ATR 72 Crash in Brazil - Preliminary Report
Posted by lukinhasb@reddit | aviation | View on Reddit | 55 comments
The official preliminary report from CENIPA was just made available: https://dedalo.sti.fab.mil.br/en/85259
hi_imnaomi@reddit
Larson
AliceInPlunderland@reddit
We don’t have all the data yet, but it is eerie how it seems this plane did basically everything Magnar warned against in his extensive videos on ATR 72 in severe icing conditions several years ago. My takeaway was that there is already a significant problem by the time you reach degraded performance alert and the #1 priority is to maintain a safe speed (and ideally escape severe icing conditions). I understand that severe icing conditions can be difficult to identify from the cockpit, but if they were at 169kts, it seems like they were below the required red icing bug plus 10kts., etc. Maybe performance was already so degraded at that point it was too late.
Given the history with ATR and icing, I hope that the final report indicates something other than ice accretion. This accident is so tragic and shocking to begin with. No one is going to forget the commercial plane that fell out of the sky in a flat spin into a residential area. The only thing that could make it worse is if it was entirely preventable.
railker@reddit
They saw it. Maybe just despite the DP caution, didn't realize how close they were to the edge.
Remarkable_Shift_421@reddit
I also read the speed kept decreasing until 169kts. How come they never caught that?
ShortDescription4712@reddit
Not to excuse missing the speed decrease but to hypothesise: The accident was on the -500 series where the ASI is a round analogue dial with a needle. Unless you’re watching that needle closely, a drop of 5/10kts can be subtle - particularly if there are other distractions on the flightdeck. Highlights the important of instrument scans and aviate-navigate, pilot flying vs monitoring roles etc.
swagoto97@reddit
the SIC had more than 3000 hours of experience in this aircraft whereas the PIC only had around 500. The SIC even made a brief comment on the icing saying "a lot of icing" but the PIC was still blissfully ignorant. This accident screams pilot error. Very tragic.
railker@reddit
To be clear just in case it's not, PIC ≠ Captain, First Officers take command and control of the flight to gain Pilot-In-Command experience quite often, usually swap back and forth between Captain and FO to change duties up each flight. But ultimately the Captain is still responsible to take over and be final authority if something's up. He'd be SIC but seated in the left seat where I believe the physical/visual ice detector is located, so perhaps that's what he was looking at when he made that comment.
But as far as we know so far, they still didn't do anything about it, they should've never been in icing in the first place, and didn't seem to be assertive enough to ATC that they needed to get out of those conditions. Complacency?
Captain-Kiwi87@reddit
PIC does mean Captain. Even if FO is doing command practice, at the end of the day the captain is ultimately responsible. They change roles of Pilot Flying and Pilot Monitoring each sector but at the end of the day, captain is PIC and responsible for the flight.
railker@reddit
I must have had PF/PM in my head or something, but man you are absolutely right. Time to go make a correction, thanks for the comment. ❤
biggsteve81@reddit
It appears to be worse than not being assertive enough to ATC - they appear to never mention icing to ATC. Their request for descent seems to be because they were approaching the airport, not to escape icing.
Complete-Height-6309@reddit
This company is plagued with such a poor safety culture that what's actually surprising is how it didn´t happen before.
PourLarryaCrown@reddit
So they had an Airframe Deicing Fault and knowingly continued flight in severe icing conditions for 5 minutes til the airplane became unable to fly. Smart.
Butchishere@reddit
15:15:49 - the AIRFRAME DE-ICING was turned off; 16:21:09 - control of the aircraft was lost So an hour and 5 minutes?
Interesting that they talked about red bug being 165kts but the aircraft stalled at 169kts. Severe icing and a turning aircraft would explain it though I guess.
GBracer@reddit
If the aircraft is not +10kts above red bug. You must be in HDG mode and Low blank mode. NAV mode is a high bank mode on the 500.
Butchishere@reddit
Yeah good point.
pochato@reddit
They said that the pilots talked about the fault but this fault was not confirmed in the data
armageddon-blues@reddit
I was watching the press conference. Right in the beginning, the official mentioned that the tower was contacted and they requested permission to descend but as there was another aircraft on the level below they were told to wait. When the tower got back to them, there was no response and soon all contact was lost.
I don’t know if this request was related to the icing condition or just regular procedure as they were approaching Guarulhos. I haven’t read the report yet as well, maybe there’s further discussion about this issue in it.
abweb87@reddit
It was just the regular procedure. They never said they had to descend. Also, in severe icing conditions, they didnt even need authorization
MaxMadisonVi@reddit
And why didn’t they descent immediately as the anti ice was faulty and they noticed they had ice
HappiestAnt122@reddit
I mean that and about half a dozen other “why didn’t they do X” questions are really the crux of this crash. The aircrafts alerts and the ice they could clearly see out the window gave them all the information they needed to make the right decisions at several key moments, but for one reason or another they repeatedly chose to press on and continue making decisions that would cumulate with an unrecoverable situation. Ignorance? Arrogance? External pressures? We can maybe make educated guesses at which of those it was based on circumstance and their past actions, but only they know why they chose those decisions in those moments.
armageddon-blues@reddit
Oh ok! Yeah, and they should’ve at least declared an emergency, something they didn’t do despite being aware of the severity of the climate conditions and the amount of ice building up on the aircraft. I’m puzzled by their decisions.
biggsteve81@reddit
It appears they were just requesting a normal descent to the airport. Not the least bit concerned about the icing situation, it appears.
Admiral_Cloudberg@reddit
They kept turning the deicing system back on even though the Airframe Deicing Fault procedure says not to do that. And then their speed bled off and the performance monitoring system generated all three levels of performance alert (cruise speed low, degraded performance, increase speed) one after another until they stalled at 169 knots.
There's a lot going on here and I don't like any of it.
doctor_of_drugs@reddit
gestures at….everything
Swedzilla@reddit
Speaking of which, I wonder if there comes a day where the aircraft decides by itself that this is a no-safe-fly condition and reacts by itself. Like a broader version of MCAS but significantly better.
ps2sunvalley@reddit
It already exists and is usually called ALS or Alpha Limiting System on fly by wire airplanes. Basically won’t let the airplane AOA enter a stall. That said it can be overridden by input as was seen in the Air France 447 crash.
sofixa11@reddit
Didn't that only happen because they were in alternate law due to unreliable airpseed/angle of attack indicators?
Autoslats@reddit
Yes, that’s correct.
Autoslats@reddit
Not in Normal Law. I guess you could do that by doing some other action that forces the plane into Alternate Law, but not through control input alone.
AF447 didn’t have the normal envelope protections because the unreliable airspeed placed it in an alternate law.
FZ_Milkshake@reddit
I know the ATR is a bit finicky with ice buildup, but this crash and some of the earlier ones seem easily preventable by following the procedures. How does the ATR seemingly attract all the pilots who are, a bit lax with rules, for lack of a better term.
Deaks2@reddit
Probably does not help that it’s often used at regionals that usually have less experienced pilots. Also, the airfoil design is not tolerant of airflow issues.
Great article on it here: https://admiralcloudberg.medium.com/into-the-valley-of-death-the-crash-of-american-eagle-flight-4184-and-the-atr-icing-story-29e64faee67c
66hans66@reddit
It looks like all of it is going on here
evergreek@reddit
incredible...
Clear_Salamander5093@reddit
I know little about aviation, would the crash have been avoidable had they descended to a lower altitude when they realized the icing conditions?
Difficult_Tutor2062@reddit
This is a CRM failure if anything and hopefully the lessons learned make an impression.
viccityguy2k@reddit
Could The SIC having only 2:16 of flying time in the last 30 days have contributed?
timbosm@reddit
No.
uburoy@reddit
The CRM failure was the big thing, as mentioned above. Hours didn’t seem to matter her. Actually, the SIC sounded like the sane one in this case. When the SIC made the call out about “taking on a lot of ice”, he was essentially saying “we are taking on too much ice, we need to do something NOW“ and essentially, the Captain did not take appropriate action.
In CRM world, at least to me, he was shouting. No idea what the Captain was thinking. The investigation will likely call out the Captain to some degree.
bravogates@reddit
The icing warning (sigmet) was for FL120-FL210, so yes.
MaxMadisonVi@reddit
The little you know is right.
F1shermanIvan@reddit
Probably yes. But that’s always debatable. If they had left icing conditions as soon as they ran the checklist they probably would have been out of it.
Glonkable@reddit
I work for an airline that flies these planes. Every single one of my pilots would have immediately called me and turned back the moment the deicing fault happened, especially with the weather going on along the route. I wouldn't have even dispatched into the severe icing in the first place. Hell I had a pilot that pretty much refused a plane with an MEL on the deice system due to a fault because of CB/TCU clouds along their route with no forecasted or reported icing, and I don't blame them at all. We both were in agreement that if it was sky clear the entire way it would have been fine, but given the weather and as we watched it get progressively worse with storm activity over the course of an hour, we both agreed flying into that with the MEL was a bad idea. I'm sure that pilot is looking at this incident and it's solidified the decision we made then was absolutely the best one.
Something isn't right in that company culture where the crew straight up ignored procedures PROVIDED BY ATR to avoid exactly this. I question their training, I question how much commercial pressure ops was putting on them, and why the hell they didn't veto based on safety because that's absolutely their job. I'd be looking at ops as to why the crew didn't feel like they could veto the flight, especially the moment the fault happened. It seems to me there's a culture of fear in prioritizing safety that should never exist in aviation and that ultimately is what led to this accident.
My heart goes out to the families and communities affected, and I'm looking squarely at the company as to who is truly at fault based on everything I've seen and my own experience with the aircraft type.
TinKicker@reddit
The flight crews of both 737 Max crashes ignored the fundamental procedures for unwanted trim movement.
biggsteve81@reddit
Those 737 crews also had significantly less time to react. This crew had at least 20 minutes to do something, and did nothing.
TinKicker@reddit
That’s why runaway trim is a memory item…the immediate actions must be committed to memory and performed immediately. This performance is required to receive a 737 type rating.
Knowing and performing all memory items in the flight manual is basic to being rated on the 737…and ALL other aircraft.
Even the Cessna 172 with electric trim has immediate actions for runaway trim…because the consequences are the same.
F1shermanIvan@reddit
First thing on the Airframe Deicing Fault QRH checklist is LEAVE AND AVOID ICING CONDITIONS.
Sounds like they did not make any effort to do that.
Omgninjas@reddit
The sad part is that's pretty much SOP for any aircraft in icing conditions with an icing system fault. It's just plain ignorant. Sounds like a case of get-there-itis infected the captain. So sad....
mattrussell2319@reddit
Right, and other human behaviour factors like the startle effect, and overwhelm. Although we don’t know a huge amount so far, it does seem like the investigation will end up focusing on how to improve management of those things rather than the technical aspects of the event.
WanderingSalami@reddit
From the sequence of events, it seems they had no clue. No sense of urgency at any moment. Poor training?
evergreek@reddit
so sad.
Old_Aviator@reddit
Just gotta say, this goes above and beyond what is normally expected in a preliminary report. Congratulations to CENIPA. Accidental investigations are often critiqued and seldom complimented.
Old_Aviator@reddit
Just gotta say, this goes above and beyond what is normally expected in a preliminary report. Congratulations to CENIPA. Accidental investigations are often critiqued and seldom complimented.
Admirable-Eagle-1128@reddit
sigma
eggSaladSandwich15@reddit
https://admiralcloudberg.medium.com/into-the-valley-of-death-the-crash-of-american-eagle-flight-4184-and-the-atr-icing-story-29e64faee67c
hundredseven@reddit
Yes this magnificent write up gives so urchins atr history on the icing issues. Once I read that; I could guess what ultimately happened leading to the loss of control with that wing design…. Exactly what happened to lead to that point given this is all known is the question..