Greenacres Learjet Crash: What We Know as NTSB Finds Evidence of Mid-Air Break-Up

All nine people on board were killed when a Learjet crash in Greenacres, Florida, brought a private jet down onto a busy road in Palm Beach County on Sunday, 1 November. The Learjet 60 was flying from Austin, Texas, to the Bahamas.

Six days on, US air accident investigators have recovered part of an engine and say there is evidence the jet began to break up in the air before it hit the ground. Around 600 local residents were moved out of their homes, and many still do not know when they can return.

Here is what we know so far about the crash, the victims and the investigation.

What happened

The Learjet 60 took off from Austin-Bergstrom International Airport at 10:37am local time, bound for North Eleuthera Airport in the Bahamas. There were two pilots and seven passengers on board.

According to the National Transportation Safety Board (NTSB), the flight was cruising at 35,000 feet at about 12:47pm when the crew told air traffic control they were flying through light clear ice and moderate turbulence. They reported the aircraft was moving up and down by about 700 feet, with an outside temperature of minus 47°C, but said they were managing the ice.

The crew then reported picking up precipitation and asked to climb to 37,000 feet, which controllers approved. Less than 30 seconds later, the jet reported it was descending and made a mayday call. At about 12:48pm it transmitted that it was "in an overspeed condition descending". The rest of the message could not be made out.

The aircraft came down at about 12:50pm in Greenacres, roughly 7 miles south-west of West Palm Beach, leaving a crater in Military Trail near a mobile home park.

Timeline of the flight

Time (Eastern)	Event
10:37am	Learjet 60 departs Austin, Texas, for North Eleuthera, Bahamas
about 12:47pm	Crew report light clear ice and moderate turbulence at 35,000 feet
moments later	Crew request a climb to 37,000 feet; controllers approve
under 30 seconds later	Jet reports it is descending and issues a mayday call
about 12:48pm	Jet transmits that it is "in an overspeed condition descending"
about 12:50pm	Aircraft crashes on Military Trail in Greenacres

Who were the victims?

The Palm Beach County Sheriff's Office has identified all nine people who died.

The co-pilot was 20-year-old Nathalia Filgueiras, and the captain was Jeffrey Gregory. The seven passengers included a family of four from Texas, among them two young children aged four and two, along with the children's nanny and two family friends. The family's father has been described in reports as a Texas technology entrepreneur.

Florida Governor Ron DeSantis described the crash as "cataclysmic". Several local outlets have described it as the deadliest air accident in Palm Beach County's history.

One person on the ground, a man driving away from the area, suffered a leg injury. Investigators plan to interview him.

What investigators have found so far

The NTSB sent a team of around 20 specialists, covering aircraft systems and structures, flight recorders, weather and air traffic control. The Federal Aviation Administration (FAA) and the Learjet's manufacturer are also taking part. The jet was operated by Aurora Aviation, which does business as Upper Jets.

The key findings so far:

• Possible break-up in the air. NTSB board member Tom Chapman said: "We do have some evidence that there was some breakup of the aircraft before impact." Investigators have recovered most of the jet's left elevator, a control surface on the tail, and are examining whether tail parts separated before impact.
• A wide debris field. Wreckage is spread across an area of about half a mile by 0.4 miles, including ball fields, businesses and the roofs of homes.
• Part of an engine recovered. Crews spent days pumping rainwater out of the crater before digging began on 4 November. They have since found part of one engine and other debris.
• Cockpit voice recorder. Maintenance records list a cockpit voice recorder on the jet, but investigators do not yet know whether it can be recovered from the crater.

The NTSB has stressed that it does not decide a cause at the scene, and it has not said what caused the crash. Weather conditions at the jet's altitude, and whether it flew into an active storm, are still being examined.

What is an overspeed condition?

Every aircraft has a maximum safe speed. An overspeed happens when the aircraft goes faster than that limit, usually during a steep, uncontrolled descent. Beyond that speed, the forces on the wings and tail can be greater than the structure is designed to take, which is one reason investigators are looking closely at whether parts came off in the air.

Icing and turbulence can both make a jet harder to control at high altitude, but the NTSB has not said whether either played a part here.

Impact on the Greenacres community

About 600 people were affected after around 77 mobile homes were evacuated, according to Palm Beach County Commissioner Joel Flores, who said the county "doesn't have a clue" when residents will be able to return. Military Trail was closed between Cresthaven Boulevard and 10th Avenue North.

The NTSB has asked anyone who finds debris to leave it where it is and report it, rather than move or keep it, as "even small pieces of the wreckage may contain important evidence". Witnesses with photos or video can email witness@ntsb.gov.

What happens next

• Wreckage examination: all recovered parts are being taken to a secure site for detailed examination.
• Preliminary report: the NTSB usually publishes a preliminary report, setting out the facts but not the cause, within about 30 days.
• Final report: a full investigation, including the probable cause, typically takes one to two years.

Sources: CBS12, NBC Miami, NBC Miami live updates, USA Today via Yahoo, Palm Beach Post via Yahoo, CBS12 victims.