The sound is just crazy and the images of the crash site seems somehow worse than what we've seen from e.g. Ukraine when a missile miss and slams into the ground.
The private jet carries up to 3.5 tons of fuel and weighs over 10 tons at take off. A Kalibr cruise missile is maximum 500kg of explosives and the heaviest variant is 2.3 tons over all.
Its not surprising at all that the jet makes a huge hole in the ground. Jet fuel is more energetic than RDX, while converting that energy slower. So both the chemical and kinetic energy is much higher with the jet then with a russian cruise missile. If anything the crater is surprisingly small.
A fully-fueled private jet is an inefficient missile, but it exceeds the raw chemical energy of most in-theater single-target tactical missiles (although the energy conversion is far less precise and efficient).
But yes, that's a lot of kinetic mass dead-stopping on a hard surface and 1 to 2 kiloliters of jet fuel.
Learjet 60 is about 18 metres long. In one frame it's a little above the ground, in the next it's gone up to about halfway between the cockpit glass and the wing roots, and in the next it's gone.
At 30fps, I make that somewhere in the region of 1000mph.
Last transmission was 22k feet/second, which is 15k mph.
(I thought ATC's cool as a cucumber 'altitude your discretion' was 'interesting' – presumably a formality they need to offer to clear the aircraft, since clearly no discretion was involved.)
It’s amazing to me that this post already feels quite old. But then I realized it only happened yesterday. I just feel that way because in today’s world we have seven different dashcam or security camera video feeds popping up on Reddit or X or whatever within minutes of a news event like this.
Sad story in this case. The cockpit audio was quite chilling.
No, throttle was surely idle. The plane was just flying vertically. In a dive, you have a 1:1 thrust/weight ratio and can go extremely fast. The pilot reported an overspeed warning on the audio (which people should not listen to if they're sensitive).
My gut says this is a sudden icing incident. Folks are pointing out that they appear to have flown straight into the center of a cell at altitude. A developing thunderstorm is MUCH warmer than the surrounding air, because the water condensing out of the rising/cooling mass buffers the temperature (due to heat of fusion). It can even be supersaturated ("higher than 100% humidity") if this happens fast enough. The water vapor is just desperate for a nucleation site to condense on.
So you have a situation where a metal jet body that is maybe 30C colder than the medium suddenly flies through this soup. It can ice over in seconds to minutes, and the plane ends up with bricks for wings and much more weight than it was designed for, and simply can't stay in the air. Then it dives inexorably.
It’s easy to get disoriented and accidentally accelerate into the ground, yes, (which is basically the procedure in a stall to get lift back anyway) but based on the ATC recording they knew what was going on and just dropped out of the sky.
The pilots were trying to save the plane up until the last moments. They declared an overspeed condition soon after they ran into trouble, so they were aware of it, but did not intentionally cause it.
Forward velocity is proportional to lift, assuming your lifting surfaces still work. If you're stalling, standard practice is to apply power and get the nose down so that gravity and engine thrust are working in your favor to put air back under your wings.
In this case though, it sounds like the icing was much worse than they thought and fatally compromised the aerodynamics of the wings, and then the overspeed would have torn at the wings and fuselage... In that circumstance, you're no longer flying a plane, you're riding a javelin.
Training would generally still encourage the pilots to apply power; in the worst-case scenario (here), failing to apply power would not have made the crash survivably slower, so the sum total of best bad actions is still "Apply power and hope you're not in the worst-case scenario."
Reading what the pilot said is pretty harrowing. We know a lot from what the pilot already said over the radio (and maybe that's the best info we'll get, are there any remains left?)
Very little will be left considering the impact speed. Even if the aircraft was equipped with a flight data recorder (black box) then its structural limits were probably exceeded.
You would never know a plane caused that crater since there was so little left. Hopefully it puts to bed the conspiracy theories of the plane that crashed into the pentagon. Doubt it though.
If there is, seems they're deep under the ground as it nosedove straight into the ground and essentially disappeared, the crater showed almost no debris at all. People been guessing on reddit that everything just got "instantly pulverized" which I doubt somewhat, the shape of the frame is perfect for it shooting into the ground so I'm guessing they'll spend some weeks digging and eventually find the wreck.
Edit: Since I can't respond to my children:
> This kind of impact in fact has tendency to turn aircraft into powder
> A similar crash that comes to mind ... where they did recover actual bodies, even if the impact was near-vertical and seemingly faster than this case.
Well, just looking at the article, I see trees, which tend to slow things down and can cause a plane to break up.
It's a tough listen and I don't begrudge your regret listening to it, however I think the pilot did a remarkable job of communication information about speed and bank angle right to the end which will indeed help this investigation and hopefully prevent future incidents.
It's unclear exactly what happened but I've heard some aviation experts talk about this and there are already some leading theories, which come down to two factors:
1. The so-called coffin corner [1] where the minimum safe speed for aerodynamic lift and the speed where the plane will stall narrows to a dangerously narrow window. This is caused in part because the speed of sound decreases at high altitude. Turbulence can throw you out of this window; and
2. It seems likely that control was lost because of ice. In released ATC recordings (which are awful to listen to, be warned) the pilot mentions ice. This is likely because of the bad weather over south Florida right now.
The pilot requested a new flight path and I believe tried to ascend from 35,000 feet to 37,000 feet and ended up in a spiral, banked at ~60 degrees, descending at ~30,000 feet per minute, crashing into the ground.
I'm not a pilot but I suspect there will be some element of this that is pilot error or at least could've been avoided and/or mitigated by an experienced pilot.
Icing was mentioned early in the ATC audio, then a request to increase altitude, then a comment that they encountered precipitation, implying the icing could get worse.
IANAP but the mention of precipitation points to conditions that could overwhelm anti-icing systems, which the Learjet was equipped with.
There will be many questions on why the pilot flew into the tops of what (at least on radar) appeared as a small-ish localized cell at that altitude. Vertical cloud development at those altitudes is a clear sign that whatever is inside is not going to be pretty.
Once the aircraft entered the conditions inside the storm, between the turbulence, icing, and up/down drafts it was likely an unrecoverable event.
That doesn't match what I'm seeing in the online discussions. I think most people who have a basic understanding of aviation or have been part of it would immediately see this as what happens when you fly a Learjet directly into a thunderstorm. The likely question is whether the first cause of loss of control was ice or something aerodynamic, like pushing the nose down in an updraft, causing the horizontal stabilizer to rip off.
In contrast, the coffin corner doesn't really have anything to do with this the plane would have been operating at standard enroute altitudes and speeds.
For context, I am in fact a pilot. I've read a little about what people are saying about this accident, but I've absolutely no new information or unique insight whatsoever.
It wasn't coffin corner. This was a Lear at reasonable altitudes, not a U2 at the edge of space. The death spiral suggest a loss of control authority. It is conceivable that one wing severely iced to the point of unrecoverable asymmetric lift but I think it was something more the icing. It might have lost part of its wing, or the controls on one wing locked into an unrecoverable position.
In the pictures, the flaps appear present but not extended. If they had been extended they would have ripped away at that speed. And they would not have been able to lower them after the overspeed began. I think the answer is in the control system. One or more control surfaces were doing something other than commanded.
Some images seem to indicate a loss/absence of the horizontal stabilizer, but it is hard to tell AI from real these days.
A lot of them are designed to explode before hitting the target for maximum damage.
Its not surprising at all that the jet makes a huge hole in the ground. Jet fuel is more energetic than RDX, while converting that energy slower. So both the chemical and kinetic energy is much higher with the jet then with a russian cruise missile. If anything the crater is surprisingly small.
But yes, that's a lot of kinetic mass dead-stopping on a hard surface and 1 to 2 kiloliters of jet fuel.
At 30fps, I make that somewhere in the region of 1000mph.
(I thought ATC's cool as a cucumber 'altitude your discretion' was 'interesting' – presumably a formality they need to offer to clear the aircraft, since clearly no discretion was involved.)
https://www.pprune.org/accidents-close-calls/674728-lear-60-...
Sad story in this case. The cockpit audio was quite chilling.
My gut says this is a sudden icing incident. Folks are pointing out that they appear to have flown straight into the center of a cell at altitude. A developing thunderstorm is MUCH warmer than the surrounding air, because the water condensing out of the rising/cooling mass buffers the temperature (due to heat of fusion). It can even be supersaturated ("higher than 100% humidity") if this happens fast enough. The water vapor is just desperate for a nucleation site to condense on.
So you have a situation where a metal jet body that is maybe 30C colder than the medium suddenly flies through this soup. It can ice over in seconds to minutes, and the plane ends up with bricks for wings and much more weight than it was designed for, and simply can't stay in the air. Then it dives inexorably.
https://en.wikipedia.org/wiki/Mach_tuck
In this case though, it sounds like the icing was much worse than they thought and fatally compromised the aerodynamics of the wings, and then the overspeed would have torn at the wings and fuselage... In that circumstance, you're no longer flying a plane, you're riding a javelin.
Training would generally still encourage the pilots to apply power; in the worst-case scenario (here), failing to apply power would not have made the crash survivably slower, so the sum total of best bad actions is still "Apply power and hope you're not in the worst-case scenario."
If there is, seems they're deep under the ground as it nosedove straight into the ground and essentially disappeared, the crater showed almost no debris at all. People been guessing on reddit that everything just got "instantly pulverized" which I doubt somewhat, the shape of the frame is perfect for it shooting into the ground so I'm guessing they'll spend some weeks digging and eventually find the wreck.
Edit: Since I can't respond to my children:
> This kind of impact in fact has tendency to turn aircraft into powder
How often? A similar crash that comes to mind is https://www.washingtonpost.com/transportation/2023/06/05/dc-... where they did recover actual bodies, even if the impact was near-vertical and seemingly faster than this case.
What specific cases are you thinking about where everything "instantly pulverized"?
The crater shows the road was destroyed. Aircraft skins are much thinner and less robust than road coverings.
Well, just looking at the article, I see trees, which tend to slow things down and can cause a plane to break up.
Highly recommend anyone reading to not make the same mistake
1. The so-called coffin corner [1] where the minimum safe speed for aerodynamic lift and the speed where the plane will stall narrows to a dangerously narrow window. This is caused in part because the speed of sound decreases at high altitude. Turbulence can throw you out of this window; and
2. It seems likely that control was lost because of ice. In released ATC recordings (which are awful to listen to, be warned) the pilot mentions ice. This is likely because of the bad weather over south Florida right now.
The pilot requested a new flight path and I believe tried to ascend from 35,000 feet to 37,000 feet and ended up in a spiral, banked at ~60 degrees, descending at ~30,000 feet per minute, crashing into the ground.
I'm not a pilot but I suspect there will be some element of this that is pilot error or at least could've been avoided and/or mitigated by an experienced pilot.
[1]: https://en.wikipedia.org/wiki/Coffin_corner_(aerodynamics)
IANAP but the mention of precipitation points to conditions that could overwhelm anti-icing systems, which the Learjet was equipped with.
Once the aircraft entered the conditions inside the storm, between the turbulence, icing, and up/down drafts it was likely an unrecoverable event.
In contrast, the coffin corner doesn't really have anything to do with this the plane would have been operating at standard enroute altitudes and speeds.
For context, I am in fact a pilot. I've read a little about what people are saying about this accident, but I've absolutely no new information or unique insight whatsoever.
In the pictures, the flaps appear present but not extended. If they had been extended they would have ripped away at that speed. And they would not have been able to lower them after the overspeed began. I think the answer is in the control system. One or more control surfaces were doing something other than commanded.
Some images seem to indicate a loss/absence of the horizontal stabilizer, but it is hard to tell AI from real these days.