Former ATR pilot here. The plane could handle moderate icing just fine. They redesigned the boots to a vertical (vs horizontal) alternating layout that went waaayyyy back on the wing. Because of this, you could let the system run continuously in icing conditions because there was no chance of ice bridging. We kept a close eye on airspeed and if the speed decreased 10 knots we knew we were picking up ice. We would turn on the boots, add power and monitor airspeed. If we kept adding power or airspeed kept decreasing, we descended. We treated the minimum icing airspeed with great respect. Under no circumstances would we go below that speed no matter what...ATC and traffic below be damned.
Juan mentioned a nose up attitude of only a small angle. Is it possible do you think that the pneumatic valve controlling the boots got the boots stuck inflated, causing even larger buildup of ice, enough to cause a stall at such a relatively small AoA? Happened to me once on a Jetstream in moderate icing. Didn't stall but certainly lost lift. We came down to below icing at a high rate with a noticeable amount of drag, which reduced after the ice melted. Landed with the boots still stuck inflated.
Question: Since you are an ATR pilot perhaps you can answer - why do you think the icing warnings fluctuated (cycled on off etc) given severe and active icing? I would imagine, with the static pressures known, on the top and bottom surface of an air foil, and the ram airspeed known, the critical angle can be estimated mathematically? Is that how the AOA warning computed in the ATR in icing? Trying to understand why the warnings were cycling back and forth?
@emdude1784 my understanding as a nonpilot is that the gauge that senses the ice below the wing sticks down and senses the ice building up on it, and then it gets heated up in order to melt the ice and then begins sensing again. So the probe is constantly in a cycle between gathering and measuring the ice building up, and then heating up to clear the ice on it in order to begin sensing again.
I am 80 years old. Over the years I have worked with a lot of people. One of the things that most disturbed me was the lack of true understanding of physics and mechanical things and how fast something can go wrong if you are not paying attention. As you know, most accidents are caused by people making more than one mistake, I have often counted 6 or more in one accident. Keep up the good work you are doing.
I too have made the statement people don’t grasp simple physics. They don’t get simple mechanics of most items or systems they use daily. And in some cases such as this flight, they turn deadly. Too many times things become routine. Any heavy object moving rapidly at any height more than head high should not be thought of as routine.
There was a good AOPA video a few years back on “single point failures” and the take home point was there were exceedingly few of them that led to a catastrophic event. Most often is is ignorance of multiple things that individually would not lead to catastrophe, but in culmination, lead to disaster.
*Second that!* Most importantly, people driving cars not realizing what energies they are playing with (downhill; turns; water; sleet; ice) and expecting brakes to always save them.... Energy is proportional to mass times speed squared. I think _most_ people forget x2 the moment they leave school.
Reading through this Preliminary Report gives the impression that the Pilots were not aware how dangerous the situation had become. That rises the question about their training and what was going on inside of this Airline. It seems to be a more complex story.
Magnar pointed out (as a training captain on the ATR) that if you get the INCREASE SPEED light that's an emergency and requires you to pitch down to increase speed immediately. Do not ask ATC, do not chat up the flight attendants. Pitch down without delay. Why did these pilots not do so? What was Voepass training like? Did the pilots get proper ice awareness training? What about stall recovery - which these pilots seem not to have attempted at all. Was Voepass doing recurrent upset recovery training? It is possible the pilots are entirely at fault, but it's also possible Voepass has been pencil-whipping training and/or their pilot culture encouraged ignoring ice warnings. If the chief pilot or line training captains set a bad example it can filter down to the whole organization.
Indeed. Looking at how scary the Pilot Errors were in this case it seems to indicate that this were not only individual failure´s of this particular two pilots but a bigger problem of the involved airline.
"What about stall recovery". It's practically speaking not possible when the yaw moment starts. Many airlines don't teach recovering. They teach and train avoidance of the problem entirely.
@@dennism8346 I am not a pilot. Just an engineer. My idea of a recovery manoeuver is: Engine on outside of rotation into reverse, inside full speed. That will work against the rotation and give the faster rotating wing less lift. Outside wing ailerons up to force wing down. Inside ailerons down to force that wing up. My intention is to counteract the yaw movement and to make the aircraft roll to the side. Hoping that it will then, with the help of the rudder, pitch down over the outside wing, gain speed and become controllable again. Should be tested out in a wind tunnel. And if successful trained.
Yikes. I vividly remember sitting in a window seat of a Dash 8, watching ice accrue on the deicing boots but on the wing. I noticed after the pilots announced they were returning to Toronto airport, shortly after departing for a short local flight. I am pretty sure they declared emergency because we came down through that cloud bank so friggin fast I couldn’t believe it and went straight in for landing, which never happens in Toronto. I knew enough to be relieved when I saw all the ice melt off the boot once we were below the clouds at a pretty low altitude. Glad I didn’t know this then.
And the Dash 8 is known to be much less sensitive to icing than the ATR. And now imagine: This Pilots of Voepass stayed in such conditions with an ATR, not a Dash 8, for more than an hour, literally without doing anything, including informing ATC.
I flew cloud seeding in a king air when I was a snot nosed 300 hour pilot. In my experience the worst icing is near the tops (where the Super Cooled Large Droplets) hang out and at a temperature of -5 to -8c. I’ve been literally knocked out of the sky by ice. We were in a turn and encountered severe ice. I distinctly remember the captain working the props back and forth to knock off the ice and shoving the nose over to maintain 140, the minimum icing speed. We ended up descending at 800fpm, at max torque (I can’t remember the setting). ATC lost radar contact with us and I was using ForeFlight to vector him to lower terrain. We reached the freezing level and cleared the terrain by 1,500 feet. We were lucky. These guys weren’t.
The very first ATR (a 42, north of Bergamo, near lake Como/Italy) that crashed had a fellow KingAir pilot flying the same track before them. That guy (I knew him personally, very experienced guy, since passed away) turned around and landed back in Bergamo because he hadn´t seen that much ice ever before and could not maintain altitude in his empty E90 at full power. The KingAirs can carry a ton of ice. (don´t ask me how I know) That was in 1987 (!) and the circumstances are very much the same than in the Voepass case: they knew about Icing and they flew way to slow, 17 kts below minimum icing and ignored degrading performance AND stall warnings (5) until they stalled and crashed.
I kind of get the feeling the pilots had previous experiences or encounters with icing conditions and probably got complacent since they could push the envelope before and got away with it. This time the icing and other factors were not as forgiving. They were already so close to stalling that initiating that turn was the final factor. Juan masterfully showed and explained it all. It's gut wrenching to watch. RIP all.
why would anyone push the envelope with icing? Go ahead and push the envelope if you must if you're flying alone, but not when you're carrying 60+ passengers!
The fo with thousands of hours of experience had without a doubt encountered icing before many times. He had seen all the warning lights and learned to ignore them. He had made several mistakes before but luck had saved him. This time his luck ran out, he made one mistake too many. I see this all the time, it’s how experienced people get hurt.
Yes, very true…. I would therefore ask the question of how the less experienced pilot survives in the first place. The answer is training, sop, and procedures. When we get experience and push our way into complacency, things get dangerous. I just changed airplanes to the 787. And it’s shocking to realize how comfortable I was on my OLD airplane. Thus making me wonder how complacent I was without realizing it.
Perhaps one of those situations where the "junior" first officer didnt want to override/chide/alert the "senior" captain , even though the FO had 1000's of hours experience, compared to the Captains few 100 hours. The classic authority/power imbalance. ( think asian/.middle eastern cultures) where FO doesnt speak up. Or is it a latin male culture of "machismo" who wont be told they are wrong?? ;(
The guy narrating in portuguese says: “At this moment, São Paulo control authorizes him to fly directly to the position SANPA, and he starts the turn to the right. The increase speed is activated at 169 knots, from there you can hear noise and vibration from the aircraft, with maximum inclination of 32 degrees. The turn is reverted, stall alarm activates, until 52 degrees to the left, and after that a small increase in altitude. And 94 degrees in a turn to the right, into spin. After that the aircraft stabilizes in vertical fall, and gets into a flat spin to the left, five degrees until colliding with the ground.“ Btw, he sounds like he's talking to someone, and not doing a planned speech....
Doing approach briefing while getting warnings that had to be dealt with immediate actions. Those pilots seemed to have no idea of what critical situation they were in.
I feel like they must have been thinking they were getting faulty ice detection warnings, and then when the first officer realized they were getting actual ice accumulating they did too little too late.
My theory is that they have successfully flown in situations like this before and gotten away with it and grown complacent. "It worked just fine the last time, no big deal."
Indeed, exactly. And that indicates to me - to repeat this - that it wasn´t "only" the failure of these particular two pilots but that it is a more complex story.
I’d like to know if they put incompetent people in there on purpose, weaponizing the crew. 6 world renown doctors were on that flight, on their way to a conference where they were going to present their peer reviewed scientific evidence regarding how the poke was increasing illnesses and “♋️“ Convenient how they just - fell out of the sky, on their way there!
They had no idea how dangerous their situation was. I don’t care what you fly, you don’t stay in moderate to severe icing. If ATC doesn’t give you what you need, declare an emergency and start a descent!
@@mattcommons5033 The ATR with functioning De-icing equipment is perfectly fine to fly in light to moderate icing. This crew had a non-functioning de-icing system (that was off for most of the flight anyways) and ignored all evidence that significant ice was building up on their aircraft.
This route presents such routine icing conditions the pilots simply get used to the warnings. They know they are riding the edge of the envelope, but with every successful flight, their complacency grows.
Correct. You cannot be unaware in situations as urgency of descisive action has to take place without delay. In this instance their complacency expired.
In this case it seems more that they didn´t know that they were riding the edge of the envelope. More than that: They seemed to be completely unaware of the danger - and that would raise the question: why?
Sorry, but there are no excuses for this scenario with the ATR. Nor any other aircraft. Icing is a very basic problem and part of flight awareness from basic training. For an ATR to result in a flat spin due to icing is a result of poor piloting, planning and communication. Fly the plane. Don't sit back in your white shirt admiring your log book and watch icing build up on autopilot when the weather briefing told you it was there. Demand lower altitude. ATC is a service to ensure safety and nothing to be feared. Get out of icing conditions even without approval. Fly the plane. Descend. Aviate, navigate then communicate. No excuses at all if icing is the cause. Such a fall for those poor passengers. Horrific. Fly the plane.
I recall many, many years ago when I was a young CFI with the owner of an airplane...I think it was a Grumman Tiger? We were IFR and I saw ice accumulate. I immediately asked ATC for a lower altitude and we deviated out of icing conditions. Be proactive. That's why I'm able to post this message today.
Yeah, ... changing your aircrafts aero dynamic shape unwittingly by ice crusting formation without realising the urgency, otherwise kiss goodbye to your life, on a downer all the way to oblivion. Inaction or inappropriate actions lead to a lot of preventable crashes.
The recreation video made me sick. Watched the aircraft falling from the sky videos 100’s of times but seeing what it looked like when they 1st lost control…. Chills. Must’ve been absolutely terrifying for everyone on that aircraft. So so sad. Thanks for breaking it down for us. Great video!
I think only the crew would have been fully aware of their situation until the last few moments. They were inside thick cloud, so a complete white out.
@@fredfred2363 No. Thick cloud or not, the passengers would have FELT something was seriously wrong when they were rolling over 90 DEGREES (17:07) or headed STRAIGHT DOWN (17:19). Anything loose in the cabin (drinks, magazines, people, etc) would not have just stayed put.
I have been a captain on the ATR 42. Similar, just a bit smaller. Our area of operations, Ireland and the UK, often had icing conditions. In such a case ALL anti - and de-icing systems would be selected ON. The leading edge boots would be cycling continuously. I never had any problems. I have all sympathy for the unfortunate crew and passengers that perished in this accident
From what you say, I suppose that cont. de-icing selected ON is the norm in the ATR when once the icing indications are triggered. The fact that de-icing was activated only intermittently, and turned off in conjunction with the chimes / fault warnings, tells me that it was likely inoperative. DEGRADED PERF up to INCREASE SPEED was a clear indication for ice accumulating and a hazardous situation occurring. Last but not least, they, as a crew, were completely inept to handle an impending stall / high AOA. Push of yoke, max cont thrust, setting flaps was the last hope. Instead, they banked the plane. Tells me they were completely dismissive of the aerodynamic conditions and what was mandated within the situation.
From the initial fault of the de-icing system all rules we not followed. It appears the de-icing never was working. They were in icing conditions nearly from the beginning of flight. Look out the window at the visual icing indicator. 17,000 ft was maintained, no mention of icing from anybody with weather indicating icing all around them A visual observation was needed. The pilots had enough experience to do this but were chatting with control and NOT FLIGHING THE AIRPLANE. Pay attention and look around. Look at the radar, look at the indication. Pay attention to the icing fault from the beginning of flight and subsequent warnings. The pilots killed themselves and all the passengers through pure total negligence and failure to fly the plane. Thanks Juan, very good info and observations. Those planes are hard as hell to fly on a good day. There is no room for error.
Thanks for the breakdown! The CMD had an all Airbus A320 career as FO (Avianca, Midlle East as far as I remember from his linkedin profile) he only recently upgraded to CMD on ATR. I have 12000 hours on A320,330,340 and B777. I would be supercareful and cautious when changing to ATR and becoming CMD same time. There is a lot of responsebility both for the pilot and the company. I wonder if this will find its way to the final report. I guess it will.
@@BlueSpruce2 You seem to value more the "style" above from the substance... As a pilot and engineer, I find Magnar and his videos truly professional and "In-Depth"... Sorry for you if you find him "boring"!...
@@alfredomarquez9777 Well that's my opinion. I happen to be an engineer as well, but I like to see practical or technical information presented with context. As a pilot I guess you would understand the data without the context and this is why I prefer guys like Petter Hornfeldt, Juan Browne and Chris Brady. You could say they bring style AND substance to their presentation. Cheers!
Many years ago a friend told me about a job interview he was on for a job he didn’t get. When asked why his IMC time was so low in relation to the amount of total time he had, which was substantial, he said, I don’t know who you’ve been interviewing, but I try to avoid IMC because there’s a lot of bad stuff in it like turbulence, icing, and imbedded thunderstorms. Mike was a turboprop guy with 10k plus hours at the time of the interview. IMC means instrument meteorological conditions.
Sadly, this is prevalent in many professions. I am a retired firefighter and you would be surprised at how many of us don't pay attention during training.
Another excellent post accident report as usual. I flew the ATR-42 out of Newark and Manchester, NH in 1992-1994. Flew out to Syracuse, Buffalo and Cleveland during winter. Great aircraft. Just had to respect the envelope. All the icing accidents in. ATRs are due to pilot error, as far as I know. The level of complacency with these two Brazilian pilots is hard to fathom I lost 2 engine anti ice systems on 747-400F, while holding at Hong Kong once. I told the F/O to tell approach that unless they descend us and put us on approach, we’re diverting to Taipei. They brought us in.
@@jeffhurckes190 The point is: We know how dangerous icing is and especially about the vulnerability of ATRs to icing because Greg Feith and his team did such an outstanding investigation of the Roselawn Disaster. Orlando Aguilar and Jeff Gagliano were the unfortunate and unvoluntary test pilots who payed the price for our knowledge. But the Roselawn Disaster is now 30 years ago. ATR pilots in the year 2024 HAVE to know about icing and how it effects their aircraft.
In the end it was complacency and not chaos in the cockpit. The autopilot left on was the icing on the cake. Once the stall happened the autopilot was turned off when it should have been turned off much earlier in these icing conditions. So many crashes linked to autopilot being on when the aircraft needs to be flown the hard way.
Years ago my CFI (chief flight instructor) told me a story how they stalled in icing in a holding pattern in Melbourne Australia. That was in SAAB 340. Similar aircraft. But thankfully they recovered from the stall....
@@shooter2055All Turboprops lack a truly powerful heating system for anti-ice (like most jets)... and their old and unrefined inflatable "boot" deicing is still crude, as it CANNOT break and throw away any ice accretion BEHIND the chordwise location where the boots end... In the ATR, it seems that after the fatal accidents it had years ago, the factory enlarged the Wing boots, but the horizontal stab still looks as if the stab boots still are diminute in chordwise lenght...
@@alfredomarquez9777 And a jet with heated leading edges will not shed ice behind them either. No transport airplane that I am aware of has every surface protected from ice. Normally, ice will only build up on the leading edges.
mayday mayday mayday voepass 8203 position xy, FL17 in icing conditions with deicing equipment fault descending immediately - that would have been the right call
Yes, indeed - and it should have been done long before the control of the aircraft was lost because they had multiple warnings for round about an hour before the crash.
Not much icing experience in my PC 12 but one time (ironically at 17,000 feet) returning up the California coast in the winter we started accreting ice faster than the 1 minute boot cycle could clear it. After two cycles my IAS had dropped from 200 to about 185ish with no power change. Disconnected AP and trimmed down aggressively (no mountains below) and informed ATC we were descending due to severe ice. They were pretty good about it and we didn’t have to declare an emergency. Exited icing conditions at about 12,000 feet and continued the flight. It can build up very quickly.
Thank you very much for this enlightening debrief of the Preliminary Report of this horrible crash! I confess I waited for it. The Pilot Errors are disturbing in this case and seems to indicate that there could be a deeper problem at this Airline. They had about an hour time to save the flight and did literally nothing until they fall out of the sky. That is really scary.
I remember my most vivid example of severe icing. C-130s have a hot bleed air system for the wings, tail and engine inlets, however it does not deice the wing sections inboard of the inboard engines. When this airplane came in, there was at least 6 inches of ice built up on the leading edge of the inboard wings. Yeesh...
Ah, a C-130. That explains it. Those things could fly severely overweight, probably up to 190,000 lbs, as long as you kept them flying and had all 4 engines.
One hour and Six minutes between Icing Fault light and losing control. First line of QRH for this say “ICING - LEAVE AND AVOID”. What were they doing? If they’d got the QRH out and acted on it, they’d all be alive now.
JB "Gas path deicing" heats the engine inlets so ice is not injested into the engine. There may be inertial separation (a flap in the engine inlet) as well.
YT actually recommended a good one. Magnar Nordal' channel "Fly with Magnar" has instructor-style detailed breakdown by a Brazillian ATR instructor. Likely overkill, but nice detailed adjunct to Juan's excellent vid.
I'm no pilot, but now it is my "understanding" that the de-icing features of any turbo-prop aircraft are there to assist in recognizing and then GETTING OUT OF icing conditions, rather than for sustained flight in icing conditions. Thanks JB.
No, the ATR can sustain flight in mild to moderate icing IF the de-icing equipment is functional. On this aircraft it wasn't functioning and was turned off.
@@stephenj4937 If I were a pilot flying the ATR or similar, I'd still not care to fly in icing conditions for any longer than absolutely necessary with all systems operational. Sustained flight in mild to moderate icing is not something that my sense of self-preservation would be comfortable with. Errors is icing evaluation or deicing systems functionality have too much potential to make things ugly fast. Humans are imperfect and make errors, avoiding icing at every opportunity might be my error, but I don't see it that way.
@@Br549-x3b I’m sure the shock of what was happening also played a factor. I used to fly this exact aircraft in the Country of Chad. We made flights from the capital N'Djamena down to Coma base 5. It was a dirt runway and getting there took about an hour in the air. I remember once when we lost hydraulic pressure and you ended up flying what felt like a brick in the sky. We turned around half way there because there was no way to make repairs at the dirt strip. It could have turned into a really bad day if we lost an engine or something.
While I am not a pilot, I greatly appreciate Juan’s insights and real world context given my engineering and physics background. Every one of his reports are excellent.
At 13:12 - “airframe de-icing turned off!” - reference 13:00 - the first checklist item (well, beyond leaving known-icing conditions) IS to shut off the airframe de-icing. Also explains the short activation period on the graph - they followed ECAM and shut it off when it faulted after they turned it on I guess. That was just an observation about procedures though - regardless, this crew had all day (and a million warnings) to react, but failed to. 😕 Also, I’m confused about ATC having “no clue” about the icing; wouldn’t they be aware of the SIGMET? The spin entry was the most incredible part of this report - many of my friends and I were curious exactly how this happened. The animation makes it a bit more clear. They were a few knots from stalling wings-level, but that’s right when they initiated their turn. With one wing stalled and subsequent roll, the recovery was impossible but also induced the spin.
ATC was aware of icing conditions (SIGMET warning was there). At least one other flight reported that. The point is that they were not aware of issues with this Voepass flight, because they never declared an emergency.
They also seem to have overcorrected in roll after the initial stall. I wonder if that what was sealed their fate? Once the aircraft started moving that erratically at low speed, a spin was inevitable 😕
@Antonio-lt1sp And if they switched the anti-icing system off due to fault alarm, they might actually have been unaware of just how bad conditions were. The flight crew appear to have suffered from a logical fallacy, believing that because they had the anti-icing switched OFF there was no longer a risk of icing. Because if they were in icing conditions then *obviously* they'd have left it ON. I wonder if one of the more experienced copilot was irritated by the alarm and switched the system off without verbalising his reasoning, and the PIC just assumed the copilot knew better and trusted what they were doing?
Never flew the ATR, but plenty of time in a Q400 dash 8. The dash didn’t have any issue in mod icing. But you still needed to be careful. Increase speed, turn on boots, and move props to 1020 rpm. If speed is decayed past 10 kts decrease altitude to maintain a safe airspeed and to warmer weather.
Great report, thank you. Very interesting tragically. I'm flying with a captain, whose name happens to be Juan, who is also a big fan of yours. I told him that I met you on that commute down to LA a few weeks ago and showed him the picture.
In my experience, if you start getting ice do something immediately to get out of it. Don't sit in the ice because that's your clearance. Pilot in command stuff. Atc is not your enemy, if you TELL them about the ice they will clear you out of it, also, if you're getting ice at that altitude so is every other aircraft, so you're helping everyone else, pilots and atc.
Good controllers will, some flim flam with your predicament. I told em after asking once and no reply, Im deviating downward. Bless mart good controllers.
Great job as always, Juan. Man, flying into known icing conditions, with every warning indicator on the plane going off, and yet no sense of urgency by the pilots. Were these warnings so commonplace they almost ignored them? That CVR must be gut wrenching to listen to.
My guess is that they flew this route many times before under incing conditions with warnings and never lost control. This gave them deadly confidence.
When this happened there was a lot of discussion online about the ATR being sensitive, almost dangerous if icing occured. This aircraft had all the warning systems though, and the recorder shows us they worked, repeatedly. Yet this ATR was doing everything it could to warn them about the ice, and even telling them to speed up and leave. Perhaps the PICs new training somehow omitted the biggest single risk to the aircraft type (because Brazil is "always" hot?!), but the SIC with thousands of hours ought to have been ready & aware. Perhaps some kind of attitude problem from the new captain? Didn't welcome advice? Usually that happens when the SIC is the novice. The single Pack put them right in the cold weather with a 17,000 max altitude. Perhaps they were too used to cruising above the weather, and never really hitting the ice. So sad.
@@StanfordJohnseyI thought they came off or were kicked out of autopilot just before or after initiating that right turn that started the sequence leading to the flat spin. I could be wrong.
The only explanation I can think of is that these ice warnings happen so frequently in previous flights that the crew is desensitized to it. They didn’t take it seriously because it wasn’t a problem before. Maybe there’s another explanation but I don’t see it yet.
One would hope that any ATR pilot would be very sensitive to icing-related systems and warnings in the same way they should be sensitive to the condition levers being moved to the Feather position.
@@BrianMorrison sadly, there are some really stupid people who can sit in those seats. I’ve met quite a few. The industry doesn’t do a very good job of policing itself.
My personal impression is that the pilots likely due to familiarity with operating in this altitude and humidity were complacent to being in icing conditions and had overconfidence in their ability to fly the plane in icing conditions. I think they failled to appreciate the situation that they were in, I'm not sure why given the weather warnings etc and act appropriately/urgently on the information they were given from the warning systems that he aircraft was building up increasing ice, did they think they were errors and the icing system and detections were malfuctioning? One confounding factor is that there are 3 different procedures referenced from the 3 different warning lights - were the crew overloaded by trying to follow 3 checklists at once? I think this is unlikely - it sounds like they just didn't appreciate what was going on but still.... Looking at what the aircraft did when it stalled it does seem that they might have been able to recover it (wiht he nose going down) if they'd gone immediately stick forwards before a full spin developed.
De-Ice and Anti-Ice systems are designed to allow the crew to immediately leave the icing conditions. The Captain and F/O both had around 5,000 hours. I remember when this was the absolute minimum required to even get an interview at an airline.
We stalled an HS748 in icing back in the day. Wing dropped and down we went. It had a fat ol’ wing so eventually it flew out ok. Back then the boots were a bit different and were operated as de-icers. I think they had a tendency to accumulate ice on the belly which might’ve been what caught us out.
14:11 That single chime was likely a fault on the airframe de-icing system. They kept turning the airframe de-icing off because it would fault a within a couple minutes of being turned on. The airframe de-icing system works on a timed cycle to inflate various boots at different times. There is a sensor that detects if the pressure in the boot air circuit is not correct for the phase of the inflation cycles and if so, the MFC would activate the fault light. The ground test for the de-icing system takes about 20 minutes because that's how long it takes to go through the cycle a couple times. The visual ice indicator is only visible from the captain's seat. I refer to it as "The Captain's Icemaker".
@mariopinho6549 It was the company's first accident with victims in 29 years. Which company has the best rate? Foi o primeiro acidente com vitimas da companhia em 29 anos. Qual companhia tem índice melhor ?
Indeed. No mentally sane Pilot would make such scary mistakes voluntarily if he knows the danger. So it looks like a more complex story and not only like the individual failure of two particular pilots.
@@wallacemjr the difference between the company with the best record, and the one with the worst is often 1 bad day. Well except for that one airline that keeps sucking ramp workers into the engines one at a time.
Great reporting on this. 30 to 35 years ago I spent 5 years studying aircraft ground de icing. At the time the automated ice detectors didn't reliably detect icing conditions. We found some areas would retain ice while others areas were ice free. We did determine that holdover times were way to optimistic and ice wasn't being given the respect it deserved. I thought that attitude changed decades ago when we had these inflight icing accidents such as Roselawn.
I once flew in severe icing for about 12 minutes in Kansas. I tested the accumulation during a single take off and return in the pattern. I picked up a half inch of clear ice. This stuff is nothing to get lazy with!!
native portuguese here .. beside the writen report and the graphics , i heard the intense verbal PRELIMINARY briefing by the BR investigators. so, besides the inatitude of the pilots since the first de icing airframe fault ,, (i believe they trused to much in their experience) .. if , if , if,,,, they had started the descend acording flight plan i think they would be alive,,, bu,, but,, but,, they were delayed by ATC on starting the normal descend for maybe 40 miles because not 1 but 2 airplanes under,,,,, plus,, somecoinciding with calls to dispatcher and flight atendent in cockpit about issues with needs of 1 passenger on arrival,,,, plus,,, the last atc waypoint to the right ... .....Very sad sittuation as usual,,, bless them and families
If the traffic had been less and plane was allowed to descend, all lives might have ben saved without anyone knowing. The complacency of both pilots including the SIC who had thousands of flying hours in this aircraft type, flying in icy conditions must now surely be the focus of the investigation. One can only wonder how many times they have been so complacent in icy conditions and got away with it. Juan, thank you for all the time you must have spent preparing this very exacting video.
Juan - your explanation which puts everything into context is the best. I watched another video from a Swedish bloke (Magnar Nordal) who is also an ATR instructor and got next to nothing from it. Because these pilots were not hand flying the aircraft they did not realize the degradation of the aircraft performance until it was too late when they went off the autopilot. It looks like they needed to descend to a lower altitude and warmer temps immediately after getting the airframe deicing fault warning. As you point out - you don't mess around in these skinny winged turboprop powered ATRs in icing conditions. They could say the plane was brought down by severe icing but it appears to me that pilot negligence with a good dash of complacency is the root cause of this avoidable accident.
I thought Magnar did a wonderful job, as of course did Juan. Magnar goes more into the deep technical details, which may or may not be what one wants to watch, but Magnar's ATR specific knowledge and experience gives him some exceptional insight into that particular aircraft. Of course, when watching him I feel like I should be taking notes in order to pass the final exam :)
I was told by a friend, this is not the first time they flew like this. That the de-icing was faulty on the A/C and the crew flew anyway. She was a former FA with the company and told me she had flown with the captain before. And spoke to a pilot currently with the company. Of course this is here say but she told me this right after it happened and its making sense now.
Only seen severe once, going into Zurich (28) one night. AP OFF, Speed up and continue. WE landed OK but never seen ice like it. We were in an AVRO RJ-100.
A second after increase speed warning came on, it looks like the pilots pushed the thrust lever to the max, as the n1 quickly started rising and hit 100%. But it was too late.
Valuable lessons learned. I AM an Electronic Engineer and I flew aircrafts. We respect both knowledges for a safe sortie. Condolences to their families.
****I think a HUGE aspect of this that's being overlooked is the fact that the CA had about 500 hours time on this a/c and just came from jet aircraft prior, where he's NOT used to ever spending cruise altitudes sitting directly in clouds and icing weather, and is used to normally punching through down or up out of it above or below, and didn't truly grasp the dangers of icing on his a/c at that altitude/speed/etc. this definitely is thus correlated to insufficient training to highlight this to him, if he was so blissfully unaware and blase about this OBVIOUSLY fatal circumstance developing around him SO CLEARLY.***
I note that in the simulation, it shows a TAT of between -2 to -3. I assume this to be in deg C ?? At this order of TAT, any ice will be slow to freeze and can run back on the upper wing surfaces behind the extent of the protected leading edge chord wrap. In the event of SLD conditions this will be exacerbated. In the case of high LWC (more likely at “warmer” icing conditions) this same effect will also be exacerbated. Such conditions are, typically, the most hazardous to turboprop aircraft that typically rely on pneumatic De ice systems. A run back ridge on the upper surface behind the extent of the Deice boots then, obviously, makes the wing incredibly sensitive to the flow tripping … and can be very dangerous if it trips the flow over control surfaces (the Roselawn incident being the classic example). Just to make things more exciting, a lot of accretary type ice detectors struggle to reliably respond to these same SLD or high LWC/near 0C ice conditions as the freezing water on the probe sheds before it has chance to actually freeze and so build. The best indicator to this type of ice threat will be the an accretion probe visible from the cockpit (which your presentation indicates is now installed to the ATR) or formation of slushy ice on side windows (I’m not very familiar with the ATR cockpit glazing). Protection from SLD conditions remains (to my knowledge) one of early recognition of the condition and immediate vacation … usually by descent … if you climb you might get above it, but it’s likely the severity will be worse as you approach the top of the cloud layer. .. but hey, what do I know?? … maybe wonderful “things” have happened in the world of ice protection in the past couple of years since I retired from the business (40 odd years in ice protection systems and certification).
Question in my mind is, "How many times has either pilot gotten away with this in the past?" To be so blithe about multiple warnings that they were in serious danger, well, it looks like maybe this wasn't the first time.
I flew a BE-1900 in the Northeast but rarely used the deice systems- it was a fast airplane with big engines so we had the means to avoid areas of icing.
Fly the 1900 in the Prairies and Northern Canada and we definitely use our boots often since we have icing conditions almost all year round. It's amazing how fast we can catch icing, especially when going fast so we have to be always aware. But she's definitely a lot more forgiving and capable in icing conditions vs the ATRs that we also have.
I can imagine the people that recorded the videos on their phones might be traumatized. Witnessing a GA accident is hurrying enough, but watching an ATR fall out of the sky is just different. Prayers to all the families and friends affected by this tragedy. Now let’s learn & get better. 🙏🏼
ATRs once served my home base non-hub primary commercial service airport. On those occasions that I had to fly commericlal to get to a hub, I always, always dreaded having to board the ATR. For this very reason. I cannot fathom why the crew continued this flight without diverting, up, down, or to an alternate. Inexcusable!
The couldn't divert up because the inop PAC restricted them to FL170. ATC told them to maintain FL170, and they didn't realise the seriousness of the situation to call PAN or MAYDAY. Diverting to an alternate probably wouldn't have helped, as it looks like it was a turn that triggered the spin. Not a pilot, just someone who's followed Juan, Mentour, and others for a while, and has an interest in engineering puzzles.
Sounds like they simply didn't realise how critical the situation was. They didn't believe they were in enough danger to justify an emergency descent. Probably thought the worst that could happen is not being able to maintain altitude and that it's not a big deal when you're at 17,000 feet. They didn't realise complete loss of control was even a possibility. [edited for typo - had the word though instead of thought which changed the meaning oops]
And that would indicate a dangerous lack of knowledge and therefore indicate that this would be a more complex story than the failure of two particular pilots. As ATR pilots they HAD to know that their aircraft isn´t able to fly in severe-icing-conditions, especially not with the de-icing-system off for most parts of the flight time.
@@NicolaW72 I agree. Hopefully there will be a deep investigation into this one. It's all very well to say it was pilot error (if that's what the conclusion ends up to be), but the bigger question is why.
One of the scariest flights I've been on was the grey skies flying out of Chicago. Totally grey and I could hear the ice slamming into the cabin on our turbo-prop. Absolutely terrifying, even the flight attendant jumped. I can't imagine why they didn't appreciate the danger but I sure hope they figure it out.
The airframe de-icing line indicates they didn’t turn the boots on from about 15.15 to 16.15 a full hour. That’s a full hour of ice accretion on the front of the aerofoil. That wing would have been so jagged that the laminar airflow would have been disrupted. Don’t forget stall speed increases with the combined weight. The de- icing boot switch needed to be selected every 10 min to break up 10 min worth of ice buildup, though was not selected for a good hour. That’s the main cause to this accident. Regardless of the fault light. If traffic was below then a PAN call needed to be declared, and decent with a vector off the airway was paramount. At no stage the airspeed red bug speed should be reached. We don’t have the voice recorder, though when that speed started going backwards, did the PM call “SPEED”. Did the PF do anything about it. A lot of Swiss cheese holes aligned, that shouldn’t have.
“15:15:42 - a single chime was heard in the cabin. The crew then reported that a Fault message had occurred on the DE-ICING AIRFRAME”. This was 15 minutes into the flight, and the real issues began an hour later. The pilots’ behavior seems consistent with them maybe having a mental picture that the icing *warning* was faulty. They flew for an hour with the ice detector warning repeatedly displaying, then stopping, without taking any action. When the icing conditions developed fully (~16:15) they were dealing with increased workload preparing for approach, which distracted from an issue they may have already mentally dismissed.
Thanks for explaining this Sir, all I can gather is that some folks might have made bad decisions but I hope/pray for all those who lost family/friends, I hope they can find solace in the things they've learned. Again, I thank you for sharing all these reports w/ us. peace & GB ALL
On my aircraft type : recall items for De-Ice fault (first recycle the bleed switch) if it does not reset AIRFRAME ANTI ICE OFF, LEAVE ICING CONDITIONS ASAP. No questions, no debate, you keep the icing symmetric, declare an emergency and descend or route clear. This applies ESPECIALLY with a degraded bleed air system, ESPECIALLY on a turboprop, and more especially on an ATR. Not blaming the crew, this should have been reinforced through training. They should have known never to have been in this type specific vulnerable zone carrying a significant MEL item
It seems like these pilots did not care about the icing warnings one bit. Like they didn't understand how dangerous this is. We'll have to see what else the investigators find out, but so far it looks like pilot error.
That was the impression which I got, too. And if this would be true it would mean that there´s a problem with this airline and not only with this particular two pilots.
Amazing it’s 2024 and we’re still watching ATR‘s ice up. Knowing the ice was at 17,000 and not changing the route or delaying the flight, possibly not using the equipment available amazing it’s 2024 and we have still haven’t learned.
Surely they had training about icing in this aircraft. The fact that their response was limited to turning the de-icing system on and off suggests that they were in a state of denial. They were denying that the deteriorating aircraft performance required major actions in order to avoid disaster .A firmly ingrained habit of following ATC instructions as well as keeping up communications with the airline may have been involved. Sadly, I suspect that if they had informed ATC of their dire situation and need for immediate descent, their request would have been immediately honored.
I should think that with this aircraft's checkered history anyone flying it would be acutely cautious in icing conditions. This just sounds like it was business as usual until they were as good as dead. Astonishing!
Thank you for your informative video. As you say, so many questions still remain. There isn't any amount of money that would convince me to fly with Voepass. RIP to all those lost after that awful spin into the ground.
Severe icing must be respected, true ! Not all turboprops are created equal. My best friend previously flew Dash 8s, as did I. That turboprop handled ice very well, and there was hardly ever residual ice left after de-ice boot activation. The design of the ATR boots does not appear very effective, having vertical bladders. The Dash had them horizontal and the airflow in this case took any ice out effectively. My buddy really dislikes the ATR and says you really have to pay attention, even on a normal approach, as you can look away for a second, and suddenly you've lost speed.
@stephenj4937 well yes, acceptable performance in icing conditions with any aircraft depends on the deice/anti-ice systems working properly. In such a case, the MEL will always say "Avoid Icing Conditions". I've had such situations on the Dash 8 and now also on my current jet type, and company Dispatch takes these limitations into consideration during flight planning. They will even phone us to discuss it.
My house is less than 30km from the crash site. That day the weather was crazy, day before the temperature was about 36°C, falling to 10/15°C in less than 24h. Cenipa has did the report in English too 👏 Sad for the people who's lost their lifes.
Facing such severe icing while being told to maintain altitude, without informing ATC of the situation, is beyond my comprehension. From that, all the holes in the Swiss cheese had aligned perfectly. Sympathies to all the victim's relatives.
Halloween 1994 is a day I will never forget. American Eagle crashed in a cornfield approaching ORD. That crash nearly ended the ATR. We need to see the CRV to get a fuller understanding. Where is it? Thank you Juan.
Wow, so the 2 leading causes of this crash were icing followed in a close second place by pilot complacency. Multiple warnings of the approaching death and they carried on business as usual . Very sad.
An exceptionally well-done report Juan. Thanks so much! It's hard to fathom a reason for the flight crew's apparent casual attitude toward the icing conditions. The final report will be fascinating and I do hope we get to read full transcripts of the CVR.,
The crew may have been led to think the ice was off the wings because the leading edge may have been clean but freezing rain and clear ice can run past the leading edge and make a ridge on top of the wing aft of the boot. That’s what happened to the American Eagle crash. As i remember ATR extended the boot coverage to try fix the problem.
The manual icing detector on the -80 was the cotter pin on the windshield wiper. To continue, I'm watching the departure from controlled flight. For the people watching this and not having any experience flying instruments, to have a airplane depart this abruptly is catastrophic. Experienced instrument pilots would have their hands full to recover from this departure, add to this it's a mult engine aircraft, they were doomed.
Another channel reported that other ATR crews said that they would never have accepted this route from dispatch because of the forecast severe icing at their altitude. There is also some information that the crew never received this weather briefing.
Former ATR pilot here. The plane could handle moderate icing just fine. They redesigned the boots to a vertical (vs horizontal) alternating layout that went waaayyyy back on the wing. Because of this, you could let the system run continuously in icing conditions because there was no chance of ice bridging. We kept a close eye on airspeed and if the speed decreased 10 knots we knew we were picking up ice. We would turn on the boots, add power and monitor airspeed. If we kept adding power or airspeed kept decreasing, we descended. We treated the minimum icing airspeed with great respect. Under no circumstances would we go below that speed no matter what...ATC and traffic below be damned.
or rather ATC and traffic below be informed
@@charlestoast4051 Yes if you are under control. Aviate, navigate, communicate.
Juan mentioned a nose up attitude of only a small angle. Is it possible do you think that the pneumatic valve controlling the boots got the boots stuck inflated, causing even larger buildup of ice, enough to cause a stall at such a relatively small AoA?
Happened to me once on a Jetstream in moderate icing. Didn't stall but certainly lost lift. We came down to below icing at a high rate with a noticeable amount of drag, which reduced after the ice melted.
Landed with the boots still stuck inflated.
Question: Since you are an ATR pilot perhaps you can answer - why do you think the icing warnings fluctuated (cycled on off etc) given severe and active icing? I would imagine, with the static pressures known, on the top and bottom surface of an air foil, and the ram airspeed known, the critical angle can be estimated mathematically? Is that how the AOA warning computed in the ATR in icing? Trying to understand why the warnings were cycling back and forth?
@emdude1784 my understanding as a nonpilot is that the gauge that senses the ice below the wing sticks down and senses the ice building up on it, and then it gets heated up in order to melt the ice and then begins sensing again. So the probe is constantly in a cycle between gathering and measuring the ice building up, and then heating up to clear the ice on it in order to begin sensing again.
I am 80 years old. Over the years I have worked with a lot of people. One of the things that most disturbed me was the lack of true understanding of physics and mechanical things and how fast something can go wrong if you are not paying attention. As you know, most accidents are caused by people making more than one mistake, I have often counted 6 or more in one accident. Keep up the good work you are doing.
I too have made the statement people don’t grasp simple physics. They don’t get simple mechanics of most items or systems they use daily.
And in some cases such as this flight, they turn deadly.
Too many times things become routine. Any heavy object moving rapidly at any height more than head high should not be thought of as routine.
I understand. I'm not 80 years old (yet) but what you wrote is truth..
I had a long career as an airline pilot, never bent any aluminum..
You are correct. Many accidents are the summation of seemingly minor mistakes.
There was a good AOPA video a few years back on “single point failures” and the take home point was there were exceedingly few of them that led to a catastrophic event. Most often is is ignorance of multiple things that individually would not lead to catastrophe, but in culmination, lead to disaster.
*Second that!* Most importantly, people driving cars not realizing what energies they are playing with (downhill; turns; water; sleet; ice) and expecting brakes to always save them.... Energy is proportional to mass times speed squared. I think _most_ people forget x2 the moment they leave school.
It seems to me that the attitude was, "We are about to descend out of icing in a couple of minutes, no big deal."
And they did...
@@HAL9000-su1mzoof
Reading through this Preliminary Report gives the impression that the Pilots were not aware how dangerous the situation had become. That rises the question about their training and what was going on inside of this Airline. It seems to be a more complex story.
Bingo.
And they didnt lose a word about this?
Magnar pointed out (as a training captain on the ATR) that if you get the INCREASE SPEED light that's an emergency and requires you to pitch down to increase speed immediately. Do not ask ATC, do not chat up the flight attendants. Pitch down without delay.
Why did these pilots not do so? What was Voepass training like? Did the pilots get proper ice awareness training? What about stall recovery - which these pilots seem not to have attempted at all. Was Voepass doing recurrent upset recovery training?
It is possible the pilots are entirely at fault, but it's also possible Voepass has been pencil-whipping training and/or their pilot culture encouraged ignoring ice warnings. If the chief pilot or line training captains set a bad example it can filter down to the whole organization.
Indeed. Looking at how scary the Pilot Errors were in this case it seems to indicate that this were not only individual failure´s of this particular two pilots but a bigger problem of the involved airline.
Being an airline pilot in Brazil I must say Passaredo might have a big role in this catastrophic event! That's for sure!
"What about stall recovery". It's practically speaking not possible when the yaw moment starts. Many airlines don't teach recovering. They teach and train avoidance of the problem entirely.
@@dennism8346 I am not a pilot. Just an engineer. My idea of a recovery manoeuver is: Engine on outside of rotation into reverse, inside full speed. That will work against the rotation and give the faster rotating wing less lift. Outside wing ailerons up to force wing down. Inside ailerons down to force that wing up.
My intention is to counteract the yaw movement and to make the aircraft roll to the side. Hoping that it will then, with the help of the rudder, pitch down over the outside wing, gain speed and become controllable again.
Should be tested out in a wind tunnel. And if successful trained.
*We need to hear the **_CVR_*
Yikes. I vividly remember sitting in a window seat of a Dash 8, watching ice accrue on the deicing boots but on the wing. I noticed after the pilots announced they were returning to Toronto airport, shortly after departing for a short local flight. I am pretty sure they declared emergency because we came down through that cloud bank so friggin fast I couldn’t believe it and went straight in for landing, which never happens in Toronto. I knew enough to be relieved when I saw all the ice melt off the boot once we were below the clouds at a pretty low altitude. Glad I didn’t know this then.
Yikes 😬
But the pilots became/were aware and acted accordingly.
Great pilot
And the Dash 8 is known to be much less sensitive to icing than the ATR. And now imagine: This Pilots of Voepass stayed in such conditions with an ATR, not a Dash 8, for more than an hour, literally without doing anything, including informing ATC.
@@NicolaW72 dumbass pilots.
I flew cloud seeding in a king air when I was a snot nosed 300 hour pilot. In my experience the worst icing is near the tops (where the Super Cooled Large Droplets) hang out and at a temperature of -5 to -8c.
I’ve been literally knocked out of the sky by ice. We were in a turn and encountered severe ice. I distinctly remember the captain working the props back and forth to knock off the ice and shoving the nose over to maintain 140, the minimum icing speed. We ended up descending at 800fpm, at max torque (I can’t remember the setting). ATC lost radar contact with us and I was using ForeFlight to vector him to lower terrain. We reached the freezing level and cleared the terrain by 1,500 feet. We were lucky. These guys weren’t.
Man, you took a big handful of coins out of your "Luck Bag", and put them into your "Experience Bag" that time. Good thing your Luck Bag wasn't empty!
The very first ATR (a 42, north of Bergamo, near lake Como/Italy) that crashed had a fellow KingAir pilot flying the same track before them. That guy (I knew him personally, very experienced guy, since passed away) turned around and landed back in Bergamo because he hadn´t seen that much ice ever before and could not maintain altitude in his empty E90 at full power. The KingAirs can carry a ton of ice. (don´t ask me how I know) That was in 1987 (!) and the circumstances are very much the same than in the Voepass case: they knew about Icing and they flew way to slow, 17 kts below minimum icing and ignored degrading performance AND stall warnings (5) until they stalled and crashed.
So you're one of them idiot weather manipulators!!
@@svytI haven’t heard that expression before but I love it.
WTH? Cloud seeding? What exactly were you putting into the atmosphere, if I may ask?
I kind of get the feeling the pilots had previous experiences or encounters with icing conditions and probably got complacent since they could push the envelope before and got away with it. This time the icing and other factors were not as forgiving.
They were already so close to stalling that initiating that turn was the final factor. Juan masterfully showed and explained it all.
It's gut wrenching to watch.
RIP all.
Yes, agreed. Normalisation of deviance is the term that sprang to my mind as I watched the video
@@gryff8400 Absolutely.
@@gryff8400 "Normalization of deviance" is the perfect phrasing. (I was hoping someone with more knowledge could state it more concisely.) Thank you.
The "Deviation Spiral" is a well know phenomenen that occurs in all walks of modern life.
why would anyone push the envelope with icing? Go ahead and push the envelope if you must if you're flying alone, but not when you're carrying 60+ passengers!
The fo with thousands of hours of experience had without a doubt encountered icing before many times. He had seen all the warning lights and learned to ignore them. He had made several mistakes before but luck had saved him. This time his luck ran out, he made one mistake too many. I see this all the time, it’s how experienced people get hurt.
Yes, very true…. I would therefore ask the question of how the less experienced pilot survives in the first place. The answer is training, sop, and procedures. When we get experience and push our way into complacency, things get dangerous. I just changed airplanes to the 787. And it’s shocking to realize how comfortable I was on my OLD airplane. Thus making me wonder how complacent I was without realizing it.
Perhaps one of those situations where the "junior" first officer didnt want to override/chide/alert the "senior" captain , even though the FO had 1000's of hours experience, compared to the Captains few 100 hours. The classic authority/power imbalance. ( think asian/.middle eastern cultures) where FO doesnt speak up.
Or is it a latin male culture of "machismo" who wont be told they are wrong?? ;(
The guy narrating in portuguese says: “At this moment, São Paulo control authorizes him to fly directly to the position SANPA, and he starts the turn to the right. The increase speed is activated at 169 knots, from there you can hear noise and vibration from the aircraft, with maximum inclination of 32 degrees. The turn is reverted, stall alarm activates, until 52 degrees to the left, and after that a small increase in altitude. And 94 degrees in a turn to the right, into spin. After that the aircraft stabilizes in vertical fall, and gets into a flat spin to the left, five degrees until colliding with the ground.“
Btw, he sounds like he's talking to someone, and not doing a planned speech....
Thank you! Very valuable to have multilingual people down here in cases like this. 👍
Thank you very much for the translation!
thank you!
Tells me they tried to recover the altitude instead of the stall, which killed all hope to regain control.
@@cruisemissle87 Indeed - and that would mean: lack of basic knowledge. What would raise the question: Why?
Doing approach briefing while getting warnings that had to be dealt with immediate actions. Those pilots seemed to have no idea of what critical situation they were in.
I feel like they must have been thinking they were getting faulty ice detection warnings, and then when the first officer realized they were getting actual ice accumulating they did too little too late.
My theory is that they have successfully flown in situations like this before and gotten away with it and grown complacent.
"It worked just fine the last time, no big deal."
@@JariJuslinyep, this has all the hallmarks of normalisation of deviance.
Indeed, exactly. And that indicates to me - to repeat this - that it wasn´t "only" the failure of these particular two pilots but that it is a more complex story.
I’d like to know if they put incompetent people in there on purpose, weaponizing the crew. 6 world renown doctors were on that flight, on their way to a conference where they were going to present their peer reviewed scientific evidence regarding how the poke was increasing illnesses and “♋️“
Convenient how they just - fell out of the sky, on their way there!
They had no idea how dangerous their situation was. I don’t care what you fly, you don’t stay in moderate to severe icing. If ATC doesn’t give you what you need, declare an emergency and start a descent!
Or start a descent and then declare your emergency.
Juan taught us to Aviate, Navigate, and Communicate of course.
@@wadepatton2433 Indeed.
You need to remove “moderate to severe” from your comment.
@@mattcommons5033 The ATR with functioning De-icing equipment is perfectly fine to fly in light to moderate icing. This crew had a non-functioning de-icing system (that was off for most of the flight anyways) and ignored all evidence that significant ice was building up on their aircraft.
Sounds like they got away with this for a while, maybe flying separately; then they met up
Juan your dedication to this channel and the aviation community is inspiring and commendable.
Amen. Great to see great brain aviators like Juan in action. So knowledgeable from C-152 to 777. Flying is flying.
This route presents such routine icing conditions the pilots simply get used to the warnings. They know they are riding the edge of the envelope, but with every successful flight, their complacency grows.
Correct.
You cannot be unaware in situations as urgency of descisive action has to take place without delay.
In this instance their complacency expired.
In this case it seems more that they didn´t know that they were riding the edge of the envelope. More than that: They seemed to be completely unaware of the danger - and that would raise the question: why?
Sorry, but there are no excuses for this scenario with the ATR. Nor any other aircraft. Icing is a very basic problem and part of flight awareness from basic training. For an ATR to result in a flat spin due to icing is a result of poor piloting, planning and communication. Fly the plane. Don't sit back in your white shirt admiring your log book and watch icing build up on autopilot when the weather briefing told you it was there. Demand lower altitude. ATC is a service to ensure safety and nothing to be feared. Get out of icing conditions even without approval. Fly the plane. Descend. Aviate, navigate then communicate.
No excuses at all if icing is the cause. Such a fall for those poor passengers. Horrific. Fly the plane.
I hope the NTSB is watching...what a timely and comprehensive preliminary report.
They'll update their standards in 10 years
@@blackmusik109 They'll need a 15-year study before that, though
Pretty sure the NTSB can't even *spell* 'comprehensive' at this point.
I recall many, many years ago when I was a young CFI with the owner of an airplane...I think it was a Grumman Tiger? We were IFR and I saw ice accumulate. I immediately asked ATC for a lower altitude and we deviated out of icing conditions.
Be proactive. That's why I'm able to post this message today.
Yeah, ... changing your aircrafts aero dynamic shape unwittingly by ice crusting formation without realising the urgency, otherwise kiss goodbye to your life, on a downer all the way to oblivion.
Inaction or inappropriate actions lead to a lot of preventable crashes.
The recreation video made me sick. Watched the aircraft falling from the sky videos 100’s of times but seeing what it looked like when they 1st lost control…. Chills. Must’ve been absolutely terrifying for everyone on that aircraft. So so sad. Thanks for breaking it down for us. Great video!
@@chrispbacon550 yeah not pretty
I can't even begin to fathom how horrifying it must have been.
Exactly my thoughts.
I think only the crew would have been fully aware of their situation until the last few moments. They were inside thick cloud, so a complete white out.
@@fredfred2363 No. Thick cloud or not, the passengers would have FELT something was seriously wrong when they were rolling over 90 DEGREES (17:07) or headed STRAIGHT DOWN (17:19). Anything loose in the cabin (drinks, magazines, people, etc) would not have just stayed put.
Juan, the gas path deicer is in the air path inside the cowling that deices the airflow just before it turns up into the air intake
I have been a captain on the ATR 42. Similar, just a bit smaller.
Our area of operations, Ireland and the UK, often had icing conditions.
In such a case ALL anti - and de-icing systems would be selected ON.
The leading edge boots would be cycling continuously.
I never had any problems.
I have all sympathy for the unfortunate crew and passengers that perished in this accident
Why wouldn’t that “constant on of anti-ice” be promulgated worldwide amongst operators?
There are situations where that's not enough
From what you say, I suppose that cont. de-icing selected ON is the norm in the ATR when once the icing indications are triggered. The fact that de-icing was activated only intermittently, and turned off in conjunction with the chimes / fault warnings, tells me that it was likely inoperative. DEGRADED PERF up to INCREASE SPEED was a clear indication for ice accumulating and a hazardous situation occurring. Last but not least, they, as a crew, were completely inept to handle an impending stall / high AOA. Push of yoke, max cont thrust, setting flaps was the last hope. Instead, they banked the plane. Tells me they were completely dismissive of the aerodynamic conditions and what was mandated within the situation.
From the initial fault of the de-icing system all rules we not followed. It appears the de-icing never was working. They were in icing conditions nearly from the beginning of flight. Look out the window at the visual icing indicator. 17,000 ft was maintained, no mention of icing from anybody with weather indicating icing all around them A visual observation was needed. The pilots had enough experience to do this but were chatting with control and NOT FLIGHING THE AIRPLANE. Pay attention and look around. Look at the radar, look at the indication. Pay attention to the icing fault from the beginning of flight and subsequent warnings. The pilots killed themselves and all the passengers through pure total negligence and failure to fly the plane. Thanks Juan, very good info and observations. Those planes are hard as hell to fly on a good day. There is no room for error.
Thanks for the breakdown! The CMD had an all Airbus A320 career as FO (Avianca, Midlle East as far as I remember from his linkedin profile) he only recently upgraded to CMD on ATR.
I have 12000 hours on A320,330,340 and B777. I would be supercareful and cautious when changing to ATR and becoming CMD same time. There is a lot of responsebility both for the pilot and the company. I wonder if this will find its way to the final report. I guess it will.
Juan, you are the GOAT of aircraft accident analysis - a critical asset to all GA pilots. Keep up the excellent job.
He cuts to the chase and doesn't clutter up the channel with unnecessary BS like Dan sometimes does.
Why are you insulting the guy?
greatest of all time
@@thomasward4505 yeah I knew. Just wanted to play ignorant
Just a few hours ago, Fly with Magnar uploaded a video where he, an ATR captain, explains the anti-icing and deicing systems in great detail.
Magnar is rather dry and boring. I would have gotten as much out of the report by reading it myself as I got from his video.
@@BlueSpruce2 You seem to value more the "style" above from the substance...
As a pilot and engineer, I find Magnar and his videos truly professional and "In-Depth"... Sorry for you if you find him "boring"!...
@@alfredomarquez9777 Well that's my opinion. I happen to be an engineer as well, but I like to see practical or technical information presented with context. As a pilot I guess you would understand the data without the context and this is why I prefer guys like Petter Hornfeldt, Juan Browne and Chris Brady. You could say they bring style AND substance to their presentation. Cheers!
Many years ago a friend told me about a job interview he was on for a job he didn’t get. When asked why his IMC time was so low in relation to the amount of total time he had, which was substantial, he said, I don’t know who you’ve been interviewing, but I try to avoid IMC because there’s a lot of bad stuff in it like turbulence, icing, and imbedded thunderstorms. Mike was a turboprop guy with 10k plus hours at the time of the interview. IMC means instrument meteorological conditions.
I'm guessing your friend is glad he didn't get that job.
This is a right-thinking pilot. I would trust him completely.
IMC time should be roughly 10% of total time. And yeah, I’m not going IMC if I can avoid it. (Also a turboprop guy)
?
It depends, a lot, on where you’re flying out of.
Also: anything over 18,000’ is IMC.
It hurts so bad when the people that are supposed to know what to do ......don't.....and cost innocent lives. This saddens my heart.
Sadly, this is prevalent in many professions. I am a retired firefighter and you would be surprised at how many of us don't pay attention during training.
Another excellent post accident report as usual.
I flew the ATR-42 out of Newark and Manchester, NH in 1992-1994. Flew out to Syracuse, Buffalo and Cleveland during winter. Great aircraft. Just had to respect the envelope. All the icing accidents in. ATRs are due to pilot error, as far as I know.
The level of complacency with these two Brazilian pilots is hard to fathom
I lost 2 engine anti ice systems on 747-400F, while holding at Hong Kong once. I told the F/O to tell approach that unless they descend us and put us on approach, we’re diverting to Taipei. They brought us in.
Would you consider Roselawn - American Eagle 4184 pilot error?
@@jeffhurckes190 The point is: We know how dangerous icing is and especially about the vulnerability of ATRs to icing because Greg Feith and his team did such an outstanding investigation of the Roselawn Disaster. Orlando Aguilar and Jeff Gagliano were the unfortunate and unvoluntary test pilots who payed the price for our knowledge. But the Roselawn Disaster is now 30 years ago. ATR pilots in the year 2024 HAVE to know about icing and how it effects their aircraft.
1) Insufficient training
and/or
2) Normalization of deviation
Maybe both of it.
In the end it was complacency and not chaos in the cockpit. The autopilot left on was the icing on the cake. Once the stall happened the autopilot was turned off when it should have been turned off much earlier in these icing conditions. So many crashes linked to autopilot being on when the aircraft needs to be flown the hard way.
Years ago my CFI (chief flight instructor) told me a story how they stalled in icing in a holding pattern in Melbourne Australia. That was in SAAB 340. Similar aircraft. But thankfully they recovered from the stall....
Son flew the 340 in north-central USA. He has several very scary ice stories.
@@shooter2055All Turboprops lack a truly powerful heating system for anti-ice (like most jets)... and their old and unrefined inflatable "boot" deicing is still crude, as it CANNOT break and throw away any ice accretion BEHIND the chordwise location where the boots end...
In the ATR, it seems that after the fatal accidents it had years ago, the factory enlarged the Wing boots, but the horizontal stab still looks as if the stab boots still are diminute in chordwise lenght...
@@alfredomarquez9777 And a jet with heated leading edges will not shed ice behind them either. No transport airplane that I am aware of has every surface protected from ice. Normally, ice will only build up on the leading edges.
mayday mayday mayday
voepass 8203
position xy, FL17
in icing conditions with deicing equipment fault
descending immediately
- that would have been the right call
Yes, indeed - and it should have been done long before the control of the aircraft was lost because they had multiple warnings for round about an hour before the crash.
Inexplicable. That minimum stall speed was chasing them like a gremlin
Not much icing experience in my PC 12 but one time (ironically at 17,000 feet) returning up the California coast in the winter we started accreting ice faster than the 1 minute boot cycle could clear it. After two cycles my IAS had dropped from 200 to about 185ish with no power change. Disconnected AP and trimmed down aggressively (no mountains below) and informed ATC we were descending due to severe ice. They were pretty good about it and we didn’t have to declare an emergency. Exited icing conditions at about 12,000 feet and continued the flight. It can build up very quickly.
Wow, that's FAST 😮
Thank you very much for this enlightening debrief of the Preliminary Report of this horrible crash! I confess I waited for it.
The Pilot Errors are disturbing in this case and seems to indicate that there could be a deeper problem at this Airline. They had about an hour time to save the flight and did literally nothing until they fall out of the sky. That is really scary.
I remember my most vivid example of severe icing. C-130s have a hot bleed air system for the wings, tail and engine inlets, however it does not deice the wing sections inboard of the inboard engines. When this airplane came in, there was at least 6 inches of ice built up on the leading edge of the inboard wings. Yeesh...
Wow. Good thing it doesn't need any lift out of that part of the wing because it sure wasn't getting any.
Ah, a C-130. That explains it. Those things could fly severely overweight, probably up to 190,000 lbs, as long as you kept them flying and had all 4 engines.
One hour and Six minutes between Icing Fault light and losing control. First line of QRH for this say “ICING - LEAVE AND AVOID”. What were they doing? If they’d got the QRH out and acted on it, they’d all be alive now.
Indeed, exactly.
All of them, in 🇧🇷?
Inappropriate responses to an ongoing situation, that is what caused the ensuing crash.
Essentially comes down to pilot era.
@@BegudMaximan-zp2tc What is "pilot era"...?
@@UserName-jm8yw pilot error (blame autocorrect)
JB "Gas path deicing" heats the engine inlets so ice is not injested into the engine. There may be inertial separation (a flap in the engine inlet) as well.
YT actually recommended a good one. Magnar Nordal' channel "Fly with Magnar" has instructor-style detailed breakdown by a Brazillian ATR instructor. Likely overkill, but nice detailed adjunct to Juan's excellent vid.
I'm no pilot, but now it is my "understanding" that the de-icing features of any turbo-prop aircraft are there to assist in recognizing and then GETTING OUT OF icing conditions, rather than for sustained flight in icing conditions. Thanks JB.
No, the ATR can sustain flight in mild to moderate icing IF the de-icing equipment is functional. On this aircraft it wasn't functioning and was turned off.
@@stephenj4937 If I were a pilot flying the ATR or similar, I'd still not care to fly in icing conditions for any longer than absolutely necessary with all systems operational. Sustained flight in mild to moderate icing is not something that my sense of self-preservation would be comfortable with. Errors is icing evaluation or deicing systems functionality have too much potential to make things ugly fast. Humans are imperfect and make errors, avoiding icing at every opportunity might be my error, but I don't see it that way.
That was a full plane. It had to be horrifying looking out the window before it crashed. My best wishes go out to the families of the deceased.
@@Br549-x3b I’m sure the shock of what was happening also played a factor. I used to fly this exact aircraft in the Country of Chad. We made flights from the capital N'Djamena down to Coma base 5. It was a dirt runway and getting there took about an hour in the air. I remember once when we lost hydraulic pressure and you ended up flying what felt like a brick in the sky. We turned around half way there because there was no way to make repairs at the dirt strip. It could have turned into a really bad day if we lost an engine or something.
While I am not a pilot, I greatly appreciate Juan’s insights and real world context given my engineering and physics background. Every one of his reports are excellent.
At 13:12 - “airframe de-icing turned off!” - reference 13:00 - the first checklist item (well, beyond leaving known-icing conditions) IS to shut off the airframe de-icing.
Also explains the short activation period on the graph - they followed ECAM and shut it off when it faulted after they turned it on I guess.
That was just an observation about procedures though - regardless, this crew had all day (and a million warnings) to react, but failed to. 😕
Also, I’m confused about ATC having “no clue” about the icing; wouldn’t they be aware of the SIGMET?
The spin entry was the most incredible part of this report - many of my friends and I were curious exactly how this happened. The animation makes it a bit more clear. They were a few knots from stalling wings-level, but that’s right when they initiated their turn. With one wing stalled and subsequent roll, the recovery was impossible but also induced the spin.
ATC was aware of icing conditions (SIGMET warning was there). At least one other flight reported that. The point is that they were not aware of issues with this Voepass flight, because they never declared an emergency.
They also seem to have overcorrected in roll after the initial stall. I wonder if that what was sealed their fate? Once the aircraft started moving that erratically at low speed, a spin was inevitable 😕
@Antonio-lt1sp And if they switched the anti-icing system off due to fault alarm, they might actually have been unaware of just how bad conditions were.
The flight crew appear to have suffered from a logical fallacy, believing that because they had the anti-icing switched OFF there was no longer a risk of icing. Because if they were in icing conditions then *obviously* they'd have left it ON.
I wonder if one of the more experienced copilot was irritated by the alarm and switched the system off without verbalising his reasoning, and the PIC just assumed the copilot knew better and trusted what they were doing?
Never flew the ATR, but plenty of time in a Q400 dash 8. The dash didn’t have any issue in mod icing. But you still needed to be careful. Increase speed, turn on boots, and move props to 1020 rpm. If speed is decayed past 10 kts decrease altitude to maintain a safe airspeed and to warmer weather.
Great report, thank you. Very interesting tragically.
I'm flying with a captain, whose name happens to be Juan, who is also a big fan of yours. I told him that I met you on that commute down to LA a few weeks ago and showed him the picture.
In my experience, if you start getting ice do something immediately to get out of it. Don't sit in the ice because that's your clearance. Pilot in command stuff. Atc is not your enemy, if you TELL them about the ice they will clear you out of it, also, if you're getting ice at that altitude so is every other aircraft, so you're helping everyone else, pilots and atc.
Indeed.
Good controllers will, some flim flam with your predicament. I told em after asking once and no reply, Im deviating downward. Bless mart good controllers.
Great job as always, Juan. Man, flying into known icing conditions, with every warning indicator on the plane going off, and yet no sense of urgency by the pilots. Were these warnings so commonplace they almost ignored them? That CVR must be gut wrenching to listen to.
They weren't flying, they were on autopilot.
My guess is that they flew this route many times before under incing conditions with warnings and never lost control. This gave them deadly confidence.
When this happened there was a lot of discussion online about the ATR being sensitive, almost dangerous if icing occured. This aircraft had all the warning systems though, and the recorder shows us they worked, repeatedly. Yet this ATR was doing everything it could to warn them about the ice, and even telling them to speed up and leave.
Perhaps the PICs new training somehow omitted the biggest single risk to the aircraft type (because Brazil is "always" hot?!), but the SIC with thousands of hours ought to have been ready & aware. Perhaps some kind of attitude problem from the new captain? Didn't welcome advice? Usually that happens when the SIC is the novice.
The single Pack put them right in the cold weather with a 17,000 max altitude. Perhaps they were too used to cruising above the weather, and never really hitting the ice.
So sad.
@@StanfordJohnseyI thought they came off or were kicked out of autopilot just before or after initiating that right turn that started the sequence leading to the flat spin. I could be wrong.
It makes me question the kind of training these pilots had? And the company culture? Why else ignore every single warning as if nothing is wrong?
The only explanation I can think of is that these ice warnings happen so frequently in previous flights that the crew is desensitized to it. They didn’t take it seriously because it wasn’t a problem before.
Maybe there’s another explanation but I don’t see it yet.
One would hope that any ATR pilot would be very sensitive to icing-related systems and warnings in the same way they should be sensitive to the condition levers being moved to the Feather position.
@@BrianMorrison sadly, there are some really stupid people who can sit in those seats. I’ve met quite a few. The industry doesn’t do a very good job of policing itself.
My personal impression is that the pilots likely due to familiarity with operating in this altitude and humidity were complacent to being in icing conditions and had overconfidence in their ability to fly the plane in icing conditions. I think they failled to appreciate the situation that they were in, I'm not sure why given the weather warnings etc and act appropriately/urgently on the information they were given from the warning systems that he aircraft was building up increasing ice, did they think they were errors and the icing system and detections were malfuctioning? One confounding factor is that there are 3 different procedures referenced from the 3 different warning lights - were the crew overloaded by trying to follow 3 checklists at once? I think this is unlikely - it sounds like they just didn't appreciate what was going on but still....
Looking at what the aircraft did when it stalled it does seem that they might have been able to recover it (wiht he nose going down) if they'd gone immediately stick forwards before a full spin developed.
De-Ice and Anti-Ice systems are designed to allow the crew to immediately leave the icing conditions.
The Captain and F/O both had around 5,000 hours. I remember when this was the absolute minimum required to even get an interview at an airline.
@@a300guy Do we need yellow post it notes on the panel to remind overconfident pilots of this real risk that kills innocent people?
Geeze, Juan. I've never flown the ATR-72, but now I know more. It's like a Ground School discussion. Good job!
That little icing check wing is so interesting. Very practical it would seem.
Very practical if you actually look at it.
We stalled an HS748 in icing back in the day. Wing dropped and down we went. It had a fat ol’ wing so eventually it flew out ok. Back then the boots were a bit different and were operated as de-icers. I think they had a tendency to accumulate ice on the belly which might’ve been what caught us out.
really excellent report - it's the background and Juan's ability to give context which make these type of videos invaluable
Brazils CENIPA did an outstanding job. My country in no way lets down in civil aviation safety culture. Rip to all the souls who perished.
@@chavijr9020 qual a graça bozo?
I hope they investigate Voepass’s training and safety culture in depth
I was surprised at such a comprehensive preliminary report. Seems impressive
14:11 That single chime was likely a fault on the airframe de-icing system. They kept turning the airframe de-icing off because it would fault a within a couple minutes of being turned on. The airframe de-icing system works on a timed cycle to inflate various boots at different times. There is a sensor that detects if the pressure in the boot air circuit is not correct for the phase of the inflation cycles and if so, the MFC would activate the fault light. The ground test for the de-icing system takes about 20 minutes because that's how long it takes to go through the cycle a couple times.
The visual ice indicator is only visible from the captain's seat. I refer to it as "The Captain's Icemaker".
Training and company culture must be investigated.
The concept of complacency, or the normalization of deviation, comes to mind
@mariopinho6549
It was the company's first accident with victims in 29 years.
Which company has the best rate?
Foi o primeiro acidente com vitimas da companhia em 29 anos.
Qual companhia tem índice melhor ?
@@wallacemjrSo what? That might be just luck it didn't happen before!
Indeed. No mentally sane Pilot would make such scary mistakes voluntarily if he knows the danger. So it looks like a more complex story and not only like the individual failure of two particular pilots.
@@wallacemjr the difference between the company with the best record, and the one with the worst is often 1 bad day. Well except for that one airline that keeps sucking ramp workers into the engines one at a time.
Great reporting on this.
30 to 35 years ago I spent 5 years studying aircraft ground de icing. At the time the automated ice detectors didn't reliably detect icing conditions. We found some areas would retain ice while others areas were ice free. We did determine that holdover times were way to optimistic and ice wasn't being given the respect it deserved. I thought that attitude changed decades ago when we had these inflight icing accidents such as Roselawn.
I once flew in severe icing for about 12 minutes in Kansas. I tested the accumulation during a single take off and return in the pattern. I picked up a half inch of clear ice. This stuff is nothing to get lazy with!!
native portuguese here
.. beside the writen report and the graphics , i heard the intense verbal PRELIMINARY briefing by the BR investigators.
so, besides the inatitude of the pilots since the first de icing airframe fault ,, (i believe they trused to much in their experience) .. if , if , if,,,, they had started the descend acording flight plan i think they would be alive,,, bu,, but,, but,, they were delayed by ATC on starting the normal descend for maybe 40 miles because not 1 but 2 airplanes under,,,,, plus,, somecoinciding with calls to dispatcher and flight atendent in cockpit about issues with needs of 1 passenger on arrival,,,, plus,,, the last atc waypoint to the right ... .....Very sad sittuation as usual,,, bless them and families
Sounds like it wasn't ATC's fault. The pilots didn't alert them to the icing. They didn't seem to have a care in the world.
If the traffic had been less and plane was allowed to descend, all lives might have ben saved without anyone knowing. The complacency of both pilots including the SIC who had thousands of flying hours in this aircraft type, flying in icy conditions must now surely be the focus of the investigation. One can only wonder how many times they have been so complacent in icy conditions and got away with it. Juan, thank you for all the time you must have spent preparing this very exacting video.
The plane would have surely been allowed to descend if the pilots made ATC aware of the icing situation. ATC can't act on what they don't know.
@@christianpetersen1782 You cannot be telling us there was no way of allowing that aircraft below regardless of traffic below.
@@ThomasS-jf9kf Indeed, exactly.
Juan - your explanation which puts everything into context is the best. I watched another video from a Swedish bloke (Magnar Nordal) who is also an ATR instructor and got next to nothing from it. Because these pilots were not hand flying the aircraft they did not realize the degradation of the aircraft performance until it was too late when they went off the autopilot. It looks like they needed to descend to a lower altitude and warmer temps immediately after getting the airframe deicing fault warning. As you point out - you don't mess around in these skinny winged turboprop powered ATRs in icing conditions. They could say the plane was brought down by severe icing but it appears to me that pilot negligence with a good dash of complacency is the root cause of this avoidable accident.
I thought Magnar did a wonderful job, as of course did Juan. Magnar goes more into the deep technical details, which may or may not be what one wants to watch, but Magnar's ATR specific knowledge and experience gives him some exceptional insight into that particular aircraft. Of course, when watching him I feel like I should be taking notes in order to pass the final exam :)
I was told by a friend, this is not the first time they flew like this. That the de-icing was faulty on the A/C and the crew flew anyway. She was a former FA with the company and told me she had flown with the captain before. And spoke to a pilot currently with the company. Of course this is here say but she told me this right after it happened and its making sense now.
Those holes in the Swiss cheese aligned up real fast
Only seen severe once, going into Zurich (28) one night. AP OFF, Speed up and continue. WE landed OK but never seen ice like it. We were in an AVRO RJ-100.
A second after increase speed warning came on, it looks like the pilots pushed the thrust lever to the max, as the n1 quickly started rising and hit 100%. But it was too late.
Valuable lessons learned.
I AM an Electronic Engineer and I flew aircrafts.
We respect both knowledges for a safe sortie.
Condolences to their families.
****I think a HUGE aspect of this that's being overlooked is the fact that the CA had about 500 hours time on this a/c and just came from jet aircraft prior, where he's NOT used to ever spending cruise altitudes sitting directly in clouds and icing weather, and is used to normally punching through down or up out of it above or below, and didn't truly grasp the dangers of icing on his a/c at that altitude/speed/etc. this definitely is thus correlated to insufficient training to highlight this to him, if he was so blissfully unaware and blase about this OBVIOUSLY fatal circumstance developing around him SO CLEARLY.***
I note that in the simulation, it shows a TAT of between -2 to -3. I assume this to be in deg C ??
At this order of TAT, any ice will be slow to freeze and can run back on the upper wing surfaces behind the extent of the protected leading edge chord wrap. In the event of SLD conditions this will be exacerbated. In the case of high LWC (more likely at “warmer” icing conditions) this same effect will also be exacerbated. Such conditions are, typically, the most hazardous to turboprop aircraft that typically rely on pneumatic De ice systems. A run back ridge on the upper surface behind the extent of the Deice boots then, obviously, makes the wing incredibly sensitive to the flow tripping … and can be very dangerous if it trips the flow over control surfaces (the Roselawn incident being the classic example).
Just to make things more exciting, a lot of accretary type ice detectors struggle to reliably respond to these same SLD or high LWC/near 0C ice conditions as the freezing water on the probe sheds before it has chance to actually freeze and so build. The best indicator to this type of ice threat will be the an accretion probe visible from the cockpit (which your presentation indicates is now installed to the ATR) or formation of slushy ice on side windows (I’m not very familiar with the ATR cockpit glazing).
Protection from SLD conditions remains (to my knowledge) one of early recognition of the condition and immediate vacation … usually by descent … if you climb you might get above it, but it’s likely the severity will be worse as you approach the top of the cloud layer. .. but hey, what do I know?? … maybe wonderful “things” have happened in the world of ice protection in the past couple of years since I retired from the business (40 odd years in ice protection systems and certification).
Question in my mind is, "How many times has either pilot gotten away with this in the past?" To be so blithe about multiple warnings that they were in serious danger, well, it looks like maybe this wasn't the first time.
I flew a BE-1900 in the Northeast but rarely used the deice systems- it was a fast airplane with big engines so we had the means to avoid areas of icing.
Fly the 1900 in the Prairies and Northern Canada and we definitely use our boots often since we have icing conditions almost all year round. It's amazing how fast we can catch icing, especially when going fast so we have to be always aware. But she's definitely a lot more forgiving and capable in icing conditions vs the ATRs that we also have.
I can imagine the people that recorded the videos on their phones might be traumatized. Witnessing a GA accident is hurrying enough, but watching an ATR fall out of the sky is just different. Prayers to all the families and friends affected by this tragedy. Now let’s learn & get better. 🙏🏼
Oh my! That plane was full of passengers and most of them would have had phones, some of which may have survived the fire.
ATRs once served my home base non-hub primary commercial service airport. On those occasions that I had to fly commericlal to get to a hub, I always, always dreaded having to board the ATR. For this very reason. I cannot fathom why the crew continued this flight without diverting, up, down, or to an alternate. Inexcusable!
The couldn't divert up because the inop PAC restricted them to FL170. ATC told them to maintain FL170, and they didn't realise the seriousness of the situation to call PAN or MAYDAY.
Diverting to an alternate probably wouldn't have helped, as it looks like it was a turn that triggered the spin.
Not a pilot, just someone who's followed Juan, Mentour, and others for a while, and has an interest in engineering puzzles.
@@alexandermonro6768the turn caused the stall as they were already below their minimum (icing) air speed
Sounds like they simply didn't realise how critical the situation was. They didn't believe they were in enough danger to justify an emergency descent. Probably thought the worst that could happen is not being able to maintain altitude and that it's not a big deal when you're at 17,000 feet. They didn't realise complete loss of control was even a possibility. [edited for typo - had the word though instead of thought which changed the meaning oops]
And that would indicate a dangerous lack of knowledge and therefore indicate that this would be a more complex story than the failure of two particular pilots. As ATR pilots they HAD to know that their aircraft isn´t able to fly in severe-icing-conditions, especially not with the de-icing-system off for most parts of the flight time.
@@NicolaW72 I agree. Hopefully there will be a deep investigation into this one. It's all very well to say it was pilot error (if that's what the conclusion ends up to be), but the bigger question is why.
@@brandyballoon Exactly. No mental sane pilot would do such mistakes if he knew better. So hopefully there will be a deep investigation.
Once again Blanco lirio on point with the report. News from people that know and understand aviation, you must listen to.
Thanks Juan.
One of the scariest flights I've been on was the grey skies flying out of Chicago. Totally grey and I could hear the ice slamming into the cabin on our turbo-prop. Absolutely terrifying, even the flight attendant jumped. I can't imagine why they didn't appreciate the danger but I sure hope they figure it out.
The airframe de-icing line indicates they didn’t turn the boots on from about 15.15 to 16.15 a full hour. That’s a full hour of ice accretion on the front of the aerofoil. That wing would have been so jagged that the laminar airflow would have been disrupted. Don’t forget stall speed increases with the combined weight. The de- icing boot switch needed to be selected every 10 min to break up 10 min worth of ice buildup, though was not selected for a good hour. That’s the main cause to this accident. Regardless of the fault light.
If traffic was below then a PAN call needed to be declared, and decent with a vector off the airway was paramount. At no stage the airspeed red bug speed should be reached. We don’t have the voice recorder, though when that speed started going backwards, did the PM call “SPEED”. Did the PF do anything about it. A lot of Swiss cheese holes aligned, that shouldn’t have.
“15:15:42 - a single chime was heard in the cabin. The crew then reported that a Fault message had occurred on the DE-ICING AIRFRAME”. This was 15 minutes into the flight, and the real issues began an hour later. The pilots’ behavior seems consistent with them maybe having a mental picture that the icing *warning* was faulty. They flew for an hour with the ice detector warning repeatedly displaying, then stopping, without taking any action. When the icing conditions developed fully (~16:15) they were dealing with increased workload preparing for approach, which distracted from an issue they may have already mentally dismissed.
in light of the weather warnings it's incomprehensible how they could think that.
Thanks for explaining this Sir, all I can gather is that some folks might have made bad decisions but I hope/pray for all those who
lost family/friends, I hope they can find solace in the things they've learned. Again, I thank you for sharing all these reports w/ us.
peace & GB ALL
On my aircraft type : recall items for De-Ice fault (first recycle the bleed switch) if it does not reset AIRFRAME ANTI ICE OFF, LEAVE ICING CONDITIONS ASAP.
No questions, no debate, you keep the icing symmetric, declare an emergency and descend or route clear.
This applies ESPECIALLY with a degraded bleed air system, ESPECIALLY on a turboprop, and more especially on an ATR.
Not blaming the crew, this should have been reinforced through training.
They should have known never to have been in this type specific vulnerable zone carrying a significant MEL item
It seems like these pilots did not care about the icing warnings one bit. Like they didn't understand how dangerous this is. We'll have to see what else the investigators find out, but so far it looks like pilot error.
That was the impression which I got, too. And if this would be true it would mean that there´s a problem with this airline and not only with this particular two pilots.
Complacency! They have probably encountered icing several times, and all was well. Not this time!!
Amazing it’s 2024 and we’re still watching ATR‘s ice up. Knowing the ice was at 17,000 and not changing the route or delaying the flight, possibly not using the equipment available amazing it’s 2024 and we have still haven’t learned.
A lot of people have learned; but evidently, not all.
@@2ndfloorsongs Indeed.
That was my reaction. I've never flown fixed wing but even I had heard about knife-edge icing in ATR and similar turboprops. It's very brutal stuff.
Surely they had training about icing in this aircraft. The fact that their response was limited to turning the de-icing system on and off suggests that they were in a state of denial. They were denying that the deteriorating aircraft performance required major actions in order to avoid disaster .A firmly ingrained habit of following ATC instructions as well as keeping up communications with the airline may have been involved. Sadly, I suspect that if they had informed ATC of their dire situation and need for immediate descent, their request would have been immediately honored.
Thank you, Juan for this follow up report.
I should think that with this aircraft's checkered history anyone flying it would be acutely cautious in icing conditions. This just sounds like it was business as usual until they were as good as dead. Astonishing!
Yes. And it raises the question why they had this lack of situational awareness.
Thank you for your informative video.
As you say, so many questions still remain. There isn't any amount of money that would convince me to fly with Voepass.
RIP to all those lost after that awful spin into the ground.
Severe icing must be respected, true ! Not all turboprops are created equal. My best friend previously flew Dash 8s, as did I. That turboprop handled ice very well, and there was hardly ever residual ice left after de-ice boot activation. The design of the ATR boots does not appear very effective, having vertical bladders. The Dash had them horizontal and the airflow in this case took any ice out effectively. My buddy really dislikes the ATR and says you really have to pay attention, even on a normal approach, as you can look away for a second, and suddenly you've lost speed.
Even the Dash 8 would struggle in ice if it had a fault with the de-icing system like this ATR did.
@stephenj4937 well yes, acceptable performance in icing conditions with any aircraft depends on the deice/anti-ice systems working properly. In such a case, the MEL will always say "Avoid Icing Conditions". I've had such situations on the Dash 8 and now also on my current jet type, and company Dispatch takes these limitations into consideration during flight planning. They will even phone us to discuss it.
Great video. Thanks for all the technical details about icing. I had questions, but they were all answered be the end.
My house is less than 30km from the crash site. That day the weather was crazy, day before the temperature was about 36°C, falling to 10/15°C in less than 24h. Cenipa has did the report in English too 👏 Sad for the people who's lost their lifes.
Facing such severe icing while being told to maintain altitude, without informing ATC of the situation, is beyond my comprehension. From that, all the holes in the Swiss cheese had aligned perfectly. Sympathies to all the victim's relatives.
Sad, sad story. Thanks for this follow-up Juan
Halloween 1994 is a day I will never forget. American Eagle crashed in a cornfield approaching ORD. That crash nearly ended the ATR. We need to see the CRV to get a fuller understanding. Where is it? Thank you Juan.
Wow, so the 2 leading causes of this crash were icing followed in a close second place by pilot complacency. Multiple warnings of the approaching death and they carried on business as usual . Very sad.
I'd flip those two around. ATRs survive these conditions every day. This was avoidable.
Yeah simple fact, .... piloting induced crash, through failing to act appropriately multiple times to an ongoing ice crusting formation aero dynamic induced stall scenario.
RIP
An exceptionally well-done report Juan. Thanks so much! It's hard to fathom a reason for the flight crew's apparent casual attitude toward the icing conditions. The final report will be fascinating and I do hope we get to read full transcripts of the CVR.,
Great follow up JB . U, Petter, and 74 gear, are my only choice for crew replacements for my dream of a Dassault Falcon 8X ✈️🤙🏻
The crew may have been led to think the ice was off the wings because the leading edge may have been clean but freezing rain and clear ice can run past the leading edge and make a ridge on top of the wing aft of the boot. That’s what happened to the American Eagle crash. As i remember ATR extended the boot coverage to try fix the problem.
The manual icing detector on the -80 was the cotter pin on the windshield wiper.
To continue, I'm watching the departure from controlled flight. For the people watching this and not having any experience flying instruments, to have a airplane depart this abruptly is catastrophic. Experienced instrument pilots would have their hands full to recover from this departure, add to this it's a mult engine aircraft, they were doomed.
Well done Juan. Nice report but 100% preventable options were available to the drew to avert the crash had crew training and procedures been followed.
Thanks for following up with the flight recorder stats. That helps explain things better.
kind of like the Avianca crash in NY a 707 that ran out of fuel and the crew didnt tell ATC of the situation
Juan, your reporting and analysis undoubtedly improves pilots' skills and saves lives.
Cheers and thank you for all you do here on the channel.
Another channel reported that other ATR crews said that they would never have accepted this route from dispatch because of the forecast severe icing at their altitude. There is also some information that the crew never received this weather briefing.
No excuse for failing to follow checklists though?
A Sigmet warning covering a large area is one thing, but that Sigwx chart should have been a very clear indication.