BA12 Severe Turbulence

[Cruiser Elite]

Not sure if posted previously - BA12 Severe Turbulence - Mods pls delete if already posted

 

[OZDUCK]

Not sure if posted previously - BA12 Severe Turbulence - Mods pls delete if already posted

The worst turbulence I have ever experienced was also over the Bay of Bengal.

 

[jb747]

The worst turbulence I have ever experienced was also over the Bay of Bengal.

Rule #1. If you are seated there is never a reason to have seat belt undone.

Rule #2. Don't fly into storms.

 

[Quickstatus]

Again the DailyFail Fails...

"The captain had no option but to TRY and turn the plane around"

Must have been an unusual manouvre the pilots have not done before......

"Severe turbulence increased 55 per cent between 1979 and 2020 and is expected to get more intense, more frequent and last longer in future"

Well the best way to prevent climate change and avoid turbulence is not to fly.......

Rule #1. If you are seated there is never a reason to have seat belt undone

From the Straits times:
"everyone flew up in the air, everyone was screaming"
.......


My recent SQ flight:
Captain illuminated SB sign just at the start of meal service and made the usual announcement
Also said CC "please be very cautious".......

 

[Quickstatus]

@jb747
The history of BA12 and QF1 shows the usual altitude in that region is approx FL300. Occasionally FL 280. The reverse is appears to be FL 350-390
It seems like a low cruising altitude. Any insights?

 

[OZDUCK]

Rule #1. If you are seated there is never a reason to have seat belt undone.

Rule #2. Don't fly into storms.

In my case all seatbelts were on. They couldn't fly around the storm as it was a massive monsoon front and this occurred at night in the mid 1970's. I don't believe aircraft weather radars were anywhere near as effective in those days - especially on a British Caledonian DC8.

 

[dajop]

"Severe turbulence increased 55 per cent between 1979 and 2020 and is expected to get more intense, more frequent and last longer in future"

I read that also. But always don’t like such statements without a reference. Without further info it would seem experience of severe turbulence should increase more than that given the explosion in air travel. But seems it is based on study of meteorological data:

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL103814

Flight turbulence increasing as planet heats up - study

Researchers found that severe turbulence had increased 55% between 1979 and 2020 on a typically busy North Atlantic route.

www.bbc.com

 

[Quickstatus]

But seems it is based on study of winds/radar across northern Atlantic

Yes I did read that research article. However it appears that it was an exercise in weather modelling analysis and did not back it up with real world data. They didn't measure actual turbulence data from aircraft.
To validate the study, one would think that it needed to be compared to real world measurements from aircraft. So at best it is a speculative study which the DailyFail reported as fact.

 

[drron]

Though that article has results that suggest a decrease clear air turbulence over the Bay of Bengal.


The change in ERA5's 197 hPa annual-mean diagnostic-mean moderate-or-greater (MOG) clear-air turbulence (CAT) probability over 1979–2020, showing (a) the absolute change and (b) the relative change. The changes are diagnosed from the linear trend. Stippling indicates statistical significance at the p = 0.05 level, according to a two-sided Wald test (Fahrmeir et al., 2022) applied to the absolute change. The two boxes represent the North Atlantic (36–60°N and 55–10°W) and USA (30–55°N and 124–60°W) areas used in Figures 3 and 4 and Table 1. See Supporting Information S1 for light-or-greater and severe-or-greater CAT versions of this figure as well as a breakdown by diagnostic for the absolute change to MOG CAT.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL103814

So basically that article has no relevance to the BA 12 experience.

 

[jb747]

Again the DailyFail Fails...

"The captain had no option but to TRY and turn the plane around"

Must have been an unusual manouvre the pilots have not done before......

"Heading select", and spin the dial.

Piss poor planning if you get to that point. Anyway, we know that the aircraft don't really care, so as long as you ensure the cabin is actually secure, going through the least bad parts is unlikely to be a real problem.

"Severe turbulence increased 55 per cent between 1979 and 2020 and is expected to get more intense, more frequent and last longer in future"

Which pretty much encompasses the period I was flying there, and I didn't see any change. If anything it got easier deal with as communications improved.

From the Straits times:
"everyone flew up in the air, everyone was screaming"

See rule #1.

My recent SQ flight:
Captain illuminated SB sign just at the start of meal service and made the usual announcement
Also said CC "please be very cautious".......

Actually this behaviour is quite common across airlines, and it is terribly unprofessional. If the seat belts are on, NOTHING should be happening. You turn them on when needed, and off, if not. Some airlines seem just leave them on. SQ is notable, but not alone.

The history of BA12 and QF1 shows the usual altitude in that region is approx FL300. Occasionally FL 280. The reverse is appears to be FL 350-390
It seems like a low cruising altitude. Any insights?

Early in the flight, and heavy, versus late and light. 350 to 390 is probably out of reach for the aircraft going to Europe. Quite a bit of strategy comes into play, as to how you manage the altitude you ask for and when. The A380 was more versatile than the 747 for this, as it could get up higher, earlier.

In my case all seatbelts were on. They couldn't fly around the storm as it was a massive monsoon front and this occurred at night in the mid 1970's. I don't believe aircraft weather radars were anywhere near as effective in those days - especially on a British Caledonian DC8.

Don't fly into the green bits. The old radars weren't all that bad.

 

[Quickstatus]

all seatbelts were on

See rule #1.

The really strange thing about illuminating the SB sign is that it also triggers the bladder nerves...

Was on an AAEagle LAX-SFO once. Terribly bumpy but not the head through the overhead compartment scenario
As soon as SB was illuminated, several people got up to try to go to loo. The FA told them to sit down but after a few minutes they stood up again. FA gave up... I guess they were on their own at that point....

 

[flyer89]

My recent SQ flight:
Captain illuminated SB sign just at the start of meal service and made the usual announcement
Also said CC "please be very cautious".......

Might be a bit bit and miss with SQ. Both flights I had a few weeks ago they employed an almost QF style attitude towards the seatbelt sign. Never illuminated on either flight in cruise and we were rocking and rolling at times. I appreciated it.

 

[Quickstatus]

rocking and rolling at times

I wonder: is there more chance of R&R leading to head through the roof, or smooth as silk then suddently head in the roof?

 

[Cruiser Elite]

Actually this behaviour is quite common across airlines, and it is terribly unprofessional. If the seat belts are on, NOTHING should be happening. You turn them on when needed, and off, if not. Some airlines seem just leave them on. SQ is notable, but not alone.

Ok at the risk of appearing to be an unarmed man fronting up to a gunfight - clearly there are different procedures / practices / protocols airline to airline is there not.

Reading through your post jb747 am I correct in saying when QF Operating Crew make a ‘calculated judgement call’ to activate seat belt sign then all pax and Cabin Crew are read to strap in?

I have just spoken to 380 Captain on SQ228 about this exact matter - his response was that if turbulence encountered Operating Crew will make a ‘calculated judgment call’ on severity - if they consider not too severe seat belt sign will be activated and all pax must strap in but Cabin Crew may continue to offer services except dispensing hot drinks and hot soup.

If Operating Crew make ‘calculated judgement call’ that turbulence is indeed too severe for Cabin Crew continue service then they too will be instructed to strap in.

I am pretty sure I have posted accurately here - is one right and the other wrong? Or do wee just not live in a world of differing views?

 

[Quickstatus]

if they consider not too severe seat belt sign will be activated and all pax must strap in but Cabin Crew may continue to offer services

I agree that SB sign illumination will always be a calculated judgement call. But once its made, why continue the calculation?
And this refers in part to my question in #13.

My only problem with SB sign on which is not applicable to everyone is I don't think that Cabin crew are any more or less affected by gravity or lack of than a passenger. And the presence of a drink/food cart can be just as dangerous at zero G. The other aspect of this is that CC are absolutely necessary in an emergency. It is of no use to anyone if they are debilitated/injured. Additionally passengers note that and some will seatbelt off (calculated risk) and maybe wander off to the loos. It is hardly enforceable if the rules dont apply to everyone (to the extent that any rule is enforceable at 39,000 fett)

So I can't understand why a SB sign once on should not apply to everyone in the cabin. Prior to that we can make all the calculation of risks but after it comes on, maybe we should accept that the calculation stops?
......

Additional info from here
Nearly all turbulence injuries occur to those who are not wearing seat belts. Of those who were injured while wearing seatbelts it's due to people/objects falling on them.
80% of turbulence injuries are Flight attendants

I really can't see how it can be justified that passengers are more protected than cabin crew.