Mournful incident , Plane carrying 62 crashes in brazil
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𝐯𝐢𝐞𝐰𝐞𝐫 𝐝𝐢𝐬𝐜𝐫𝐞𝐭𝐢𝐨𝐧 𝐚𝐝𝐯𝐢𝐬𝐞𝐝
https://youtube.com/watch?v=-5YWCRD4azQ
𝐩𝐥𝐞𝐚𝐬𝐞 𝐚𝐯𝐨𝐢𝐝 𝐰𝐚𝐭𝐜𝐡𝐢𝐧𝐠 𝐢𝐟 𝐢𝐭 𝐦𝐢𝐠𝐡𝐭 𝐝𝐢𝐬𝐭𝐮𝐫𝐛 𝐲𝐨𝐮 𝐭𝐨 𝐰𝐚𝐭𝐜𝐡 𝐭𝐡𝐞 𝐩𝐥𝐚𝐧𝐞 𝐠𝐨 𝐝𝐨𝐰𝐧
Going by the ADS-B data, it seems like the ATR-72-212A (performing flight 2Z-2283) might have faced severe icing conditions or other factors leading to unreliable speed.
(In what I could study off of the ADS-B data.. there were continous spikes in speed. Not to speculate but if the pitot tubes get blocked or there is other instrument malfunction.. then the aircraft cannot get the correct readings DESPITE THE BUILT IN REDUNDANCIES.)
The frame by frame analysis by some.. also indicates heavy rudder inputs to try to correct for the sudden tail spin induced stall.
However this is a developing story and it would be better to wait for at-least the preliminary report from CENIPA.
Voepass Linhas Aereas Avions de Transport confirmed that the aircraft (registration# PS-VPB) carrying fifty eight passengers and four crew had an accident near Vinhedo, SP (Brazil).
They did not specify the exact circumstances of the accident.
The airline also did not specify on the situation of the people on board.
However the flight was in its approach at Flight Level 170 (FL170) as things started going off.. hence I can only hope for there being more survivors than casualties.
No casualties on ground have been reported as yet, but our heart goes out to the bereaved and our thoughts and prayers🛐 are with those who perished.
https://dawn.com/news/1851182/plane-crashes-near-brazils-sao-paulo-all-62-on-board-presumed-dead
https://blog.voepass.com.br/nota-3-16h55-09-de-agosto-de-2024
The airline revised its earlier statement with the number of passengers being fifty-seven, along with the MANDATORY (minimum) two cabin crew and two cockpit crew.
Brazil has announced three days of national mourning.🛐
While parallels are being drawn with last year's (2023) Yeti 691 crash (operated by another ATR 72-500) which was mainly attributed to 'feathering' of the (propeller) blades by the crew and with another ATR crash in the 1990s..
given the SIGMET (significant meteorological) advisories of severe icing conditions, the CENIPA has not given any statements yet.
Although in the press statement the CENIPA confirmed the recovery of both, the Flight Data Recorder (FDR) and the Cockpit Voice Recorder (CVR).
The ATR-72 has the typical "T" tail design.
This means that the horizontal stabilizer is mounted high up on the vertical stabilizer.
Thus for the horizontal stabilizer and the elevators to be effective, the aircraft has to be within a certain 'angle of attack'. The horizontal stabilizer and the elevators (along with the 'trim' that they are in) are CRUCIAL for maintaining altitude, pitch and are amongst the critical control surfaces.
Now as I went through the plotted granular data of the flight path, ground speed, vertical speed, true air-speed etcetera https://www.flightradar24.com/blog/voepass-atr72-crashes-near-sao-paulo it waa ear that initially there was a sudden drop of about 1000 feet, from which the aircraft recovered.. but then overshot its intended altitude of FL170 (17,000)
and soon after.. literally fell like a brick.
Given 👆🏼that👆🏼, I a could not help but be reminded of this feature which the ATR 72 have.
Although Captain Abdullah' type-rating is on the ATR 72-600,
the automatic stick pusher would work the same way.. in the 72-500 too.
If the computers feel that speed is decaying too much or the aircraft would soon 'stall' (wings not being able to provide enough 'lift')..
.. then in an effort to gain speed AT THE COST OF ALTITUDE,
once the stall warning is sounded and the stick shaker is activated.. the pilots have a limited time to act.
If pilots do not (act) as deemed fit, then the automated stick pusher sequence would push the nose down by jarring forward.
As already seen in the T_tail_design.png tail design and the horizontal stabilizer configuration, if the vertical stabilizer falls in the 'shadow' of the wings.. then too the plan can stall.
The assumption or guesstimate in my previous comment too was based on a mix of these factors.
Although there are multiple computers, the speed data is mostly fed via the pitot tubes (which are OPEN to the oncoming wind).
If for ANY reason (including dead bugs , ice, other debris in the tubes or the unremoved caps) the pitot tubes feed unreliable data or if the computers feel that the speed has gone towards the stall speed.. then they WILL activate the automatic 'stick pusher' mechanism.
The data https://www.flightradar24.com/blog/voepass-atr72-crashes-near-sao-paulo shows the spike where the aircraft first 'suddenly' went down a bit, then recovered.. before finally having less then 54 knots speed and 'falling'.
Those 90 seconds would have been terrifying for those on board.😔
Hopefully the investigations would be completed within 10-12 months and the recommendations, findings help make air travel an even safer mode of transport.
The airline was formed barely in 2019, after merging other regional carriers and claims the forth biggest airline spot in the domestic market.
Hopefully they will bounce back from this setback and have even better training, procedures and protocols.
Ridiculous and sad things happening in Nepal also, repeatedly....
Scary video...cant even imagine what people must have been going through.
To make it worse it crashes in a residential neighborhood.
Terrible news!! My heart goes out to the victims and their families. May God give them the strength to bear the loss!! May their soul attain moksha!! Om Shanti!
Very sad. Can't imagine what they must have felt inside the plane. Flying into icing conditions can be fatal.
Some info I learned: https://en.wikipedia.org/wiki/Icing_(aerona...s)
For anyone interested "Lost: The Mystery of Flight 447" is a gripping and tragic documentary
https://avherald.com/files/voepass_at72_ps_vdb_sao_paulo_240809_preliminary_report.pdf
At the on-set, they are very clear that it is more about presenting the factual information. They do not seek to establish guilt or just liability, but focus on the prevention of accidents.
also, by its very nature, the preliminary report is a work in progress and new information and analysis is continually happening and so
the final report would give a more comprehensive picture.
Hopefully it will be out in 18-20 months.
sadly, (despite this not being about assigning blame) it does NOT look good, if the three main (likely) factor highlighted by Cenipa are;
● Human factors: explore the individual, psychosocial and organizational conditions related to the crew's performance in the situation experienced.
● Material factor: check the airworthiness condition, with special attention to the aircraft's anti-Icing , de-icing and stall protection systems.
● Operational factors: analyze aspects related to the technical performance of the crew and elements related to the operational environment in the context of the accident.
Unsure if SIGMET advisories and the severity of the weather registered with the cockpit crew.
I say this because as was already known, this aircraft had been in maintenance for a while, prior to this flight.
The Reporte Preliminar confirms that
one (out of the two) pneumatic pack was in-op (inoperative).
And while it might be legal to fly with just one of the pneumatic packs, as the Minimum Equipment List (MEL) allows for the ATR to fly with one pack in-op
it mandates the ceiling to around FL170 (aircraft with such inoperative pneumatic is only fit to fly upto 17000 at most).
THAT is why i wondered if the cockpit crew even soaked in the complete picture or just followed the instructions of despatch!
Soon after taking off and gaining near cruise altitude, the electronic "ice detector" went off.
The crew did switch on the de-icing, but then a air-frame de-icing fault (light) came up.
So in under a minute of starting de-icing, it was switched off.
With all these issues, even if the company despatcher insisted,
the PIC (pilot in command) had the complete authority to NOT be there in such weather.
The had the option to deviate OR EVEN return.
Yet the CVR (cockpit voice recorder) data shows no such concerns among the (reasonably experienced) pilots.
An hour after being switched off for the first time, while advised by ATC to still hold 17000 feet (due to traffic below)
degraded performance alert was triggered.
So for the second time, the de-icing systems were turned ON.
But again, in under a minute and a half, the airframe de-icing was turned OFF.
As per the cockpit voice recorder (CVR) data.. for all this while.. neither of the crew ever voiced concerns about these alerts or the likely build up of ice on the leading edges of the wings and other flight control surfaces.
Everything seems to be moving as though nothing was wrong.. with them make radio calls with ATC, doing the approach briefing and so on.
Finally, just about two minutes prior to the crash.. the de-icing was turned ON for the third time.
Unfortunately, given the nature of flat spins and as per the design of the ATRs..
there is no 'recovery procedure' on which the pilots ever get trained to cone out of/ recover from a flat spin.
But even before the plan stalls (no long generates enough lift) and eventually enter a spin.. there ARE checks and balances to not let the plane 'stall'.. in the first place.
Further investigation by the authorities would hopefully she'd more light on how to make things more safe and what recommendations come out of it.
One thing that I (like many others) am sure of, is that while the stall may occur due to an excessively high 'angle of attack' (nose pointed too high towards the sky)
it can only progress to develop in a flat spin.. due to abnormal 'yaw' (yawing motion).
I myself am keen to know as to what caused it. Could it be something avoidable and one that one can watch out for in the future? Was it some sudden, uncontrollable change in the center of gravity (COG) or a combination of these and other factors.
All in all, the next of kin of the 62 lives lost.. too look forward to a closure.
(Initially it was said that there were 58 passengers, then updated as 1 passenger missed the flight. But as per this report, someone else.. other than the original passenger.. did board the flight. So total fatalities were 58 passengers and 4 crew on-board.)
Magnar Nordal is himself an ATR pilot and an instructor too.
He too previously released a video after the preliminary investigation report had come.
Since his soft voice and accent are a bit hard to follow, I did not highlight it.
but this, hybrid animation style cockpit instrument panel and outside orientation view, adds to our understanding of the sequence of events.
Om Shanti