Posted on 08/10/2024 4:42:22 AM PDT by Libloather
Witnesses have described their horror at watching a plane 'fall out of the sky and explode' in Brazil on Friday - as experts scramble to make sense of what happened.
Dramatic video showed the moment a Voepass Airlines plane came spiralling down over populated areas before crashing behind a cluster of trees, near homes.
'I almost believe the pilot tried to avoid a nearby neighbourhood, which is densely populated,' Daniel de Lima, a resident of Vinhedo near the crash site, told Reuters.
All 61 people on board have been reported dead, though relatives are still waiting for confirmation of the fate of their loved ones.
Voepass has since revealed that all those on board - including 57 passengers and four crew - were carrying Brazilian-issued documents.
Some of the passengers were doctors from Parana heading to a seminar, Governor Ratinho Junior told reporters.
'These were people who were used to saving lives, and now they've lost theirs in such tragic circumstances,' he said.
Daniel de Lima said he heard a loud noise on Friday before looking outside his condo and seeing the plane in a horizontal spiral.
'It was rotating, but it wasn't moving forward,' he told Reuters. 'Soon after it fell out of the sky and exploded.'
'When I heard the sound of the plane falling, I looked out my window at home and saw the moment it crashed,' witness Felipe Magalhaes told Reuters.
'Terrified and not knowing what to do, I jumped over the wall,' he said.
The plane was on its way from Cascavel to Guarulhos cruising at 17,000 feet when it began the sudden descent.
Brazil's Civil Defense says the plane struck several houses within the residential area, CNN Brasil reported.
(Excerpt) Read more at dailymail.co.uk ...
I read somewhere that ATR’s don’t have anti icing capabilities for wings.
Former Boeing engineer, I’ll fly in a Dash 8 any day, but will refuse an ATR trip.
I’m speculating. But, based on the inflight data, I’d bet this will be related to ice accumulation inflight. ATR aircraft have had a troublesome history with ice.
Of course, a contributing factor will be pilot error. When in severe icing you should get out of it asap. Generally a quick descent into warm air will solve all your problems. This option was available to this crew.
Turboprop
The spin started at 17,000 ft.
Pilot didn’t try to miss anything. He was not in control of the aircraft in any way.
Flat spin. Not possible to recover from in that type of airplane.
Once the plane started the flat spin they were all doomed.
Most likely ICE. Had deicing, but not good enough if they didn’t realize it soon enough, probably because they were on autopilot.
Look at the photo in Post #17: the deicing boots on the wings and the stab are clearly visible.
How can a twin with large engines get into a flat spin?
>ATR aircraft have had a troublesome history with ice.<
The operative word is “had”. Following an accident in Roselawn Indiana 25 years ago, they flight tested the crap out of the airplane, in icing conditions, and slightly modified the wing deice boots and icing detection system. I doubt any other aircraft type was put through that rigorous type of testing.
I have several thousand hours in the ATR42 and ATR72. During that testing we transposed our fleet sending all of the ATRs to do Texas flying and the rest of the fleet to Newark. It was dubbed Ice Tour 94 and I remember it dearly. Oh the stories.
My unofficial (non CNN credentialed) opinion is the Roselawn plane flew into severe icing. Planes were never designed for that.
Regarding Sao Paolo, I’m withholding speculation until there is more data. A flat spin is not normal unless one prop went to full reverse. A flat spin is not normal unless the rudder falls off. A flat spin is not normal unless the CG abruptly moves way aft.
The authorities have the flight recorder and should be able to make a determination fairly quickly. If our press doesn’t get distracted by some other shiny object, maybe they will stick with this story long enough to learn something.
EC
I noticed the sound of the engines on one of the clips. It seemed unusual, more like a bat-bat-bat instead of the deep hum you would expect. I wonder if the pitch was wrong as you suggested.
They don't work very well in heavy icing conditions. That is why airlines got rid of them in the midwest years ago. I remember seeing a crash investigation about the ATR-72 that crashed in Indiana while in a holding pattern to land at O'Hare. The pilots had the aircraft trimmed out in such a way that ice still built up on the wings.
Ice building up on the wings destroys the lifting (airfoil) shape of the wings. If it builds up too fast, the aircraft cannot keep flying normally, even at full engine power. Airlines spend a huge amount of money deicing aircraft before takeoff and many planes have vibrating “boots” and heated sections to shed ice in the air.
Eventually MentourPilot will do an episode on this accident.
With that said, who writes this stuff:
"Aimer said the most likely cause of the crash was that the aircraft suffered a low speed stall - when the airflow over the wings is too slow to provide enough lift. This happens when planes move too slowly. The three reasons this happens are either a technical fault, extreme turbulence, pilot error or something hitting the wing, like a bird.
"Three reasons," but the author lists four. Also, "either" as used in the sentence, refers to one of two choices, not multipole choices.
"One top aviation expert told MailOnline that the plane could have experience engine failure, flight control malfunction, or a critical part of the aircraft falling off."
Stupid headline.
Considering that over 100,000 airplanes fly every day and we only hear about a crash every once in a while, the safety record has got to be pretty spectacular.
It was in a flat spin, not a common or easy attitude to achieve. Usually associated with weight and balance issues. Recoverable by an experienced pilot.
Commercial aircraft all have de-icing and anti-icing equipment on the wings, engine air inlets, and windscreen. Significant icing doesn't appear instantaneously and automagically, it accumulates over a period of time, giving pilots opportunity to find a warmer or drier altitude before it becomes a problem.
Possible icing leading to a stall. Dew point and temperature were within 2 degrees C. It’s winter there. Twin engine turboprop stalls are very hard to recover from. Not enough rudder authority to counter act the rotation of the flat spin.
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