In the United States, the ATC audio of Learjet 60 N722BD is widely searched for: the radio exchange between the crew and Miami Center in the final minutes before the crash in Palm Beach County, Florida, on 1 November. All nine people on board died2. Below is the recording, with a timeline and verbatim quotes. More on the crash itself is in our first report, on ice at FL350 in our follow-up and on the NTSB's first findings in our report on the briefing.

Timeline of the radio calls

Times are local (EST, UTC minus 5 hours) and come from the NTSB2. The quotes are verbatim from the recording, each followed by what is happening.

• About 12:47. "We have light clear ice that is manageable and moderate turbulence." The crew reports clear ice that it describes as manageable, and moderate turbulence12.
• "350, moderate turbulence, plus or minus, okay now 700 feet, 600 feet." At FL350, 35,000 feet, the turbulence moves the aircraft up and down by 600 to 700 feet12.
• Miami Center asks for the outside air temperature. "Negative 47 degrees Celsius, we're managing the ice, but it is moderate turbulence, we're direct Freeport." It is minus 47 degrees and the aircraft is heading direct to Freeport on Grand Bahama12.
• "If you have any better rides, let us know." The crew asks about smoother air. The controller replies that conditions improve ahead: "You can expect better rides ahead"16.
• "Now we're picking up precipitation. We need to climb 370." The aircraft is in precipitation and the crew asks to climb to FL37012.
• Miami Center: "Climb and maintain flight level 370." The climb is approved, with an instruction not to turn further right because of traffic12.
• Less than 30 seconds later. "We're descending 8,000. Mayday, mayday, we're descending 10,000 feet per minute." The aircraft is descending instead of climbing and the crew declares a distress124.
• About 12:48. "We are in an overspeed condition descending 20,000 feet per minute." The aircraft is above its maximum permitted speed25.
• The controller leaves the altitude to the crew and asks what they need. A further call from the aircraft follows: "We are descending 22,000 feet and we are banking 60 degrees"3. The NTSB described these later calls as reports of a rapid descent with an altitude2.
• Miami Center keeps calling, including "November 722 Bravo Delta, how do you hear?", without a reply1.
• About 12:51. The aircraft strikes the ground at Military Trail in Palm Beach County2.

What you are hearing

The aircraft was at FL350, 35,000 feet, with callsign N722BD; the controller uses "November 722 Bravo Delta" and the crew the short form "722 Bravo Delta"1. The NTSB called ice and turbulence "certainly a factor" in its investigation2. What the FAA says about ice at this altitude is covered in our follow-up.

The request to climb to FL370 was approved within seconds. Less than 30 seconds later the aircraft reported a descent and the mayday followed2. Overspeed means the aircraft is above its maximum operating limit speed, which under US certification rules may not be deliberately exceeded in any phase of flight7. The NTSB has evidence that the aircraft began to break up before impact and has yet to confirm it2.

The NTSB has not said who on board made which call. Whether the co-pilot was at the controls is not yet known, according to the NTSB2.

The full recording and the NTSB briefing

An unedited version of the recording, including the final seconds before impact, is on the SpaceCoastDaily YouTube channel3. The recordings come from LiveATC.net, which receives the Miami Center frequencies1. Below is the full NTSB media briefing, in which the radio calls are explained with times.

Everything established so far is collected in the dossier on Learjet 60 N722BD.