For more than four years, the final moments of China Eastern Flight 5735 remained shrouded in secrecy, with few clues to a baffling descent from 29,000 feet that left no survivors.

四年多来，中国东方航空5735号航班的最后时刻始终笼罩在重重迷雾中，外界几乎找不到任何线索，能够解释这架飞机为何会从约8840米高空突然急剧坠落，最终无人生还。

Now, new data from the Boeing 737 suggests the crash was no accident. The plane’s fatal dive was a deliberate act initiated from within the cockpit, aviation experts say, following what appears to have been a struggle for control of the aircraft.

如今，来自这架波音737的新数据表明，这场空难并非意外。航空专家表示，在驾驶舱内似乎发生了对飞机的控制权争夺之后，这架飞机的致命俯冲是有人蓄意为之。

The plane, which was operated by highly experienced pilots, had been traveling from Kunming, in southwestern China, to Guangzhou when it plunged almost vertically into a hillside, driving pieces of the aircraft as deep as 60 feet into the earth.

这架飞机由经验极为丰富的飞行员驾驶，当时正从中国西南部的昆明飞往广州，它几乎垂直俯冲撞上一处山坡，机体碎片嵌入地下约18米深。

The report by the National Transportation Safety Board shows that the dive began when a pilot or pilots pressed the cutoff levers — essentially, fuel switches — for both engines on the plane mid-flight, according to Jeff Guzzetti, a former accident investigator for the Federal Aviation Administration and the N.T.S.B.

国家运输安全委员会的报告显示，联邦航空局和国家运输安全委员会前事故调查员杰夫·古泽蒂称，俯冲始于一名或一名以上的飞行员在飞行途中按下两台发动机的切断手柄——即燃油开关。

Pressing down the two levers simultaneously stopped fuel flow to the engines and shut them down, Mr. Guzzetti said.

古泽蒂说，同时按下两个手柄切断了发动机的供油，导致发动机停止工作。

Almost immediately, data from the cockpit controls show, the plane entered a terrifying dive and spun in at least one 360-degree roll, Mr. Guzzetti said. The data shows that control wheels in the cockpit — one each in front of the captain and first officer — were turned to produce that roll, Mr. Guzzetti said. (The control wheels on a plane are a little like the steering wheels in a car, but they cause the plane to bank.)

古泽蒂称，驾驶舱控制装置的数据显示，几乎就在同一时刻，飞机进入了可怕的俯冲状态，并至少旋转了360度。古泽蒂说，数据显示驾驶舱内的两个驾驶杆——机长和副驾驶面前各一个——被转动，从而导致了翻滚。（飞机上的驾驶杆有点类似汽车的方向盘，但它们的作用是使飞机倾斜转弯。）

The herky-jerky, back-and-forth movement of the wheels suggests that at least two people were fighting to turn them in different directions. That could mean two pilots were struggling over a single wheel or that the captain and first officer were pushing in different directions on their own wheels, which are set to move in unison.

驾驶杆来回剧烈晃动表明，至少有两人在争夺控制权，试图将其转向不同方向。这可能意味着两名飞行员在争夺同一个驾驶杆，或者机长和副驾驶各自朝相反方向推动本人的驾驶杆——而两个驾驶杆本是联动设计的。

“Aggressive movements to pitch the airplane down and to roll it dramatically tell me this was an intentional act,” Mr. Guzzetti said.

古泽蒂表示：“强行将机头向下压并猛烈滚转的激烈动作告诉我，这是一次蓄意行为。”

The data about the crash, which was one of the deadliest in China in more than a decade, was released in response to a Freedom of Information Act request to the National Transportation Safety Board. The safety board had assisted in the investigation into the crash and helped retrieve the information from the plane’s flight data recorder, one of the aircraft’s “black boxes.”

这是中国十余年来伤亡最惨重的空难之一，相关数据是有人根据《信息自由法》的规定向国家运输安全委员会提出申请后公布的。该委员会曾协助调查此次坠机事故，并协助从飞行数据记录仪（即其中一个黑匣子）提取信息。

It was not immediately clear who submitted the request, or when the N.T.S.B. released the report, which can be found on its website.

目前尚不清楚是谁提交了这份申请，以及国家运输安全委员会何时公布了这份可在其官网查阅的报告。

The data is especially sensitive in China, where the government has released very little information from its own investigation into the crash. Xi Jinping, China’s most dominant leader in decades, has tightened controls on information, particularly when it comes to major disasters, which are seen as potential threats to social stability. In the days after the crash, Chinese officials censored reports and discussion about it.

这些数据在中国尤为敏感，因为中国政府几乎没有公布过自身对这起空难调查的任何信息。中国几十年来最强势的领导人习近平收紧了信息管控，尤其是重大灾难的相关信息——这类事件被视为对社会稳定的潜在威胁。在空难发生后的数日内，中国官方对相关报道和讨论实施了审查。

China’s Ministry of Foreign Affairs and Civil Aviation Administration did not respond to faxed questions about the new data. In 2024, the aviation administration said that the pilots and cabin crew had passed preflight medical checks on the day of the crash.

中国外交部和中国民用航空局均未回应通过传真发去的提问。2024年，民航局曾表示，飞行机组和客舱机组当日飞行前健康体检合格。

Mr. Guzzetti, the former N.T.S.B. accident investigator, said other aspects of the data supported the idea that there might have been a struggle between the two pilots for the flight controls.

国家运输安全委员会前事故调查员古泽蒂表示，其他方面的数据也支持两名飞行员曾争夺飞机控制权的判断。

“If you’re going to roll the airplane, it’s a smooth roll,” he said. “Here the control wheel is going back and forth and back and forth. That kind of indicates to me that there was a struggle.”

“如果要让飞机横滚，动作应该是流畅的，”他说。“但这里驾驶杆却是来回反复晃动。这在我看来，表明存在争夺。”

John Cox, an aviation safety consultant and retired airline pilot, said he agreed that the fuel cutoff and other commands to the aircraft came from the cockpit, possibly by a single pilot. “A pilot can shut off fuel to both engines at the same time, by moving the levers from run to cutoff,” he said.

航空安全顾问、退休民航机长约翰·考克斯表示，他认可燃油切断以及对飞机的其他操控指令均来自驾驶舱的判断，可能是一名飞行员单独所为。“飞行员可以通过将驾驶杆从运行位置切换至切断位置，同时关闭两台发动机的供油，”他说。

The irregular movement of the control wheel suggested a struggle, “but the evidence is not overwhelming or totally conclusive,” Mr. Cox added.

考克斯补充说，驾驶杆的不规则运动确实表明存在争夺，“但证据并不充分，也非完全确凿。”

The N.T.S.B. said that the flight data recorder stopped running while the plane was still in descent, at around 26,000 feet. Without the engines functioning, there was no electricity to power the recorder.

国家运输安全委员会表示，飞行数据记录仪在飞机仍处于下降过程中、约7925米的高度停止运转。由于发动机停止工作，记录仪失去了电力供应。

The recorder was severely damaged in the crash, the N.T.S.B. said. Information from the cockpit voice recorder, the plane’s other black box, was not released.

国家运输安全委员会表示，飞行数据记录仪在坠机中严重受损。飞机的另一个黑匣子——驾驶舱语音记录仪——的信息尚未公布。

The flight recorder also revealed that during the initial part of the dive, the plane was descending at as much as a 40-degree angle — far steeper than the few degrees needed for a normal descent, Mr. Guzzetti said.

古泽蒂表示，飞行数据记录仪还显示，在俯冲初始阶段，飞机的下降角度高达40度——正常下降仅需要几度。

“It’s the kind of movement you see aerobatic airplanes perform in an air show,” Mr. Guzzetti said. “It would have been a shock to the passengers because of the forces imparted on them from these drastic maneuvers.”

“这是你在航展上才会看到的特技动作，”古泽蒂说。“由于这些剧烈飞行动作产生的巨大作用力，乘客当时一定承受了极大的冲击。”