According to meteorlogical reports, there was a severe icing warning in effect for the region from 12- to 21,000 feet (it's winter in Brazil now).

Taking Off

Logically, I know there probably wasn't much the fellow that took the video could do, but I cannot stand to see how casual he seems to be about it. I would have to try to go and try to do something.


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quote:

Originally posted by TigerDore:
Logically, I know there probably wasn't much the fellow that took the video could do, but I cannot stand to see how casual he seems to be about it. I would have to try to go and try to do something.


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I certainly understand that sentiment, and normally we tend to criticize people who during tragedy have an inclination to do nothing but stand around and record the event with their phones. But in a case such as this, clear and abundant video recordings will be immensely helpful for the crash investigators.

quote:

Originally posted by TigerDore:
Logically, I know there probably wasn't much the fellow that took the video could do, but I cannot stand to see how casual he seems to be about it. I would have to try to go and try to do something.
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Looking at the video, you can tell the distance from where he was to where the plane crashed is not just across the street. Not only that, but the likelihood of having a straight unobstructed path to the crash site in zero. This is some dense neighborhood, not an open field. So, not sure you can try to do anything.

I'm going with ice.

quote:

Originally posted by 12131:

quote:

Originally posted by TigerDore:
Logically, I know there probably wasn't much the fellow that took the video could do, but I cannot stand to see how casual he seems to be about it. I would have to try to go and try to do something.
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Looking at the video, you can tell the distance from where he was to where the plane crashed is not just across the street. Not only that, but the likelihood of having a straight unobstructed path to the crash site in zero. This is some dense neighborhood, not an open field. So, not sure you can try to do anything.

Not to mention, you see it fall like a rock, then a plume of smoke. You know all souls on board have perished.
What’s left to do? Sprint over and start giving Last Rights?

I probably would have said WTF a few times, and most likely changed the inflection of my voice, but unlikely I would go over to gawk.

quote:

Originally posted by tigereye313:
I'm going with ice.

I’m going with weakness on the part of the pilots. Sorry.

Nose heavy planes fly poorly.

Tail heavy planes fly once.

FWIW, here's a 1994 ATR-72 crash caused by icing:

https://en.wikipedia.org/wiki/...an_Eagle_Flight_4184

I am not blaming ice for the crash in Brazil, our professional pilots can comment on that.

quote:

Originally posted by sourdough44:

I’m going with weakness on the part of the pilots. Sorry.

Could be both.

Fwiw, early reports suggest icing conditions were present at the cruise altitude that ATR was flying.

Maybe he flew through another planes jet wash...

It sounded like the engines were under power, one moving forward the other backwards along the axis of rotation.

Pretty clear from the pictures it just pancaked in.

16,000 ft falling at 1,100 ft per minute is a heck of a decent rate, not to mention the forces on the flight deck given that spin.

quote:

Originally posted by Rightwire:

16,000 ft falling at 1,100 ft per minute is a heck of a decent rate,

Yeah, try more like 12,000 ft per minute descent.

I'm sure you just made a typo.

quote:

Originally posted by Balzé Halzé:

quote:

Originally posted by Rightwire:

16,000 ft falling at 1,100 ft per minute is a heck of a decent rate,

Yeah, try more like 12,000 ft per minute descent.

I'm sure you just made a typo.

Demmit!!!

and this just in...

quote:

Originally posted by kkina:
One question, does a high-tail rudder have inherently less yaw authority in a flat spin situation?

No, a T tailed airplane doesn’t inherently have less rudder authority. The problem is that T tailed airplanes can be susceptible to what is called a “deep stall”, where the T tail is “flying” in the turbulent air coming off the stalled wing. The result is there there is little to no elevator authority, leaving the pilots unable to break the stall by lowering the nose. Even if they use the rudder (or the rudder and differential thrust) to stop the spin, they are like riding the airplane in in a vertical descent.

quote:

Originally posted by Skins2881:

quote:

Once the aircraft stalls with the tail airflow disrupted it can be impossible to pitch down to recover from the stall.

Increasing the engine power could flatten out a spin. So where we see the aircraft pitched steeply nose down at first

I know nothing about airplanes other flying a flight simulator once. To someone like me with below novice level of knowledge, how does this happen? It seems to me that you would go full throttle and down to gain speed so that your flight surfaces had enough lift?

Having never been in a cockpit in my life, what am I missing?

With a T tailed airplane if you allow it to get into a deep stall you lose the ability to use the elevator to lower the nose and accelerate. If you are spinning, in most airplanes adding power causes the spin to flatten out and adds energy to the spin making the recovery take longer once the pilot uses the PARE recovery method. Basically, this was a likely unrecoverable situation. It may have been caused by pilot error, icing, or both.

Multi engine aircraft are a bitch in a flat spin.

The engines being extended from the centerline in a spin condition add a greater moment and the torque is quite significant, to the effect of flight controls that are designed and optimized to stable flight parameters.

When a multi/twin starts "flat pinning" the engine weight, (and if outboard tip tanks are added, and contain fuel) make the forces multiplied to the spin a great dynamic to counter, and often are well beyond the flight control's ability to counter.

And what happens is a "stable" spin, all the way to the crash site, that the pilot and aircraft cannot overcome.

A great deal of research and testing of spin recovery, from engine power settings, from symmetrical to asymmetrical, gear, flaps and in the case of "military fighter aircraft, using drag chutes deployed to help arrest a flat spin and get the nose down, and the wing flying, the realization was, "do not get into a flat (fucking) spin!"

I am "speculating" icing, and resultant stall, entering spin and nothing that could be done beyond that.

While the various videos may show that the pilot did try to do everything he could to get the nose down and recover, he just could not overcome all the crap I said, way up there in the first of my post.

I have a good deal of knowledge, of training and experience in flight control systems rigging, testing and understanding of function and all that goes on when you push the stick forward and the trees get bigger, and you pull the stack back and the trees get smaller, unless you continue to hold the stich back and the trees get bigger, again!!!

It's all about the "lifties" on the wing. Pull the stick back and the lifties roll back, push the stick forward and the lifties roll forward. But if you hold the stick back too long, the lifties roll back and fall of the wing, and then you are fucked...

And no matter how many nickels you toss in the grass, it won't help.


Ice Ice Baby. Those wings are unable to handle even a minimal amount of ice, and the weather reports suggest icing conditions were a bitch. And that aircraft was in the "worst" (14-17,000 feet) conditions for icing.

It takes very little ice to fuck up a wing's lift component.

The ATR s had a blowup deicing system that was real problematic. I remember AA had issues with them, crashed several of them. they dont fly them any more.

I would’ve guessed that a twin engined plane could counter a flat spin by reversing the prop pitch on one engine.

Or by simply stopping one engine and max throttle on the other.

There were 2 turboprop accidents where icing was a primary factor, which led to significant changes to the use of deicing systems. One was the Roselawn accident involving an ATR, the other was Detroit involving an Embraer EMB120 Brasilia.

The short version is that in both accidents the aircraft accumulated an excessive amount of ice on the wing which disrupted airflow. This led to a stall and loss of control at airspeeds and maneuvers which normally would not cause a stall. Also, imho as someone with many thousands of hours as Captain in the EMB120 in all weather conditions, the crews of both flights failed to recognize the developing situation.

Turboprops have rubber leading edges which inflate to break off ice. The revised requirement became to run the boots continuously whenever in potential icing conditions (visible moisture, air temperature below about 50 degrees F). The boots will inflate for about 6 seconds, then deflate for about a minute, then repeat.

Boots can get punctures, and then that section does not work. The puncture can be repaired if not too large, or the boot replaced. Flight into known or forecast icing with an inop section is prohibited.

In other countries idk what their requirements would be for turning on the boots before entering visible moisture or for flying with known inop deice equipment.

This crash investigation will be looking at whether the deice boots were fully operational, and whether they were being used. I've been in severe icing numerous times, with horns on the spinner and growing behind the boots (not good). We had plenty of time to change altitude to leave those conditions, meaning even in severe icing it can be managed if done so without delay. Extreme icing is quite rare, where the deice system is completely overwhelmed.

The crash investigation should look into to all this.

quote:

Originally posted by 6guns:
God bless those poor people!

Amen and amen.