Lear jet crash in Florida

[offshore171]

A considered early analysis from an understandably emotional Captain Steeve

I have to say, the young woman copiloting died an absolute hero. She was 20 years old, got licence at 17 and living her dream. Despite everything going on, and with the plane in a near vertical dive, she kept ATC informed every step of the way. She made her callsign on every single call.

And an excellent comment from NASA chief Jared Isaacman

https://twitter.com/x/status/2117292922693431496

 

[RooFlyer]

And Juan Brown. A lot of technical stuff on the capabilities of the Learjet, and also the meteorology

 

[Quickstatus]

And this one makes a lot of sense

 

[markis10]

More speculation, somewhat ill informed, it was the same plane not the same crew that got caught out earlier I believe. If it’s relevant it will be in the forthcoming report along with actual details of the crew etc.

 

[offshore171]

(NTSB) Left elevator has been located, several km away from the crash site

This gives creedence to the reports that parts of the T-tail were missing before impact.

https://twitter.com/x/status/2117733845747306580

 

[Quickstatus]

This gives creedence to the reports that parts of the T-tail were missing before impact.

Due to overspeed exceeding structural limits?

Or overspeed + pilot input to pitch up = exceeded structural limits?

Did the overspeed also induced a high speed stall or Mach tuck which essentially also disrupted airflow over the horizontal stabiliser whose normal function is to maintain pitch balance?. Making the loss of the horizontal stabiliser a moot issue?

 

[offshore171]

Due to overspeed exceeding structural limits?

Or overspeed + pilot input to pitch up = exceeded structural limits?

AFAIK that hasn't been determined yet. Give them time. I'm sure they have some of the best investigators available working on this.

Also it's been mentioned that they believe this particular aircraft wasn't fitted with a flight data recorder but likely had a coughpit voice recorder fitted.

Whether either type of device could survive such an impact vertically into the ground at something like mach 0.8 is another question.

 

[jb747]

Commentary re the co-pilot is way off the mark. The fact that she was 20 does not matter. I know of both an A-4 and an F-111 pilot of that age. Some young people can achieve much.

 

[Quickstatus]

Whether either type of device could survive such an impact vertically into the ground at something like mach 0.8 is another question.

It could be buried deep in the crater.

The airplane vertical acceleration would be 1G + engine thrust - drag - lift vector (if not a vertical fall)
Gravity acceleration = 9.8ms⁻² = 1G
An object falling in a vacuum (no air resistance) from 37,000 feet at 1G achieves a final speed of 1500 feet/sec (90,000 feet/min) or Mach 1.3
I dont know what the aircraft's final vertical speed is- it is suggested that it was more than 32,000 feet/min
Using Mach 0.8 = 54,000 feet/min

So this aircraft likely final acceleration less than 1G.
My understanding is the CSMU (Crash Survivability Memory Unit) in the CVR are designed to survive acceleration at point of impact of >3000G