YazataToday 12:29 AM (This post was last modified: Today 12:51 AM by Yazata.)
The aircraft was a Learjet 60 en-route from Austin TX to Eleuthera in the Bahamas. It's clear that nobody aboard the plane survived. Unknown if there were any fatalities on the ground. The FAA says there were nine people on the plane.
Very preliminary information that may or may not be accurate suggests the plane belonged to a private equity company in Florida. But it might have been associated in turn with a jet charter company the firm owns and it's unknown who had chartered it or who was aboard.
Very dramatic recordings of the female pilot talking to air traffic control in Miami are on X.
Here's the tail end of it:
N722BD: Seven two two bravo delta, we're descending 8,000 Mayday, Mayday! We're descending 10,000 feet per minute!
ATC: November 722 Bravo Delta, roger.
N722BD: Declaring emergency, 722 Bravo Delta! We are in an overspeed condition, descending 20,000 feet per minute!
ATC: November 722 Bravo Delta, roger, altitude's your discretion, let me know what you need.
N722BD: We're going to crash into the ground, 722 Bravo Delta!
ATC: November 2 Bravo Delta, I'm here with you, talk to me.
N722BD: We are descending 22,000 feet, and we are banking 60 degrees
There may have been thunderstorms in the area. The pilot starts out talking about turbulence and icing, and requests to ascend to a higher altitude. ATC oks it.
Then the pilot declares an emergency and shrieks the plane is in a dive.
Video from the ground shows the plane diving straight into the ground at high speed. It looks like a missile impact in Ukraine or the Persian Gulf, and people on the ground initially thought it was a missile. (The crash site is in the same general area as Mar a Lago. But that appears to be a coincidence.)
Extreme slow-motion screen-shot here, which appears to show that the aircraft had lost its elevators, the horizontal tail surfaces that control pitch. I'm thinking that turbulence shouldn't make a plane's tail break off.
Yazata10 hours ago (This post was last modified: 9 hours ago by Yazata.)
RT (the Russian network) has posted photos of air defense missile batteries around Mar a Lago and are trying to suggest that the jet was shot down by trigger-happy Trumpists. It probably won't be long before we see that particular conspiracy theory being repeated on MSNOW.
I'm seeing comments by pilots on X who say that icing can cause control surfaces to stall out. They hypothesize that icing caused the plane to pitch over and go into a dive in which it exceeded its design speed (the pilot said that it was in an "overspeed condition" on the radio). And that might have been sufficient to cause the plane to start to come apart with the horizontal stabilizers separating from the aircraft, which in turn would have eliminated pitch control entirely, dooming the plane. Apparently it's happened before and it's a danger well known to pilots.
Of course we won't really know until the NTSB concludes its investigation.
I asked Grok the AI whether icing can cause aircraft to stall during flight and it replied:
Yes. In-flight icing can cause an aircraft to stall and enter a dive (or a steep nose-down pitch upset), and this is a well-documented aviation hazard.
Quote:Definition
The term "Ice Contaminated Tailplane Stall", or ICTS, refers to those events that involve flow separation from the horizontal stabilizer, due to ice accretion, which leads to an aerodynamic stall of the tailplane and results in a nose-down pitch upset of the aircraft.
The procedures for recovery from a tailplane stall are essentially opposite to those for recovery from a wing stall; misidentifying the type of stall and applying the wrong procedures will make the situation significantly worse.
Description
...In most aircraft, the Centre of Gravity(CG) is somewhat forward of the wing or mainplane Centre of Pressure. The exact distance between the cg and the Centre of pressure will depend on aircraft loading, configuration, thrust setting and drag. However, cg forward of the Centre of Pressure produces a nose-down pitching moment. The horizontal stabilizer, or tailplane, then provides a downward force to overcome this normal, nose-down, pitching moment.
The tailplane behaves as an ‘upside down’ wing and operates with negative Angle of Attack (AOA)...
...If the horizontal stabiliser becomes contaminated with ice, airflow separation from the surface can prevent it from providing sufficient downward force or negative lift to balance the aircraft and a nose-down pitch upset can occur...
Tailplane stall can occur at relatively high speeds, well above the normal 1G stall speed of the mainplane. Typically, tailplane stall induced by icing is most likely to occur near the flap limit speed when the flaps are extended to the landing position, especially when extension is combined with a nose down pitching manoeuvre, airspeed change, power change or flight through turbulence. Aircraft stall warning systems provide warnings based on an uncontaminated mainplane stall so during a tailplane stall-induced upset there will be NO artificial stall warning indications, such as a stick shaker, warning horn or the mainplane or flap buffeting normally associated with a mainplane stall.
We know that it was very cold where the plane was, that it was experiencing turbulence and icing (though they thought they had that under control) and then had run into precipitation (which would have made icing worse. We know that they had started to climb in an attempt to get above the thunderstorm. So we have icing conditions, airspeed and power changes, and turbulence.
(Today 01:33 AM)Syne Wrote:
(Today 12:29 AM)Yazata Wrote: Very dramatic recordings of the female pilot talking to air traffic control in Miami are on X.
And if it weren't for DEI, we wouldn't instantly question whether she had sufficient experience.
The pilots on X point out that there would have been two pilots in the cockpit, with the senior pilot in the left seat focused on flying the plane and trying to save everyone's life, while the junior pilot in the right seat would have been the one working the radio.
Damn, that was moving fast. Be a tough one to investigate. Do Lear jets require flight data and cockpit voice recording black boxes? If so, would there be anything left of those?
Why can’t they just send the data while in flight to ground stations? Possibly an AI computer which might be able to head a problem off before it gets worse.
Today 12:29 AM
(This post was last modified: Today 12:51 AM by Yazata.)
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