Brazilian ATR 72 Crash Cause

[@helianocabral9832]

I happen to live some 18 miles from the accident site. The ATR72 was performing a Standard Arrival (STAR) into Sao Paulo's Guarulhos airport (the accident happened inside Sao Paulo TMA (Terminal Area). During the couple of hours before the accident, several crews reported severe icing throughout the whole region. The ATR has deice boots. Turboprop engines such as the Pratt & Whitney PW series can not afford to provide the amount of bleed air required for hot air anti-ice systems. The ATR wing uses a 5-digit modified NACA airfoil ranging from 43018 to 43013. This airfoil seems to be very bad at handling SLD (Supercooled Large Droplets) icing. If ice accretion becomes asymmetric, the asymmetric drag will cause the aircraft to yaw, which, combined with a stall, results in a spin.

[@Robsoncwb86]

Whom has more fault to the rules ? Dispatcher by making the route thru the SIGMET severe icing or the pilot by accepting it ?

[@AnythingForSouls]

@@Robsoncwb86 Id argue the dispatcher they have a lill more information but honestly its probably more like a 50/50 either one of them should of seen it and think hmmmm maybe we shouldn't

[@analogman9697]

I'm no pilot but I follow several of the guys that re-create accidents. I know I've seen several situations like this one and icing leading to a stall is usually the culprit..

[@mikemicksun6469]

The fact is the pilot should have requested a different altitude with the reports he was getting. He was in the ice. ATR sucks in ice. Elevator on top is a problem also. Autopilot into ice and not watching the air speed.

[@capchuckpriceutyoub]

Looking at the ADS-B data, my gut tells me they were flying on autopilot, which is a very bad thing to do in icing, especially severe. This is all opinion, and we have to wait for the facts, but if that was the case, they probably had no idea how bad it was getting, because the autopilot would be rolling the trims back in response to the degraded flight performance, masking the condition. By the time the pilots realized they had a problem, their plane may have been too close to the stall. RIP pax and crew.

[@tramlink8544]

theres a reason ATR pilots in chicago refused to fly them in the winter. theyve had the icing issues since the 1980s!

[@bmc9504]

ATRs are popular in the UK and I found them relaxing due to the slow and low pitched takeoff, as I get older it makes me very uncomfortable as anything can go wrong whereas the Q400s takeoff fast and steep.

[@j.o.1516]

At high altitudes, winter or summer, given the right conditions, icing can be a hazard, anywhere on earth. Take for example the Swiftair MD80 that stalled and crashed In 2013 - due to icing - over the Sahara desert! Also remember AF447 suffered icing from super cooled droplets at FL350 in May just north of the equator.

[@shaun1293]

@@bmc9504I’ve been on a few on my travels and they’ve taken off quite steep for me. Perhaps it’s a case of reduced thrust for take off on longer runways?

[@rakimalston3074]

American Eagle Airlines

[@jimru5574]

Excellent and thorough presentation. One additional detail, after the ATR72 American Eagle crash in 1994, we tested an ATR72 out at Edwards AFB, CA, using our icing testbed KC-135. The air refueling boom had a misting spray ring, which sprayed colored water on the leading edge of the ATR72 one wing at a time (to retain primary flight controls of the ATR72). We photographed an “ice fence” build up 2”-4” tall directly in front of the aileron hinge. This ice fence acted as a spoiler, destroying laminar airflow over the aileron (and rendering that aileron useless). For safety, the ATR only “lost” one aileron during these tests, as the other wing was always in clean, dry air. Had both wings been subjected to this ice fence buildup, the aircraft would have lost all roll control and spun in. All major ATR72 operators moved their aircraft to warmer climes to avoid this risk.

[@flyingformoney777]

Good info. Thanks for the details. You have any idea where I could find those photos?

[@jimru5574]

I don’t remember which agency/sponsor requested the testing. I was assigned to the USAF Test Pilot School, and think it might have been a NASA request, or possibly the FAA. The Air Force Flight Test Center (AFFTC) historian or Public Affairs Office might have the test results/reports available. I also think Aviation Week & Space Technology (AW&ST) ran an article (1995?) with photos of the yellow-dyed accumulation of ice immediately upstream of the aileron hinge. Hope this helps some. Jim

[@FoxMikeHotel]

The manufacturer later made modifications to the aircraft, increasing the areas covered by deicing boots. They seem to fly throughout Europe in the winter without much issues, perhaps because here airline and pilots respect procedures and won't dispatch a plane into known severe icing conditions

[@Sokol10]

>>> _"...to warmer climes to avoid this risk."_ In July 16, 2013 an ATR-72 PP-PTU of TRIP Linhas Aéreas in a night flight of Northeast of Brazil enter in ice formation area, the pilotos turn on the anti-ice and de-icing devices - but not the boots for wings and engines nacelles; the aircraft, under autopilot control loose speed, stall and fall for ~5000 feet's. The PIC fight against the stick pusher, and the PM feathered the props - the aircraft manual instruct the opposite; anyway the control was regained and the aircraft land safety in destination. Serious Incident report: FINAL REPORTIG-136/CENIPA/2013

[@davidh9820]

@@FoxMikeHotel is there any weather conditions that determine severe icing areas? For example: if a temp range, weather it’s cloudy or even if it’s sunny etc. Please explain how they predict this conditions. Thanks

[@tonywebbywebb5019]

Mate that was by far the best vid I've ever watched on KZbin, absolutely brilliant how well you explained that, I have a basic knowledge of aviation and they way you broke it down was excellent !

[@flyingformoney777]

Awesome, thank you!

[@rxw5520]

The US has stricter rules against flying the ATR 72 in these conditions due to American Eagle Flight 4184 that crashed in 1994. Not to be overly dramatic, but these rules are written in the blood of 68 Americans. That means this problem was more or less resolved THIRTY years ago. It’s a shame other countries seemingly don’t take them as seriously.

[@kevinsoto15]

Absolutley right! You know how many old ATR pilots had complained and spoke up against the concerns of the ATR back in the day. It was awful for them and 4184 just kind of sealed the fate

[@TrainerAQ]

Yea that American Eagle crash made it abundantly clear the ATR is a death trap in ice.

[@redbird444]

@@kevinsoto15 Many of us did raise concerns. It took 4184 to get recognition and even then, the airplane wasn’t grounded in icing conditions for 7 weeks.

[@msr1116]

Wikipedia has a very detailed and informative page on this 1994 crash. However, if you understandably choose to avoid this source , the NTSB permits anyone to access accident reports online.

[@Peopleareusuallygood]

68, and one of them lived in my neighborhood 😢.

[@cnvi08]

Why this flight was allowed to fly into known icing conditions published in the SIGMET is unfathomable. Blame will go to the airlines flight dispatchers and the pilot that flew into known icing.

[@Bruno-tm3xo]

The captain is responsible for the flight. No other person. If he decided to fly an icing area …..that s his responsibility. No one forced him, no one forces a pilot to do what he doesn’t want to do

[@nigelwalsh804]

That is just so much horlicks mate.

[@williambaker1136]

Severe icing, known (as in reported) or forecast would disallow for dispatch of a flight here in the US.

[@Amr_a82]

Just dispatch in a lower fl like fl100

[@williambaker1136]

@@Amr_a82 Absolutely

[@david_cazalwa]

Apparently the pilot did request the ATC to level down the cruising altitude, but it was declined. However, more recent, our transportation minister here in Brazil said that there wasn't any contact (at first) to the ATC about that. And in my opinion, it is most likely not even the pilots were aware of the icing holding on the aircraft and probably there wasn't enough ice to cause dragging issues to reported on the performance panel.

[@FoxMikeHotel]

@@david_cazalwa If you encounter icing threatening the safety of flight, you do not request the ATC to let you fly at a lower level, you state to the ATC that you have to descend. And if there wasn't enough ice to be detected by the pilots or reported on the performance panel, there was likely not enough to bring the aircraft down

[@williambaker1136]

@david_cazalwa It appears that the ATR windshield wipers would be just visible to the crew if the seat is adjusted high enough. That is a place one can detect even a trace to light icing as it tends to build on an obstruction which protrudes into the airsteam. Not familiar specifically with the ATR, but there have to be signs of icing if one is alert to them.

[@Stone_Horse]

Thanks for the detailed explanation but all I can think of is the terrifying ride to the ground for all on board. My wife told me some people missed boarding this flight because they were late getting to the gate. As for the souls on board, RIP.

[@georgeross9834]

Autopilot in alt hold will try and maintain height in icing conditions by raising the nose and slowing down , the wing with ice can’t maintain lift and stalls any yaw will result in a spin. This could have been insidious and the pilots didn’t notice until the stall warning and spin. Real shame so sorry for everyone involved.

[@victorguerra9176]

It's strange. Why did the pilots choose to stay on autopilot if they knew about the severe icing conditions?

[@apatriot4698]

This is exactly what happened to a Cessna 404 in Austria in the decade of 1980. In the Tyrol Alps, a cold front "collided" with a moist air mass from the Mediterranean region, resulting in severe icing at FL110. In the wreckage they found the elevator trim screw at the stop of the pitch up position.

[@StanfordJohnsey]

@@victorguerra9176 Because they always fly on autopilot.

[@shaun1293]

⁠​⁠​⁠​⁠​⁠@@victorguerra9176if they’re flying through clouds it’s actually difficult to sense change in pitch and roll until it becomes extreme, so unless they’re actually paying attention to the instruments, they probably just had faith in the autopilot. Remember they’ve probably flown this journey hundreds, if not thousands of times and then this happens. Just like drivers, you get lazy with time.

[@frisk151]

I'll just say this as a r/c patter, 3-D, heli pilot for 35 years and full scale rotary and fixed wing as an adult today (not commercial.. Personal). I don't think I've ever seen a scale airplane somewhat similarly spec'd go that flat... Easy to do with other airframes but that was scary impressive.. I don't mean impressive like I'm happy.. It is SCARY as heck to watch and know how long it took to come all the way down with them cycling the throttles trying to get out, at least lower down.. Like a lot of people.. FL170 is a bad place to be for icing... I hope they don't sit on the FDR too long.. Not that I'm into listening to aviators freak out but as someone who has always studied crash or death / injury investigations in things I do... The CVR too.. Well, transcript.. RIP to all..

[@apatriot4698]

You are right. Only, you'll never fly your models with a CG at the extreme aft position. My reaction when I saw these horrible videos of that deathly flat spin "I want to see the load sheet". Flight planning for this accident has to be analyzed very closely as the icing conditions with this arriving cold front meeting warmer moist air in that Sao Paulo region were predicted.

[@RichardWagenknecht]

Great and detailed explanation. Sorry to all the families that lost their loved ones.

[@thehaygoods]

Dude it's awesome to see the face behind the voice. Thank you for making these videos. We are all pilots. Fascinating stuff.

[@fitloft1]

Yes this guy does a fantastic job of explaining this complex chain of events in conjunction with this aircrafts dynamics for both novice pilots to highly experienced alike to take note of.

[@LOTFI__TECH]

i've flown the ATR72 for many years as a first officer than captain than as an instructor . we practiced a lot the exercise of stall recovery in the simulator and the ATR has many protection " stick shaker and pusher" , it's hard to get it in a flat spin . the only thing it comes in to my mind is LOWPITCH in Flight it's a vitious failure if not treated quickly . you can get in a spin , it resembles a flat spin . i'm really looking for the result of the investigation .

[@nynphose]

all the expertz have diz figured out already no need to waitz

[@keithdurose7057]

I think that you have a very viable explanation here. The icing may have contributed to this situation, but I don't think that this is the whole story.

[@djpalindrome]

The ATR is notorious as a flying coffin any time it encounters icing conditions

[@rickc1410]

don't fly in icing with auto pilot on. learned this lesson early on in my flying

[@apatriot4698]

Just to add something to your otherwise very correct video. The analysis of the tragic AF447 accident showed also some overconfidence in Airbus philosophies that the aircraft will "take care of everything" as their CEO at that time stated, "even my cleaning lady could fly this A/C". Resulting that there was no training provided for pilots to to recover a Loss of instruments event in HIGH ALTITUDE, they trained it only for situations after Take Off. The problem with these A330 pitot-systems was detected before this accident happened, there were some incidents with it where the crews just did the right thing. The A330 fleet had to change these sensors to another type, the accident aircraft were still to change the sensors. To my mind there is way too much trust in automated systems (= less costly simulator training) and less training for Pitch & Power, especially at higher altitudes.

[@Riverplacedad1]

Best explanation of stalls and spins I’ve seen. As an ex Navy spin instructor, I will say I’m impressed. I will also say when I switched from military to commercial, I was amazed that the cockpits didn’t have AOA indicators because any fighter pilot will tell you it’s all about Angle of Attack. You can stall at 300 IAS if you pull enough Gs. I will also add how surprised I am at the civilian community and how little emphasis there is on spins and how far it is in their training they they even practice them. CFI I believe?

[@barrett313]

Don’t need AOA in transport category aircraft which is only certified for 2.5G. Follow the procedures and AOA is not an issue. Also, no need to practice spins in transport category acft as the video mentioned, you’ll rip the wings off in the recovery. Airline training departments need to focus on stall prevention and proper AAURS procedures if approaching a stall.

[@cristianomallmann3842]

​@@barrett313but a AoA indicator represent one more vital information when the music changes..scary to know about a lack of such a important gauge in a comercial aircraft.

[@Riverplacedad1]

@@cristianomallmann3842 exactly..it can be a great backup to failure of gyro/airspeed indicators. Would have saved that A330 out of South America a few years ago. Also a good backup to wind shear recovery. If you maintain optimum AOA, you will get a better recovery. In jets a AOA less than optimum will confirm a departure-from controlled flight vs a genuine spin. If your AOA is greater than optimum(max)you are in a spin and need to first neutralize controls and if the spin continues put in anti spin controls (opposite rudder to the direction of turn)

[@ae747sp5]

Which crash involving A330? ​@@Riverplacedad1

[@Pakbaz1]

@@Riverplacedad1 i once flew in a small turboprop & saw pilots having a hand held device that exhibited the speed of the aircraft as well as it's position, the device worked with GPS data & was an alternate to the aircraft TAS indicator. I wonder if the A330 would have been saved if the pilots had such alternate device with them, but the A330 Captain never applied the golden rule, " wings level, nose down to recover from stall", when the A340 was being flown with 5° nose up attitude!

[@roba7737]

I wouldn't fly on an ATR. They are too susceptible to icing.

[@humbertomonteiro6742]

😂😂

[@eugeniustheodidactus8890]

..........and.................................. enter the new DEI pilots.................... OMFG

[@roba7737]

In the US, the FAA banned ATR flights in icing conditions, probably due to the way they tend to fall out of the sky like a brick. Those poor people had plenty of time to think about the fact that they were gonna die. Horrible. Prayers for the families.

[@juanmanuelgomezmartinez3795]

Hello. And very sensitive to vertical windshear. ATR72 Accidente in Manizales Colombia. Good airplane but with sone important limitations that industry want to hide. MONEY

[@jeffhaggarty9879]

@@eugeniustheodidactus8890 Another guy just like Orange Jesus that likely can't explain what DEI even is.

[@arthouston7361]

Icing was my first thought. About 25 years ago, the ATR brand was badly tarnished by a crash caused by icing. The ice extended rearward beyond the boot, making it impossible for the boot to remove it when activated. I haven't kept up with it, but I thought that the other operators avoided known icing with the remaining fleet, and I am not certain whether the boot system was ever redesigned to accommodate the icing problem.

[@sgriffith2353]

It was redesigned by extending the deicing boots rearward.

[@BlingtingSam]

This plane model is always crashing; recently in Nepal. Looks like it’s easy to stall the damn thing without getting much warning.

[@iplayerbass]

@@BlingtingSam It's not quite like that!...The accident that occurred in Nepal was due to Human error, according to the Report of the Responsible Authorities of that Country, after an extensive investigation!!!.... According to the Report, the Pilots made a mistake in the Engine Configuration during approach to Landing, leaving the Propellers flagged, that is, not producing Traction Force!....

[@BlingtingSam]

@@iplayerbass that was my point. The plane doesn’t seem to have enough safety systems to make it more fool proof.

[@malumello17]

​@@BlingtingSamI don't think any airplane is full proof to dumbness. Look what happened with AirFrance A380 flight 447. A modern airplane in the hands of 3 clowns.

[@jaidenshadow2710]

100% agree in this analogy when I first seen the video i flash backed to air france and the ATR american crash where icing was suspected and led to recommendation of the deicing system on all atr craft. I seen the weather in the area first thought was unreliable airspeed due to severe icing which is a notorious issue to turbo prop high wing aircraft.the fact it got into a flat spin is incredibly rare. the power reduction on some of the videos is noticeable to attempt to recover but was too late to change the outcome.. the horrific ordeal these passengers and crew endured is unbelievably sad. 😢

[@mauricio471]

Greetings from Jundiaí, Brazil. It's very sad to witness this. I live near the crash site and I've seen fire brigade trucks rushing to where the plane crashed. Now, there must be respect for the victims, their families, friends, there should be patience to solve this investigation and vultures, the press and lawyers should be away from this and not to prey on or exploit families.

[@dvpro1]

Best there is explaining technical details. Thank you, sir!

[@flyingformoney777]

Glad it was helpful!

[@rsacchi100]

Thank you for the detailed explanation of what apparently happened and how it probably happened.

[@JohnDrysdale73]

I think it's fair to say GMT is no longer the current vernacular; UTC is the time standard used in aviation for flight plans and air traffic control and is what most people use here in Europe anyway. Greenwich Mean Time (pronounced Gren itch), is a bit of a blast from the past of naval square rigged ships etc, calculating their longitude position using a clock set to GMT. RIP to the passengers and crew and a good insight, thank you.

[@ericsonhazeltine5064]

“GMT” is so much more romantic.

[@quicksesh]

correct - GMT is now a time zone whereas UTC is a time standard with no offsets and no 'national' ownership

[@tonylam9548]

I remember at least one crash of an ATR in US, the plane just dived into the ground, the NTSB suspect ice formed in front of the ailerons ? The French insist there is nothing wrong with their plane.

[@msr1116]

Oct. 31, 1994...I remember it. American Eagle 4184 was circling in a hold pattern for quite a while. The weather was cold with wind whipped rain and likely caused landing delays. I find the French inability to admit to being wrong mindboggling. One reason why the Concorde crashed was the airport's runway crew's failure to check the tarmac for any debris, which was law and to be done after every takeoff. That plane was overloaded as well and fuel tank locations were also to blame. It was travel show host Peter Greenberg who brought the aforementioned to light.

[@dougtaylor7724]

Was it the same type plane? When I heard about this crash I remembered the other crash from icing.

[@msr1116]

@@dougtaylor7724 ... Yes. An ATR 72 200.

[@thomasconley3429]

I just got through saying to my wife that I remember an American Airlines ATR crashing in upstate New York... and that the cause was a problem with deicing. I also remember the Concorde accident where the French blamed the crash on a United DC10 that had taken off just previously. If they had been honest about what really happened, the Concorde might still be flying... or a newer version.

[@franknewt2202]

@@thomasconley3429 American Airlines ATR flight from Indy to Chicago . Crashed on Halloween night in NW. Indiana

[@pvkoinch]

Why ATR engineers aren't yet able to get rid of this imperfections for almost 30 years? The technology has advanced so much.

[@rvo9744]

Very good explanation for people like me who do not know much about flying or avionics. The resulting hypothesis and the rationale behind it was superb. Thanks so much

[@flyingformoney777]

Glad it was helpful!

[@tidronefly1180]

Thanks for an easy to understand explanation of why the plane fell from the sky.

[@IdeasBox]

Well explained and well spoken too. As an ex RAAF aircraft tech I enjoyed your video and the way you explained the pitot system and aerodynamics. Thanks.

[@fr57ujf]

I'm amazed at your concise and thorough explanation of flight aerodynamics which you made understandable even for a layman like me. Excellent job.

[@flyingformoney777]

Glad it was helpful!

[@vladimirrojas6653]

There was another atr 72 down due to icing problems in Cuba in 2010, something is wrong with this system

[@9Thunder5]

Aero Caribbean 883 you can watch simulations online

[@bluecoffee8414]

Super interesting. Thanks for the video and RIP to all the victims.

[@mikethompson3534]

I don’t understand how the ATR 72 could even be certified all these years with all these icing conditions happening numerous incidents

[@victorguerra9176]

They always want to blame human error (which, to be fair, is also a factor). But it's clear that there's a higher risk of accidents when severe icing conditions are involved with ATR aircraft. I hope this accident is the tipping point that finally leads to changes.

[@Mikinct]

The company has made modifications to reduce ice fence bu7ldup along with moving planes to fly in warmer areas. But since ATR does fly at 17,000 flight levels ice still has potential even in warmer climate areas when weather permits. Commercial airliners fly above clouds at 30,000 while ATR are stuck at lower altitudes typically in the soup

[@dcartier100]

Don't discount failure of secondary low pitch stop on one of the engines. Not discounting ice. But if left engine failed and wouldn't autofeather. Bad situation!

[@eugeniustheodidactus8890]

occum's razor.....

[@kevinsoto15]

Well the only issue with that is you still have the other propeller. While yes it might not be producing as much thrust and helping but look at the Transasia flight in Taiwan a coulle years back that crashed. They had a single eng/prop failure and they were fine but the pilots mistook shutting down the wrong engine. Usually an engine failure like that you dont just fall out of the sky like that unless ofcourse you do stall but if the pilots were monitoring their instruments like normal they wouldve caught on and disconnected the AP

[@kevinsoto15]

My main red flag when I initially saw the fr24 was the unrelaible/crazy readings of the airspeed that right there just made me think icing right away

[@JoshuaC0rbit]

They've had this issue with control surfaces icing up since the 90s. It's really a shame.

[@Drainage_Eli]

That was an amazingly educational video. RIP to all those that perished. Such a tragedy.

[@FernandoHaddadMinistro]

What a video!!! So much technical explanations on a easy way to understand

[@flyingformoney777]

Thanks!

[@bbat2159]

Very good video. Informative in a straightforward manner. Thank you for referring to the pilots as captain and first officer. Not captain and copilot.

[@afrophoenix3111]

Always appreciate your videos, but I gotta do an obligatory "um, akchually......" The "equal-transit theory" around the 3:00 mark is a common incorrect explanation for how wings lift. Two neighboring air particles that split at the leading edge are not forced to come back together at the trailing edge. Plenty of wind tunnel tests show this. The general Newton 3rd Law summary between 2:40 and 3:00 is spot on - the wing pushes air downward with a force that matches the aircraft weight, letting you "float" in the current. And for the scope and audience of this video, that's the best quick-and-easy explanation we can do. The bit about the wing's curvature making the upper air mass travel faster than the lower is also perfectly correct, but the simple reason is...that's just the nature of air flowing around a wing. The lesson's complexity spikes VERY quickly beyond that (very basic) level of detail.

[@skydancerforever]

So if wings have a curvature on the upper side to make air travel faster and create lift then how do airplanes fly upside down with no problems even climb upside down? See it all the time in air shows. Also looking at some wings i don't see a greater curvature on the upper side of the wing compared to the lower side? Some wings look the same top and bottom?

[@afrophoenix3111]

@skydancerforever Excellent question. Aerobatic flying adds some critical items that GA and the airlines don't have: 1) High power and high performance aircraft, and 2) Highly specialized pilot training. If you refer back to the video, wings produce lift because of their surface curvature and angle of attack with incoming air. From normal flight, you can absolutely nose over enough that your highly nose-down AoA creates negative lift. There are any number of ways to get positive (away from ground) lift with an inverted airfoil. Combine that with the extreme amounts of thrust that you can get out of an aerobatic engine, and a pilot who knows every last inch of his flight envelope. Aerobatic pilots work on THE very edge of their flight envelope, in ways that would kill us mere mortals in normal category aircraft. But with the skill and nerve of an aerobatic pilot, they can pull off a hell of a show.

[@pawelwolski1316]

I do enjoy your vids. Watching way to many of these crash videos, I find it absolutely disgusting the inability of the "modern" pilots to fly the airplane. They keep pushing buttons, can't hand fly......So how about this, auto pilot on, alt hold, guys drinking coffee or talking about girls. Finally they wake up to slower actual airspeed, don't know to lower the nose, attempt to maintain altitude......done.

[@pervertt]

Daniel Bernoulli got it right in 1738.

[@jonaarbakke9633]

@@skydancerforever When you fly upside-down you are not using the curvature, but relying on a AOA and Newton's 3rd.

[@W4t3rf1r3]

I'm not sure unreliable airspeed is all that likely to have happened. To my knowledge, there have been 4 previous ATR crashes involving in flight icing, and only one had any unreliable airspeed. The wings of the ATR are particularly sensitive to ice and the deice boots are considered by some to be undersized. It doesn't matter if the airspeed is accurate or not; when the wings stop working, you stop flying.

[@MrJackal43]

As soon as I found out it was an ATR I knew it was their lousy de-icing boots…

[@jekanyika]

If the icing is severe most de-icing systems are going to struggle

[@bobace83]

I do not like flying on that airplane

[@Polux721]

That was exactly my thoughts, this will make the 5th accident if it happens to be icing the cause, every time I hear ATR-72 I think icing no matter what.

[@skydancerforever]

Yes once they said there was severe icing in the area and the plane flew right in the middle of it at 17k feet, We all pretty much know what the cause will be for the accident. Nothing new or strange here. The ATR is not good in icing conditions! period.

[@JariJuslin]

It's more about being a turboprop than ATR itself. Having to cruise at the worst icing altitudes is the core of the problem.

[@brentsummers7377]

In Ernest K Gann's book, Fate is the Hunter, he describes an incident when as co-pilot in a DC-2, they encountered extreme icing. Gann's captain was able to divert and land safely but they were fortunate to survive. IIRC it took mechanics a long time to de-ice the DC-2. Gann said that the DC-2 handled ice better than a DC-3. He also despised the C-87 (Liberator) because of its inability to deal with ice that a DC-2 or DC-3 would have been able to handle without a problem.

[@kaiboshvanhortonsnort359]

Cutting severely between angles on this host put me into a flat spin. Dude. Stop.

[@carlo_berruti]

Extremely clear - I subscribed right away. A throughout and detailed explanation of how lift, stall, airflow, CG, airspeed (measured via pitot tubes) etc. work - all concepts I knew about decently well already, but that I rarely found explained so well. I’ll be in for other videos too. Quick question: isn’t the “T-tail” (typical of the ATR family) in any way to be considered a culprit, too? I read in the past that this particular tail configuration is prone to deep stall / super stall outcomes (impossible to recover even when they are flat stalls). I don’t find it mentioned anywhere (also in other analyses), but that’s probably because all the rest (ice, plane attitude, inability to prevent the stall in the first place) are already explaining what happened more than enough…

[@flyingformoney777]

The t-tails in the 2-seat Piper Tomahawk had a bad rep for stall handling, but there’s nothing inherently wrong with the configuration. King Airs (and many small jets) also have t-tails. They can be prone to tail stalls in ice, but this is usually associated with extended flaps at relatively high speeds. Thanks for the sub! More to come soon!

[@ramineghbali5580]

Super thorough video. Also appreciate all the commentary from other fellow pilots. What I also appreciate about you the narrator is how articulate and to the point you are. So many videos are extremely frustrating and painful to listen to, this one was easy. Not a fan of the ATR either way. Those poor soles. What a tragedy. We all try our best to mitigate risk in this business and sometimes the equipment lets us down, sometime we let ourselves down and sometimes it’s both in addition to Mother Nature. Hopefully we can get to the bottom of this sooner rather than later for everyone’s sake.

[@jamesfenton7338]

I remember Chuck Yeager saying about one of his test aircraft "I couldn't recover from a flat spin, but I could recover from an inverted flat spin". This depends upon getting the verticle stabilizer into the air stream, I don't know if a high T tail would recover, but it's a good question to ask.

[@jekanyika]

I've been on some half empty ATRs where they have had to rearrange all the passengers for balance.

[@twiff3rino28]

I've been on A320s and 757s where they had to do that.

[@stoobydootoo4098]

??? All aircraft need to be careful where they locate freight and passengers.

[@jekanyika]

@@Plutogalaxy I never said there was anything wrong with it.

[@LowandFast357]

Dude..... Where have you been? I'm glad we have two videos from you in recent weeks, but man, that's not enough. You're too good of an articulator to not grace the YT aviation universe with your take on things.

[@flyingformoney777]

@@LowandFast357 thanks. I’m cranking back up. 2 talking heads, a recreation and an article a month are my goal. Appreciate the support!

[@LowandFast357]

@@flyingformoney777 For sure. Forgive me for assuming you have all the time in the world for videos like this. I'm sure you have a personal life. I would guess that the time and effort it takes to make these productions isn't commensurate with the monetization level at this stage. I've been a pro pilot for 22 years and have spent the last six years as an aircraft broker, and I can't even begin to imagine how I'd find the time for such quality content and production, so kudos. There are a handful of solid aviation channels on YT, but even more that are less impressive. We need yours to ascend. Cya!

[@redbird444]

It may have been a repeat of AE4184 involving rollback ice resulting in hinge moment reversal of the ailerons, disconnect of the autopilot following with a departure from controlled flight, vs. erroneous airspeed and traditional stall/spin.

[@jamesdellaneve9005]

I know that this is rare, but I wonder if a tail cone chute could stop the spin. We had this for flight test on the C-17 aircraft.

[@karlhaese7183]

Exactly what I just saw on the Tupolev crash in 1985, where I also(for the first time in my life) heard of such a chute. In that crash the pilots didn't sleep for 30 hours and fell asleep, letting the autopilot accend till it stalled and fell like an autumn leaf exactly like the ATR

[@joevignolor4u949]

I thought the same thing. During flight testing of jet fighters they attach drag chutes to allow for recovery from stall spins. The chute raises the tail and lowers the nose and stops the yaw. The chute substitutes for the horizontal and vertical stabilizers when there is no horizontal airspeed and the airplane is flat and falling straight down.

[@keithwalker6892]

Refer to the US NTSB report on the ATR accident over Chicago a few years back. It seemed there had been a few crashes like this one caused by icing on the wings. The NTSB found an icing problem on the wing and in previous accidents the pilot was blamed but it was the wing ,NOT the pilot.

[@RCB58Hustler]

That was the best explanation I have ever heard. I understand stalls but I will save this to show people who don't understand what happens. Thanks

[@phj223]

Take home message: don't enter a spin with a commercial plane.

[@jborthodoc]

Grest Production, great info. This channel can blow up. Keep rolling!

[@moiraatkinson]

That was so informative! I just came across this channel from the short regarding this accident and have subscribed. I was fascinated to learn about spins etc - in fact I was just chatting in the comments of another channel on this very subject. There’s a Cirrus plane with a “wings level” setting and I wondered why the mechanics of that couldn’t be something the pilot was capable of doing. I must correct your pronunciation of “Greenwich”. Forget green - it’s Greenwich as in “friend”.

[@roland-p9u]

I remember an accident in the alps with an ATR where the aircraft flew into icing conditions but with the anti icing system off. When the pilots noticed this and turned it on then the ice was disodged but slippped back across the wing and lodged jamming the ailerons thus causing a loss of control. Just a thought but we will have to wait for the aircraft accident investigators report. The French BEE are extremey thorough so together with the Brazilian authorities the investigation is in good hands.

[@SamuelBarringer]

I think what happened is tragic. If grounding the Boeing 737 Max by the FAA, EASA and many other governing bodies around world was the correct. The FAA might do the same thing with the ATR 72. ATR needs to make their planes less susceptible to severe icing.

[@eugeniustheodidactus8890]

it's not thaaaaat easy .... it would require a complete redesign for an airplane that never should have existed

[@FoxMikeHotel]

Or operators and pilots should start respecting procedures regarding operational limitations of the aircraft and not decide to send an aircraft into known severe icing anyway despite what the manual and regulations say... It's like having a plane fly through volcanic ashes and crash because of it and saying the manufacturer should make their aircraft more volcanic ashes proof...

[@onlyyou7171]

Hey just so you know. GMT is used for all navigational vehicles and purpose because it's the zero hour on the clock and it is known by that all around the world. That way reports and vital navigational information can be used and passed with a common time format. Military, civilian, every country agrees to use it. It's existed for eons.

[@garykildea6117]

What!!?? If you're talking about UTC / Zulu time (not GMT) are you seriously trying to teach this man what it is!!? Aviation people (let alone the rest of the viewing public) reference local time when it's called for. In this context it obviously is! He's talking about the (local) time of day when the accident occurred . Amateurs might feel the need to use jargon for effect. This guy flies for money. Just so you know.

[@flyingformoney777]

A little dry humor. Yours is not the only comment on it. Perhaps it was a bit too dry…

[@ColinVance-q8u]

As soon as I saw the video I thought it was a CofG related incident. I was in a similar aircraft in the Caribbean years ago where an inexperienced and uneducated local air hostess organized all passengers to the rear of the aircraft for her convenience. Being a pilot I insisted on talking to the pilot and we repositioned the passengers thereafter much to her chagrin and indignation! Good analysis video about a tragedy!

[@flyingformoney777]

Yep. The self-loading baggage sometimes has a mind of their own…

[@timothyparker7739]

Another classic. Thank you from Australia…

[@flyingformoney777]

Thanks for watching!

[@lusher00]

The equal transit theory of lift has been debunked many times. There’s no reason to believe the same air molecules converge at the trailing edge, thus causing higher velocity and lower pressure. We now attribute lift purely to the “flinging of air.” You won’t hear about equal transit in any modern description of lift, unless it’s to mention it’s just not true. Google equal transit theory and you’ll see what NASA has to say about it.

[@treelectronica7868]

Can you say this in layman’s terms

[@richardwyse7817]

we fly, but we dont know why!

[@lusher00]

@@treelectronica7868wing fling air, air fling wing.

[@mebeasensei]

I’m theory, had every passenger rushed to the front of the cabin, might there be a chance that the aircraft fell into a nose-down attitude and thus recovered?

[@karlhaese7183]

Interesting......have thought about this for ages.....but getting unsuspecting passengers to all get up and rush towards the cockpit would endue in chaos and would take longer than the time needed to recover from that stall

[@georgemetaxas9227]

It seems that ATR's wing was made for performance to the detriment of the ice accumulation resistance, in conjunction to an inadequate boot deicing system.

[@Pensivata]

The second ATR to go down in not so many months...

[@AnetaMihaylova-d6f]

When was the other

[@Pensivata]

@@AnetaMihaylova-d6f Yeti Airlines in Nepal

[@peterpv592]

the other one was pilot error

[@flyingkiwi215]

That one was the co pilot feathering the prop instead of putting the flaps out

[@stoobydootoo4098]

​@@flyingkiwi215 That incident was c 18 months ago in Nepal.

[@philipmartin708]

I'm wondering if having the throttles at idle would have made much of a difference. With the engines reved up, and the aircraft yawing to the left, the gyroscopic precession of the props, (I don't know about the turbins, if they spin the same direction as the props) would have caused a nose up force. In my opinion, the aircraft wasn't rotating fast enough around a vertical axis to explain its almost flat attitude.

[@electricannulus8854]

Why is it that there are no readily available releases or discussion of the communication's from the plane to any control? Surely during the time of the emergency there was.

[@apatriot4698]

There are reports that the crew requested a descend to lower, denied by ATC due to traffic. My decision would have been emergency authority, turning 90° to the left and descend and declare emergency. As I have seen there is even an ATR procedure to do by memory items in case of icing.

[@JariJuslin]

​@@apatriot4698: Indeed. Blancolirio showed that manual page - memorized item, descend first, then inform ATC. Not a place to wait for permission.

[@kkfoto]

@@apatriot4698 The so-called reports are hearsay. Authorities have reported no communication preceding the accident. No request to descend, no Mayday.

[@9Thunder5]

@@apatriot4698happened in cuba a few years ago… ATR they requested to decend for icing but there was another plane at that altitute so they waited a few minutes … the plane crashed short after you AERO CARIBBEAN FLIGHT 883 you can watch the simulations on youtube

[@somedumbozzie1539]

i was on a very casual one third full twin turbo prop in NZ and one of the pilots coming back and asked us to spread out around the cabin to trim the aircraft.

[@brentsummers7377]

Yes, that is similar to seating people taking a ride in a single engine 4 seater plane like a Cessna 172 etc. The biggest person sits next to the pilot while kids sit in the back.

[@thestoo8328]

Was this midway through the flight by any chance? Could be the change in weight with fuel consumption or they got the math wrong at the start of the flight. Usually this is all figured out using the check in data, along with fuel and cargo weight vs. flying conditions.

[@somedumbozzie1539]

@@thestoo8328 It was before take off everybody was in a block and they said we could all have window seats for the flight along the back bone of the NZ Alps, Mt Cook and the Glaciers on route to the north island.

[@jamesrecknor6752]

Excellent teacher

[@flyingformoney777]

Thank you!

[@leokimvideo]

Severe icing and autopilot not turned off. It's that simple, the pilots would have been fighting the automated systems that are designed to save the aircraft

[@mikeabc5355]

ATR is a good aircraft but it has issues with icing.

[@patrickodonnell9891]

Then it is NOT a good aircraft, maybe ok!

[@mikeabc5355]

@@patrickodonnell9891 No aircraft is perfect but poor anti-ice / deice systems is critical for for commercial aircraft is a fixable issue that is ignored because some people worship money. Perhaps TKS or some form of not-yet-developed hot wings for turboprop aircraft would be a better solution than boots.

[@Bruno-tm3xo]

Which makes it crap

[@orcstr8d]

WWII history in the CBI, flying the Hump on dangerous missions I recall pilot Earnest Gann saying about the B24 cargo variant that its wings "couldn't carry enough ice to chill a highball." The chord on those C-87/B24's wings were much skinnier compared to contemporary WW2 AC, much like the ATR.

[@FutureSystem738]

These damn ATRs are obviously lethal in icing conditions. Most other turboprops handle it much better. I can’t believe they flew right through the middle of the predicted icing levels.

[@david_cazalwa]

They factually flew all over the state of Sao Paulo first and only encountered the stall issue around Campinas region, near the Viracopos Airport, in the city of Vinhedos, where the crash happened, more specifically speaking. Why did they only face the issue at this region? I guess the ice was building up all the way from the south until it reached an unrecoverable point near the descent path

[@FoxMikeHotel]

A Q400 doesn't do much better in ice, it's just intrinsiqual to turboprops, their engines don't produce enough bleed air to be able to have leading edge anti ice like on bigger airliners plus they fly slower and lower, typically in the layers of the atmosphere where you're the most likely to encounter icing. Your second sentence is the key, dispatching an aircraft, and then have the pilot fly into known weather conditions that are prohibited by the aircraft's operational limitations is a huge no no

[@oleleclos]

It's important to understand that icing categories depend on the aircraft type as they relate to how a particular aircraft type copes with icing. So what may be "light" icing to one aircraft type may be "severe" to another. But if anti-icing and de-icing equipment is not maintained, tested and used exactly as intended, an aircraft that may be normally able to cope with "moderate" icing may in fact be unable to do so - which by definition turns "moderate" icing into "severe". This has been the cause of many icing accidents, for example Roselawn in 1993 - another ATR 72.

[@alexissuazo3122]

I appreciate your knowledge on this insightful information of the ATR.

[@9Thunder5]

⁠happened in cuba a few years ago… ATR … they requested atc to decend for icing but there was another plane at that altitute so they waited a few minutes … the plane crashed short after you AERO CARIBBEAN FLIGHT 883 you can watch the simulations on youtube

[@kentstallard6512]

Great info. I watch a ton of crash videos so I'm familiar with some of the basics but I've learned a ton from this.

[@Captndarty]

I’ve flown ATR’s in Southeast Alaska, where you can’t get any more severe icing than that and without any problem. I’m sure the pilots could’ve been trained better to deal with this….

[@OffendingTheOffendable]

Thats why that plane isnt used in cold climates in the US. Its junk at deicing

[@mt_baldwin]

Didn't this same thing happen in the US in the 90s which led to a big hubbub about this particular plane's ability to handle ice? I sorta recall in this incident the plane went into a spin too, the pilots very nearly recovered from the spin but the tail got torn off in the process. I might be mixing up incidents, it's been a awhile seen I've read about this.

[@msr1116]

American Eagle 4184 in 1994 in northwest Indiana.

[@amantedar123]

A eyewitness on the ground said that she heard a loud noise and went to look out of the window. It was then when she saw the plane staling.

[@lucasmatsuoca]

@@Plutogalaxy The aircraft's motors were very loud, I guess the pilot kinda panicked and went full throttle trying to gain some horizontal speed, ofc it wouldn't work but what to do.

[@lozjones315]

Correct. At least one prop is making an odd sound at the last stages. Did a prop issue contribute?

[@david_cazalwa]

It's not yet confirmed that icing was the main cause of that accident, since the accident happened so recent, and the official investigation is still undergoing, it's too early to say it was just mere icing. The ice itself, when isolated does not necessarily cause a stall and then a crash. It surely does have an effect on aerodynamics, but when in combination with other factors that still needs to be investigated as well, such as probable pilot error, incorrect flight informations, and even engine failure, ice didn't cause the crash.

[@katyshepherdess6104]

That would be the quickest investigation ever. I'll wait until the final results are in. All speculation until proven otherwise.

[@iitzfizz]

Yeah that's what I keep saying, it is a strong possibility but it's not been confirmed yet, when NTSB start on their report then we should find out.

[@david_cazalwa]

@@iitzfizz it's not the NTSB that will investigate, it happened here in Brazil, our accident investigation group is called CENIPA, maintained by the Brazilian air force

[@gcf1978]

I live 11km from the accident site, it was a freezing day with light rain, an unusual cold that is only getting better today! The pilots probably didn't expect this, as we are in a tropical country, climate change is here, aviation needs to be prepared, if that is possible.

[@jake-qw4or]

Excellent video. Many Thanks for the refresher course.

[@Quickrex]

A good indications on the ATR are when you see thick Ice running back on the side windows, you know that you are in trouble and you are in sever icing condition and you need to descent fast and keep maximum speed to prevent any stalls . I flew the ATR in Scandinavian, in the freezing cold, snow and lots of ice and the aircraft performed well . but again always on the lookout for that dreadful snow and ice . I flew the Short in those conditions as well and that was more like sailing an over iced fishing boot than flying ( Scarry as Hell )

[@FellipeRodrigues89]

this is consise and straight to the point. great video!

[@karlhaese7183]

Very well laid out. Sad to think they had so much altitude to recover from the spin, yet failed to do so. Reminds me of the 747 carrying tanks in the middle east , which came loose and completely screwed up the CFG resulting in a identical pancake drop.

[@driftinso]

Which is why cargo securement is so critical in aircraft, and often not given enough attention.

[@djr5372]

If in a flat spin rotating to the left, what effect would reducing power on the right engine and increasing on the left have while increasing right rudder? Gear down, flaps approach? Wish I had an ATR sim to try that on.

[@lucasmatsuoca]

doesn't matter, not even close to enough altitude to recover

[@grumman38]

It’s complicated as bring power up will raise the nose not allowing the pilot to lower the angle of attack. Turbo props spend much more time in icing than jets, the pilots must be very aware of their flight profile (angle of attack) when in icing conditions. They must also be very aware of temperatures aloft and make changes to azimuth and altitude for an escape, they can’t simply ride along. You must know your environment and be proactive, in 33 years I’ve never felt seriously threatened by ice aloft. I have had to make timely decisions though. DEI will claim lives.

[@scott-qk8sm]

Either anti icing equipment failed or the pilots failed

[@nwwarehouse9320]

Pilot had over ten years of experience. Sabotage because Doctors on board had info turbo cancers connection to jab.

[@nwwarehouse9320]

Pilot had over ten years of experience. Sabotage because Doctors on board had info turbo cancers connection to jab.

[@philgooddr.7850]

also a 15deg flaps on this plane is a definite no go during icing conditions since it shifts the icing build up to the rear or the wing and since some tragic accidents, the de-icing rubber been extended upward on the 600 version because this particular icing can drastically deteriorate the wing lift..this was demonstrated and tested following a C130 spaying water in order to come up with a proper upgrade,,

[@derincattelane43]

This crash reminds me a lot of Aero Carribean Flight 883. It also encountered icing, stalled and entered a flat spin just like this plane did. You can find an animation of the crash on youtube easily.

[@ChristopherSLucas-hv7nz]

I love the Third Law explanation of wing function!!

[@shaun1293]

Y’all blaming the ATR for being lousy in ice know absolutely nothing and have clearly gone off hearsay. List of ATR72 crashes with icing involved: AE 4184: ATR did not provide/left out adequate documentation regarding deicing. Company fault, not the aircraft. TransAsia 791. Pilot was satisfactory with icing procedure but was noted to be lacking in situational awareness. TransAsia was also lacking in training and rating of severe icing. AeroCaribbean 883. Aircraft experienced severe icing at 20,000ft, the pilots made bad decisions. UTAir 120. Incorrect de-icing procedures at takeoff. Next is Voepass but since it has not been concluded I haven’t listed.

[@paulopavan1979]

My lay opinion is that the shape and proximity of the propeller blades has a lot to do with the accident. I have a fan of this type and in strong crosswinds it oscillates and falls if poorly supported.

[@Noahberlinsberg]

ADR 72 has the worst possible reputation

[@FoxMikeHotel]

Perhaps because it's cheap so it's bought by dodgy airlines in less developed parts of the world where safety culture and pilot training are not a major concern

[@ab_gsk]

@@FoxMikeHotel Flight safety in Brazil follows the same standards as USA or Europe. No wonder Brazilian airlines are allowed to fly to USA and Europe.

[@FoxMikeHotel]

@@ab_gsk might be true for Brazil, the investigation will tell us about that, but definitely not true for most of the ATR crashes out there that were mostly due to pilot error, incorrect crew reaction to icing, or maintenance defects

[@thestoo8328]

Brazil has excellent aviation standards. As for the ATR-72, there are thousands of regional flights here in Scotland yearly, by reliable airlines, including in winter conditions much worse than what's experienced in Brazil and there are no issues. Changes to the ATR to minimise icing risks were made many years ago, and they're doing quite well. The record speaks for itself, it's a great plane for regional transit Accidents will happen sadly, lessons can be learned from them, whether that's pilot guidance or training, or if any modifications can make the plane even safer. Let s see what the report says, if there was an icing element, how did that impact the attitude of the plane, why were the pilots unable to correct the issue, was there a mechanical element? Was it a misfortune combination of events etc. This plane is getting so much hate because of a handful of incidents many of which are actually pilot error.

[@RBoas]

Engineers searching for”slide rule” increased as a result of this video.

[@publicmail2]

Sever icing in this plane is an emergency and has to be treated as such per POH. Changing altitude, and adding speed to minimums, autopilot off...

[@PabloDezon]

I’ve flown the ATR for almost 5 years. The ATR removed the steps to descend from the Memory Items part of the Severe Icing checklist about 2016 or so. The Pilots declared to the ATC the necessity to descend “due to Severe Icing” but the ATC did not allowed!

[@lonnywilcox445]

That really doesn't make sense, that ATC wouldn't allow it and that the pilots wouldn't have done it anyway since it was their butts in the seats. If the pilots recognized the icing was a problem, the correct response is to get out of the icing and let ATC know you are doing it and let them get other traffic out of the way for you. Severe icing is an emergency in any aircraft and flying out of the emergency is more important than communicating to ATC. Sure ATC will get bent out of shape, but you can be sure the ATC that denied them descent permission is bent out of shape right now anyways.

[@richardwyse7817]

pilot has authority.

[@johndonovan6840]

This has been DEBUNKED! The pilot NEVER REQUESTED LOWER ALTITUDE! And, on top of that, this would’ve been an EMERGENCY. Mayday,mayday, mayday, initiating descent due severe icing. No need for an “authorization” from ATC.

[@kennaljo]

"for whatever reason"....ignorance is no excuse.

[@garyprince7309]

Nicely composed explanation. You have an easy delivery style to listen to. Thank you for the presentation and heartfelt condolences to the families of the lost ones.

[@crimony3054]

The aircraft operates at that level and in those conditions normally.