媒体报道，”萨姆沃特说，不过他强调，这些问题都是不可接受的。
Kyra Dempsey, who writes about aviation accidents in a blog called Admiral Cloudberg, said that United’s recent issues were being “falsely conflated with Boeing’s troubles.”
凯拉·邓普西在名为克劳德伯格上将的博客上撰写有关航空事故的文章，她说，美联航最近的问题被“错误地与波音的麻烦混为一谈”。
“While it’s bad luck that United had so many incidents in such a short period, in general such incidents happen frequently around the world and they aren’t on the rise overall,” Ms. Dempsey said.
“美联航在这么短的时间内发生了这么多事故，虽然这很不走运，但总的来说，这类事件在世界各地经常发生，总体上并没有上升的趋势，”邓普西说。
How has United responded?
美联航是如何回应的？
Mr. Kirby’s 270-word message to United customers, including to members of the airline’s frequent flier program, started to be sent on Monday morning, said Josh Freed, a spokesman for United.
联合航空发言人乔希·弗里德说，柯比向美联航的客户（包括该公司的常旅客计划成员）发送的270字信息从周一早上开始发送。
Starting in May, United pilots will have an extra day of in-person training, a change that was already planned before the incidents, Mr. Kirby wrote. The airline will also use a “centralized training curriculum for our new hire maintenance technicians” and will dedicate additional resources to the carrier’s supply chain.
柯比写道，从5月开始，美联航飞行员将有一天额外的面授培训，这一变化在事故发生前就已经计划好了。该公司还将“为我们新雇佣的维修技术人员提供集中培训课程”，并将为该航空公司的供应链投入更多资源。
What government agencies oversee these issues, and how are they responding?
由哪些政府机构负责监督这些问题，他们作何回应？
The Federal Aviation Administration regulates the country’s aviation system and investigates safety incidents on U.S. airlines, while the N.T.S.B. investigates the causes of accidents, collisions and crashes involving planes flown by U.S. carriers, in addition to other accidents involving commercial and mass transit operators. Both agencies have discretion on what they investigate, Mr. Sumwalt said.
联邦航空管理局管理国家航空系统，并调查美国航空公司的安全事故，而国家运输安全委员会负责调查涉及美国航空公司飞机的事故、碰撞和坠毁原因，以及涉及商业和公共交通运营商的其他事故。萨姆沃特说，这两个机构都有权决定对谁发起调查。
Currently, the N.T.S.B. is investigating the incident that occurred on March 8 in Houston, when the plane veered off the runway, an agency spokesperson said. The N.T.S.B. is also looking into a Feb. 10 Los Angeles-to-Newark flight, operated by United, that experienced severe turbulence, leading to injuries among more than a dozen passengers. (The Boeing 777 landed normally, but the flight was met by medical personnel.)
国家运输安全委员会发言人说，目前该机构正在调查3月8日在休斯顿发生的飞机偏离跑道事故。委员会还在调查2月10日由美联航运营的一个洛杉矶至纽瓦克航班，该航班经历了严重的湍流，导致十几名乘客受伤。（执飞航班的波音777飞机正常着陆，但有医务人员迎接。）
Safety experts said some issues don’t necessarily rise to the level of an investigation by either agency.
安全专家说，有些问题不一定会达到两个机构都要调查的程度。
For example, partial loss of some of an airplane’s multiple hydraulics systems is common, said Michael McCormick, an assistant professor at Embry-Riddle Aeronautical University and a former F.A.A. control tower operator. The F.A.A. may or may not get involved for this kind of issue, unless there’s a pattern, Mr. Sumwalt said.
例如，安柏瑞德航空大学助理教授、前联邦航空管理局控制塔操作员迈克尔·麦考密克说，飞机的多个液压系统部分受损是很常见的。萨姆沃特说，联邦航空管理局介不介入都有可能，除非事故中有规律可循。
The January episode involving the blown door plug aboard the Alaska Airlines jet is under investigation by the N.T.S.B. and the Justice Department.
美国国家运输安全委员会和司法部正在调查今年1月阿拉斯加航空公司客机上的嵌门板飞脱事件。
Christine Chung是时报记者，报道航空业和消费旅游。点击查看更多关于她的信息。
翻译：晋其角
