What the NTSB is examining as it investigates why a Learjet plunged into the ground

Greg Lovett/Palm Beach Post/USA Today Network/Reuters

Nearly 4 miles separated a piece of a Learjet’s tail from the burning crater gouged into the pavement where the aircraft came down.

The plane, carrying nine people including a couple with children, plunged 35,000 feet, nose-first, into a South Florida roadway on Sunday afternoon. The aircraft was reduced to fire, ash and a field of debris, and all aboard were killed. Now investigators are trying to figure out how a flight ended in catastrophe.

National Transportation Safety Board investigators are sifting through neighborhoods and a waterlogged crater in Palm Beach County for debris and analyzing the plane’s final radio calls to answer questions at the center of their work: Why did the plane plummet, and when and why did the plane start to come apart?

On Tuesday, NTSB member Tom Chapman said investigators had recovered a critical component of the plane: Part of the tail – the aircraft’s left elevator – was found in three pieces far from the crater. But investigators don’t yet know if the broken pieces caused the tragic dive or came off because the plane was plunging.

The first warnings came over the radio minutes before the crash. Flying at about 35,000 feet as scattered storms moved across South Florida, one of the pilots calmly told air traffic control that ice was forming on the plane but was manageable, and turbulence was throwing the craft up and down by about 700 feet. Moments later, she declared an emergency.

Aviation experts say the answers will most likely come from a variety of places: the dispersed wreckage; the cockpit voice recorder, if it was on board and its data survived; the weather the jet flew into; the decisions made in the cockpit and by air traffic control; the procedures of the pilots’ employer; and the plane’s maintenance history.

Finding those answers will take time. The NTSB is expected to release a preliminary report in about a month, a spokesperson told CNN, but determining a probable cause will take between one and two years.

Here are some of the things investigators will examine:

Weather is “certainly a key focus of the investigation,” Chapman said.

The pilots had been working around bad weather for much of the Bahamas-bound flight from Texas. While the plane was near Florida’s Gulf Coast, less than 20 minutes before the crash, an air traffic controller warned that the turn they’d requested toward the Bahamas could take them into a thunderstorm.

“The turn to Freeport looks pretty bad,” the controller said in audio captured by LiveATC.net . “There is moderate to extreme precipitation 11 o’clock, and 25 miles. 100 miles in diameter.”

The jet flew south around the storm before it was cleared to turn east. The controller said the pilots could change course as needed to avoid the worst of it.

When the co-pilot later checked in with a controller covering the West Palm Beach area, she reported that turbulence was bouncing the plane up to 700 feet and that light ice was building on the aircraft.

“If you have any better rides, let us know,” she said.

Audio captures moments before Learjet crash

Minutes before the crash, the pilot of the plane reported ice accumulating on the aircraft, an outside air temperature of -47 degrees Celsius, and moderate turbulence.

“The rides do improve in my airspace,” the controller replied. “You can expect better rides ahead.”

Moments later, the crew reported precipitation and asked to climb to 37,000 feet, and the controller approved. Less than 30 seconds later, something went terribly wrong and the plane plummeted toward the ground.

Vanessa Lara/UGC/Reuters

Eduin Cruz/UGC/Reuters

“We’re descending 8,000 – mayday, mayday – we’re descending 10,000 feet per minute,” the co-pilot said. It wasn’t long before she cried out, in her final transmission, “We’re out of time.”

The plane passed through a strong storm cell just before the sudden descent. Though it is unclear if the weather contributed to the crash, federal investigators have said it will be part of their investigation.

A timeline of the learjet's final moments

9:37 a.m. CT / 10:37 a.m. ET: The plane takes off from Austin-Bergstrom International Airport in Texas.

12:47 p.m. ET: The plane is flying over Palm Beach County, Florida, when it turns right to fly toward Freeport, Bahamas. The pilot says the temperature is -47C (-52F) and reports “light, clear ice that is manageable and moderate turbulence.”

12:48:00 p.m. ET: The pilot reports precipitation and asks to climb to 37,000 feet. Air traffic control grants the request.

12:48:28 p.m. ET: The pilot declares “mayday” as the plane starts dropping 8,000 feet per minute, then 10,000 feet per minute.

12:48:36 p.m. ET: The plane is plummeting 20,000 feet per minute (333 feet per second), which the pilot says exceeds the aircraft’s limits.

12:48:54 p.m. ET: “We’re going to crash into the ground!” the pilot tells air traffic control.

12:49:01 p.m. ET: The pilot says the plane is falling at a rate of 22,000 feet per minute (367 feet per second).

12:49:17 p.m. ET: In the plane’s final transmission, the pilot says, “We’re out of time.”

Sources: LiveATC.net audio and FlightRadar24

Ice – one of the most dangerous hazards in aviation – also will be considered. It adds weight and drag and reduces a plane’s lift and thrust, which can slow it or push it downward.

The higher the altitude, the colder the air gets, and the co-pilot reported an outside temperature of minus 47 degrees Celsius (minus 53 degrees Fahrenheit), cold enough that liquid water should already be frozen. But powerful updrafts inside thunderstorms can carry supercooled water droplets to high altitudes – droplets that remain liquid until they hit a plane and freeze on contact.

Former NTSB managing director and CNN aviation analyst Peter Goelz expects the weather to be central to the investigation.

“It could (have been because of the) ice. It could be severe updraft or downdraft,” Goelz told CNN , adding the weather may have been more serious than the pilots knew.

“Did their radar show them this storm in all its fury? I don’t know if it did,” Goelz said. A cockpit voice recorder, if one is recovered, could reveal “what they thought they were flying into and what they were really flying into.”

Mary Schiavo, a CNN transportation analyst and former inspector general of the US Department of Transportation, said that in weather-related crashes she has worked on, pilots often lacked accurate information. Some checked the forecast too long before takeoff and never rechecked it. Others got bad information or didn’t have, or didn’t use, onboard radar and in-flight weather services.

It’s too soon to speculate, Schiavo said, about the reasons for and timing of the Learjet’s route as they related to the weather, and whether they mattered.

One of the big clues investigators will be looking at fell miles from the crash site.

Most of the jet’s left elevator, the part of the tail that helps pilots control whether the nose tilts up or down, was found in three pieces between 1.3 and 3.8 miles from the crash site, Chapman said Tuesday. That distance shows it broke away before the plane hit the ground, but investigators don’t yet know whether the breakaway caused the dive, or whether heavy forces from the dive caused the breakaway, Chapman said.

The debris could point to the latter, Goelz said.

“It’s unlikely that the elevator caused the upset,” Goelz told CNN. “If it had caused the upset, it would have detached at a higher altitude and they would have found it, if they found it at all, miles (farther) away.”

“My guess is … the elevator is a result of the disrupted flight, not the cause of it,” he said.

Investigators will study the broken edges of the elevator for “witness marks,” the traces metal leaves when it separates, Goelz said. Those marks can show whether the elevator was violently torn away or had an earlier weakness, such as metal fatigue.

Schiavo reads the debris the same way Goelz does. In her view, the parts most likely came off “in this horrific dive,” not before it. That still would leave the question of what started the dive. Schiavo expects investigators to turn their focus “to the weather, to the storm cell, to the icing.”​‌

A severe storm could have threatened the jet in several ways, Schiavo said. It could have caused both engines to flame out, or coated the wings or tail in ice. The recovered tail pieces could become “the pivotal point in the investigation,” she said, because they may help investigators work out which of those happened.​‌

Much of the remaining evidence may be in the crater. The jet hit the ground almost straight down at high speed, and days of rain flooded murky water into the hole it left, slowing the recovery.

“We expect to find critical airplane components within the crater,” Chapman said Tuesday, though those pieces “are going to be very likely in smaller pieces.”

For now, investigators are documenting the scene, examining the wreckage and collecting perishable evidence, NTSB spokesperson Jennifer Gabris told CNN. The wreckage will then be moved to a secure facility for evaluation.

More pieces could still turn up, and what would be one of the jet’s most important witnesses, a cockpit voice recorder, may be somewhere in that wreckage.

Matias J. Ocner/Miami Herald/Tribune News Service/Getty Images

“There have been a number of investigations I can recall where pieces did show up, you know, a week or 10 days after the accident,” Goelz said. “So every piece is critical. But at 35,000 feet … you’re talking about a very wide area to search.”

Determining whether the plane was equipped with a cockpit voice recorder will be essential. Aircraft maintenance records show one was installed on the plane, but it is unclear whether it was still on board, Chapman said.

Chapman said investigators could work without it: “Our folks are very, very good. We’re still able to do some incredible detective work.”

If there was a recorder and it survived the impact, it will be critical, Goelz said. Along with the crew’s voices, it could show how the pilots judged the weather as they flew into it.

“It will have the discussion of the flight crew looking at the weather and saying something about it,” Goelz said. “But more importantly, it will have hopefully sounds and chimes from inside the cockpit. For instance, if the autopilot goes off uncommanded, there’s an alert that says you just lost your autopilot, and you’ll hear it on the voice recorder.”

Even a recovered recorder doesn’t guarantee answers. After a Learjet 55 crashed in Philadelphia in January 2025, its recorder sat for days in water and fuel at the bottom of an impact crater. NTSB specialists cut through the case and cleaned and dried the tape before they could play it. When they did, they found no recording of that flight was made ; the tape’s audio was from a previous landing, and the recorder had jammed, according to an NTSB report released in March.

There’s also a chance a recorder, if the plane had one, will never be recovered, Schiavo said.

“It’s hard for people to fathom that an entire aircraft disappeared into a hole. … With such an explosion, in the cases I’ve worked over decades, the times when the cockpit voice recorder has not been recoverable has been situations where there have been huge fireballs in the explosion.”

NTSB investigations focus on three areas: the pilot, the aircraft and what the agency calls the “operating environment,” Gabris told CNN. Investigators will collect flight tracking data, air traffic control recordings, plane maintenance records, and forecast and weather around the time of the crash. They’ll also review the pilots’ licenses, recent flight experience and activities in the 72 hours before the flight.

But some of the most valuable evidence may come from people on the ground.

Investigators are reviewing dashboard camera footage and other video recorded by drivers and bystanders. That footage and eyewitness accounts will “help us better understand the condition of the aircraft and the circumstances of the crash,” Chapman said.

Residents can also help by reporting wreckage.

“If members of the community come across items that they believe may be part of the aircraft or the aircraft wreckage, please don’t touch them or move them. Please contact NTSB or local authorities, and we will take appropriate action,” Chapman said.

Where a piece lands matters as much as the piece itself, Schiavo said. People who live or work nearby can “serve a tremendous public service” by reporting debris, she said.

Aki Kuusisto/UGC/Reuters

“They shouldn’t move them. They shouldn’t touch them, but they should call them in because where they find the pieces will give the NTSB clues as to how this plane came apart.”

For hundreds of others, the crash has upended daily life. The wreckage blocked the only entrance to a nearby mobile home park, forcing residents out of their homes, according to Joel Flores, a Palm Beach County commissioner. Some had stepped outside to see what happened and couldn’t get back in once police set up a perimeter. Many still can’t reach their belongings or the vehicles they need to get to work. Up to two weeks could pass before they can return, Flores said Monday.

It will likely take more than a year for the NTSB to determine what caused the crash.

“Our mission is to understand not just what happened, but why it happened, and to recommend changes to prevent it from happening again,” Chapman said.

格雷格·洛维特/棕榈滩邮报/今日美国网络/路透社

一架里尔喷气式飞机的尾翼碎片与飞机坠落处在路面上留下的燃烧弹坑相距近 4 英里。

周日下午，一架载有九人（包括一对带着孩子的夫妇）的飞机从35000英尺的高空机头朝下坠入南佛罗里达州的一条公路。飞机化为一堆火焰、灰烬和残骸，机上人员全部遇难。目前，调查人员正在努力查明这起灾难性事故的起因。

美国国家运输安全委员会的调查人员正在棕榈滩县的居民区和被水淹没的弹坑中搜寻飞机残骸，并分析飞机最后的无线电通话，以解答他们工作的核心问题：飞机为什么坠落，以及飞机何时、为何开始解体？

周二，美国国家运输安全委员会（NTSB）成员汤姆·查普曼表示，调查人员已找到飞机的一个关键部件：尾翼的一部分——飞机的左侧升降舵——在距离坠机坑较远的地方被发现，碎片共三块。但调查人员目前尚不清楚这些碎片是导致飞机坠毁的原因，还是飞机坠落过程中脱落的。

坠机前几分钟，无线电里就传来了第一批警告。当时飞机在约35000英尺的高空飞行，零星风暴席卷南佛罗里达。其中一位飞行员冷静地告诉空中交通管制，飞机上正在结冰，但情况尚可控制，湍流使飞机上下颠簸约700英尺。片刻之后，她宣布飞机进入紧急状态。

航空专家表示，答案很可能来自多个方面：散落的飞机残骸；驾驶舱语音记录器（如果机上有且数据保存完好）；飞机飞入的天气；驾驶舱和空中交通管制部门做出的决定；飞行员雇主的程序；以及飞机的维护历史。

找到这些答案需要时间。美国国家运输安全委员会（NTSB）发言人告诉CNN，NTSB预计将在一个月左右发布初步报告，但确定事故的可能原因需要一到两年时间。

以下是调查人员将要调查的部分内容：

查普曼说，天气“无疑是调查的一个重点”。

从德克萨斯州飞往巴哈马的途中，飞行员们一直在恶劣天气中艰难飞行。飞机坠毁前不到20分钟，当它接近佛罗里达州墨西哥湾沿岸时，一名空中交通管制员警告说，他们请求的飞往巴哈马的转弯可能会使他们进入雷暴区。

“飞往弗里波特的航线看起来很糟糕，”管制员在LiveATC.net网站录制的音频中说道。“11点钟方向，方圆25英里，直径100英里，有中度到极端强降水。”

这架喷气式飞机绕过风暴向南飞行，之后获准转向东飞。管制员表示，飞行员可以根据需要改变航向，以避开风暴最猛烈的部分。

后来副驾驶与负责西棕榈滩地区的管制员联系时报告说，湍流使飞机上下颠簸高达 700 英尺，并且飞机上开始结冰。

“如果你有更好的车，请告诉我们，”她说。

音频捕捉里尔喷气式飞机坠毁前的瞬间

飞机坠毁前几分钟，飞行员报告说飞机上积聚了冰，外界气温为零下47摄氏度，并且有中等程度的湍流。

“我辖区内的飞行体验确实有所改善，”管制员回答说。“您可以期待接下来会有更好的飞行体验。”

几分钟后，机组人员报告有降水，并请求爬升至37000英尺，管制员批准了请求。不到30秒后，情况急转直下，飞机急速坠向地面。

Vanessa Lara/UGC/路透社

埃杜因·克鲁兹/UGC/路透社

“我们正在以每分钟8000英尺的速度下降——紧急求救，紧急求救——我们正在以每分钟10000英尺的速度下降，”副驾驶说道。没过多久，她在最后一次通话中喊道：“我们没时间了。”

飞机在突然下降前曾穿过一片强烈的风暴云团。虽然目前尚不清楚天气是否是造成坠机的原因，但联邦调查人员表示，天气因素将纳入调查范围。

里尔喷气机最后时刻的时间线

美国中部时间上午 9:37 / 美国东部时间上午 10:37：飞机从德克萨斯州奥斯汀-伯格斯特国际机场起飞。

美国东部时间下午12:47：飞机飞越佛罗里达州棕榈滩县时，向右转弯飞往巴哈马自由港。飞行员称气温为零下47摄氏度（零下52华氏度），并报告“有轻微的透明冰，易于控制，并伴有中等程度的湍流”。

美国东部时间下午12:48:00：飞行员报告有降水，并请求爬升至37000英尺。空中交通管制批准了该请求。

美国东部时间下午 12:48:28：飞机开始以每分钟 8,000 英尺的速度下降，然后以每分钟 10,000 英尺的速度下降，飞行员发出“遇险”信号。

美国东部时间下午 12:48:36：飞机正以每分钟 20,000 英尺（每秒 333 英尺）的速度下降，飞行员表示这超过了飞机的极限。

美国东部时间下午 12:48:54：“我们要坠毁了！”飞行员告诉空中交通管制员。

美国东部时间下午 12:49:01：飞行员说飞机正在以每分钟 22,000 英尺（每秒 367 英尺）的速度下降。

美国东部时间下午 12:49:17：在飞机的最后一次通讯中，飞行员说：“我们时间不够了。”

来源：LiveATC.net 音频和 FlightRadar24

冰是航空领域最危险的隐患之一，也将纳入考虑范围。冰会增加飞机的重量和阻力，降低飞机的升力和推力，从而导致飞机减速或下坠。

海拔越高，气温越低。副驾驶报告称，机外温度为零下47摄氏度（零下53华氏度），如此低温足以使液态水结冰。然而，雷暴内部强大的上升气流可以将过冷水滴带到高空——这些水滴在接触飞机之前一直保持液态，一旦接触飞机就会立即冻结。

美国国家运输安全委员会前总经理兼 CNN 航空分析师彼得·戈尔茨预计，天气将是调查的核心。

戈尔兹告诉CNN：“这可能是因为结冰，也可能是强烈的上升气流或下降气流。”他还补充说，天气状况可能比飞行员们意识到的要严重得多。

“他们的雷达是否显示了这场风暴的全部威力？我不知道，”戈尔茨说。如果能找到驾驶舱语音记录器，或许可以揭示“他们当时以为自己要飞入的风暴和他们实际飞入的风暴之间的区别”。

美国有线电视新闻网（CNN）交通分析师、美国交通部前监察长玛丽·斯基亚沃表示，在她参与调查的与天气相关的坠机事故中，飞行员往往缺乏准确的信息。有些飞行员在起飞前查看天气预报的时间过长，之后再也没有复查。还有一些飞行员获取了错误的信息，或者没有配备机载雷达和飞行气象服务，或者没有使用这些设备。

Schiavo表示，现在就推测里尔喷气机航线的缘由和时间安排与天气的关系，以及这些因素是否重要，还为时过早。

调查人员将要调查的重要线索之一，来自距离坠机地点数英里之外的地方。

查普曼周二表示，这架喷气式飞机左侧升降舵的大部分残骸（升降舵是机尾的一部分，用于帮助飞行员控制机头上下倾斜）已分成三块，散落在距离坠机地点1.3至3.8英里（约2.1至6公里）的范围内。查普曼说，这个距离表明升降舵是在飞机撞击地面之前脱落的，但调查人员目前尚不清楚是升降舵的脱落导致了飞机俯冲，还是俯冲产生的巨大冲击力导致了升降舵的脱落。

戈尔茨说，这些碎片可能指向后者。

戈尔茨告诉CNN：“电梯不太可能是造成飞机失控的原因。如果真是电梯造成的，它应该会在更高的高度脱离，而且即使他们最终找到了它，也应该在几英里之外。”

“我的猜测是……电梯故障是航班延误的结果，而不是航班延误的原因，”他说。

戈尔茨表示，调查人员将研究电梯断裂边缘的“痕迹”，即金属分离时留下的痕迹。这些痕迹可以显示电梯是被暴力撕裂的，还是之前就存在其他缺陷，例如金属疲劳。

希亚沃对残骸的解读与戈尔茨相同。在她看来，这些部件很可能是在“这次可怕的潜水”中脱落的，而不是在此之前。但这仍然无法解答潜水是如何发生的。希亚沃预计调查人员会将重点转向“天气、风暴云团和结冰情况”。

希亚沃表示，一场严重的风暴可能从多个方面威胁到这架喷气式飞机。它可能导致两台发动机同时熄火，或者使机翼或尾翼结冰。她说，回收的尾翼碎片可能成为“调查的关键”，因为它们或许能帮助调查人员确定究竟是哪种情况发生了。

剩余的大部分证据可能都在陨石坑里。这架喷气式飞机几乎垂直高速坠落地面，连日暴雨将浑浊的雨水灌入陨石坑，延缓了搜寻工作。

查普曼周二表示：“我们预计会在陨石坑内发现关键的飞机部件”，不过这些部件“很可能是一些较小的碎片”。

美国国家运输安全委员会（NTSB）发言人詹妮弗·加布里斯告诉CNN，目前调查人员正在记录现场情况，检查残骸并收集易腐烂的证据。之后，残骸将被转移到安全设施进行评估。

可能还会发现更多碎片，而这架喷气式飞机最重要的见证物之一——驾驶舱语音记录器，或许就藏在残骸的某个地方。

Matias J. Ocner/迈阿密先驱报/论坛新闻社/盖蒂图片社

“我记得之前有好几次，事故发生一周或十天后，都发现了残骸碎片，”戈尔茨说。“所以每一块碎片都至关重要。但事故发生在35000英尺的高空……搜索范围非常广阔。”

查普曼表示，确定飞机是否配备驾驶舱语音记录器至关重要。飞机维修记录显示飞机上曾安装过此类记录器，但目前尚不清楚它是否仍在机上。

查普曼表示，即使没有它，调查人员也能开展工作：“我们的人员非常非常优秀。我们仍然能够完成一些非常出色的侦查工作。”

戈尔茨说，如果飞机上有录音机并且在撞击中幸存下来，那将至关重要。录音机里有机组人员的声音，可以显示飞行员在飞入险境时是如何判断天气状况的。

戈尔茨说：“它会记录机组人员观察天气状况并发表意见的过程。但更重要的是，它有望包含来自驾驶舱内部的各种声音和提示音。例如，如果自动驾驶仪在未经指令的情况下关闭，就会发出警报，提示自动驾驶仪已失效，而且你会在语音记录器中听到这个警报。”

即使找到了录音机，也无法保证找到答案。2025年1月，一架里尔55型喷气式飞机在费城坠毁后，其录音机在撞击坑底部浸泡在水和燃料中数日。美国国家运输安全委员会（NTSB）的专家切开录音机外壳，清洗并干燥磁带后才得以播放。播放后，他们发现并没有录制到那次飞行；磁带上的音频来自之前的一次着陆，而且录音机已经卡壳。这是NTSB在3月份发布的一份报告中所述。

Schiavo表示，如果飞机上有记录仪，也有可能无法找到。

“人们很难想象一架飞机竟然会消失在一个洞里……在我几十年处理过的案例中，如果发生这样的爆炸，而驾驶舱语音记录器又无法找回，那么爆炸中通常都会出现巨大的火球。”

加布里斯告诉CNN，美国国家运输安全委员会（NTSB）的调查重点在于三个方面：飞行员、飞机以及该机构所谓的“运行环境”。调查人员将收集飞行跟踪数据、空中交通管制录音、飞机维护记录以及坠机前后一段时间的天气预报和天气情况。他们还将审查飞行员的执照、近期飞行经验以及飞行前72小时内的活动。

但一些最有价值的证据可能来自一线人员。

调查人员正在查看行车记录仪录像以及司机和路人拍摄的其他视频。查普曼表示，这些录像和目击者证词将“帮助我们更好地了解飞机状况和事故发生的情况”。

居民也可以通过报告事故现场来提供帮助。

查普曼说：“如果社区成员发现任何疑似飞机残骸或飞机部件的物品，请不要触摸或移动。请联系美国国家运输安全委员会（NTSB）或当地政府部门，我们将采取适当措施。”

希亚沃表示，碎片落在哪里与碎片本身同样重要。她说，居住或工作在附近的人们可以通过报告碎片来“为公众做出巨大贡献”。

Aki Kuusisto/UGC/路透社

“他们不应该移动这些碎片，也不应该碰它们，但他们应该把碎片送来，因为碎片的位置将为美国国家运输安全委员会提供线索，帮助他们了解这架飞机是如何解体的。”

对数百人来说，这场车祸彻底打乱了他们的日常生活。棕榈滩县专员乔尔·弗洛雷斯表示，事故残骸堵塞了附近一个移动房屋园区的唯一入口，迫使居民离开家园。一些居民走到外面查看情况，但警方设置警戒线后，他们就无法返回家中。许多人至今仍无法取回自己的财物或上班所需的车辆。弗洛雷斯周一表示，他们可能需要长达两周的时间才能返回家园。

美国国家运输安全委员会可能需要一年以上的时间才能确定事故原因。

查普曼说：“我们的使命不仅是了解发生了什么，还要了解为什么会发生，并提出改进建议以防止此类事件再次发生。”