Severe turbulence LHR-SIN. One dead.
07:49:43 with +640fpm (3,2m/sec)
07:49:46 with -1536fpm (-7,7m/sec)
I suppose this is GPS data derived, as good as it gets.
This makes a change of speed of -10,9 m/sec from up to down. In 3 seconds. That would give an acceleration downwards of 3.6 m/s² (i.e. still positive! 0.6 g), IF averaged smoothly over the 3 seconds.
It must have been a very short peak of negative g, rather a slam. From the damages (broken panels) I would assume a 75kg body with impact speed: 3m/sec.
Speed of 3m/sec to be achieved within 1 meter (head to panel distance).
Again a bit of calculus would deliver a negative acceleration of -4,5m/s², which would give -0,46 g (rel. 9.81 m/s²). The time from sitting to impact 1 meter further up would be: 0.7 seconds.
Less than a startle moment (1s) if totally unprepared, but with a very good reflex response you would have a little chance to throw up your arms to protect.
Eagerly waiting for the flight recorder plots now ...
Just how many videos have I witnessed over the last 10 years or so from PPL's to Senior BA Captains claiming "turbulence is uncomfortable, but never dangerous?"
I cringe when I see such.
Aircraft (although rare) have been ripped apart in turbulence. This story shows that you can never take anything for granted? You just do not know?
Pax... always keep your belt fastened, as tight as is comfortable.
Pilots... don't needlessly sit in turbulence, find smoother air.
I experienced nearly 4 decades in aviation and always found a way out of unpleasant conditions. Not always 100% for sure but I do remember being tossed around like crazy in a GV at FL450 so went down in increments to FL350 to find something acceptable. Pax were very very grateful, I had one less thing to worry about, FA could continue working and we all arrived safely. Operator picked up the extra fuel bill... so what?
I cringe when I see such.
Aircraft (although rare) have been ripped apart in turbulence. This story shows that you can never take anything for granted? You just do not know?
Pax... always keep your belt fastened, as tight as is comfortable.
Pilots... don't needlessly sit in turbulence, find smoother air.
I experienced nearly 4 decades in aviation and always found a way out of unpleasant conditions. Not always 100% for sure but I do remember being tossed around like crazy in a GV at FL450 so went down in increments to FL350 to find something acceptable. Pax were very very grateful, I had one less thing to worry about, FA could continue working and we all arrived safely. Operator picked up the extra fuel bill... so what?
Let's close the investigation
Captain Hindsight has been in and through this forum like a dose of the salts and concluded his investigation! The amount of conjecture, assumption and confirmation bias you get on these threads are amazing, especially the level of assumption and condescension about the crew experience and composition, which, of course few, if any commenting on these forums will actually know. As they say, there's a thin line between confidence and arrogance and even thinner line between arrogance and stupidity!
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Screen grab from the satellite overlay
About two minutes before the event, this is the position of the aircraft. I'm not an expert at reading satellite weather images but it looks like they are about to cross the end of a distinct band of clouds, which could have been cumulonimbus or similar.
Who knows what the visibility was like, I have seen such complicated haze, stratus and cumulus interactions in the zone that have obscured what's just below. Surely the crew couldn't have been flying the icz without monitoring the weather ahead? On that basis you'd have to assume whatever the event was it wasn't seen from the cockpit, or appeared on the weather radar.??
Who knows what the visibility was like, I have seen such complicated haze, stratus and cumulus interactions in the zone that have obscured what's just below. Surely the crew couldn't have been flying the icz without monitoring the weather ahead? On that basis you'd have to assume whatever the event was it wasn't seen from the cockpit, or appeared on the weather radar.??
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I guess I am an "old-timer" maybe like you.. I agree with your statements. I share this as it was a different encounter with weather than I have had before. A few years back, in the mid A.M. hours as we descended for Punta Del Este Uruguay on a flight from Mendoza Argentina (G550). As we entered a benign area of mid level, mostly flat clouds over the waters separating Argentina and Uruguay. At about 12,500 it felt like the bottom dropped out. EVERYTHING went to the ceiling and immediately back down with force. Best I could tell we entered air that was feeding two developing CB's. They were small but feeding them, I believe, was directly coming from the air we had entered. Quick but nasty
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The route was maybe a little bit weird. I think they were getting a pretty good tailwind as they stayed north but with the countries they were bordering it really could have been geopolitical routing.
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The discussion and comments in the link provide an excellent analysis and conclusion based on the data so far:-
Note satellite wx picture, and forecast severity.
https://www.linkedin.com/posts/guido...ium=member_ios
Note satellite wx picture, and forecast severity.
https://www.linkedin.com/posts/guido...ium=member_ios
As my career approached retirement in intensive European short-haul ops I saw an ever increasing unwillingness in otherwise superbly trained and eminently capable-as-trained FOs to dim the lighting at night to a sensible degree - as time went on more and more expected (few ever asked) to have lighting in full bright which totally prevents any situational awareness outside. OK, I'm Old School, taught that when night flying cockpit illumination should be reduced to the minimum level to permit clear reading of instruments. The reposte (as if FOs ever dared a riposte to their Captain's reasonable request when I was an FO) was always "But we're IFR! There's no need to look outside" (as if their £150K zero to hero training had endowed them with the inate ability to outsmart a decades-experienced Captain). I was very well aware that 'airmanship' had become a swearword and thus all but eradicated in that company as it implied a degree of independent thought and judgement, something I'd always believed a fundamental and essential quality in an aviator - but which was at total variance with the required rigid diktat of slavish and invariable adherence to SOPs, but having avoided various unwanted encounters with nebulous areas of sky with stars obscured over the Pyrenees and Caucuses over the years due to retaining a modicum night vision I disagreed, to the obvious discomfort of some of the uber-slavishly SOP compliant FOs. It is possible that this insistence of dazzling light levels at night was related to the ever increasing expectation that the reading of books/novels/magazines and fiddling on personal tablets that they felt was so normal it wasn't necessary to even ask the Capt if it was OK...I even had FOs trying to watch videos, and then showing indignation when disabused of the idea! (A serious concern, as the behaviour of FOs naturally tends to reflect the lead given them by Captains...) Equally the "Why on earth, we're in IFR, we must save fuel" was frequently touted to defend an insistence to switch off landing/turnoff/taxi lights in even the London TMA according to the company accountant's-led dogma - as "no one needs to look outside"!
I wonder if any of this might have been a factor?
Further, my only encounter with severe turbulence in 25+ years of jet airline flying was descending to a cleared FL150 over the Jura Alps into GVA while avoiding nearby weather returns and a huge - evidently skyward-racing- return just burst onto the radar three or four miles ahead, went flashng magenta instantly and the impact felt like a car crash. There was no question of controlling airspeed (which was making such extreme excursions I had to ignore it) , rate of descent or climb were irrelevent, all I could do was try to keep pitch and roll attitude in some sort of credible regime and wait for it to stop. It was quiteb literally like flying the 737 in a washing machine. Thank God the cabin was already secure . After - I don't actually know - maybe 20-30 seconds I became aware of the FO urgently calling "altitude bust" (among other things) and we regained control at FL125. I consider myself a pretty capable and assertive stick and rudder man and not shy of aggressive handling when required but this was way beyond any human capability. GVA approach (bless'em) must have been used to this sort of event as they just asked if we were OK and continued to vector us in as usual.
Just saying that such events can overtake anyone - and coping with it satisfactorily may well be beyond any pilot's ability. The forces Nature can call to bear on us are well able to totally overwhelm control over our craft, though thankfully modern airframes are ever better at absorbing such punishment even if the occupants aren't.
But the lookout thing/awareness, even on long sectors in the cruise, especially in active tropical met is surely a matter for serious and widespread consideration.
I wonder if any of this might have been a factor?
Further, my only encounter with severe turbulence in 25+ years of jet airline flying was descending to a cleared FL150 over the Jura Alps into GVA while avoiding nearby weather returns and a huge - evidently skyward-racing- return just burst onto the radar three or four miles ahead, went flashng magenta instantly and the impact felt like a car crash. There was no question of controlling airspeed (which was making such extreme excursions I had to ignore it) , rate of descent or climb were irrelevent, all I could do was try to keep pitch and roll attitude in some sort of credible regime and wait for it to stop. It was quiteb literally like flying the 737 in a washing machine. Thank God the cabin was already secure . After - I don't actually know - maybe 20-30 seconds I became aware of the FO urgently calling "altitude bust" (among other things) and we regained control at FL125. I consider myself a pretty capable and assertive stick and rudder man and not shy of aggressive handling when required but this was way beyond any human capability. GVA approach (bless'em) must have been used to this sort of event as they just asked if we were OK and continued to vector us in as usual.
Just saying that such events can overtake anyone - and coping with it satisfactorily may well be beyond any pilot's ability. The forces Nature can call to bear on us are well able to totally overwhelm control over our craft, though thankfully modern airframes are ever better at absorbing such punishment even if the occupants aren't.
But the lookout thing/awareness, even on long sectors in the cruise, especially in active tropical met is surely a matter for serious and widespread consideration.
Last edited by meleagertoo; 23rd May 2024 at 19:12.
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Piers Morgan and Richard Quest; neither are credible aviation experts
Passengers are coming to be very complacent, thinking that for $99, they can hurtle through the sky without hitting a bump every now and then! I have personally ripped a seatbelt out of the airframe (albeit, it was a crash, not just turbulence), but it was a stark reminder of how important they are - all the time. As SLF a few years back, I was coming home on KLM, AMS to YYZ. The captain came on and said "in 15 minutes we're going to encounter some really rough air. We'll do what we can give you a smooth ride, but it's going to be bumpy. I've instructed the cabin crew to secure everything, and I want everyone belts in." Yes, it was rough! For about 20 minutes we were really bounced. I heard some wimpers, and slight screams from a few nearby passengers, but it was the ride that the captain promises! To be 100% certain of not encountering turbulence, remain on earth, otherwise, you take your chances like everyone else who flies!
I have little sympathy for those who, while seated, do not keep their seatbelts fastened. I have a lot of sympathy for cabin crew who have to be up and about....
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Children of the magenta line will follow the screens, I keep having to remind first officers to look out the window. The radar display isn’t always a true picture of what’s going on and mark one eyeball still has its place. An isolated cell can easily be missed if it’s close to the aircraft and the radar range is set to 160nm or more, it becomes a crushed up speck at the bottom of the screen.
I'm thinking they ran into an embedded CB or TCu. Fatigue after ten hours in the air and incorrect use of the radar may have played a part. They were in the wrong place at the wrong time.
I'm thinking they ran into an embedded CB or TCu. Fatigue after ten hours in the air and incorrect use of the radar may have played a part. They were in the wrong place at the wrong time.
Passengers are coming to be very complacent, thinking that for $99, they can hurtle through the sky without hitting a bump every now and then! I
And, of course, if the flight costs nore than $99 - what then is the expectation, turbulence free?
The closest data sample for a "negative g" is at time stamps
07:49:43 with +640fpm (3,2m/sec)
07:49:46 with -1536fpm (-7,7m/sec)
I suppose this is GPS data derived, as good as it gets.
This makes a change of speed of -10,9 m/sec from up to down. In 3 seconds. That would give an acceleration downwards of 3.6 m/s² (i.e. still positive! 0.6 g), IF averaged smoothly over the 3 seconds.
It must have been a very short peak of negative g, rather a slam. From the damages (broken panels) I would assume a 75kg body with impact speed: 3m/sec.
Speed of 3m/sec to be achieved within 1 meter (head to panel distance).
Again a bit of calculus would deliver a negative acceleration of -4,5m/s², which would give -0,46 g (rel. 9.81 m/s²). The time from sitting to impact 1 meter further up would be: 0.7 seconds.
Less than a startle moment (1s) if totally unprepared, but with a very good reflex response you would have a little chance to throw up your arms to protect.
Eagerly waiting for the flight recorder plots now ...
07:49:43 with +640fpm (3,2m/sec)
07:49:46 with -1536fpm (-7,7m/sec)
I suppose this is GPS data derived, as good as it gets.
This makes a change of speed of -10,9 m/sec from up to down. In 3 seconds. That would give an acceleration downwards of 3.6 m/s² (i.e. still positive! 0.6 g), IF averaged smoothly over the 3 seconds.
It must have been a very short peak of negative g, rather a slam. From the damages (broken panels) I would assume a 75kg body with impact speed: 3m/sec.
Speed of 3m/sec to be achieved within 1 meter (head to panel distance).
Again a bit of calculus would deliver a negative acceleration of -4,5m/s², which would give -0,46 g (rel. 9.81 m/s²). The time from sitting to impact 1 meter further up would be: 0.7 seconds.
Less than a startle moment (1s) if totally unprepared, but with a very good reflex response you would have a little chance to throw up your arms to protect.
Eagerly waiting for the flight recorder plots now ...
Attempting to compute the acceleration as a second derivative of the reported altitudes gave me a higher peak average g delta over a 3 minute interval: -1.1g. Adding the normal 1g experienced while sitting, that would give a -0.1g average acceleration towards the ceiling for 3 seconds. Assuming one meter between their head and the ceiling, they would have impacted the ceiling at about 5km/h, after about 1.5 seconds. Even an impact at just 5 km/h with a sharp object can be quite dangerous to your head, but spikes in vertical acceleration could have been even higher in reality.
And, again, I don't think we can rely on the accuracy of this data much. Also, not all passengers may have experienced the same apparent accelerations towards the ceiling, depending on their position in the plane, and the pitch changes. I say apparent accelerations because, if you want to be pedantic, in reality the ceiling would have been accelerating towards them, faster than they were accelerating towards the ground.
To conclude, since are talking about averages over 3 seconds, and we can't be sure about the accuracy of the data, the numbers you have guessed based on the damage could very well be closer to reality than any attempts to deduce anything from the currently available data.
Mike Snow, that was so brilliantly written that I'm struggling to ascertain whether you were taking the piss or genuinely attempting to make a cerebral contribution. The farsical nature of some on here making self certified analytical conclusions based on the limited data published is hilarious. The satellite photo showing the cloud system that the flight in question was operating through in that atmospherically unstable part of the world says significanly more about what 'might' have happened than anything else.
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I’ve observed that B787 pilots tend to be more conservative in avoiding weather due to the difficulty in repairing the composite airframe after a lightning strike. A minor strike on a metal airplane might require an inspection and a simple repair, whereas the B787 might be grounded for specialised repairs in consultation with Boeing.
Reading the sky is becoming a lost skill, those of us who didn’t have a large colour screen in front of us early on in our careers learned what sort of weather we could fly through and what needed to be avoided. Sometimes we learned the hard way. Many of today’s EFIS pilots only know to stay away from red returns and couldn’t identify common cloud types visually.
Reading the sky is becoming a lost skill, those of us who didn’t have a large colour screen in front of us early on in our careers learned what sort of weather we could fly through and what needed to be avoided. Sometimes we learned the hard way. Many of today’s EFIS pilots only know to stay away from red returns and couldn’t identify common cloud types visually.
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Here is another article with some new information on the injuries
https://www.abc.net.au/news/2024-05-...ulen/103887396
Twenty-two with spinal injuries is a sobering thought. How many of those will be parapalegics?
Does anyone know of any other turbulence incidents, outside those that led to loss of airframe and all onboard, with such high level of serious injuries?
https://www.abc.net.au/news/2024-05-...ulen/103887396
One passenger died of a suspected heart attack and dozens were injured after Singapore Airlines flight SQ321 encountered what the airline described as sudden, extreme turbulence while flying over Myanmar.
Of the 40 people on the flight still under treatment, 22 patients have spinal cord injuries and six have brain and skull injuries, Dr Adinun said.
The oldest patient at the hospital was 83 years old and the youngest a two-year-old child who suffered a concussion, he added.
Dr Adinun had said 41 people were still under treatment, but later said one person had been discharged.
Ten British, nine Australian, seven Malaysian and four Philippine citizens were among the 41 people, according to a presentation made by Dr Adinun.
Of the 40 people on the flight still under treatment, 22 patients have spinal cord injuries and six have brain and skull injuries, Dr Adinun said.
The oldest patient at the hospital was 83 years old and the youngest a two-year-old child who suffered a concussion, he added.
Dr Adinun had said 41 people were still under treatment, but later said one person had been discharged.
Ten British, nine Australian, seven Malaysian and four Philippine citizens were among the 41 people, according to a presentation made by Dr Adinun.
Mr Davis said it may be weeks before his wife Kerry Jordan, who suffered a spinal injury when she was thrown into luggage doors and landed in the aisle, would be able to fly home.
"She fell flat straight into the aisle and from that moment, she didn't move," he said.
"That's where she remained for the rest of the flight. It was really horrifying."
"She fell flat straight into the aisle and from that moment, she didn't move," he said.
"That's where she remained for the rest of the flight. It was really horrifying."