One dead as London-Singapore flight hit by turbulence

[flee 5]

One person has been killed and several others injured on a Singapore Airlines flight from London that was hit by severe turbulence.

The Singapore-bound Boeing 777-300ER was diverted to Bangkok and landed at 15:45 local (08:45 GMT).

https://www.bbc.com/news/articles/c8889d7x8j4o

[JuliusWong 0]

The incident has claimed second death, updated few mins ago. From 37,000ft to 10,000ft in less than 30mins.....crazy...RIP to the departed. Speedy recovery for those injured. 

[jahur 0]

28 minutes ago, JuliusWong said:

The incident has claimed second death, updated few mins ago. From 37,000ft to 10,000ft in less than 30mins.....crazy...RIP to the departed. Speedy recovery for those injured. 

I dont think the 37000 to 10000feet is related to the turbulence but rather standard descent(with priority due to medical) to the diversion destination. Anyways it seems they got into the bad part of the weather in Andaman sea.

Andaman sea, Bay of Bengal, and the area around Japan are well known for Moderate to heavy turbulence related cases.

[Pall 0]

12 hours ago, JuliusWong said:

The incident has claimed second death, updated few mins ago. From 37,000ft to 10,000ft in less than 30mins.....crazy...RIP to the departed. Speedy recovery for those injured. 

A typical descend from cruise to landing is about 25mins if they are on a CDO (Continuous Descend Operation) . I wonder which part of this statement is crazy.

It was a normal descend or just probably slightly expedited as the pilots opted for high speed descend due to the event led to a medical emergency, high speed descend will result in higher rate of descend.

During turbulence, pilots may request higher or lower level to clear bumpy levels. But based on FR24 data, there was nothing unusual with the descend. Except for a part where they requested lower level momentarily after the incident which is FL370 down to FL310. Following which the aircraft then continued for their descend and approach into BKK. 

Edited May 22 by Pall

[flee 5]

 

[Alif A. F. 0]

Frightened flyers renew Boeing boycott after Singapore Airlines disaster flight where turbulence killed passenger and left others covered in blood | Daily Mail Online

Public misperception continues...

Edited May 22 by Alif A. F.

[KK Lee 5]

“Suddenly the aircraft starts tilting up and there was shaking so I started bracing for what was happening, and very suddenly there was a very dramatic drop so everyone seated and not wearing seatbelt was launched immediately into the ceiling,” a passenger said.

 

Sound like high altitude stall.

 

[jahur 0]

8 minutes ago, KK Lee said:

“Suddenly the aircraft starts tilting up and there was shaking so I started bracing for what was happening, and very suddenly there was a very dramatic drop so everyone seated and not wearing seatbelt was launched immediately into the ceiling,” a passenger said.

 

Sound like high altitude stall.

 

Clear air turbulence. Unseen on weather radar 99% of the time, You then get a rough wave get something that jolts u up like crazy and then throws u down quite after usually even causes the autopilot to disengage. Again so many people are not wearing their seatbelt. This is something you should always wear regardless how blue sky clear it is outside.

[jahur 0]

Turbulence related incidents are rising

More Clear-Air Turbulence From Climate Change Raises Safety Concerns

Quote

Data from the National Transportation Safety Board shows that flight attendants are most likely to suffer severe injuries during turbulence events. From 2009 to 2022, there were 163 serious injuries related to turbulence on commercial airlines in the U.S. Of these, 34 were injured passengers, and 129 were injured crew.

Researchers from the University of Reading found turbulence rising over busy airspaces like the North Atlantic, where the annual duration of severe turbulence had increased by 55% from 1979 to 2020. Moderate turbulence increased by 37%, and light turbulence increased by 17% during this period. Other flight routes over the U.S., Europe, the Middle East, and the South Atlantic also significantly increased.

“Airlines will need to start thinking about how they will manage the increased turbulence, as it costs the industry $150 to $500 million annually in the United States alone,” says Mark Prosser, a meteorologist who led the study. “Every additional minute spent traveling through turbulence increases wear-and-tear on the aircraft, as well as the risk of injuries to passengers and flight attendants.”

 

Edited May 22 by jahur

[Alif A. F. 0]

7 minutes ago, jahur said:

Clear air turbulence. Unseen on weather radar 99% of the time, You then get a rough wave get something that jolts u up like crazy and then throws u down quite after usually even causes the autopilot to disengage. Again so many people are not wearing their seatbelt. This is something you should always wear regardless how blue sky clear it is outside.

Since this incident happened about 2 hours from Singapore, meal service could have commenced then and most passengers waking up from slumber, and some lined up for lavatories. But then could also be some pax not wearing seatbelts while in their seats.

[jahur 0]

3 minutes ago, Alif A. F. said:

Since this incident happened about 2 hours from Singapore, meal service could have commenced then and most passengers waking up from slumber, and some lined up for lavatories. But then could also be some pax not wearing seatbelts while in their seats.

Lining up Lavatories understandable especially when the seatbelt sign is off. But i saw some of the cabin images even the overhead luggage compartment door and overhead panel above the passenger seats got damaged from passenger hitting head on the ceiling from their seats as a result from the rough the drop. I've seen passengers in my trips unfastening their seat belt during meal time due to tightness of the seat design.

[flee 5]

I think it is about time that technology used in car seat belt design is used on aircraft. We keep hearing how expensive the seats are to the airlines. As such, fitting inertia reel seatbelts and a reminder system for pax to fasten seat belts should not be cost prohibitive.

[Alif A. F. 0]

39 minutes ago, flee said:

I think it is about time that technology used in car seat belt design is used on aircraft. We keep hearing how expensive the seats are to the airlines. As such, fitting inertia reel seatbelts and a reminder system for pax to fasten seat belts should not be cost prohibitive.

It is more costly to airlines when you got smashed overhead panels, bodily injuries and worse - death.

And also, wouldn't be too far off to say that climate change has made flying more turbulent?

[Pall 0]

2 hours ago, Alif A. F. said:

Frightened flyers renew Boeing boycott after Singapore Airlines disaster flight where turbulence killed passenger and left others covered in blood | Daily Mail Online

Public misperception continues...

Lucky its a 77W. God knows how bad things might have turned out if its A359 or A388. 777s generally withstand turbulence much better than their European widebody competitors.

[JuliusWong 0]

The back galley took the major hit. The aircraft will be out of service for some time that's for sure.

The rescue flight SQ9071 9V-SHH landed in Singapore this morning 04 57 local time. 79 passengers remain in BKK.
https://www.flightradar24.com/data/flights/sq9071

Thumbs up for the pilot and cabin crew for their remarkable skill in bringing the aircraft down safely.

[KK Lee 5]

1 hour ago, JuliusWong said:

The back galley took the major hit. The aircraft will be out of service for some time that's for sure.

 

Galley ceiling likely damaged by cart.

[Alif A. F. 0]

5 hours ago, Pall said:

Lucky its a 77W. God knows how bad things might have turned out if its A359 or A388. 777s generally withstand turbulence much better than their European widebody competitors.

Can you point the technical evidence suggesting so?

I always think wide bodied planes in general can withstand turbulence better than small regionals (like ATRs for example) ...

[KK Lee 5]

7 hours ago, Pall said:

Lucky its a 77W. God knows how bad things might have turned out if its A359 or A388. 777s generally withstand turbulence much better than their European widebody competitors.

Perhaps you could elaborate more.

[jahur 0]

1 hour ago, KK Lee said:

Perhaps you could elaborate more.

A lot of crew from the B767 B777 who moved to the A330, B738, A320 mentioned the same thing the ride handling when going into bumps seems to be smoother on the 767 777. Its something likely related to the broad and large wing size and sturdier fat fuselage ratio.

There's also this on the 787 and something similar on the A380 and A350.
What is a gust alleviation system?

 

The older aircrafts and the A320, B737, A330, A340 simple wing design as a result makes the ride a bit more wonky.

Still throwing any aircrafts into moderate to severe turbulence regardless how much inhibitors or alleviation system is installed wont be a nice ride. People would still get tossed into the ceiling if they dont have seat belts fasten.

Edited May 22 by jahur

[jahur 0]

Aviation experts urge flight passengers to buckle up, and for airlines to identify turbulence-prone areas

Quote

Malaysian Pilots Association president Captain Abdul Manan Mansor said there were not much pilots could do to avoid clear air turbulence, which could be undetected by aircraft's weather radar.

He said the southwest monsoon season, which occurs from May to August, could bring about strong turbulence for flights in the region.

He reminded passengers not to be complacent and to fasten their seatbelts when seated, especially during meal service.

"Passengers tend to forget to buckle up during meal service.

"So passengers and cabin crews need to be aware of the slightest turbulence, usually through signs like the aircraft cabin shuttering."

Universiti Kuala Lumpur Aviation Technology Institute search and rescue department head Associate Professor Major Dr Mohd Harridon Mohamed Suffian also urged airlines to identify turbulence-prone areas.

"It is difficult to detect this turbulence using technology, but airlines can calculate the probability of clear-air turbulence in certain areas and stay away from that area."

He reminded passengers to adhere to the weight size and dimensions of cabin luggage as additional weight would lead to more stresses and strains on overhead compartments.

"This would reduce the strength of overhead compartments and increase fatigue as well."

 

[Sandeep G 1]

1. Situational Awareness - Perceive, Comprehend, Project.

Great opportunity for a refresher on terms. https://skybrary.aero/articles/clear-air-turbulence-cat#:~:text=Jet Stream.&text=Although not all jet streams,the wind shear is greatest.

CAT is being thrown around quite freely by pundits and commentators in the media a lot. Whilst radars do not necessarily detect the presence of CAT, meteorological knowledge is important - e.g. Rules of thumb like, avoid the "cold-side" of a Jet-stream... Avoid Convective build-ups (development stage of CB cloud) in the ITCZ... Be aware of the combination effect of land-mass/daytime max temperatures and moisture (e.g. river delta on a peninsula).... Be aware of season (e.g. NE Monsoon/SW Monsoon) - These typically can be read off a Significant Weather chart forecast for a flight plan, and assessed for "risk", and nowadays, SATCOM wi-fi connectivity with Company iPads could deliver secondary information (albeit slightly delayed) about weather in the area and even PIREPs from other aircraft... and finally combine all this with weather radar technique with knowledge of its capabilities and limitations - the primary means for effecting safe navigation through/around weather. 

2. Application of Knowledge/ Threat & Error Management

If you can't avoid, then "trapping" and "mitigating" against the threat become important. https://aerospace.honeywell.com/content/dam/aerobt/en/documents/landing-pages/white-papers/C61-1471-000-000-IntuVue-wp.pdf Page 8, figure 7 shows this modern multi-scan weather radar that within 40NM range (~5 mins flight time) (in some cases, 60NM/~7.5 min flight time) magenta returns can display areas of turbulence - particularly associated with CB/Convective weather development. The Auto-mode of this particular weather radar, with a flight-plan programmed, would display moisture returns (green/yellow/red) up to 320NM away (~40 mins away) from surface to FL600, and even filters the weather using thatched/non-thatched returns for greater Pilot SA. Be aware, that returns behind larger cells/ or ice-crystals, may NOT necessarily display, and thus in areas of forecast "embedded" CBs, extra judicious caution/management may be required. 

3. Communication

Communication with ATC; maintaining a listening watch to what other aircraft in the area ahead of you are doing. Possible to also monitor TCAS returns if within range as a means of understanding the weather avoidance preceding aircraft are taking. Reliability of ATC can be an issue - VHF reception? CPDLC? HF? If comms/approval for deviation/re-route not possible - application of "Contingency Procedures" such as laterally deviating and climbing/descending 300ft when >5NM/10NM (airspace specific), declaring PAN-PAN for weather avoidance and broadcasting to ATC/121.5 simultaneously.. 

Alerting Cabin Crew with as much notice as possible (minimum 5 mins when navigating in/around CB cells/convective weather), especially with regard to cabin-state - e.g. lull period? Delay/advance Service? crew-rest? Seat-belt signs/suspension of service via intercom with Cabin Manager and PA are means of accomplishing this. 

....

Specifically to this unfortunate case, the Annex 13 investigation and final report of this accident will be interesting. It appears that Thailand (State of Occurrence[?*]) has delegated the investigation to Singapore (State of Operator/State of Registry), as allowed under ICAO Annex 13. Have a read of this, if interested: https://sso.agc.gov.sg/SL/ANA1966-OR7/Historical/20210102?DocDate=20231228&ValidDate=20210102&ViewType=Pdf&_=20240122181212.

[?*] Note:The "delegation" is interesting because, technically, the occurrence was in Yangon FIR; but the issues involved with that given the current "at-war" state of Myanmar complicates things... In any case, multiple agencies such as US NTSB (State of Design/Manufacture), UK AAIB, Australian ATSB and even Malaysian AAIB, can be parties to the investigation, the latter three owing to having citizens on board that died/suffered serious injuries, are entitled to request to participate with their own expert(s).

Remembering, Annex 13 is not to apportion blame, but to determine probable cause and contributing factors, as well as examine the resilience of existing technology, SOPs and event-handling, with valuable safety lessons from any "gaps" found, that ought be "plugged" to deliver an additional level of safety in the future. 

Speculation, whilst "exciting" and "thought-provoking", is often overwhelmingly filled with noise and, unfortunately subjective contribution. 

Great reminder to all to comfortably wear one's seat belt whenever seated, and try to hold on to something (eg seat corner/handle brace, whenever walking/moving about the cabin.

 

Edited May 23 by Sandeep G

[jahur 0]

Interesting document for any readers to download this one more on mountain waves which can cause something intense moderate turbulence.

Inside The Hidden Dangers of Mountain Wave Turbulence

BOAC Flight 911

Quote

It then turned right again toward the mountain, flying over Gotemba on a heading of approximately 298°, at an indicated airspeed of 320 to 370 knots (590 to 690 km/h; 370 to 430 mph), and an altitude of approximately 16,000 feet (4,900 m), well above the 12,388 ft (3,776 m) mountain peak.[1] The aircraft then encountered strong turbulence, causing it to break up in flight and crash into a forest.

Actual aircraft killed by mount fuji without even crashing into the terrain.

[Alif A. F. 0]

3 hours ago, jahur said:

Interesting document for any readers to download this one more on mountain waves which can cause something intense moderate turbulence.

Inside The Hidden Dangers of Mountain Wave Turbulence

BOAC Flight 911

Actual aircraft killed by mount fuji without even crashing into the terrain.

Mountain wave is a common phenomenon in Crocker range region of Sabah. Sometimes, lenticular aka 'UFO' clouds can be seen at early mornings. Used to frequent flew between KK and Sandakan. Pilots would sometimes take long detour around Kudat/Kota Marudu area to avoid those huge thunderstorm clouds hanging above Mt Kinabalu/Crocker range region at late afternoons.

[Pall 0]

On 5/22/2024 at 5:58 PM, Alif A. F. said:

Can you point the technical evidence suggesting so?

I always think wide bodied planes in general can withstand turbulence better than small regionals (like ATRs for example) ...

No manufacturer will produce such documents on turbulence penetration performance between one model to another. Except for procedures on dealing with severe turbulence during different phases of flight. (I.e climb/descend speed, ignition setting and thrust selection)

This are based on feedback of Pilot's who have flown both types as well as Cabin Crew's experience operating those types day in and day out. 

Perhaps you can try speaking to them, they have real world experiences on this as part of their daily routine. 

Edited May 24 by Pall

[jahur 0]

11 hours ago, Alif A. F. said:

Mountain wave is a common phenomenon in Crocker range region of Sabah. Sometimes, lenticular aka 'UFO' clouds can be seen at early mornings. Used to frequent flew between KK and Sandakan. Pilots would sometimes take long detour around Kudat/Kota Marudu area to avoid those huge thunderstorm clouds hanging above Mt Kinabalu/Crocker range region at late afternoons.

I remember taking an evening Fokker 50 flights from SDK-BKI when i was small it was not fun. Where you cant see much outside the window, looking for the crocker range or mount kinabalu but all you see is gloomy greyish dark as your inside the cloud, you cant go up higher as well cause the flight is short and you need to descent so a lot of tossing around. Nowadays if things are not good some would file a flightplan to go up north via KABDU waypoint. For the flight returning they can also opt to descent quite after to avoid weather while flying overhead the VJN Beacon on top of KK towards the sea and  then circling back.

Meanwhile they plan to relocate BKI to Kimanis a well known weather inducing area in the evenings LOL. Meaning airlines will have fun time gauging for poor OTP in the evenings due to weather(holding, go around, diversions). Lucky this was thrown out or put on hold.