ATR 72 crash, Cascavel and São Paulo, 9th August 2024

[DELETED WITHOUT PREJUDICE]

I'd personally prefer to wait for a report before I decide that it was a mechanical issue. There are many, many possible causes for an aircraft going into a flat spin like this.

Could a mod change the thread title to ‘Brazil plane crash’ or something more descriptive?

Interesting tweet about the accident

https://x.com/scottiebateman/status/1822246416594747674

Yes ,they are extremely common worldwide

Can you provide details of the "loads of issues"? There have been a handful of ice-related accidents with the ATR series in the forty years since the basic type first flew, and almost 1,800 have been delivered to date.

Yes ATRs have deicing boots, the whole fleet was retrofitted with more effective boots after an icing related crash in the US. That said the ATR isn't certified for severe icing conditions and the boots can be overwhelmed by large ice accretions. The sigmet from the time of the incident definitely suggests ice as a root cause but we won't know for sure until the investigation is done

To my knowledge and having flown 3 types including the ATR, no aircraft is certified to operate in severe icing conditions. Happy to be corrected though!

Are a handful of crashes not enough? There have been plenty of reports of ice related issues over the years but pilots recovered the plane.

How is it acceptable to have a plane that suffers from ice related issues when it flies at a height, which another poster said, will be in temps of -13c?

I'll preface my comment by saying we don't know if ice was a factor in this crash, time will tell.

That said, I think it would be beneficial to the more casual visitors on this thread to explain the difference between anti-icing and de-icing.

Most, if not all modern jet passenger aircraft use an anti-icing system to keep the wing leading edges and the engine nacelles free of ice build up. It's critical that these particular surfaces are kept free of ice build up because ice disturbs the aerodynamic flow significantly. Disturbed airflow into an engine can cause the compressor to stall. Disturbed airflow over the wing can cause the wing to stall. Anti-ice systems typically take hot air from the engine compressor and send it where it's needed through a system of ducts. This prevents ice from forming.

The ATR uses a mechanical de-icing system. Rubber boots along the wing leading edge are inflated at set intervals to mechanically break away ice that has begun to form. So the system is designed to allow a small amount of ice to build before removing it (hence de-icing) and this cycle continues whilst icing conditions prevail. In severe icing conditions it's possible that ice forms so quickly that the boots are unable to break it off and are simply inflating and deflating under a layer of ice. It's important to note that anti-icing systems as described above are also not immune to severe icing and pilots of all aircraft types will be trained to avoid known areas of severe icing and, if they encounter such an area unwittingly, to get out of it immediately by turning around or descending to warmer air. It is also worth mentioning that both anti-icing systems and de-icing systems are not on at all times, they need to be switched on by the pilots. On the airbus, engine anti-ice is switched on when there is visible moisture outside and the temperature is between +10 and -40. Wing anti-ice is switched on when icing is visible on a probe outside the windshield (or any other surface including the wing which may be visible from the cockpit side window).

I don't know why the ATR was designed with a de-icing system rather than an anti-icing system. I would be inclined to say that anti-icing is the superior solution to the problem. However, no matter what system is installed on the aircraft, if the pilots don't recognise the severe icing threat quickly enough or take appropriate actions to get out of the situation, the end result will be the same.

Again, we don't know if icing is a factor in this particular accident. RIP to all the lost souls.

Seems like the same frame had a tail strike a few months previously:

https://avherald.com/h?article=51c4be1b&opt=0

The preliminary report is out. Very much looks like icing along with some sort of de-icing system fault before a stall and spin

https://dedalo.sti.fab.mil.br/en/85259